RU2814684C2 - Indicator release system and method of use - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: group of inventions relates to a device and a method for releasing an indicator into a production well for measuring flow and monitoring inflow profiles in a wellbore during production. Indicator output system for an oil producing well contains at least one indicator output device intended for connection to the production string. Said device comprises, at least, one outlet, at least one indicator chamber, indicator material arranged in said indicator chamber and, at least, one valve. Indicator chamber is in fluid communication with the said at least one outlet hole. Valve is configured to selectively control fluid flow through said at least one outlet. Said at least one valve is configured to suspend said at least one indicator release device to increase concentration of indicator molecules in the volume of the fluid medium in the indicator chamber.

EFFECT: increasing concentration of the indicator molecules and their selective release without the need to suspend the well, controlling the effect on the indicator source with the produced fluid medium in order to prolong the life of the indicator in the well.

29 cl, 70 dwg

Description

The present invention relates to a device and method for releasing a tracer into a production well to measure flow and monitor inflow profiles in the wellbore during production. Aspects of the invention include an indicator release device for storing and selectively releasing an indicator, and a method of use.

PREREQUISITES FOR CREATION OF THE INVENTION

Downhole indicators placed in production wells have proven effective in assessing which fluids are flowing in which parts of the well and at what rates. Traditionally, different indicators have been placed in different inflow zones to the well production equipment installed in the well.

Methods for monitoring fluid flow in a well are known, including transient flow-based quantification where individual indicators are placed at different flow zones in the well. The well is shut down for a period of time to allow high concentration tracers to accumulate in selected inflow zones, and then the well is restarted to bring the tracers to the surface. Sampling and concentration analysis of various indicators are used to obtain qualitative and quantitative performance data.

EP 2633152 discloses a method for estimating the influx profile of well fluids (oil, gas or water) into an oil well with inflow locations into the production stream. The method includes placing indicator sources with indicator materials at well levels and creating a transition process in the working flow rate of the entire produced flow by stopping the well. The method includes sampling and analysis of samples based on the specified concentrations, and the sequence of sampling, as well as the geometry of the well, calculating inflow volumes using flow models.

However, these methods limit the number of possibilities for obtaining these indicators, since shutting down a well is a complex and very expensive operation that requires careful project planning and leads to loss of revenue due to interruption in production.

Regularly restarting a well after a shutdown can pose risks to the well infrastructure. Forcing the fluid column in a well to begin moving after a long period of rest can result in very complex changes in pressure, flow rate and temperature in the infrastructure. Sudden changes can pose a real threat to equipment, in the worst case scenario, irreversibly reducing productivity or even requiring re-completion or sidetracking of the well.

There may also be a problem with the rise of a column of heavy fluids when restarting a well after a shutdown. In some cases, restarting a well may not be possible.

Another problem with known downhole tracer methods is that due to downhole conditions, there may be pressure fluctuations in the well, which can affect the flow of tracers into the well. This can lead to situations where tracers move upstream or flow into other areas of the formation, known as cross-flow. Cross-flow introduces uncertainty and can affect the accuracy of the flow analysis.

SUMMARY OF THE INVENTION

One of the objects and objects of the invention is to provide a tracer release device for selectively releasing tracer into the production stream so that measurement profiles of flow parameters and inflow into the wellbore can be calculated and controlled.

Another object of the present invention is to provide a tracer release device that is capable of producing a high or increased concentration of tracer molecules and selectively releasing tracer molecules without the need to shut down the well.

It is yet another object of one aspect of the invention to provide an indicator release device that is capable of releasing a high concentration of indicator molecules in the form of an indicator cloud that can be detected during surface mining, but also controls the exposure of the indicator source to the produced fluid to extend the life of the indicator. in the well.

Further objects and objects of the invention will become apparent from the following description.

In accordance with a first aspect of the invention, there is provided a tracer release system for a producing oil well, comprising:

at least one indicator release device for connection with the production string, wherein said at least one indicator release device comprises:

at least one outlet,

at least one indicator chamber in fluid communication with said at least one outlet,

indicator material located in said at least one indicator chamber, and

at least one valve configured to selectively control the flow of fluid through said at least one outlet.

By providing the indicator release device with at least one valve configured to selectively control the flow of fluid through the at least one outlet, it can be possible to suspend the device to increase the concentration of indicator molecules in the fluid volume of the device. Subsequently opening the valve to release a higher concentration of tracer may create an tracer transient. The increased concentration of tracer molecules travels downstream with the production stream as a cloud, slug, or charge of tracer that can be detected downstream of the device and/or at the wellhead as a tracer response signal or peak at the downstream detection point.

The transient processes of the indicator are caused by the velocity field in the well. The appearance of various indicators at the wellhead or the complete transient process of various indicators can be used to estimate the velocity field in the well. Using the velocity field, the inflow profile can be calculated.

Said at least one indicator release device may comprise at least one inlet hole. Said at least one inlet opening may be in fluid communication with said at least one indicator chamber. The at least one valve may be configured to selectively control the flow of fluid through the at least one inlet.

The at least one valve may be configured to pause the device to release the indicator during production in the well. The at least one valve may be configured to selectively open and close the at least one inlet and/or outlet to control the flow of fluid through the at least one inlet and/or outlet.

The at least one valve may be configured to selectively open and close the at least one inlet between a fully open position, a fully closed position, or an intermediate position between a fully open and fully closed position. The at least one valve may be configured to selectively open and close the at least one outlet between a fully open position, a fully closed position, or an intermediate position between a fully open and fully closed position. The at least one valve may control the flow and change the flow area through the at least one inlet and/or the at least one outlet.

The indicator material may be configured to selectively release indicator molecules from the indicator material into a wellbore fluid in an indicator chamber upon contact with a particular wellbore fluid. Preferably, the indicator material is designed to release indicator molecules into the indicator chamber when the indicator material is exposed to a target fluid, ie oil, gas or water. The indicator material may be solid, liquid or gas.

Preferably, said at least one indicator chamber has a flow channel with a volume of fluid. The volume of fluid may be a fixed volume of fluid.

The fluid volume dimensions can be calculated to produce a known volume of fluid with an increased concentration of indicator molecules when the fluid volume is suspended. The release of increased concentrations of tracer molecules into the production stream as an tracer cloud can create a tracer transient that can be detected as a peak tracer response at the downstream detection point.

The volume of suspended fluid may be enriched or saturated with indicator molecules. Fluid volume sizes can be calculated for different types of indicators or different types of target fluid. Depending on the detection limit of the indicator, different fluid volume sizes may be used. For example, to provide detection for an indicator with a low detection limit, it may be necessary to release a larger volume of indicator-enriched fluid.

The dimensions of the fluid volume can be adjusted or configured depending on the required operation or resource of the indicator release device. For example, a tracer release device designed for long downhole life may require a smaller volume of fluid to limit the amount of tracer released during each tracer release operation.

The indicator material can be selected from the group including chemical, fluorescent, phosphorescent, magnetic, DNA and radioactive compounds. The indicator material may contain chemical indicators selected from the group consisting of perfluorinated hydrocarbons or perfluoroethers. Perfluorinated hydrocarbons can be selected from the group consisting of perfluorobutane (PB), perfluoromethylcyclopentane (PMCP) and/or perfluoromethylcyclohexane (PMCH).

The indicator material may be chemically immobilized within and/or on the indicator chamber. The indicator material may comprise an indicator and a carrier. The carrier may be a matrix material. The matrix material may be a polymeric material.

The indicator may be chemically immobilized in and/or on the support. The indicator material can be chemically immobilized through chemical interaction between the indicator and the carrier. The indicator material can be chemically immobilized such that it releases indicator molecules or particles in the presence of a chemical trigger.

By varying the chemical interaction between the indicator and the polymer release mechanism, the rate at which indicator molecules are released from the indicator material can be controlled. Preferably, the indicator is released from the indicator carrier at a uniform release rate.

The carrier may be selected from polymethyl methacrylates (PMMA), polymethyl acrylates, polyethylene glycols (PEG), polylactic acid (PLA) or polyglycolic acid (PGA), commercially available polymers or copolymers thereof.

The carrier may be selected from polymers with higher indicator release rates, such as polyethylene and polypropylene. The indicator material may be physically dispersed and/or physically encapsulated in the carrier.

The indicator material may release indicator molecules into the fluid as a result of dissolution or decomposition of the carrier and/or indicator into the fluid. The carrier may be selected to provide controlled degradation upon contact with a fluid. The carrier may be selected to ensure degradation by hydrolysis of the carrier. The indicator material and/or carrier may be specific to the fluid such that indicator molecules will be released from the indicator material in response to contact with the target fluid.

The tracer material and/or carrier may be chemically intelligent such that tracer molecules will be released from the tracer material in response to certain events, for example they respond to flow of oil (oil-bearing) but do not respond to flow of water (water-resistant). In the same area, another group of chemical compounds can be placed that release indicators in the flow of water (water-active), but do not react to the flow of oil (oil-resistant). The indicators and/or carrier may be chemically intelligent such that indicator molecules will be released from the indicator material in response to the influence of the indicator material on the wellbore fluid and/or the target wellbore fluid.

Indicator molecules can be detected and their concentration can be measured using various methods such as optical detection, optical fibers, spectrophotometric methods, PCR methods combined with sequential analysis, chromatographic methods or radioactive analysis. The invention is not limited to the above-mentioned technologies.

Indicator molecules can be detected and their concentration can be measured by sampling the produced fluid. Sampling may be conducted at one or more of the specified sampling times. Sampling may be carried out downstream of the tracer release device or at the surface. Samples can be collected for later analysis.

The indicator molecules can be detected by a detection device such as a sensor. The detection device may facilitate monitoring and/or analysis of the tracer in the produced fluid in real time.

The indicator material may be located in the indicator chamber to allow the fluid to contact the indicator material as it passes around the indicator material in the indicator chamber.

The at least one valve may be an electrically actuated valve, a mechanical valve and/or a thermodynamic valve. The at least one valve may be a controllable valve. The at least one valve may be configured to selectively open and/or close in response to an event in the well. The at least one valve may be configured to selectively open and/or close in response to a signal from the surface. The at least one valve may be configured to selectively open and/or close in response to changes in temperature, pressure and/or speed. The at least one valve may be configured to selectively open and/or close in response to the at least one electronic signal.

The at least one valve may be configured to selectively open and/or close in response to a transient in the flow of the produced stream. The transient may be a temporary transient in the flow rate of the produced stream.

The at least one valve may be a pressure difference controlled valve. The at least one valve may be configured to selectively open and/or close in response to a pressure difference across the valve.

The at least one valve may be configured to selectively open and/or close in response to changes in fluid pressure in the well. The at least one valve may be configured to selectively open and/or close in response to a pressure difference between the at least one inlet and the at least one outlet. The at least one valve may be configured to selectively open and/or close in response to a pressure difference between the indicator release device and the production string. The at least one valve may be configured to selectively open and/or close in response to a pressure difference between the fluid volume and the production string.

The at least one valve may be configured to selectively open and/or close by changing the pressure of the fluid in the well, or by changing the pressure difference between the at least one inlet and the at least one outlet, or by changing a pressure difference between the indicator release device and the production string and/or by changing the pressure difference between the fluid volume and the production string.

Said at least one valve may be a kinematic valve. The at least one valve may be configured to selectively open and/or close in response to changes in fluid flow rate in the production stream.

The at least one valve may be an electrically actuated valve. The at least one valve may be configured to selectively open and/or close in response to receipt of at least one electrical or electronic signal. The at least one valve may be wired or wireless controlled. The signal to control actuation of the valve may come from a surface or other external source. The at least one valve may comprise or be connected to a wireless communication system. The wireless communication system may include at least one wireless receiver capable of receiving data via wireless communication to control and actuate the electrically actuated valve. The wireless communication system may include at least one transmitter for transmitting a signal.

The at least one valve may be set as normally open or normally closed. Said at least one valve may be a flap valve or a spool valve. The at least one valve can be configurably set to be normally open or normally closed.

Preferably, said at least one valve is configured to respond to the velocity or pressure of a fluid in the well. The at least one valve may be configured to open and/or close at a predetermined speed or predetermined pressure of the fluid flow. The valve may have at least one actuation threshold level.

Said at least one valve can be installed with the possibility of partial opening and/or partial closing. The valve may be configured to open and/or close in positions intermediate between a fully open position and a fully closed position.

Said at least one valve may comprise a bias mechanism. The at least one valve may be balanced or biased by a bias mechanism that is configured to position the valve at a predetermined fluid velocity or fluid pressure level that must be achieved before the valve is actuated. The bias mechanism may be a spring. The bias mechanism may be a coil spring, a leaf spring, or a gas spring such as a nitrogen spring.

The bias mechanism can be adjusted to set the valve actuation threshold. Preferably, the valve is pressed by a spring, which can be adjusted by changing the type, length or tension of the spring. The valve actuation threshold can be set.

