RU2816938C2 - Method and device for quantitative downhole monitoring of multiphase flow - Google Patents

Abstract

FIELD: oil, gas and coke-chemical industry.

SUBSTANCE: group of inventions relates to a method and a device for quantitative downhole monitoring of a multiphase flow containing at least two phases of any of oil, water or gas in an oil well. Method comprises using at least one discharge chamber comprising a flow phase separation section, a delay chamber, one or more outlet ports, at least two flow limiters, an indicator outlet system with one or more indicators, separation of the withdrawn flow in the discharge chamber into a low-density flow phase and a high-density flow phase. At least one indicator is released into said delay chamber. Separated low-density flow phase is passed through at least a first flow restrictor, and the high-density flow phase is passed through at least a second flow restrictor. Low-density flow phase and the high-density flow phase with an indicator are washed out from the discharge chamber through outlet ports into the local flow inside the well. Said at least one indicator is monitored in produced flow at detection point downstream of outlet ports. Concentration of said one or more indicators in controlled flow is measured.

EFFECT: increased efficiency of downhole monitoring of multiphase flow in oil well.

29 cl, 47 dwg

Description

The present invention relates to monitoring flow from a production well and, in particular, to apparatus and methods for measuring overall production in a well in two separate phases. Aspects of the invention include measuring total productivity for oil and water phases, gas and water phases, or oil and gas phases.

PREREQUISITES FOR CREATION OF THE INVENTION

Permanent indicators placed in production wells have proven to be useful in assessing “what flows where and how much,” that is, which fluids are flowing in which parts of the well and at what rates. Traditionally, different indicators are placed in different inflow zones to the 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 closing the well. The method includes sampling and analysis 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.

Tracer injection systems for downhole use are described in US 6840316 B2 and WO 2016/137328 A1. The tracer is usually pumped into the main flow path of the well. However, WO 2016/137328 A1 describes an indicator release system with an outlet chamber and a flow restrictor.

A common problem with known tracer injection methods is that the injected tracers are added to the production stream and there is limited control over whether the tracers are exposed to the target fluid or not. This represents uncertainty in the pre-test at the wellhead.

Due to the complexity of multiphase flow, there are no tracer-based methods to accurately measure the zonal flow rates of different phases. Some problems in multiphase conditions arise from the fact that the presence of water is not proportional to production due to differences in slip and gravity.

SUMMARY OF THE INVENTION

An object of one aspect of the present invention is to provide a method and apparatus for quantitative downhole monitoring of multiphase flow in an oil well.

It is yet another object of the present invention to provide a diverter chamber device capable of improving quantitative multiphase downhole oil monitoring by measuring the produced flow of each phase in the multiphase flow.

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

According to a first aspect of the invention, there is provided a method for quantitative downhole monitoring of a multiphase flow comprising at least two phases of any of oil, water or gas in an oil well, the method comprising:

installation of at least one outlet chamber containing:

phase separation section in the flow,

indicator camera,

one or more outlets,

at least one flow limiter,

indicator release system with one or more indicators,

dividing the diverted flow in the diverting chamber into a low-density flow phase and a high-density flow phase,

releasing at least one indicator into the indicator chamber,

passing separated low-density flow phase and high-density flow phase through each flow restrictor,

washing out the low-density flow phase and the high-density flow phase with an indicator from the outlet chamber through the outlets into the local flow inside the well,

monitoring the tracer in the production stream at a detection point downstream of the outlets.

The method may include measuring the concentration of one or more indicators in the monitored stream.

Installation of at least one outlet chamber capable of releasing or flushing tracer into the production stream may create an tracer transient. The tracer molecules travel downstream with the production stream as a tracer cloud, slug or charge, which 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 arrival at the surface of the first different tracers or the complete transient process 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.

The method may include washing out a low density flow phase and a high density flow phase with a cloud indicator.

The method can be applied to a well design that is substantially horizontal, inclined and/or slightly inclined. The method can be applied to one or more positions in the well. It can be used for one more position of the indicator source. There may be one or more local multiphase flows inside the well.

The method may include introducing a portion of the diverted flow into a locally located diverter chamber. The method may include directing a portion of the local flow to a discharge chamber.

The method may include separating the diverted stream into a low-density stream phase and a high-density stream phase in a stream-phase separation section before introducing it into a delay chamber or at least one flow restrictor.