The at least one indicator release device can be retrofitted for installation in an existing column. The at least one indicator release device can be removed, installed, replaced and/or adjusted using a cable, wire rope, coiled tubing, drill pipe or similar means of transportation. The at least one indicator release device may be installed or replaced and may be transported along the production string by wireline, wire rope, coiled tubing, drill pipe, or similar means of transportation. The at least one indicator release device can be moved onto at least one landing nipple. Said at least one landing nipple may have holes communicating with the production string and/or with the annulus.

The at least one tracer release device or a component of the at least one tracer release device may be installed or replaced and may be transported along the production string by wireline, wireline, coiled tubing, drill pipe or similar means of transportation. .

The at least one valve may be installed in an existing indicator release device located in the well. Said at least one valve can be removed, installed, replaced and/or adjusted using a cable, wire rope, coiled tubing, drill pipe or similar means of transportation. The at least one valve may be installed or replaced and may be transported along the production string by wireline, wire rope, coiled tubing, drill pipe or similar means of transportation. Said at least one valve can be moved by at least one landing nipple. Said at least one landing nipple may have holes communicating with the production casing and/or with the annulus.

The settings of the at least one valve can be adjusted by directly connecting to the surface of the valve. The valve settings may be adjusted through an intervention operation by lowering the intervention device using a cable, wireline, coiled tubing, drill pipe, or similar vehicle to control and adjust the setting of the at least one valve.

The indicator release device may comprise at least one flow limiting device. Said at least one flow limiting device may be located in the indicator chamber. The at least one flow restriction device may be located in the at least one inlet and/or in the at least one outlet.

The at least one flow restriction device may be selected from the group consisting of a nozzle, an orifice, a Venturi tube, a pitot tube, or a deflection path.

The at least one flow limiting device may be configured to control and/or delay the release of indicator molecules from the indicator chamber of the indicator release device into the production string. Said at least one flow limiting device may be adjustable to change the rate of release of indicator molecules from the indicator chamber.

The at least one flow limiting device may be adjusted to change the release of the indicator and/or adjust the amplitude and/or duration of the indicator response peak at the detection point.

The release of the tracer from the tracer release device into the production string may be delayed or prolonged by a flow restriction device. Increasing the resistance of the flow limiting device to the fluid flow passing through it leads to an increase in the washout time of the indicator.

The release of the indicator from the indicator release device may produce a characteristic signal called a washout signal. The washout signal may have a concentration peak followed by a concentration decline. The decline in concentration after a peak can be expressed by a slowly decreasing function, such as an exponential function or a power function. The coefficient in the slope functions may be proportional to the velocity of the fluid within the indicator release device, and thus the velocity of the fluid within the indicator release device may be calculated based on the measured decay curve of the indicator concentration. A steeper curve, ie shorter washout time, corresponds to a higher fluid velocity within the indicator release device.

The duration of the indicator signal can be determined by sampling or real-time measurement. The signal must be long enough so that it is not destroyed by scattering as it travels to the detection point, which may be located behind the top well production equipment and liner extension. The output and dispersion of indicators can be modeled using flow models. Signal dispersion during movement to the detection point can be compensated for by modeling based on the well geometry and/or the well model.

The indicator release device may comprise at least one inlet valve. The at least one inlet can control the flow of fluid through the at least one inlet. The indicator release device may comprise a release valve for controlling the flow of fluid through the at least one outlet. The at least one inlet and/or outlet may be configured to control the release of indicator molecules from the indicator chamber of the indicator release device into the production string. The at least one inlet and/or outlet may act as a limiting device and may be adjusted to vary the rate of release of indicator molecules from the indicator chamber. Said at least one inlet valve and said at least one exhaust valve may be configured to operate independently of each other. The at least one inlet valve and the at least one outlet valve may be configured to operate in cooperation with each other. The at least one inlet valve and the at least one outlet valve may be configured such that one valve operates as a main valve and the other valve operates as a secondary valve, such that the secondary valve imitates the actions and reactions of the main valve.

Said at least one inlet and/or said at least one outlet may be in fluid communication with the production string. Said at least one inlet and/or said at least one outlet may be in fluid communication with the annulus. The production string may be an internal pipe into which the production fluid enters the production zone. The production string may extend from the downhole space to the surface.

The indicator release system may contain two or more indicator release devices. These two or more indicator release devices may be configured to be connected to the production string at various positions along the production string. The tracer release device may be located downstream of the inflow zone at known locations in the well. Each indicator chamber of a corresponding indicator release device may contain a separate indicator material. Each indicator release device may be located downstream of another influent zone and exposed to fluids from the influent zone.

In accordance with a second aspect of the invention, there is provided a method of releasing an indicator into a production stream, comprising:

placing at least one indicator release device connected to the production string, wherein said at least one indicator release device comprises:

at least one outlet in fluid communication with the produced stream,

at least one indicator chamber in fluid communication with said at least one outlet,

indicator material located in the indicator chamber,

at least one valve configured to selectively control the flow of fluid through said at least one outlet, and

opening said at least one valve to release indicator molecules from said at least one indicator chamber through said at least one outlet.

The at least one indicator release device may comprise at least one inlet in fluid communication with the produced stream. Said at least one inlet opening may be in fluid communication with said at least one indicator chamber. The at least one valve may be configured to selectively control the flow of fluid through the at least one inlet.

The method may include opening and/or closing the at least one valve in response to a change in fluid velocity or fluid pressure in the well. The method may include opening and/or closing the valve in response to a pressure difference between the at least one inlet and the at least one outlet. The method may include opening and/or closing the valve in response to a pressure difference between the indicator chamber of the indicator release device and the production string.

The method may include creating a pressure difference between said at least one inlet and said at least one outlet. A pressure difference can be created by adjusting the speed of the produced flow.

The method may include adjusting and/or setting at least one threshold fluid velocity or pressure level to operate the valve to selectively open and/or close the at least one outlet.

The method may include opening said at least one valve to a position intermediate between a fully open and fully closed position.

The method may include closing the at least one valve for a certain period of time to suspend the indicator release device and increase the concentration of indicator particles or molecules released into the indicator chamber fluid volume. The method may include closing the at least one valve for a period of time sufficient to create a high or increased concentration of tracer molecules that can be detected as a high or increased amplitude tracer response signal at the downstream detection point when the tracer particles or molecules are released from the indicator release device. By high or elevated concentration is meant an increased concentration of tracer molecules compared to the concentration of tracer molecules present in the well fluid that was not suspended in the tracer release device.

The period of time during which the indicator release device may be suspended may range from hours to months. Said at least one valve may be closed for less than 24 hours to suspend the indicator chamber. Said at least one valve may be closed for more than 24 hours to suspend the device for releasing the indicator.

The method may include opening a valve to release fluid and indicator molecules from the indicator chamber of the device to release the indicator through the at least one outlet into the production stream.

The method may include releasing indicator molecules from the indicator chamber by flushing out a volume of fluid with a produced fluid entering the fluid volume of the indicator chamber.

The method may include adjusting the flow rate of the produced stream to control the flow rate of the fluid acting on the at least one valve. The method may include increasing the flow rate of the production stream to create a pressure difference between the volume of fluid in the display chamber and in the production string. The method may include reducing the flow rate of the production stream to create a pressure difference between the volume of fluid in the display chamber and the production string.

The method may include restricting flow from the indicator chamber of the device to release the indicator into the production string. The method may include restricting flow through the indicator release device to control and/or delay the release of fluid from the indicator release device into the production string.

Embodiments of the second aspect of the invention may include one or more features of the first aspect of the invention or embodiments thereof, or vice versa.

In accordance with a third aspect of the invention, there is provided a method for estimating the inflow profile for at least one of the downhole fluids into a production well with two or more inflow zones into the production stream, comprising:

placing two or more tracer release devices connected to the production string at known well levels,

the device for releasing the indicator contains:

at least one outlet in fluid communication with the produced stream,

at least one indicator chamber in fluid communication with said at least one outlet,

separate indicator material located in said at least one indicator chamber,

at least one valve configured to selectively control the flow of fluid through said at least one outlet,

opening said at least one valve to release indicator molecules from the indicator chamber into the production stream through said at least one outlet, and

measuring an indicator concentration and estimating a flow profile for at least one of the well fluids based on the type of indicator and the measured indicator concentrations.

Downhole fluids may be oil, water and/or gas. Each tracer release device may be connected to the production string at a different location in the inflow zone. By placing tracer release devices in inflow zones, the contribution of each individual zone to the overall well production can be estimated and/or calculated.

The method may include analyzing tracer release characteristics, sampling times, and/or cumulative volume produced from influent volumes from different influent zones.

The at least one indicator release device may comprise at least one inlet in fluid communication with the produced stream. Said at least one inlet opening may be in fluid communication with said at least one indicator chamber. The at least one valve may be configured to selectively control the flow of fluid through the at least one inlet.

The method may include closing the at least one valve for a certain period of time to suspend the indicator release device and increase the concentration of indicator particles or molecules released into the indicator chamber fluid volume. The method may include closing the at least one valve for a period of time sufficient to create a high or elevated concentration of indicator molecules that can be detected downstream when the indicator molecules are released from the indicator release device.

The method may include opening said at least one valve to release fluid and tracer molecules from the tracer release device through said at least one valve outlet into the production stream.

The method may include opening said at least one valve by adjusting the fluid velocity and/or fluid pressure in the production string. The method may include closing the at least one valve by adjusting the speed and/or pressure of a fluid in the production string.

The method may include opening said at least one valve in response to a pressure difference between said at least one inlet and said at least one outlet. The method may include opening and/or closing a valve in response to a pressure difference between the indicator chamber and the production string.

A pressure difference can be created by adjusting the flow rate of the produced stream. The method may include opening said at least one valve on each of said two or more tracer release devices at substantially the same time to release tracer molecules into the production stream.

The method may include adjusting and/or setting the valve to operate above or below a predetermined threshold or flow range. The method may include adjusting and/or setting the valve to actuate at several predetermined thresholds or flow ranges.

The method may include releasing indicator particles or molecules from the indicator chamber fluid volume of each indicator release device by introducing the produced fluid into the indicator chamber through at least one inlet and/or outlet and flushing the indicator molecules from the indicator chamber.

The method may include adjusting the flow rate of the production stream to create a pressure difference to operate a valve to close the inlet and/or outlet after the tracer molecules have been released from the tracer release device.

The method may include controlling and/or delaying the release of fluid from the tracer release device into the production string by limiting the flow from the tracer release device into the production string.

The method may include sampling a well fluid downstream of the tracer release device.

Wellbore fluid samples may be taken at the surface or in the wellbore. Samples can be collected for further analysis at or off site. A sample of the well fluid can be measured in real time.

The method may include generating at least one detectable tracer peak at a detection point downstream of the tracer release device.

The method may include analyzing the arrival of concentration peaks of each indicator to determine the percentage of influx that occurs between the locations of the indicators. The method may include analyzing the rate of decline of the tracer concentration from each tracer location and/or tracer release device location to determine the percentage of formation inflow from each inflow zone.

Samples can be collected and/or measured downstream at a known sampling time. The influx volume can be calculated based on the measured concentrations and their sampling sequence, and the well geometry. Inflow volumes can be calculated from transient flow models. Inflow volumes can be used to estimate a well's inflow profile.

The method may include using the calculated inflow profile as parameters to control production flow or to characterize the formation.

The method may include modeling and/or interpreting inflow rates in a model well. The modeled influx profile and/or rates can be adjusted until the calculated concentrations of the model indicators compare with the measured concentrations of the identified indicators to estimate the influx profile.

Embodiments of the third aspect of the invention may include one or more features of the first or second aspect of the invention or embodiments thereof, or vice versa.

In accordance with a fourth aspect of the invention, there is provided a method for monitoring fluid inflow into a hydrocarbon production well, comprising:

placing at least one indicator release device connected to the production string in a hydrocarbon production well at an inflow location, wherein the indicator release device comprises:

a volume of fluid, an indicator material located in said volume of fluid, an outlet into said volume of fluid, and a controllable valve configured to selectively control the flow of fluid through the outlet,

wherein the indicator release device has a first state in which the control valve is closed to substantially or completely prevent the passage of fluid and indicator from said volume of fluid into the produced fluid through the outlet, and a second state in which the control valve is open to allowing fluid and indicator molecules to pass from said volume of fluid into the production string through said outlet,

the method includes:

- production of hydrocarbons from the well when the indicator release device is in its first state at the first flow rate of the produced stream in the production string,

- changing the flow rate of the production stream in the production string to a second flow rate of the production stream to operate a controllable valve to cause fluid and tracer material from said volume of fluid to flow into the production string, creating an increased concentration of tracer in the production string, and

- detection of the presence of an indicator in the produced stream below the inflow point.

The method may include detecting the presence of an indicator at a detection location. The detection location may be located in the well, or it may be located at the surface, or may be located toward the surface of the production well.

The method may include changing the flow rate of the production stream in the production string to a third flow rate of the production stream to operate the controllable valve to close it to prevent the passage of fluid and indicator from the specified volume of fluid into the produced fluid through the specified outlet.

The second flow rate of the produced stream may be higher than the first flow rate of the produced stream. Alternatively, the second flow rate of the production stream may be lower than the first flow rate of the production stream.

The third flow rate of the produced stream may be lower than the second flow rate of the produced stream. Alternatively, the third production stream flow rate may be lower than the second production stream flow rate.

Preferably, the indicator release device has an inlet into said volume of fluid. Said volume of fluid may be an indicator chamber.

The method may include operating a controllable valve to open the inlet and/or outlet. The method may include operating a controllable valve to close the inlet and/or outlet. The controllable valve may be located in the outlet between the specified volume of fluid and the production string. The controllable valve may be located in the inlet between the specified volume of fluid and the production string.

The device may comprise a first controllable valve located at an outlet between said volume of fluid and the production string, and a second controllable valve located at an inlet between said volume of fluid and the production string. The method may include operating a controllable valve to open the inlet and/or outlet. The method may include operating a controllable valve to close the inlet and/or outlet.

The first, second and third costs of the produced flow may be non-zero. At least one of the first, second and third production flow rates may be zero.

The flow rate of the produced stream can be changed using a throttle connected to the production string. The choke can be underwater or land-based. The choke may be a downhole choke.

The third flow rate of the production stream may be substantially the same as the first flow rate of the production stream. Thus, the controllable valve can be actuated to open by temporarily changing the flow rate of the production stream to a higher or lower flow rate of the production stream.

The indicator release device may have a third state in which the control valve is in a position intermediate between the fully open and fully closed positions to throttle the flow of fluid and indicator materials passing from the fluid volume into the production string through the outlet.

By providing an indicator release device capable of being suspended and controlling the accumulation and selective release of a high or elevated concentration of indicator, the detectable level of the indicator can be controlled downstream as needed.

This method can also extend the life of the downhole indicator, since the impact of the produced flow on the indicator material can be controlled. When the indicator release device is paused, indicator molecules may be released into a specified fluid volume of the device until the fluid volume becomes enriched in indicator molecules. The specified volume of fluid may be enriched or saturated with indicator molecules, after which the release of the indicator into the specified volume of fluid is substantially or completely stopped.

This method may also enable the use of tracer systems or tracer types that were previously considered unsuitable due to the high rate of release from the tracer source into the target fluid under downhole conditions. In fact, the high release rate of such tracers may provide the ability to create high concentrations of tracers in a short period of time. This can be useful when indicator release operations need to be performed in quick succession.

The method may include sampling the produced stream. Sampling may be carried out in one or more sampling periods. Sampling may be carried out downstream of the tracer release device or at the surface. Samples may be collected for later analysis.

Detection and/or analysis of the tracer in the production fluid may be a separate method from releasing the tracer from the tracer release device and/or sampling. Samples can be collected and the indicator detected at a time or location that is independent of the location of the well and therefore the sampling.

The method may include monitoring the influx of fluid into a hydrocarbon production well in real time. The method may include performing optical monitoring to detect indicators in the production stream. The method may include determining the type of indicator. The method may include monitoring the concentration of the indicator. The method may include tracking the arrival time of the indicator.

The method may include estimating or calculating an influx profile based on the concentration and type of tracer as a function of sampling time.

Embodiments of the fourth aspect of the invention may include one or more of any of the features of the first through third aspects of the invention or embodiments thereof, or vice versa.

In accordance with a fifth aspect of the invention, there is provided a method for monitoring fluid inflow into a hydrocarbon production well, comprising:

placing at least one indicator release device connected to a production string in a hydrocarbon production well at an inflow location, wherein the indicator release device comprises:

a volume of fluid, an indicator material located in said volume of fluid, an outlet into said volume of fluid, and a controllable valve configured to selectively control the flow of fluid through said at least one outlet,

wherein the indicator release device has a first state in which the control valve is open to allow fluid and indicator to pass from said volume of fluid into the production string through the outlet, and a second state in which the control valve is substantially or completely closed preventing the passage of fluid and indicator from said volume of fluid into the produced fluid through the outlet,

the method includes:

- production of hydrocarbons from the well when the indicator release device is in its first state at the first flow rate of the produced stream in the production string,

- changing the flow rate of the production stream in the production string to a second flow rate to operate a controllable valve to prevent the passage of fluid and indicator from the specified volume of fluid into the production fluid through the outlet,

- changing the flow rate of the production stream in the production string to a third flow rate to actuate the controllable valve to actuate the controllable valve to cause fluid and tracer to flow from said volume of fluid into the production string, creating an increased concentration of tracer in the production string,

- detection of the presence of an indicator downstream from the inflow point.

The second flow rate of the produced stream may be higher than the first flow rate of the produced stream. Alternatively, the second flow rate of the production stream may be lower than the first flow rate of the production stream. The third flow rate of the produced stream may be lower than the second flow rate of the produced stream. Alternatively, the third production stream flow rate may be lower than the second production stream flow rate.

Preferably, the indicator release device has an inlet into said volume of fluid.

The method may include operating a controllable valve to open the inlet and/or outlet ports. The method may include operating a controllable valve to close the inlet and/or outlet. The controllable valve may be located in the outlet between the specified volume of fluid and the production string. The controllable valve may be located in the inlet between the specified volume of fluid and the production string.

The first, second and third costs of the produced flow may be non-zero. At least one of the first, second and third flow rates of the produced stream may be zero.

The flow rate of the produced stream can be changed using a throttle connected to the production string. The choke can be underwater or land-based. The choke may be a downhole choke.

The third flow rate of the production stream may be substantially the same as the first flow rate of the production stream. Thus, the controllable valve can be actuated to open by temporarily changing the flow rate of the production stream to a higher or lower flow rate of the production stream.

The indicator release device may have a third state in which the control valve is in a position intermediate between a fully open and fully closed position to throttle the flow of fluid and indicator materials passing from said volume of fluid into the production string through the outlet.

By making the tracer release device capable of controlling the accumulation and selective release of a high concentration of tracer, a detectable level of tracer can be released as needed without requiring a complete shutdown of the well.

Embodiments of the fifth aspect of the invention may include one or more of any of the features of the first through fourth aspects of the invention or embodiments thereof, or vice versa.

In accordance with a sixth aspect of the invention, there is provided a method for monitoring fluid inflow into a hydrocarbon production well, comprising:

placing two or more tracer release devices connected to a production string in a hydrocarbon production well, each tracer release device being located at a different location in the inflow,

the device for releasing the indicator contains:

a volume of fluid, an indicator material located in said volume of fluid, an outlet into said volume of fluid, and a controllable valve configured to selectively control the flow of fluid through said at least one outlet,

wherein each tracer release device has a first state in which the control valve is closed to substantially or completely prevent the passage of fluid and tracer from said volume of fluid into the produced fluid through the outlet, and a second state in which the control valve is open to allow the fluid and indicator to pass from the specified volume of fluid into the production string through the outlet,

wherein the method includes:

- production of hydrocarbons from the well when the indicator release device is in its first state at the first flow rate of the produced stream in the production string,

- changing the flow rate of the production stream in the production string to a second flow rate of the production stream to operate a controllable valve to cause fluid and tracer to flow from said volume of fluid into the production string, creating an increased concentration of tracer in the production string, and

- detection of the presence of an indicator downstream from the inflow point at the detection point towards the surface of the production well.

The method may include changing the flow rate of the production stream in the production string to a third flow rate of the production stream to operate a controllable valve to prevent the passage of fluid and tracer material from the specified volume of fluid into the production fluid through the outlet.

The second flow rate of the produced stream may be higher than the first flow rate of the produced stream. Alternatively, the second flow rate of the production stream may be lower than the first flow rate of the production stream. The third flow rate of the produced stream may be lower than the second flow rate of the produced stream. Alternatively, the third production stream flow rate may be less than the second production stream flow rate.

The method may include opening a controllable valve for each indicator release device simultaneously to allow fluid and tracer materials to pass from said volume of fluid into the production string through the outlet of each indicator release device.

The third flow rate of the production stream may be substantially the same as the first flow rate of the production stream. Thus, the controllable valve can be actuated to open by temporarily changing the flow rate of the production stream to a higher or lower flow rate of the production stream.

Embodiments of the sixth aspect of the invention may include one or more of any of the features of the first through fifth aspects of the invention or embodiments thereof, or vice versa.

In accordance with a seventh aspect of the invention, there is provided a method for monitoring the influx of fluid into a hydrocarbon production well, comprising:

placing two or more tracer release devices connected to a production string in a hydrocarbon production well, each tracer release device being located at a different location in the inflow,

the device for releasing the indicator contains:

a volume of fluid, an indicator material located in said volume of fluid, an outlet into said volume of fluid, and a controllable valve configured to selectively control the flow of fluid through said at least one outlet,

wherein each indicator release device has a first state in which the control valve is open to allow fluid for the indicator to pass from the specified volume of fluid into the production string through the outlet, and a second state in which the control valve is substantially or completely closed, preventing the passage of fluid and indicator from said volume of fluid into the produced fluid through the outlet,

wherein the method includes:

- production of hydrocarbons from a well when two or more indicator release devices are in the first state at the first flow rate of the produced stream in the production string,

- changing the flow rate of the production stream in the production string to a second flow rate of the production stream to operate a controllable valve in each indicator release device to prevent the passage of fluid and indicator from the specified volume of fluid into the produced fluid through the outlet,

- changing the flow rate of the production stream in the production string to a third flow rate of the production stream to actuate a controllable valve in each indicator release device to actuate the controllable valve to cause fluid and indicator from the specified volume of fluid to flow into the production string, creating increased indicator concentration in the production string,

- detection of the presence of each indicator downstream of the inflow point.

The second flow rate of the produced stream may be higher than the first flow rate of the produced stream. Alternatively, the second flow rate of the production stream may be lower than the first flow rate of the production stream. The third flow rate of the produced stream may be lower than the second flow rate of the produced stream. Alternatively, the third production stream flow rate may be lower than the second production stream flow rate.

The method may include changing the flow rate of the production stream in the production string to a fourth or additional flow rate of the production stream to actuate controllable valves in one or more indicator release devices to prevent the passage of fluid molecules and indicators from the specified volume of fluid into the production fluid through the outlet hole.

Embodiments of the seventh aspect of the invention may include one or more of any of the features of the first through sixth aspects of the invention or embodiments thereof, or vice versa.

In accordance with an eighth aspect of the invention, there is provided a method for monitoring fluid inflow into a hydrocarbon production well, comprising:

- placing at least one indicator release device connected to the production string in the producing hydrocarbon well at the inflow location, wherein the indicator release device comprises:

fluid volume,

indicator material located in the specified volume of fluid,

an outlet into a specified volume of fluid, and a controllable valve configured to selectively control the flow of fluid through the outlet,

- changing the flow rate of the produced stream between the first flow rate of the produced fluid at which the control valve closes to suspend the specified volume of fluid and substantially or completely prevent the passage of fluid and indicator from the specified volume of fluid into the produced fluid through the outlet, and the second flow rate of the produced fluid a flow at which a controllable valve is actuated to cause fluid and tracer from a specified volume of fluid to flow into the production string, creating an increased concentration of tracer in the production string,

and detecting the presence of an indicator downstream of the inflow location.

At normal production, the flow rate may be equal to the first production flow rate, and the valve is closed at normal production flow rate in the well. The at least one indicator release device is suspended for an extended period of time. The method may include opening the valve by temporarily changing the flow rate of the produced stream to a higher or lower flow rate of the produced stream.

The method may include changing the flow rate of the production stream to a third flow rate of the production stream, at which the controllable valve is closed to suspend the specified volume of fluid and substantially or completely prevent the passage of fluid and tracer material from the specified volume of fluid into the production fluid through the outlet. The third flow rate of the production stream may be substantially the same as the first flow rate of the production stream.

At normal production, the flow rate may be equal to the second production flow rate, and the valve is open at normal production flow rate in the well. The method may include temporarily closing the valve by temporarily changing the flow rate of the production stream to a higher or lower flow rate of the production stream. The at least one indicator release device is suspended for a short period of time.

Changing the flow rate of the production stream between the first and second flow rates may be repeated to repeat the actuation of the valve to pause and subsequently release the indicator.

Embodiments of the eighth aspect of the invention may include one or more of any of the features of the first through seventh aspects of the invention or embodiments thereof, or vice versa.

In accordance with a ninth aspect of the invention, there is provided a method of releasing a tracer into a production stream of a hydrocarbon producing well, comprising:

placing at least one indicator release device connected to the production string in a hydrocarbon production well at an inflow location,

wherein the device for releasing the indicator contains:

a volume of fluid, an indicator material located in said volume of fluid, an outlet into said volume of fluid, and a controllable valve configured to selectively control the flow of fluid through said at least one outlet, and

creating a transient process in the produced stream for releasing at least one indicator from said at least one device for releasing the indicator into the production string.

The method may include providing a transient for actuating a controllable valve to release at least one tracer from said at least one tracer release device into a production string. The method may include changing the speed of the produced stream to create a transient in the produced stream.

Embodiments of the ninth aspect of the invention may include one or more of any of the features of the first through eighth aspects of the invention or embodiments thereof, or vice versa.