The method may include dividing the diverted stream into a low-density stream phase and a high-density stream phase in a flow phase separation section before adding the indicator.

The method may include adding an indicator before separating the diverted stream into a low-density stream phase and a high-density stream phase in a flow phase separating section.

The method may include dividing the diverted stream into a low-density stream phase and a high-density stream phase in a flow phase separation section before releasing the indicator or exposing the indicator to the flow.

The method may include releasing at least one tracer into the diverted stream or exposing the stream to the tracer before separating the diverted stream into a low density stream phase and a high density stream phase in a stream phase separation section.

Flow restrictors can be designed for a specific fluid and/or phase. The indicator chamber can have a specified volume. The at least one outlet chamber may be configured to be used for one or more positions of the indicator source in the well.

The at least one outlet chamber may comprise a first flow restrictor for the low density flow phase and a second flow restrictor for the high density flow phase. The low density stream phase may be a hydrocarbon phase. The high density flow phase may be an aqueous phase. In some cases, the low density flow phase may be an aqueous phase. The high density flow phase may be a hydrocarbon phase such as heavy oil.

Said at least one outlet chamber may comprise one or more inlet openings. The diverted stream may be divided into a low density phase and a high density phase after the diverted stream has entered the inlets. The one or more inlet openings may be located upstream of the one or more outlet openings.

The method may include moving and/or aligning said at least one flow restrictor with a separated low density flow phase and/or a high density flow phase. The method may include setting the position of the at least one flow restrictor to allow the separated low density flow phase and/or the high density flow phase to pass through the at least one flow limiter.

The at least one flow restrictor may be a low density flow restrictor. The at least one flow restrictor may be a high-density flow restrictor. The outlet chamber may include a first flow restrictor for the low density flow phase and a second flow restrictor for the high density flow phase. The method may include setting the position of the at least one flow restrictor and passing the separated phase of the low density flow through the combined restrictor for the low density flow phase. The method may include setting the position of the at least one flow restrictor and passing the separated phase of the high density flow through the combined restrictor for the high density flow phase.

The indicator release system may be actuated to release the at least one indicator into the chamber to form an indicator cloud or multiple individual clouds in one chamber. The indicator cloud may have tracer concentrations higher than the background tracer concentrations.

Said at least one outlet chamber may comprise at least one valve configured to selectively control the flow of fluid through said one or more outlets. Said at least one outlet chamber may comprise at least one valve configured to selectively control the flow of fluid through said one or more outlets.

The method may include washing out the low density flow phase and the high density flow phase with the tracer from the outlet chamber through the outlets into a local flow within the well. The method may include washing out the indicator in the form of an indicator cloud.

The method may include opening said at least one valve and flushing the indicator from the flow channel and through said one or more outlets.

The method may include opening and/or closing the at least one valve in response to changes in fluid flow or fluid pressure in the well. The method may include opening and/or closing a valve in response to a pressure difference between said at least one fluid inlet and said at least one fluid outlet. The method may include opening and/or closing the valve in response to a pressure difference between the indicator chamber of the vent chamber device and the production string. The method may include opening and/or closing the at least one valve in response to a signal from the surface.

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 pause the outlet chamber and increase the concentration of tracer particles or molecules released into the fluid volume of the delay chamber.

The method may include closing the at least one valve for a period of time sufficient to cause a high concentration of tracer to accumulate in the discharge chamber, which can be detected as a high amplitude tracer response signal at a downstream detection point when the tracer particles or molecules are released from the discharge chamber. . By pausing the outlet chamber, one or more indicator clouds can be formed. A tracer cloud is a locally elevated or high concentration of tracer molecules that, when released into the flow, can be detected as a high amplitude tracer response signal at a detection point downstream of the outlet chamber. The time period can vary from hours to months.

The at least one valve may be closed for less than 24 hours to stop the discharge chamber. Said at least one valve may be closed for more than 24 hours to suspend the outlet chamber device.

The method may include using a pressure difference between the inlet and outlet ports to flush the tracer cloud from the outlet chamber.

The method may include calculating a characteristic time of leaching of each indicator from the indicator chamber or time of passage of each indicator through the outlet chamber based on the concentration of the one or more indicators in the controlled stream.