In accordance with a tenth aspect of the invention, there is provided a method for collecting samples for analysis in assessing the flow profile of a hydrocarbon production well, the method comprising:

placing at least one indicator release device connected to the production string in a hydrocarbon production well at an inflow location,

wherein the device for releasing the indicator contains:

a volume of fluid, an indicator material located in said volume of fluid, an outlet into said volume of fluid, and a controllable valve configured to selectively control the flow of fluid through said at least one outlet,

creating a transient in the production stream to release at least one tracer from said at least one tracer release device, and

sampling (c) at a location downstream of indicator sources after creating a transient in the produced stream.

The method may include providing a transient for actuating a controllable valve to release at least one tracer from said at least one tracer release device into a production string.

Embodiments of the tenth aspect of the invention may include one or more of any of the features of the first through ninth aspects of the invention or embodiments thereof, or vice versa.

In accordance with an eleventh aspect of the invention, there is provided a method for estimating the inflow profile of at least one of the downhole fluids into a production well with at least one inflow zone into the production stream, comprising:

placing at least one indicator release device connected to the production string at known well levels,

wherein the device for releasing the indicator contains:

a volume of fluid, an indicator material located in said volume of fluid, an outlet into said volume of fluid, and a controllable valve configured to selectively control the flow of fluid through said at least one outlet,

opening said at least one valve to release indicator molecules from the indicator chamber into the production stream through said at least one outlet, and

measuring an indicator concentration and estimating a flow profile for at least one of the well fluids based on the type of indicator and the measured indicator concentrations.

The method may include analyzing tracer release characteristics, sampling times, and/or cumulative volume produced from influent volumes from different influent zones.

The method may include analyzing the arrival of concentration peaks of each indicator to determine the percentage of influx that occurs between the locations of the indicators. The method may include analyzing the rate of decline of the tracer concentration from each tracer location and/or tracer release device location to determine the percentage of formation inflow from each inflow zone.

The method may include using the calculated inflow profile as parameters to control production flow or to characterize the formation.

The method may include modeling inflow rates in a model well. The modeled influx profile and/or rates can be adjusted until the calculated concentrations of the model indicators compare with the measured concentrations of the identified indicators to estimate the influx profile.

Embodiments of the eleventh aspect of the invention may include one or more of any of the features of the first through tenth aspects of the invention or embodiments thereof, or vice versa.

In accordance with a twelfth aspect of the invention, there is provided a method for monitoring the influx of fluid into a hydrocarbon production well, the method comprising:

placing at least one device for releasing an indicator in a producing hydrocarbon well, at an inflow point, wherein said at least one device for releasing an indicator comprises:

volume of fluid, and

indicator material located in the specified volume of fluid,

suspending the indicator release device during production to create a high concentration of indicator molecules in the specified volume of fluid,

releasing a high concentration of indicator molecules from the indicator release device into the production stream, and

detecting the presence of an indicator downstream of the inflow location.

The method may include pausing the device to release the tracer to limit the tracer's impact on the production stream. The method may include pausing the device to release the indicator at the first flow rate of the production stream. The method may include releasing a high concentration of tracer molecules from the tracer release device at a second flow rate of the production stream.

Said at least one indicator release device may comprise at least one controllable valve. The method may include changing the flow rate of the production stream in the production string to actuate the at least one controllable valve to suspend the tracer release device and/or release high concentration tracer molecules from the tracer release device.

Embodiments of the twelfth aspect of the invention may include one or more of any of the features of the first through eleventh aspects of the invention or embodiments thereof, or vice versa.

BRIEF DESCRIPTION OF THE DRAWINGS

Below, by way of example only, various embodiments of the invention are described with reference to the drawings, in which:

Fig. 1 is a simplified cross-sectional view of a production well with a tracer release system installed in accordance with one aspect of the invention;

Fig. 2A-2C are enlarged cross-sectional views of an indicator release device of the indicator release system shown in FIG. 1, illustrating the steps of operation of a device for releasing a short-lived tracer suspended in a well with a normally high production flow rate;

Fig. 3A to 3C are enlarged cross-sectional views of an indicator release device of the indicator release system shown in FIG. 1, illustrating the steps of operation of a device for releasing a short-lived tracer suspended in a well with a normally low production flow rate;

Fig. 4A-4C are enlarged cross-sectional views of an indicator release device of the indicator release system shown in FIG. 1, illustrating the steps of operation of a device for releasing a long-lived tracer suspended in a well with a normally low production flow rate;

Fig. 5A to 5C are enlarged cross-sectional views of an indicator release device of the indicator release system shown in FIG. 1, illustrating the steps of operation of a device for releasing a long-lived tracer suspended in a well with a normally high production flow rate;

Fig. 6A to 6C are enlarged cross-sectional views of an indicator release device of the indicator release system shown in FIG. 1 illustrating the operating steps of pausing the device to release an indicator at two valve thresholds;

Fig. 7A to 7D are enlarged cross-sectional views of an indicator release device of the indicator release system shown in FIG. 1, illustrating the steps of operation of a device for releasing a short-lived tracer suspended in a well with a generally high productivity;

Fig. 8A to 8D are enlarged cross-sectional views of two indicator release devices of the indicator release system shown in FIG. 1, illustrating the steps of operation of a device for releasing a short-lived tracer suspended in a well with generally low productivity;

Fig. 9A through 9D are enlarged cross-sectional views of two indicator release devices of the indicator release system shown in FIG. 1, illustrating the steps of operation of a device for releasing a long-lived tracer suspended in a well with generally low productivity;

Fig. 10A-10D are enlarged cross-sectional views of two indicator release devices of the indicator release system shown in FIG. 1, illustrating the steps of operation of a device for releasing a long-lived tracer suspended in a well with a generally high productivity;

Fig. 11A-11C are enlarged cross-sectional views of a tracer release apparatus with two valve assemblies, in accordance with one aspect of the invention, illustrating the operation of an inlet valve and an outlet valve for a short-lived tracer release apparatus suspended in a typically high-producing well;

Fig. 12A-12C are enlarged cross-sectional views of a tracer release device with two valve assemblies, in accordance with one aspect of the invention, illustrating the operation of an inlet valve and an outlet valve for a short-lived tracer release device suspended in a generally low-producing well;

Fig. 13A-13C are enlarged cross-sectional views of a tracer release device with two valve assemblies, in accordance with one aspect of the invention, illustrating the operation of an inlet valve and an outlet valve for a long-lived tracer release device suspended in a generally low-producing well;

Fig. 14A-14C are enlarged cross-sectional views of a tracer release apparatus with two valve assemblies, in accordance with one aspect of the invention, illustrating the operation of an inlet valve and an outlet valve for a long-lived tracer release apparatus suspended in a typically high-producing well;

Fig. 15A-15C are enlarged cross-sectional views of an indicator release device with a flow limiting device in the indicator release device in accordance with one aspect of the invention;

Fig. 16A-16C are enlarged cross-sectional views of an indicator release device with an inlet in fluid communication with the annulus, in accordance with one aspect of the invention;

Fig. 17 is an enlarged cross-sectional view of an indicator release device with an inlet and an outlet in fluid communication with the annulus, in accordance with one aspect of the invention;

Fig. 18A and 18B are schematic views of components of a kinematic valve assembly for use in an indicator release apparatus, in accordance with one aspect of the invention;

Fig. 19A and 19B are schematic views of components of a kinematic valve assembly for use in an indicator release apparatus, in accordance with a further aspect of the invention;

Fig. 20A and 20B are schematic views of components of a kinematic valve assembly for use in an indicator release apparatus, in accordance with one aspect of the invention;

Fig. 21A and 21B are schematic views of components of a differential pressure valve assembly for use in an indicator release apparatus, in accordance with a further aspect of the invention;

Fig. 22A, 22B and 22C depict schematic views of control mechanism components for use in an indicator release apparatus, in accordance with one aspect of the invention;

Fig. 23A, 23B, and 23C are enlarged cross-sectional views of a tracer release apparatus with an outflow section in fluid communication with a production string, in accordance with one embodiment of the invention, illustrating the steps of operation of a long-lived tracer release apparatus suspended in a generally low-producing well; And

Fig. 24A, 24B, and 24C are enlarged cross-sectional views of a tracer release apparatus with an outward flowing section in fluid communication with the annulus, in accordance with one embodiment of the invention, illustrating the steps of operation of a long-lived tracer release apparatus suspended in a generally low-producing well; And

Fig. 25A and 25B are simplified cross-sectional views of a production well showing steps for installing a tracer release system in accordance with one aspect of the invention.

DETAILED DESCRIPTION OF PREFERRED IMPLEMENTATION OPTIONS

Fig. 1 is a simplified cross-sectional view of a production well 10. The well contains a central production string 12 surrounded by an annular space 11. Volumes of fluid influx enter the well from the formation into the central production string 12 through individual inflow points. An indicator release device 16 is installed in or on the production string and is located adjacent to each inflow point. Tracers are released and measured at the surface to provide information about where inflows are occurring and at what rates. In this example, there are four inflow points 14a, 14b, 14c and 14d and four indicator release devices 16a, 16b, 16c and 16d, each with an indicator source with separate indicator material different for each inflow location. However, there may be a different number of inflow zones and/or indicator release devices than that shown in FIG. 1. The controlled throttle unit 15 is designed to control the speed of the produced flow. In FIG. 1, a controllable throttling assembly 15 is connected to the production string to control fluid flow or system pressure downstream of the production string. However, it should be understood that the choke can be located in the well in different places.

The arrows in the examples below indicate the direction of fluid movement and indicate the flow rate (for example, two arrows indicate a higher flow rate than one arrow and vice versa).

Fig. 2A-2C are enlarged cross-sectional views of the indicator release device 100. A device for releasing the indicator is installed on or in the production string 12. The indicator release device has an inlet 118 and an outlet 120 in fluid communication with the production string 12. The indicator release device 100 surrounding the production string has an annular indicator chamber 121 with a fluid volume 122 that contains indicator material 124. The indicator material can be located in the fluid volume to allow the fluid to contact the indicator material and pass around the indicator material in the fluid volume 122. Tracer material 124 may release tracer molecules or particles when exposed to a target well fluid, ie, oil, gas, or water.

The valve assembly 126 is mounted stationary with a movable closure member to selectively open and close the outlet 120a to control the flow of fluid from the fluid volume 122 into the production string.

In the examples shown in FIGS. 2A-2C, the valve assembly is installed on the outer wall of the indicator chamber. However, it should be understood that the valve assembly may be mounted on the inside wall of the indicator chamber.

In this example, valve assembly 126 is a differential pressure valve configured to open and close in response to changes in the pressure difference between the production string and the indicator release device. In this case, the change in pressure difference is controlled by regulating the flow rate of the produced stream. The valve assembly is configured to open at a flow rate above a preset production flow threshold and to close at a flow rate below a preset threshold.

Under normal performance, as shown in FIG. 2A, the production flow rate is above a preset flow threshold value and therefore the differential pressure valve remains open. Fluid flows from the production string through inlet 118 into fluid volume 122 of the indicator chamber. The indicator material is exposed to the fluid and the indicator particles are released into the fluid. The indicator-enriched fluid passes through the outlet into the production string and is carried by the production fluid to the surface.

To pause the tracer release device, a choke assembly (not shown) connected to the production string is adjusted to reduce the production flow to a second flow rate. The second flow rate is lower than a preset threshold value for the valve assembly and the valve closes, which selectively closes the outlet 120.

The fluid volume 122 of the fluid cannot exit the indicator chamber. The tracer material 126 remains exposed to the fluid volume during the period of time that the valve assembly is closed, creating a high concentration of tracer particles 126a in the fluid volume. Depending on the type of indicator, the rate of its release into the target fluid and the period of time during which the valve assembly is closed determine the level of saturation or enrichment of the fluid volume with the indicator.

To open the valve, the throttle assembly is adjusted to increase the production flow rate above the preset valve threshold. As shown in FIG. 2C, the valve assembly opens, allowing the fluid and high concentration of tracer to pass through outlet 122 into production string 12. The high concentration of tracer, also known as tracer cloud, is transferred to the surface where the fluid is sampled. The tracer cloud produces a high amplitude peak signal at the detection point and the tracer concentration is determined.

The indicator transients generated when the device is paused to release the indicator increase the concentration of the indicator and the subsequent release spreads to the surface in the form of high concentration indicator clouds, bursts or charges. The transient processes of the indicator are caused by the velocity field in the well. The arrival at the surface of the first of the various tracers, or the complete transient of the various tracers, can be used to estimate the velocity field in the well. Using the velocity field, the inflow profile can be calculated.

Fig. 3A-3C describe a check valve assembly for the indicator release device 100 described in FIG. 2A-2C. In FIG. 3A-3C, the indicator release device 150 has a pressure difference valve 176 that is configured to close above a preset production flow rate threshold and open below a preset threshold. At normal low production flow rates, as shown in FIG. 3A, the production flow rate is below the set production flow rate threshold for the valve, and therefore the valve 176 remains open. Fluid flows from the production string through inlet 168 into fluid volume 172.