The indicator chamber may be a delay chamber. The method may include using a predetermined chamber volume, estimating the downhole pressure difference between the inlet and outlet ports, and/or calculating delay and/or flow rate for each phase of the local multiphase flows.

The two separate phases may be oil and water, or gas and water, or oil and gas. For simplicity, these will generally be referred to below as the oil/water fluid combination and the corresponding oil/water affinity indicator combination, but it should be considered as any combination described above.

The method may include the following steps:

- influx of well fluid into the outlet chamber through inlet ports,

- phase separation after entering the outlet chamber,

- introduction of an indicator cloud into the outlet chamber,

- washing out the indicator cloud by the flow of separated fluid from the outlet chamber back into the well through the outlet ports, and

- detection of indicators at the detection point.

The collection, detection, analysis and/or interpretation of tracer data in a production fluid may be separate methods and performed at different times or locations. Detection, analysis and/or interpretation of the tracer in the production fluid may be separate methods of phase separation, release of the tracer cloud from the outlet chamber and/or sampling. 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.

The outlet chamber may include inlet and outlet ports, a delay chamber, an indicator release system for introducing indicators into the delay chamber, flow limiting assemblies for each phase, and a section in the outlet chamber in which phase separation can occur.

The method may include calculating the production flow rates of each of the two phases, which may be based on the measured washout time of the tracers from the delay chamber or the transit time of the tracer in the delay chamber and the known capacity of the flow restriction units for a given pressure difference between the inlet and outlet ports. The method may include providing a pressure difference between the inlet and outlet ports to cause a portion of the well fluids to pass through the delay chamber and flow restriction assemblies.

This method can use tracers with similar properties to two target phases, which can be detected either online or through post-sampling fluid analysis. The method may use one or more phase-specific indicators.

The method may include separating the phases within the outlet chamber and bringing each phase into contact with an indicator and passing through a known limiter specific to each phase. This means that the behavior of each phase within the outlet chamber is known and the velocity will be proportional to the pressure difference between the inlet and outlet of the outlet chamber within a pipe such as the main pipe, i.e. in the production stream.

The method may include passing the separated streams through the outlet chamber using a pressure difference. The amount of each separated phase within the chamber and the design of the limiter can determine the duration of the trace at the monitoring point, considered as a concentration value. You can get a long trace signal.

The method may include adding an indicator to the not yet divided portion of the flow in the delay chamber. The method may include adding an indicator to each individual phase after the stream is separated.

The method may include the use of indicators that have similar properties to one or more fluid phases, ie, hydrocarbon phase indicators such as oil or gas, and water phase indicators.

The method may include the use of neutral tracers that have similar properties to both phases, and the trace signal can be read in accordance with the specified limiting properties and expected behavior of the phases through the outlet chamber and the well with different time constants.

This method can use tracers with similar properties to two target phases, which can be detected either online or through post-sampling fluid analysis. The two separate phases may be oil and water, or gas and water, or oil and gas.

By measuring the transit time or washout time, knowing the well geometry and the exit chamber geometry, it is possible to calculate the fraction of target fluid at the exit chamber position, pressure differences, well retention and production rates, among other things.

The method can use a predetermined chamber volume by estimating the pressure difference in the well between the inlet and outlet ports. The method may include calculating delays and/or flow rates for each phase of local multiphase flows.

The method may include providing or directing a bleed flow into a bleed chamber from the annulus of a production string in a well. The method may include introducing or directing the diverted flow into a diverter chamber from within a production string in a well. The diverted thread may be a local diverted thread. The diverted thread may be part of a local diverted thread.

The method may include combining said at least one restriction assembly with a low density phase, which may be in an upper or high position in the outlet chamber. The method may include combining said at least one restrictor assembly with a high density phase, which may be in a low or low position in the outlet chamber. The method may include aligning said at least one restriction assembly before providing or directing a portion of the diverted flow to the diverter chamber.

The method may include activating the opening of the inlet and/or outlet sealing device. The method may include causing the inlet and/or outlet sealing device to open before a portion of the diverted flow enters the diverter chamber.

The method may include providing or directing indicators to be introduced into the delay chamber and generating an increased or increased concentration of the indicator to form an indicator cloud before the flow enters the flow restrictors. The method may include releasing indicators into a delay chamber and forming an indicator cloud before introducing into flow restrictors.

The method may include operating an indicator release system to release the indicator from the polymer matrix, from the indicator liquid or solid injector, releasing the indicators from the matrix and/or injecting the indicators using the injector or releasing from the container.

The method may include the system releasing a first dose indicator of at least one of the indicators into a first end of the delay chamber and a second dose of at least one of the indicators into a second end of the delay chamber.

One or more local multiphase production flows may be the sum of the spaced flow in the annulus through the discharge chamber and the internal volume of the main pipe. The concentration of tracers may be at least twice the background concentration of tracers.

The method may include performing monitoring by in-stream detection, probe detection, delayed measurement, or by physical sampling.

The indicator release system may be actuated at a certain point in time to release at least a dose of at least one of the indicators.

The inlet ports may be opened to allow shunt flow to enter the outlet chamber. The inlet ports can be closed to create an indicator release signal to form an indicator cloud by keeping the ports closed for a preset time. The inlets can subsequently be opened to direct the diverted flow through the diverter chamber due to the pressure difference.

The method may include installing two or more release chambers, each with a separate indicator, at known different locations in the well. Each outlet chamber may be located downstream of another inflow zone and open to fluids from the inflow zone.

In accordance with a second aspect of the invention, there is provided a method for quantitative downhole monitoring of a multiphase flow comprising at least two phases of any of oil, water or gas in an oil well, the method comprising:

using at least one outlet chamber containing

- flow phase separation section,

- delay chamber,

- one or more inlet ports and one or more outlet ports, the inlet ports being located upstream of the outlet ports,

- at least one flow limiter,

- indicator release system with one or more indicators,

dividing the diverted flow in the diverting chamber into a low-density flow phase and a high-density flow phase,

actuating the indicator release system to release at least one indicator into the delay chamber,

wherein a separated low-density flow phase and a high-density flow phase flow through each flow restrictor,

washing out the low-density flow phase and the high-density flow phase with an indicator cloud from the outlet chamber through the outlet ports into the local flow inside the well,

performing tracer monitoring in the production stream at a detection point downstream of the outlet ports.

The method can be carried out in a substantially horizontal, inclined and/or slightly inclined well structure. The method can be carried out for one or more positions in the well. The method can be carried out for one or more positions of the indicator source. There may be one or more local multiphase flows inside the well.

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 diverter chamber device for quantitative multiphase downhole oil monitoring, the device comprising:

a flow-through outlet chamber for the diverted flow, containing:

- one or more outlets,

- a flow phase separation section for dividing the diverted flow into a low-density flow phase and a high-density flow phase,

- delay chamber,

- an indicator release system for at least one indicator, and

- at least one flow limiter in fluid communication with the delay chamber.

The flow outlet chamber may have an elongated body. The flow outlet chamber may have a cylindrical body, at least in part. The flow outlet chamber may be configured to be located peripherally in the oil well.

Preferably, the flow outlet chamber includes one or more inlet openings. The one or more inlet openings may be inlet ports. The one or more outlets may be outlet ports. Said one or more inlet openings may be located in an upstream portion, and said one or more outlet openings may be located, respectively, in a downstream portion of the indicator outlet chamber.

The at least one indicator may have properties similar to one or more phases of the oil flow.

Said at least one flow limiter may be phase dependent. The at least one flow restrictor may be a low density flow phase restrictor. The at least one flow restrictor may be a high density flow phase restrictor.

The flow outlet chamber may include at least one low density flow phase limiter and at least one high density flow phase limiter in fluid communication with the delay chamber. Flow restrictors may have a predetermined restriction efficiency.

The at least one flow restrictor may be configured to distribute the tracers over a sufficiently large volume of downhole fluid such that the tracer signal can be captured at a detection point at the wellhead or downhole with an available measurement resolution or sampling rate at the detection point. The design of the chamber, the use of a delay chamber and a flow restrictor facilitates the separation of the two phases and gives a predictable washout rate for each phase.

The flow outlet chamber may include at least one valve configured to selectively control the flow of fluid through one or more inlet openings and/or one or more outlet openings. Said at least one valve may be configured to selectively open and close said one or more fluid inlets and/or said one or more outlets to control the flow of fluid through said one or more fluid inlets and/or or said one or more outlets.

The at least one valve may be configured to selectively open and close the one or more fluid inlets 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 one or more fluid outlets 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 operative to control the flow and change the flow area through the one or more inlet openings and/or through the one or more outlet openings.