To pause the indicator release device 150, a throttling assembly (not shown) connected to the production string is adjusted to increase the flow rate of the production stream to a second flow rate, which in this case is higher than the preset threshold value for the valve 176. The valve is actuated when which closes the outlet 170. The indicator material remains exposed to some volume of fluid during the suspension period of the indicator release device, creating a high concentration of indicator particles in the fluid volume.

To open the outlet 170, the throttle assembly is adjusted to reduce the production flow rate below a preset threshold, as shown in FIG. 3C. The valve is actuated to open the outlet, allowing fluid and tracer at a high concentration to pass through the outlet 170 into the production string. The high concentration indicator is washed out of the indicator chamber 172 due to the influx of produced fluid into the indicator chamber through the inlet 168. The high concentration indicator is carried to the surface in the form of an indicator cloud.

The above embodiment is used in wells where sand reduction may be a problem at high production rates.

Fig. 4A-4C depict an alternative design of the indicator release device 200. The differential pressure valve 226 is configured to open above a preset production flow rate threshold and close below the threshold.

At normal low production flow rates, the flow rate is below a preset production flow rate threshold, so valve 226 remains closed. The indicator material 224 in the fluid volume in the indicator chamber 222 remains exposed to the fluid volume in the indicator chamber 222 during the period of time that the valve 226 is closed, creating an increased concentration of indicator molecules 224a in the internal fluid volume of the indicator release device.

When a tracer analysis operation is required, the throttling assembly is temporarily adjusted to increase the flow rate of the production stream to a second flow rate that is higher than a preset threshold value for valve 226, valve 226 opens outlet 220, releasing the fluid with high levels of tracer molecules or an increased concentration in the form of an indicator cloud are released into the production string 12. The indicator cloud is carried to the surface by the produced fluid.

To pause the tracer release device, the throttling assembly is adjusted to reduce the production flow to a flow rate that is lower than a preset threshold value for the valve assembly, the valve assembly closes the outlet 220, pausing the tracer release device and allowing the tracer concentration to accumulate.

By exposing the indicator to the production stream only when the indicator analysis operation needs to be performed and the indicator cloud is to be released, the life of the indicator can be increased. A small volume of fluid within the indicator chamber fluid volume can quickly become enriched in indicator particles. As a small volume of fluid becomes rich or saturated, the rate of release of indicator particles from the indicator material decreases.

This may enable the use of a wide range of indicator types, including polymer systems with rapidly produced indicators. By providing polymer systems with quickly released indicators in the indicator release device, significant time delays between indicator analysis operations can be avoided. This is in contrast to the standard practice of increasing tracer life by reducing the rate of tracer release so that it remains in the well as long as possible.

Fig. 5A-5C depict the arrangement of the high flow check valve assembly compared to FIGS. 4A-4C. In FIG. 5A-5C, indicator release device 250 has a valve assembly 276 configured to open below a preset production flow rate threshold and close above that threshold.

Under normal high production flow rates, as shown in FIG. 5 A, the production flow rate exceeds a preset production flow rate threshold and, therefore, valve 276 remains closed. The indicator material in the indicator chamber remains exposed to the volume of fluid, with a high concentration of indicator particles accumulating in a fixed volume of fluid.

To actuate valve 276 to open outlet 270, the throttle assembly is temporarily adjusted to reduce the production stream to a flow rate that is lower than a preset threshold for valve 276, the valve assembly opens releasing an indicator cloud into the production stream.

When the throttle assembly is adjusted to return to normal production flow rate that exceeds the valve threshold level, valve 276 is actuated to close the outlet.

Fig. 6A-6C depict an alternative design of the indicator release device 200 shown in FIG. 2A and will be clear from the above description of FIG. 2A-2C.

However, the indicator release device 300 has a differential pressure valve 326 with two adjustable response thresholds for actuating the valve 326 to close the outlet 320. The valve is configured to close the outlet 320 at a flow rate above a first preset production flow rate threshold. flow and below a second preset production flow rate threshold. Therefore, valve 326 is configured to open over a flow range between two threshold levels.

Under normal high production flow rates, as shown in FIG. 6A, the flow rate is above the first preset flow rate threshold and therefore valve 326 is actuated to close the outlet 320. However, adjusting the throttle to reduce the flow rate below the preset production flow rate threshold operates the valve to open the outlet and allow release indicator cloud as shown in FIG. 6B.

Further adjustment of the throttle to reduce the production flow rate below a second preset production flow rate threshold actuates the valve to close the outlet. This means that in the event of a well shutdown, the valve closes the outlet and limits the volume of fluid with which the indicator material comes into contact, thereby increasing the life of the indicator.

Fig. 7A-10D illustrate various operations of two indicator release devices for releasing the indicator into the production stream. In wells with more than one tracer release device, the valve assemblies for each tracer release device may be configured to simultaneously release the accumulated concentration of tracer molecules (indicator cloud).

Fig. 7A-7D depict operating steps of valve assemblies for synchronously releasing tracer from two devices for releasing tracer into a wellbore.

Fig. 7A depicts enlarged cross-sectional views of an indicator release system 350 having two indicator release devices 366a and 366b. Each indicator release device has an inlet 368a, 368b and an outlet 370a, 370b, respectively, in fluid communication with the production string 12. Each indicator release device 366a, 366b has an indicator chamber 372a, 372b, which contains a separate indicator material, respectively. 374a, 374b.

Two different indicator release devices 366a and 366b are located at different locations in the well. For clarity, the devices for releasing the indicator are located nearby. However, in reality the distance between the indicator release devices may be hundreds or even thousands of meters.

The valve assemblies 376a and 376b of the indicator release device 366a and 366b are configured to open above a preset production flow rate threshold and close below the threshold level. At normal high flow rates, the flow rate is above a preset flow threshold value, so valves 376a and 376b are actuated to open the outlet, as shown in FIG. 7A.

Fluid flows from production string 12 through inlets 368a, 368b into the fluid volume of indicator chambers 372a and 372b. The indicator material 374a and 374b is exposed to the fluid, and the indicator particles are released into the fluid in each fluid volume of the indicator release device 366a and 366b.

To suspend the indicator release device 366a, 366b, a throttling assembly connected to the production string is adjusted to reduce the flow rate of the production stream from a first flow rate, which is the normal flow rate of the production stream, to a second flow rate, which is lower than a preset threshold value for valve 376a. and 376b, as shown in FIG. 7B. However, since the two tracer release devices are located at different locations in the well, they may be subject to changes in local pressure and, therefore, the pressure difference required to close each valve assembly may not be the same. As a result, valve assembly 376a is actuated to open outlet 370a while valve assembly 376b remains in the closed position despite the production flow rate being below a preset threshold.

The throttle assembly is adjusted to further reduce the produced flow to a third flow rate. The third expense is lower than the first and second expenses. At the third flow rate, the pressure difference is sufficient to actuate valve 376b and close outlet 370b, as shown in FIG. 7C.

The indicator material 374a, 374b remains exposed to the volume of fluid in the indicator chamber 372a, 372b of the indicator release device 366a, 366b, creating a high or increased concentration of indicator molecules in a fixed volume of fluid.

To simultaneously release indicator clouds from indicator release devices 366a and 366b, the production flow throttling assembly is adjusted to increase the flow rate from the third flow rate back to the first flow rate (equivalent to high flow in FIG. 7A). The first flow rate exceeds the closing thresholds of valves 376a and 376b, as shown in FIG. 7D.

Fig. 8A-8D show the reverse arrangement shown in FIG. 7A-7D, for indicator release system 400. In FIG. 8A-8D, the indicator release device 416a, 416b has valve assemblies 426a and 426b, respectively, configured to close outlets above a preset production flow rate threshold and open outlets below a preset threshold.

The valve assemblies 426a and 426b of the indicator release devices 416a and 416b are configured to close the outlets 420a, 420b above a preset flow threshold and to open the outlet below the threshold level.

At normal low flow rates, the flow rate is below a preset flow threshold value and therefore the valve assemblies 426a and 426b open the outlets 420a, 420b as shown in FIG. 8A. Fluid flows from the production string through inlets 418a, 418b into an indicator chamber 422a, 422b. The indicator material is exposed to the fluid and the indicator particles are released into the fluid.

To suspend the indicator release device 416a, 416b, the throttling assembly connected to the production string is adjusted to increase the production flow from a first flow rate, which is the normal flow rate of the production stream, to a second flow rate, which is higher than a preset threshold value for valves 426a and 426b. However, since the two tracer release devices are located at different locations in the well and are subject to local pressure fluctuations, the pressure difference required to close the valve assemblies is not the same. As a result, valve assembly 426b closes outlet 420b while valve assembly 426a is not actuated, outlet 420a remaining open despite the production flow rate being below a preset threshold.

The throttle assembly is adjusted to further increase the produced flow up to a third flow rate. The third expense is higher than the first and second expenses. At the third flow, valve 426a closes outlet 420a, as shown in FIG. 8C. The indicator material remains open to the volume of fluid in the indicator chamber of the indicator release device 416a, 416b, creating a high or increased concentration of tracer particles in a fixed volume of fluid.

To simultaneously release the accumulated indicator clouds from the indicator release device 416a, 416b, the throttle assembly is adjusted to reduce the flow to a flow rate that is below the flow thresholds for opening the valve assemblies 426 and 426b. The valve assemblies 426a and 426b are actuated to simultaneously open the outlets 420a, 420b, as shown in FIG. 8D.

In FIG. 9A-9D describe an indicator release system 450 having a valve device configured to open above a preset production flow rate threshold and close below the threshold. Valves 476a, 476b close at normal low flow rates and open at temporary high flow rates.

The valve 476a and 476b of the indicator release device 466a and 466b is configured to open above a preset production flow rate threshold and close below the threshold level. During normal low flow rates, the flow rate is below a preset flow threshold value and therefore the valve assemblies 476a and 476b remain closed, as shown in FIG. 8A. Fluid flows from the production string through inlets 468a, 468b into an indicator chamber 472a and 472b. The indicator material is exposed to the fluid and the indicator molecules are released into the fluid.

To release fluid enriched in tracer molecules, the production string choke assembly is adjusted to increase the flow rate of the production stream to a second flow rate that is significantly greater than the preset threshold flow rate for valve assemblies 476a and 476b. As a result, the valve assemblies 476a, 476b open simultaneously, allowing indicator clouds to be released simultaneously from the indicator release device 466a, 466b, as shown in FIG. 9 V. The tracer clouds move toward the surface in the production flow and create a noticeable high amplitude tracer response peak signal at the detection point.

To pause the device to release the indicator, the throttle assembly is adjusted to reduce the flow rate of the produced stream to a third flow rate. The third flow rate is higher than the first and lower than the second. At the third flow rate, valve assembly 476b closes, as shown in FIG. 9C. However, since the two different tracer release devices are located in different locations in the well, they are subject to changes in local pressure and, therefore, the pressure difference required to close the valve assemblies is not the same. As a result, valve assembly 476b closes while valve assembly 476a remains open.

The throttle assembly is adjusted to reduce the flow rate of the produced stream back to the first flow rate. Upon first flow, valve assembly 476a returns to the closed state, as shown in FIG. 9D.

In FIG. 10A-10D describe an indicator release system 500 that has an alternative valve arrangement to that described with reference to FIG. 9A-9D, configured to close the outlets above a predetermined production flow rate threshold and open below the threshold. The valves close during normal high flow rates and open during temporary low flow rates.

The valve assemblies 526a and 526b of the indicator release device 516a and 516b are configured to open above a preset production flow rate threshold and close above the threshold level.

At normal high flow rates, flow exceeds a preset flow threshold and therefore valve assemblies 526a and 526b remain closed, as shown in FIG. 10A.

To release the tracer cloud, the choke assembly coupled to the production string is adjusted to reduce the flow rate of the produced stream to a second flow rate that is significantly lower than the preset threshold flow rate for valve assemblies 526a and 526b. As a result, the valve assemblies 526a, 526b open simultaneously, allowing indicator clouds to be released simultaneously from the indicator release device 516a, 516b, as shown in FIG. 10V. The resulting indicator clouds are detected as peak indicator response signals at the detection point.

To pause the indicator release device, the throttle assembly is subsequently adjusted to increase the production flow rate to a third flow rate to close the valve assembly 526b and the outlet 520b, as shown in FIG. 10C. Due to changes in local pressure, additional adjustment of the throttle back to the first flow is required to achieve the pressure difference required to close valve 526a and outlet 520a.

Fig. 11A depicts an indicator release device 550 comprising two valve assemblies 576a, 576b. In this example, the valve assemblies are differential pressure valves.

The indicator release device 550 has an inlet 568 and an outlet 570 in fluid communication with the production string 12. The indicator release device has an indicator chamber 572, which contains indicator material 574. This indicator material may be located in the indicator chamber to allow fluid flow. medium to pass around the indicator in channel 572. The indicator material 574 is configured to release indicator molecules or particles when exposed to a target fluid, such as oil, gas or water.

The first valve 576a is configured to selectively open and close the outlet 570 to control the flow of fluid from the display chamber to the production string. A second valve 576b is installed to selectively open and close the inlet port 568.