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 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 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 changes in fluid velocity or fluid pressure in the well and/or production string.

The at least one valve may be a pressure difference controlled valve. The 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 valve may be configured to selectively open and/or close in response to a pressure difference between the at least one fluid inlet and the at least one fluid outlet. The valve may be configured to selectively open and/or close in response to a pressure difference between the flow chamber device 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 velocity in the production stream. 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 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 wirelessly to control and actuate the electrically actuated valve. The wireless communication system may include at least one transmitter for transmitting a signal, for example, from a surface.

Said at least one valve may be adjustable and/or set to normally open or normally closed. Preferably, the valve is configured to respond to the speed or pressure of the fluid in the well.

The at least one valve may be set to open and/or close at a predetermined flow rate or rate of change in pressure of the fluid flow. The at least one valve may be configured to have at least one actuation threshold level. Said at least one valve may be configured to partially open and/or partially close the valve. The valve may be configured to open and/or close in positions intermediate between a fully open and 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 set 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 flow-through outlet chamber device can be retrofitted for installation in an existing production string. The flow chamber device may be removed, installed, replaced, and/or adjusted by wireline, wire rope, coiled tubing, drill pipe, or similar means of transportation.

The flow chamber device or component of the flow chamber device may be installed or replaced and may be transported along the production string using wireline, wire rope, coiled tubing, drill pipe or similar means of transportation. The flow outlet chamber device can be moved by at least one landing nipple. The at least one landing nipple may have ports in communication with the production string and/or the annulus.

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 set 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 wave 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 biased 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 flow outlet chamber device may include an inlet valve at the at least one inlet to control the flow of fluid through the at least one inlet. The flow outlet chamber device may include an outlet valve for controlling the flow of fluid through the at least one outlet.

The inlet valve and the outlet valve may be configured to operate independently of each other. The inlet valve and the outlet valve may be configured to cooperate with each other. The inlet valve and the outlet valve may be configured such that one valve operates as a main valve and the other valve operates as a secondary valve.

Preferably, the fluid inlet and fluid outlet are in fluid communication with the production string. 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 flow restrictors may have a matching arrangement for positioning according to the positions of the low-density phase, upper, and the high-density phase, lower, in the outlet chamber. The combining device may be a gravity-controlled system. Said at least one stop may be located in a rotating annular insert for independent rotation. The annular part can be mounted on bearings between the annular insert and the stationary parts of the outlet chamber. The matching device may be a closure means in combination with a large number of possible stops located around the periphery of the outlet chamber.

A plurality of flow restrictors may be located around the periphery of a portion of the outlet chamber, and the flow restrictors may have a plugging means and an activation means for alignment. The method may include activating a closure means to hold a restrictor located in an uppermost position and a restrictor that has a lowermost circumferential position to act as flow restrictors.

The outlet chamber can be designed as a section of the production string. The outlet chamber can be retrofitted. The housing can be cylindrical and for coaxial arrangement with the main pipe, production string, or casing in the well.

Said one or more inlet ports may have openings facing the flow within the production string. Said one or more inlet ports may be positioned open to a flow outside the production string, an annulus, a gravel pack, etc. The one or more inlet ports may have openings to a flow outside the production string and to a flow inside the production string. Said one or more inlet ports may have openings to flow within the production string. The outlets may be located open to the flow outside the production string, to the annulus, gravel pack, etc. The outlets may have openings to a flow outside the production string and to a flow inside the production string.

Flow restrictors may be elongated tubes. Flow restrictors can be elongated narrow tubes.

The tracer release system may be a mechanical release system for releasing a dose of the tracer. The indicator release system may be an indicator injection system. The indicator release system may be a matrix indicator carrier system. The indicator can be solid, liquid or gas. The indicator may be selected from the group consisting of chemical, fluorescent, phosphorescent, magnetic, DNA and/or radioactive compounds.

The indicator 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), perfluoromethylcyclohexane (PMCH). The indicator may be chemically immobilized within and/or on the delay chamber. The indicator may comprise indicator molecules and a carrier. The carrier may be a matrix material. The matrix material may be polymeric.

The indicator molecules may be chemically immobilized within and/or on the support. The indicator molecules can be chemically immobilized due to the chemical interaction between the indicator and the carrier.

By changing the chemical interaction between the indicator and the polymer, the release mechanism and rate of release of indicator molecules 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 commercially available polymers or copolymers of polylactic acid (PLA) or polyglycolic acid (PGA) of polymethyl methacrylates (PMMA), polymethyl acrylates, polyethylene glycols (PEG), polylactic acid (PLA) or polyglycolic acid (PGA). The carrier can be selected from polymers with higher rates of release of indicator molecules, such as polyethylene and polypropylene.

The indicator may be physically dispersed and/or physically encapsulated in the carrier. The indicator may release indicator molecules into the fluid by dissolving or decomposing the carrier and/or indicator into the fluid. The carrier may be selected for controlled degradation upon contact with a fluid. The support may be selected for decomposition by hydrolysis of the support.

The indicator and/or carrier may be fluid specific such that indicator molecules will be released from the indicator in response to contact with the target fluid.

The indicator 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), perfluoromethyl cyclohexane (PMCH). 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 can be carried out downstream of the outlet chamber device or at the surface. Samples can be collected for later analysis.

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 well geometry. The method may include estimating or calculating an influx profile based on the concentration and type of tracer as a function of sampling time. Inflow volumes can be calculated from transient flow models. Inflow volumes can be used to estimate a well's inflow profile.

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

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

The indicator may be configured to selectively release indicator molecules from the indicator material into a fluid in a delay chamber upon contact with a particular well fluid. The indicator is preferably configured to release indicator molecules into the indicator chamber when the indicator is exposed to a target fluid, ie oil, gas or water.

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

In accordance with a fourth aspect of the invention, there is provided an outlet chamber device for quantitative multiphase downhole oil monitoring, the device comprising:

a flow outlet chamber for the diverted flow, comprising: one or more outlet openings,

a flow phase separating section for separating the diverted flow into a low density flow phase and a high density flow phase,

delay chamber,

an indicator release system for the at least one indicator, and

at least one flow restrictor in fluid communication with the delay chamber, and

at least one valve configured to selectively control the flow of fluid through said one or more outlets.

The outlet chamber device may include one or more inlet openings. The at least one valve may be configured to selectively control the flow of fluid through said one or more inlet openings.

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

In accordance with a fifth aspect of the invention, there is provided a method for quantitative downhole monitoring of a multiphase flow comprising at least two phases of any of oil, water or gas in an oil well, the method comprising:

using at least one outlet chamber containing:

- flow phase separation section,

- indicator camera,

- one or more outlets,

- at least one flow limiter,

- indicator release system with one or more indicators,

- at least one valve configured to selectively control the flow of fluid through said one or more outlets,

dividing the diverted flow in the diverting chamber into a low-density flow phase and a high-density flow phase,

releasing at least one indicator into the indicator chamber,

passing separated low-density flow phase and high-density flow phase through each flow restrictor,

opening of said at least one valve,

washing out the low-density flow phase and the high-density flow phase with an indicator cloud from the outlet chamber through the outlet holes into the local flow inside the well,

monitoring the tracer in the production stream at a detection point downstream of the outlets.

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

In accordance with a sixth aspect of the invention, there is provided a method for quantitative downhole monitoring of a multiphase flow comprising at least two phases of any of oil, water or gas in an oil well, the method comprising:

installation of at least one outlet chamber containing:

- flow phase separation section,

- indicator camera,

- one or more outlets,

- at least one flow limiter,

- indicator release system with one or more indicators,

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

dividing the diverted flow in the diverting chamber into a low-density flow phase and a high-density flow phase,

passing separated low-density flow phase and high-density flow phase through each flow restrictor,

closing said at least one valve for a certain period of time to pause the outlet chamber,

opening said at least one valve to release indicator molecules,

washing out the low-density flow phase and the high-density flow phase with an indicator cloud from the outlet chamber through the outlet holes into the local flow inside the well,

monitoring the tracer in the production stream at a detection point downstream of the outlets.