In the example shown in FIG. 11A, the valve assembly is mounted on the outer wall of the indicator chamber 572. However, it should be understood that the valve assembly may be mounted on the inner wall of the indicator chamber 572.

In FIG. 11A-11C show the operating steps of two valve assemblies in the indicator release device. This embodiment can prevent cross-flow, especially when the fluid has high mobility, such as gas, to prevent cross-flow or in heterogeneous formations with large pressure differences between zones in the well. The indicator release device in FIG. 11A is configured to pause the short-lived indicator release device to allow the concentration of indicator molecules to increase and accumulate in the fluid volume of the device.

Valve assemblies 576a and 576b are configured to close the outlet and inlet ports below a preset flow threshold and open the outlet and inlet ports above the threshold. During normal high flow, flow is above a preset flow threshold and therefore valve assemblies 576a and 576b remain open. Fluid flows from the production string through inlet 568 into indicator chamber 572. The indicator material is exposed to the fluid and indicator particles are released into the fluid. The indicator-enriched fluid passes through the outlet into the production string and is carried by the production fluid to the surface. However, when a large volume of fluid is in contact with the indicator, its concentration in the fluid becomes low.

To pause the indicator release device 550, the production string choke assembly is adjusted to reduce the flow rate of the production stream to a second flow rate that is lower than the preset flow threshold for valve assemblies 576a and 576b. Valves 576a and 576b close inlet 568 and outlet 570, respectively. Fluid present in the indicator chamber is prevented from leaving the indicator chamber, causing a high concentration of indicator molecules to accumulate in a fixed volume of fluid in the indicator chamber. The indicator chamber is sealed and the fluids surrounding the indicator material in the indicator chamber fluid volume become saturated with indicator particles.

Once paused to release the accumulated high concentration of tracer, the throttling assembly is adjusted to increase the production flow rate above a preset threshold. Valve assemblies 576a and 576b open, which opens inlet 568 and outlet 570, respectively, allowing fluid and high concentration tracer to pass through outlet 570 into the production string and fluid to enter the indicator chamber fluid volume through the inlet. . High or increased concentrations of indicator molecules (indicator cloud) are brought to the surface and are detected as peak signals with large amplitude.

In FIG. 12A-12C show an alternative design of the indicator release device 550 shown in FIG. 11A and can be understood from the above description of FIG. 11A-11C.

However, in FIG. 12A-12C, the indicator release device 600 is configured for use in a well with normal low productivity. The indicator release device shown in FIG. 12A is configured to allow the short-lived indicator release device to be paused to allow an increased concentration of indicator molecules to build up. In this example, the valve assemblies are configured to close above a preset production flow rate threshold and open below the threshold.

During normal low flow rates, flow is below a preset flow threshold and therefore valve assemblies 626a and 626b maintain outlet 620 and inlet 618 open. However, adjusting the throttle to increase the flow rate of the production stream above a preset flow threshold actuates valve assemblies 626a and 626b to close outlet 620 and inlet 618. The indicator chamber is sealed and the fluids surrounding the indicator material in the indicator chamber fluid volume are sealed. can be saturated with indicator molecules. Switching the throttle to reduce flow below the valve flow threshold actuates the valve and opens outlet 620 and inlet 618, allowing the release of tracer molecules, as shown in FIG. 12C.

In FIG. 13A-13C and 14A-14C show alternative designs for the indicator release device shown in FIG. 11A and will be clear from the description of FIG. 11A-11C above. However, in FIG. 13A-13C and Figs. 14A-14C show an indicator release device configured to cause the long-lived indicator release device to be suspended during normal performance to allow an indicator cloud to accumulate and be released only as needed.

In FIG. 13A-13C, the indicator release device is configured for use in a well with normally low productivity. Valve assemblies 676a and 676b are configured to open above a preset production flow rate threshold and close below the threshold. Under normal low performance, as shown in FIG. 13A, the flow rate is below a preset flow threshold value and valve assemblies 676a and 676b close outlet 670 and inlet 668, respectively.

The volume of fluid contacting the indicator material in the indicator chamber 672 allows an indicator cloud to accumulate, as shown in FIG. 13V. The indicator chamber is sealed and the fluids surrounding the indicator material in the indicator chamber fluid volume become saturated with indicator molecules. The throttling assembly is adjusted to temporarily increase the flow in the production string above a preset threshold flow rate, which actuates valve assemblies 676a and 676b to open, respectively, outlet 670 and inlet 668, allowing increased concentrations of tracer molecules to flush out of the tracer release device. in the form of an indicator cloud.

In FIG. 14A-14C, the indicator release device 700 is configured for use in a normal high-productivity well. Valve assemblies 726a and 726b are configured to open, respectively, outlet 720 and inlet 718 below a preset flow threshold and close, respectively, outlet 720 and inlet 718 above the threshold.

During normal high flow, flow exceeds the actuating threshold of valves 726a and 726b, and therefore valves 726a and 726b are closed. The volume of fluid contacting the indicator material in the indicator chamber 722 allows for the formation of an increased concentration of indicator molecules and an indicator cloud.

To release the tracer cloud, the throttling assembly is adjusted to temporarily reduce the flow rate in the production string below a preset production flow rate threshold, which actuates the valve assemblies 726a and 726b to open, respectively, the outlet 720 and the inlet 718, so as to flush out the tracer cloud. cloud from the device to release the indicator.

Shown above in Fig. 11A-14C examples describe intake and exhaust valves having the same threshold level. However, it should be understood that the intake and/or exhaust valve may have different threshold levels or actuation ranges. Therefore, one valve may be actuated at the first flow rate of the production stream, and the second valve may be actuated at the rate of the production stream.

In FIG. 15A-15C show an alternative design of an indicator release device 750 intended for a low flow well where it may be difficult to create a pressure difference between the indicator chamber fluid volume and the production string. The indicator release device 750 and its operating method are similar to the indicator release device 200 described with reference to FIG. 4A-4C above. However, the fluid volume contains a flow restriction device 778. The flow restriction device is located or attached to the inner wall of the indicator release device so as to extend inwardly into the fluid volume to reduce the flow area of the fluid volume. In this example, the flow restriction device is a nozzle. However, it should be understood that other types of restraint devices may be used.

Nozzle 778 is located between inlet 768 and outlet 770 in the fluid volume of indicator chamber 772. Nozzle 778 allows for a pressure gradient to be created across inlet 768 and outlet 770. In low-productivity wells, the choke assembly may not be able to increase the flow rate to a level exceeding a preset threshold value of the flow rate of the produced stream. By placing a flow restriction device in the indicator release chamber 771, the pressure difference is increased to allow valve assembly 776 to be actuated.

In FIG. 16A-16C show an enlarged section through an alternative design of an indicator release device for exposing the indicator material to fluid from the production casing and annulus. An indicator release device 800 is mounted on the production string 12. The indicator release device has a first inlet 818 in fluid communication with the production string and a second inlet 829 in fluid communication with the annulus 11. The indicator release device has an outlet 820. Arrows in Fig. 16A-16C indicate the direction of movement of the fluid.

The indicator release device 800 has an indicator chamber 822 that contains indicator material 824. The indicator material may be located in the indicator chamber to allow fluid to contact the indicator material and flow around the indicator material in the indicator chamber 822. The indicator material 824 is configured to releasing indicator molecules or particles when exposed to a target well fluid, such as oil, gas or water.

The indicator release device has a differential pressure valve 826 configured to selectively open and close the outlet 820 to control the flow of fluid from the indicator chamber 822 to the production string.

Valve assembly 826 is a differential pressure controlled valve configured to open and close as the pressure difference changes. In this case, the change in pressure difference is controlled by regulating the flow rate of the produced stream. The valve assembly is configured to open above a preset production flow rate threshold and close below a preset threshold.

Under normal performance, as shown in FIG. 16A, the production flow rate is below a preset flow rate threshold and therefore the differential pressure valve remains open. Fluid flows from the annulus 11 through inlet 829 and from the production string 12 through inlets 818 into indicator chamber 822. The indicator material is exposed to the fluid and the indicator particles are released into the target fluid. The indicator-enriched fluid passes through the outlet into the production string and is carried by the production fluid to the surface.

The release of fluid contained in the indicator chamber 822 from the indicator chamber is prevented and an increased concentration of indicator molecules is allowed to accumulate and form an indicator cloud.

To open outlet 820, the throttling assembly is adjusted to increase the flow rate of the production stream above a preset flow threshold for the valve. As shown in FIG. 16C, the valve assembly opens, allowing high concentrations of fluid and tracer molecules to pass through outlet 822 into production string 12.

In FIG. 17 shows an enlarged section through an alternative design of an indicator release device for exposing the indicator material to fluid from the annulus and releasing an indicator cloud into the annulus. The released tracer cloud may enter the production string at the inlet downstream of the tracer release device. An indicator release device 850 is mounted on the production string 12. The indicator release device has an inlet 868 in fluid communication with the annulus 11 and an outlet 870 in fluid communication with the annulus 11. Arrows in FIG. 17 indicate the direction of movement of the fluid.

The indicator release device 850 has an indicator chamber 872 that contains indicator material 874. The indicator material may be mounted in the indicator chamber to allow a fluid to contact and flow around the indicator material in the indicator chamber 872. The indicator material 874 is configured to release indicator molecules or particles when exposed to a target well fluid, such as oil, gas or water.

Valve assembly 876 is configured to open and close the outlet in response to a change in pressure difference in the fluid stream. In the example shown in FIG. 17, the valve assembly is installed on the outer wall of the indicator chamber. However, it should be understood that the valve assembly may be mounted on the inside wall of the indicator chamber.

The valve assemblies described above are configured to open or close when the valve is subjected to a pressure difference that reaches a predetermined level. For example, when the pressure difference created by a change in the produced flow causes the movable spool element to move to the closed position.

When the valve opens, the accumulated tracer cloud is released into the annulus, where it can enter the production string at an inflow point further downstream, where it moves to the surface.

In FIG. 18A-21B show various examples of valve assemblies that may be used in the indicator release assemblies described with reference to FIGS. 1-17 and 23. A kinematic valve assembly or a differential pressure valve assembly, described below, can be used to allow, throttle, or prevent flow into and/or out of the indicator release device.

In FIG. 18A shows an indicator release device 900 with a kinematic valve assembly 926. The kinematic valve is located in the inner diameter of the production string. The kinematic valve has a spool drive element 910, which in FIG. 18A is shown biased to the closed position by spring 912. Valve spool actuator 910 is configured to reciprocate between a closed valve position and an open position shown, respectively, in FIG. 18A and 18B.

In the first valve device shown in FIG. 18A, spring 912 is a compression spring biased to the fully closed position at low production flow. In response to the high velocity of the produced flow, the flow acting on the spool element 910 is sufficient to compress the spring 912, which moves the spool element 910 to the fully open position. Under low production flow conditions, the force exerted on the spool element 910 by the produced flow is insufficient to overcome the force of the spring 912. The spring expands and moves the spool element to the fully closed position, as shown in FIG. 18V.

Fig. 19A illustrates an indicator release device 950 with a kinematic valve assembly 976. Spring 962 is an extension spring biased toward the open position. In response to high production flow, such as during normal production, the flow acting on the spool element 960 is sufficient to overcome the force of the spring 962. The spring expands, moving the spool element 960 to the closed position. Under low production conditions, the force exerted on the spool element 962 by the produced flow is insufficient to overcome the spring force. The spring retracts to the previous position and moves the spool element to the open position, as shown in FIG. 19V.

Although in Fig. 18A, 18B, 19A and 19B show a spool element movable between fully open and fully closed positions, it is understood that the spool element may be located in positions intermediate between the fully open and fully closed positions. The spool element can be adjusted to partially open and partially close depending on the production flow rate to throttle or restrict flow through the valve.

In FIG. 20A and 20B show an enlarged view of the pressure and velocity controlled valve valve assembly 1026 in the indicator release device 1000. Other components of the device are not shown for clarity. The valve assembly has a valve body 1010 having a port 1012 extending through a wall of the valve body that is aligned with an indicator outlet 1020. The spool element 1014 is supported by a valve body with seals 1013 and 1015 at each end. The spool element can move axially relative to the valve body. Spool member 1014 has a port 1017. The spool member is movable from a closed position in which the spool member port 1017 is not aligned with port 1012 and outlet 1020, as shown in FIG. 20A to an open position in which the spool port 1017 is aligned with the port 1012 and outlet 1020, as shown in FIG. 20V.

The spool element biasing mechanism, in this case spring 1019, is located between a protrusion 1021 on the valve body and a protrusion 1023 on the spool element.

In this example, the spool element biasing mechanism is a spring 1021, but it should be understood that other biasing mechanisms may be used, such as a pressure chamber containing a gas such as nitrogen.

The spool element 1014 acts as a piston that can be moved axially by a working flow applied to the spool element 1014 through the spool element protrusion 1025. When the flow applied to the protrusion 1025 reaches a predetermined value, the flow force compresses the spring 1014 to move the spool element axially so that the spool element port 1017 is aligned with the port 1012 and the outlet 1020.

The spool element will remain in the open position as shown in FIG. 20B until the force of the produced flow is sufficient to keep the spring 1014 in a compressed state.

Once the production flow rate decreases below a predetermined value, the spring force can overcome the pressure force acting on the spool element protrusion 1025. The spool element is moved to a closed position in which the spool element port 1017 is not aligned with the port 1012 and the outlet 1020.

The force acting on the spool element can be adjusted to reduce or increase the flow rate in the production string by controlling a throttle connected to the production string.

In this example, the spring is a compression spring. However, it will be understood that an extension spring can be used.

Fig. 21A and 21B depict an enlarged view of the differential pressure controlled valve assembly 1126 in the indicator release device 1100. Valve assembly 1126 is located within the indicator release device so that it is not constrained by the internal diameter of the production string. Other components of the device are not shown for clarity.

Valve assembly 1126 has a valve body 1110 having an outlet 1112 extending through a wall of the valve body that is aligned with an indicator outlet 1120. The spool element 1114 is movable axially relative to the valve body. Valve body 1110 has an inlet port 1117 in fluid communication with valve seat 1119. In the closed valve position, the spool element is located in the valve seat 1109, with the spool element covering the outlet port 1112 and the outlet 1120, as shown in FIG. 21A. In the open position of the valve, the spool element moves axially from the valve seat, and the outlet 1112 and the outlet 1120 are in fluid communication with the internal volume within the indicator release device, as shown in FIG. 21B.

The spool element bias mechanism, in this case spring 1119, is located between a lug 1121 on the valve body and a lug 1123 on the spool element.

In this example, the spool element bias mechanism is a spring 1121, but it should be understood that other mechanisms for generating bias voltage, such as a pressure chamber containing a gas such as nitrogen, can be used.

The spool element 1114 acts as a piston that can be moved axially by a pressure difference between the indicator release device and the production string. Pressure from the indicator release device is applied to the spool element 1114 through the inlet port 1117. Pressure from the production string is applied to the spool element 1114 through the outlet port 1112 and the outlet port 1120. When the pressure applied to the inlet port 1117 reaches a predetermined value, the pressure force compresses a spring 1114 to move the spool element axially away from the valve seat 1109 so that the spool element opens the outlet port 1112 and the outlet 1120.

The spool element will remain in the open position as shown in FIG. 21B until the pressure difference between the indicator release device and the production string is sufficient to keep the spring 1114 compressed.

As soon as the pressure difference between the indicator release device and the production string decreases below a predetermined value, the spring force can overcome the pressure force acting on the spool element. The spool element moves to the closed position when the spool element is in the valve seat 1109.

The pressure acting on the spool element can be adjusted by decreasing or increasing the pressure in the production string by controlling a throttle connected to the production string.

In this example, the spring is a compression spring. However, it will be understood that an extension spring can be used.

Although in the above examples described with reference to FIGS. 18A-21B, the valves are described as normally closed, it should be understood that the valves can be configured to be normally open and move to a closed position in response to a change in flow rate and/or a change in pressure difference.

In FIG. 22A shows a valve control mechanism 1200 for controlling actuation of the valve. In this example, the valve is a spool valve.

The control mechanism 1200 has a spool element 1264 with a keyway 1280, best illustrated in FIG. 22V. The keyway 1280 includes a plurality of axial grooves or tracks 1282 formed along the outer surface of the spool element. A fixed locating pin 1284 mounted on the valve body 1260 is located between the spool element and the valve body and is movable within the keyway. The spool member has a port 1267 that is configured to align with the outlet of the device to release the indicator when it is in the open valve position. The valve element port 1267 is configured to close in the closed position of the valve.

Axial movement of the spool element 1264 in response to a change in fluid velocity, as described with reference to FIG. 18A, 18B, 19A, 19B, 20A and 20B, and/or in response to a change in pressure difference, as described with reference to FIG. 21A and 21B causes the locating pin 1284 to move in the keyway 1280.

Depending on the design of the keyway 1280, the spool element 1264 is prevented from moving to the open position until a selected number of pressure or fluid velocity cycles are applied to the spool element. Alternatively, the spool element 1264 is prevented from moving to the closed position until a selected number of pressure or fluid velocity cycles are applied to the spool element.

When the locating pin 1284 passes through the keyway 1280, the spool element 1264 moves to actuate the valve between the closed or open positions. Guides 1282 in the keyway are of varying lengths and are used to control valve actuation.

In the example shown in FIG. 22B and 22C, the keyway 1280 has alternating long tracks 1290 and short tracks 1292 located around the periphery of the spool element. When the locating pin is located within the long track 1290, the valve is in the open position and the spool port is aligned with the outlet of the indicator release device. Movement of the spool element in response to flow rate or pressure difference moves the spool element into a short path. When the pin is in the short track 1292, the spool element moves to a position in which the spool element port is not aligned with the outlet of the indicator release device. Further movement of the spool element in response to flow rate or pressure difference moves the spool element, but if the locating pin is still in the short track, the valve remains in the closed position.

Another embodiment of the valve control mechanism 1250 is that the spool element may have ports 1265a, 1265b of different sizes, as best illustrated in FIG. 22A. Each port size may correspond to a different axial track 1282 in the keyway 1280. For example, when the locating pin 1284 is in the first track, the spool member ports 1265a, 1265b may be blocked and the valve is closed. When the locating pin 1284 is in the second track, the spool member can be locked. moves to align the small spool port or series of small ports 1265a with the outlet of the indicator release device, thereby gradually releasing the indicator from the device through the small spool port. However, when the locating pin 1284 is located in the third track, the spool element moves to align the larger spool element port or set of large ports 1265b with the outlet of the indicator release device, thereby quickly releasing the indicator from the device through the large spool element port.

Another feature of the valve control mechanism may be configured such that the spool member port may be positioned at positions intermediate between fully open and fully closed positions corresponding to different axial paths in the keyway. This allows controlled opening, closing, partial opening or partial closing of the valve.

While the above examples describe a control mechanism used to control actuation of a valve to open and close an outlet on an indicator release device, it should be understood that the control mechanism is used to alternatively or additionally control actuation of a valve to open and close an inlet port of the device to release the indicator.

In the above examples, the valve is a spool valve. However, it should be understood that other types of valves can be used.

Fig. 23A-23C are enlarged cross-sectional views of the indicator release device 1300. The indicator release device is mounted on the production string 12. The indicator release device 1316 has an outflow section 1316a with an inlet 1318a in fluid communication with the production string and an outlet 1320a in fluid communication with the annulus 11. The outflow section 1316a has an annular chamber. 1321a surrounding the production string, with a fluid volume 1322a between inlet 1318a and outlet 1320a.

The indicator release device 1300 has an inward outlet section 1316b with an inlet 1318b in fluid communication with the annulus 11 and an outlet 1320b in fluid communication with the production string 12. Arrows in FIG. 23A-23C indicate the direction of movement of the fluid. The inward discharge section 1316b has an annular indicator chamber 1321b surrounding a production string with a fluid volume 1322b that contains indicator material 1324. The indicator material may be located in the indicator chamber to allow fluid to contact and pass around the indicator material in the volume 1322b. fluid medium. The indicator material 1324 is configured to release indicator molecules or particles when exposed to a target downhole fluid, ie, oil, gas or water.

The valve assembly 1326 is supported by a movable closure member to selectively open and close the outlet 1320b to control the flow of fluid from the display chamber 1321b into the production string.

In this example, valve assembly 1326 is a differential pressure valve configured to open and close in response to changes in the pressure difference between the production string and the indicator release device. In this case, the change in pressure difference is controlled by regulating the flow rate of the produced stream. The valve assembly is configured to open when the production flow rate exceeds a preset threshold value.

Under normal performance, as shown in FIG. 23A, the production flow rate is below the preset flow threshold and therefore the valve assembly remains closed. Fluid flows from the production string through inlet 1318a into fluid volume 1322a of annular chamber 1321a and through outlet 1320a of outflow section 1316a into annulus 11. Fluid enters fluid volume 1322b of inward section 1316b from annulus 11 through inlet 1318b.

In fluid volume 1322b, the indicator material is exposed to the target fluid and tracer particles are released into the fluid. The indicator material 1324 in the fluid volume remains exposed to the fluid volume in the fluid volume 1322 during the period of time that the valve 1326 is closed, creating a high concentration of tracer particles in the internal fluid volume of the indicator release device.

When a tracer release operation is required, the throttling assembly is temporarily adjusted to increase the flow rate of the production stream to a second flow rate that is higher than the preset flow threshold for valve 1326, valve 1326 opens outlet 1320b, releasing fluid and a high concentration tracer cloud into production string 12. Fluid flow through the deflected path of inlet 1318a, outlet section 1320a, and inlet 1318b gradually washes a high or elevated concentration of indicator molecules from the display chamber fluid volume into the production string as an indicator cloud. The released indicator cloud produces a high amplitude peak signal at the detection point, followed by a decay curve of the indicator signal, which is a gradual movement and washout of the indicator from the indicator release device.

Fig. 24A-24C depict enlarged cross-sectional views of the indicator release device 1400. The indicator release device is mounted on the production string 12. The indicator release device 1416 has an outward outlet section 1416a with inlet ports 1418a and outlet holes 1420a in fluid communication with the annulus 11. The outward outlet section 1416a has an annular indicator chamber 1421a surrounding the production string with a fluid volume 1422a that contains indicator material 1424. The indicator material is located in the indicator chamber to allow the fluid to contact and pass around the indicator material in the fluid volume 1422a. The indicator material 1424 is configured to release indicator molecules when exposed to a target well fluid, i.e. oil, gas or water.

The indicator release device 1400 has an inward discharge section 1416b with inlets 1418b in fluid communication with the annulus 11 and outlets 1420b in fluid communication with the production string 12. Arrows in FIG. 24A-24C indicate the direction of movement of the fluid. The inward discharge section 1416b has an annular chamber 1421b surrounding the production string, with a fluid volume 1422b between the inlet 1418b and the outlet 1420b.

The valve assembly 1426 is supported by a movable closure member to selectively open and close the outlets 1420b to control the flow of fluid from the annular chamber 1421b into the production string.

In this example, valve assembly 1426 is a differential pressure controlled valve configured to open and close in response to changes in the pressure difference between the production string and the indicator release device. In this case, the change in pressure difference is controlled by regulating the flow rate of the produced stream. The valve assembly is configured to open above a preset production flow rate threshold and close below a preset threshold.

Under normal performance, as shown in FIG. 24A, the production flow rate is below a preset flow threshold and therefore the valve assembly remains closed. Fluid flows from the annulus through the inlet 1418a into the fluid volume 1422a of the annular indicator chamber 1421a and through the outlet 1420a of the outflow section 1416a into the annulus 11.

In fluid volume 1422a, the indicator material is exposed to the target fluid, and indicator molecules are released into the fluid.

Fluid enters the fluid volume 1422b of the inward discharge section 1416b from the annulus 11 through the inlet 1418b. Fluid containing indicator molecules cannot enter the production string while valve 1426 is closed.

When an indicator release operation is required, the throttling assembly is temporarily adjusted to increase the flow rate of the production stream to a second flow rate that is higher than the preset flow threshold for valve 1426, valve 1426 opens outlet 1420b, releasing fluid and tracer molecules into the production string. 12. The indicator-rich fluid is gradually washed out from the fluid volume 1422b into the production string.

The released indicator produces a high amplitude peak signal at the detection point, followed by an indicator signal decay curve, which is a gradual movement and washout of the indicator from the indicator release device.

In the above example, the indicator material is located in the annular chamber 1421a of the outflow section 1416a. However, it should be understood that the indicator material may alternatively or additionally be placed in the annular chamber 1421a of the inward venting section 1416b. In examples in which the indicator material is located in the outward outlet section 1416a and in the inward outlet section 1416b, the indicator material in the inward outlet section may be the same as or different from the indicator material in the outward outlet section.

In the above examples described with reference to FIGS. 23A-24C, the indicator release device is configured to close the indicator release device at normal low production rates and release a high or increased concentration of tracer by temporarily increasing the flow rate of the produced stream. However, it should be understood that the tracer release device may alternatively be configured to shut down at normal high production rates in high production wells and release the tracer by temporarily reducing the flow rate of the produced stream.

It should also be understood that the indicator release device can be configured to allow the indicator to be released at normal production and temporarily suspended by adjusting the flow rate of the produced stream.

Moreover, it should be understood that although the above examples described with reference to FIGS. 23A-24C have a valve located at the indicator outlet 1420b, it will be understood from the above examples that valves may be located at any and/or all of the inlets and/or outlets of the indicator outlet. For example, valve assemblies may control the flow of fluid through outlets 1420a and/or 1420b. Alternatively or additionally, valve assemblies may control fluid flow through inlet ports 1418a and/or 1418b.

Fig. 25A depicts a simplified cross-section of a portion of a production well 1510. A central production string 1512 is located in the well, surrounded by an annular space 1511. A landing nipple 1520 is positioned in the production string during completion of the wellbore.

Figure 25A shows a setup for retrofitting device 1550 to release a tracer into a well without having to remove the production string from the wellbore.

As shown in FIG. 25A, the indicator release device 1550 is transported through the production string from the surface using a wireline 1515. It should be understood that other transportation methods can be used, including wireline and coiled tubing. The indicator release device 1550 is sized to interact with and connect to the mounting nipple 1520 for mounting the indicator release device 1550, as shown in FIG. 25V.

The indicator release device 1550 can be installed and/or replaced without the need to bring the production string to the surface. For example, the indicator release device may be removed and/or replaced due to component failure or requirements to change or replace the indicator material or operating parameters of the indicator release device.

Additionally or alternatively, the indicator release device 1550 component can be removed, replaced, or adjusted without having to lift the indicator release device 1550 to the surface. For example, a valve on an indicator release device may be removed, replaced, or adjusted due to valve failure or requirements to change valve type or valve operating parameters.

It should be understood that, depending on the operation and configuration of the indicator release device 1550, the landing nipple may have holes in the side wall of the nipple. The openings may be in communication with the production string and/or annulus, and when the indicator release device is mounted on the nipple, the indicator release device 1550 may be in fluid communication with the production string and/or annulus through ports in the nipple.

Data collected at the detection point, as described in the examples above, can be analyzed to identify the arrival of each tracer's concentration peaks to determine the percentage of influx that occurs between tracer locations. The locations of the indicators in the well geometry can be known.

When tracer is released from two or more tracer release devices to the surface, their arrival at the surface is monitored and analyzed to determine the distribution of the influx. The volume between reaching each indicator peak is proportional to the influx that occurs upstream of each indicator.

The transient processes of the indicator are caused by the velocity field in the well. The arrival of tracers up can be used to estimate the velocity field in the wellbore. Using the velocity field, the inflow profile can be calculated. The concentration of tracers on the surface as a function of time is related to the influx into the well by the velocity field. The concentration of the indicator is determined by the velocity field. The velocity field is affected by the geometry of the well and the path of fluid flow transfer.

The model can be used based on the geometry of the production well, which assumes a specific inflow distribution scenario, simulates the arrival times of the tracer peaks, and compares the modeled results with the actual arrival times of the peaks. After several iterations, the model can arrive at a solution that provides an inflow distribution that best matches the actual data. The model may include a simulated transport path corresponding to the actual well transport path downstream of the inflow zones.

The model must include an inflow model that matches the actual influx locations, a tracer system model that even has a model leakage or release rate that matches the actual tracer sources, and a model well transfer path that matches the actual producing well.

The concentration of the indicator can be calculated as a function of time. Measured tracer concentrations can be compared with modeled tracer concentrations to provide information about well flow profiles.

Samples can be collected and/or measured downstream at a known sampling time. The influx volume can be calculated based on the measured concentrations, their sampling sequence, and the well geometry. Inflow volumes can be calculated from transient flow models.

Model concentrations for each tracer material can be calculated along the simulated downstream flow path of the well as a function of time during the simulated transient occurring in the model.

Additionally or alternatively, data collected at the detection point, as described in the above examples, can be analyzed to determine the rate of decline of the tracer concentration from each tracer location to determine the percentage of formation inflow from each inflow zone.

As indicator is washed out of the indicator release device, zones with high influx rates wash out the indicator faster than zones with low influx rates, thereby maintaining a high concentration of indicator molecules and creating a profile with steep decay rates. Conversely, the concentration of tracer molecules in the fluid that is washed out of the low-productivity zone becomes more dilute as it enters the main stream and moves to the surface. Consequently, the indicator concentration profile has a less steep rate of decline compared to the high-productivity zone. Data can be analyzed to compare the rate of decline of tracer concentrations between each monitored area and quantify the corresponding relative influx rates.

The selection, detection, analysis and/or interpretation of tracer data in a production fluid may be considered separate techniques performed at different times or locations. Detection, analysis and/or interpretation of an indicator in a production fluid may be separate methods for releasing an indicator cloud from the indicator release and/or sampling device. Samples may be collected and the indicator detected, analyzed and/or interpreted at a time or location that is separate and distinct from the location of the well and hence the sampling.

Although the above examples describe control and actuation of at least one valve due to pressure differences or changes in flow rate, additionally or alternatively, the at least one valve may be controlled and actuated electrically. Said at least one electric valve can be controlled remotely using wired and/or wireless communication.

The invention provides an indicator release system and a method of use. The indicator outlet contains at least one indicator chamber for connection with the production string. Said at least one indicator chamber contains at least one inlet, at least one outlet, a fluid volume, and an indicator material located in the fluid volume. The indicator chamber also includes a valve configured to selectively open and/or close said at least one outlet.

The indicator release system may be capable of selectively suspending each indicator release device located in or adjacent to the inflow zone. A high concentration of indicator accumulates in the indicator release device, which is selectively flushed out when the indicator release device is opened. By analyzing the nature of the flow of indicators to the surface and the decline in the concentration of indicators, it is possible to determine the influx profile into the well, both qualitatively and quantitatively.

The tracer release system may be capable of selectively releasing a high or elevated concentration of tracer particles from each tracer release device, also known as a tracer cloud, into the production stream, allowing wellbore inflow profiles and flow measurements to be calculated and monitored.

An advantage of the tracer release system is that it is capable of selectively generating increased or high concentrations of tracer particles in the tracer release device and releasing tracer particles from the tracer release device without the need to shut in the well.

Another advantage of the tracer release system is that it is capable of releasing an elevated or high concentration of tracer in the form of a tracer cloud that can be detected during surface mining, but it also controls the exposure of the tracer material in the tracer release device to the produced fluid for increasing the resource of the indicator in the well.

Throughout the specification, unless the context clearly indicates otherwise, the terms “comprise” or “include” or variations such as “comprises” or “comprising”, “includes” or “comprising” are to be understood to imply the inclusion of the whole element or group of elements, but not to the exclusion of any other entire element or group of elements. In addition, relative terms such as “downstream”, “upstream”, etc. are used herein to indicate directions and locations as they apply to the accompanying drawings, and should not be construed as limiting the invention and its functionality to particular devices or orientations. Likewise, the term "outlet" should be interpreted to mean an opening that, depending on the direction of flow of the fluid, may also serve as an "inlet" and vice versa.

The foregoing description of the invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The described embodiments are selected and described to better explain the principles of the invention and its practical application, thereby enabling others skilled in the art to best use the invention in various embodiments and with various modifications as are suitable for the particular intended use. Accordingly, additional modifications or improvements may be included without departing from the scope of the invention as defined by the appended claims.

Various modifications to the embodiments described above may be made within the scope of the invention, and the invention extends to combinations of features other than those expressly claimed herein.

Claims (56)

1. Indicator release system for producing oil well, containing: at least one indicator release device for connecting to the production string, wherein the at least one indicator release device comprises at least one outlet, at least one indicator chamber in fluid communication with said at least one outlet, indicator material located in the indicator chamber, and at least one valve configured to selectively control the flow of fluid through said at least one outlet, wherein said at least one valve is configured to suspend said at least one indicator release device to increase the concentration of indicator molecules in the volume of fluid in the indicator chamber. 2. The system of claim 1, wherein said at least one indicator release device comprises at least one inlet port in fluid communication with said at least one indicator chamber. 3. The system of claim 1 or 2, wherein said at least one valve is configured to selectively open and close said at least one outlet between a fully open position, a fully closed position, or an intermediate position between a fully open and fully closed position . 4. The system of any one of the preceding claims, wherein the indicator material is configured to release indicator molecules from the indicator material into a fluid in the indicator chamber upon contact with a particular well fluid. 5. A system as claimed in any one of the preceding claims, wherein the indicator material comprises an indicator and a carrier. 6. A system as claimed in any one of the preceding claims, wherein said at least one valve is an electrically actuated valve, a differential pressure valve, or a kinematic valve. 7. The system as claimed in any one of the preceding claims, wherein said at least one valve is configured to suspend said at least one indicator release device at a predetermined production fluid flow rate and/or production fluid pressure. 8. The system of any one of the preceding claims, comprising at least one flow limiting device configured to control the rate of release of indicator molecules from the indicator chamber of the indicator release device into the production string. 9. A method for releasing an indicator into a produced stream, including: placing at least one indicator release device connected to the production string, said at least one indicator release device comprising: at least one outlet, at least one indicator chamber in fluid communication with said at least one outlet, indicator material located in the indicator chamber, at least one valve configured to selectively control the flow of fluid through said at least one outlet, opening said at least one valve and releasing indicator molecules from said at least one indicator chamber through said at least one outlet, closing said at least one valve to suspend said at least one indicator release device to increase the concentration of indicator molecules released into the indicator chamber. 10. The method according to claim 9, in which said at least one valve is opened by changing the flow rate of the produced stream in the production string. 11. The method according to claim 9, in which said at least one valve is closed by changing the flow rate of the produced stream. 12. The method according to any one of claims 9 to 11, wherein the flow through the indicator release device is limited to control and/or delay the release of fluid from the indicator release device into the production string. 13. A method of estimating the inflow profile for at least one of the downhole fluids into a production well with two or more zones of inflow to the produced stream, comprising placing two or more tracer release devices connected to the production string at known levels of the well, each The indicator release device contains: at least one outlet in fluid communication with the produced stream, at least one indicator chamber in fluid communication with said at least one outlet, a separate indicator material located in each indicator chamber, and at least one valve configured to selectively control the flow of fluid through said at least one outlet, wherein said at least one valve is configured to suspend said at least one indicator release device to increase the concentration of indicator molecules in volume of fluid in the indicator chamber, opening said at least one valve to release indicator molecules from the indicator chamber into the production stream through said at least one outlet, measuring an indicator concentration and estimating a flow profile for at least one of the well fluids based on the type of indicator and the measured indicator concentrations. 14. The method of claim 13, wherein the arrival of peak concentrations of each indicator is analyzed to determine the percentage of influx that occurs between the locations of the indicators. 15. The method of claim 13, wherein the rate of decline of the tracer concentration from each tracer location and/or tracer release device location is analyzed to determine the percentage of formation inflow from each inflow zone. 16. The method of claim 13, wherein the characteristics of indicator release, sampling time and/or cumulative volume produced from influent volumes from different influent zones are analyzed. 17. The method according to any one of claims 13-16, in which said at least one valve is opened by adjusting the flow rate and/or pressure in the production string. 18. The method according to any one of claims 13 to 16, wherein said at least one valve is closed to suspend the indicator release device to increase the concentration of indicator molecules released into the indicator chamber by adjusting the flow rate and/or pressure of the production string. 19. The method according to any one of claims 13 to 18, wherein at least one detectable peak of the indicator is generated at a detection point downstream of the indicator release device. 20. The method according to any one of claims 13 to 19, wherein said at least one valve on each of said two or more indicator release devices is opened at substantially the same time to release indicator molecules into the production stream . 21. The method according to any one of claims 13 to 20, wherein the release of fluid from the tracer release device into the production string is controlled and/or the release of fluid is delayed by limiting the flow from the tracer release device into the production string. 22. The method according to any one of claims 13-21, in which the concentrations of the indicator are measured in real time or samples are taken for further analysis at the mining site or beyond. 23. A method for monitoring the influx of fluid into a producing hydrocarbon well, including: placing at least one indicator release device connected to a production string in a hydrocarbon production well at an inflow location, wherein the indicator release device comprises: fluid volume, indicator material located in the specified volume of fluid, outlet into a specified volume of fluid, and a controllable valve configured to selectively control the flow of fluid through the outlet, changing the flow rate of the production stream between the first flow rate at which the control valve is closed to suspend the specified volume of fluid to increase the concentration of indicator molecules released into the indicator chamber and prevent the passage of fluid and tracer material from the specified volume of fluid into the production fluid through the outlet , and a second flow rate at which the controllable valve is actuated to cause fluid and tracer material from said volume of fluid to flow into the production string, creating an increased concentration of tracer in the production string, and detecting the presence of an indicator downstream of the inflow location. 24. The method of claim 23, wherein the presence of the tracer material is detected at a detection location in the well, at a detection location on the surface, or at a detection location toward the surface of the production well. 25. The method of claim 23 or 24, wherein the flow rate of the produced stream is changed to a third flow rate of the produced stream to actuate the control valve to close it to prevent the passage of fluid and indicator from said volume of fluid into the produced fluid through said outlet hole. 26. The method according to claim 25, wherein the second flow rate of the produced stream is greater than the first flow rate of the produced stream and/or the third flow rate of the produced stream. 27. The method according to claim 25, wherein the second flow rate of the produced stream is less than the first flow rate of the produced stream and/or the third flow rate of the produced stream. 28. The method according to any one of claims 23 to 27, wherein the device for releasing the indicator has an inlet, wherein the method operates a controllable valve to open and/or close the inlet and/or outlet to selectively control the flow of fluid through the outlet. 29. The method of any one of claims 23 to 28, wherein two or more tracer release devices are placed attached to a production string in a hydrocarbon production well, each tracer release device being placed at a different location in the inflow.

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