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

In accordance with a seventh aspect of the invention, there is provided a method for quantitative downhole monitoring of multiphase flow containing at least two phases of any of oil, water or gas in an oil well, the well being substantially horizontal and/or slightly inclined at the locations of the indicator sources. a structure containing one or more positions of indicator sources having one or more local multiphase flows inside the well,

providing a portion of the local flow, the diverted flow, with the ability to enter a locally located outlet chamber, wherein the outlet chamber contains:

flow phase separation section,

delay chamber of a given volume,

one or more inlet ports and one or more outlet ports, the inlet ports being located upstream of the outlet ports,

at least a first flow restrictor for the low density flow phase and a second flow restrictor for the high density flow phase,

one or more indicator release systems,

one or more indicators having similar properties to one or more phases of the fluid medium,

after the diverted stream has entered the inlet ports, allowing the diverted stream to separate into a low density stream phase, typically a hydrocarbon phase, and a high density stream phase, typically an aqueous phase,

activating the indicator release system to release at least one dose of at least one of the indicators into the delay chamber to form an indicator cloud or multiple discrete clouds in the same chamber with an indicator concentration higher than the background concentration of indicators,

passing separated low density flow phase and high density flow phase, i.e. water and oil phases or gas and oil phases, through each additional flow restrictor, before

using a pressure difference between said inlet ports and said outlet ports to release a low-density flow phase and a high-density flow phase with an indicator cloud from the outlet chamber through the outlets (into the local flow within the well),

performing flow monitoring based on indicator responses in the produced stream at the detection point downstream of the outlets, and

calculating the characteristic washout time of each indicator in the outlet chamber or the transit time of each indicator through the outlet chamber based on the concentration of one or more indicators in the controlled flow.

One or more indicators may be added to the undivided portion of the stream in a delay chamber or after the streams have been allowed to separate, and then indicators are added to each separate phase.

Indicators may have properties similar to one or more fluid phases, for example, indicators for hydrocarbon phases such as oil or gas, and indicators for the aqueous phase.

Neutral tracers that have similar properties to both phases can also be used, and the trace signal can be read according to the specified limiting properties and expected behavior of the phases passing through the outlet chamber and the well at different time constants.

The use of a system without phase separation and having only a common limiting unit does not allow the use of a neutral indicator. This can be advantageous when it comes to the indicator release system within the outlet chamber, as well as the number of available or possible indicators.

The method may include using a water indicator and a neutral indicator in combination, instead of water and oil indicators for a water-oil system.

The method can use a given chamber volume by estimating the pressure difference in the well between the inlet and outlet ports.

The method may include calculating delays and/or costs for each phase of local multiphase flows.

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

In accordance with the eighth aspect of the invention, there is provided a tracer release device with an outlet chamber for quantitative multiphase downhole oil monitoring,

wherein the flow-through outlet chamber for the diverted flow has an elongated, at least partially cylindrical, housing for placement in an oil well and containing:

one or more inlet openings and one or more outlet openings located, respectively, in the upstream and downstream portion of the indicator outlet chamber,

flow phase separation section,

delay chamber,

an indicator release system for at least one indicator having properties similar to one or more phases of the oil flow,

at least one flow restrictor for the low density phase, and

flow limiter for the high-density phase, in fluid communication with the delay chamber,

wherein flow limiters having a predetermined limiting efficiency.

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

In accordance with a ninth aspect of the invention, there is provided an interpretation method for quantitative multiphase downhole monitoring for an oil well with a producing well flow, comprising:

providing data from a production well having at least one production chamber with separated flow phases through separate flow restrictors for one or more indicator positions, and one or more local multiphase production flows,

wherein the data includes measurements of tracers in the production stream at a detection point (D) downstream of the delay chamber to determine tracer concentration values for one or more tracers, and

- calculation of the characteristic washout time or time of passage of separated phases in delay chambers based on the concentration of the indicator.

The interpretation method may include using the known chamber volume and known restriction efficiency for the specified flow restrictors, estimating the pressure difference in the main pipe, and calculating the delay for the monitored locations.

The interpretation method may include using the known chamber volume and known restriction efficiency for the specified flow restrictors, estimating the pressure drop in the main pipe, and calculating the flow rates for each phase for the monitored locations.

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

In accordance with a tenth aspect of the invention, there is provided a method of releasing at least one tracer into a multiphase stream containing at least two phases of any of oil, water or gas in an oil well, the method comprising:

installation of at least one outlet chamber containing:

- flow phase separation section,

- indicator camera,

- one or more outlet ports,

- at least one flow limiter,

- indicator release system with one or more indicators,

dividing the diverted flow in the diverting chamber into a low-density flow phase and a high-density flow phase,

releasing at least one indicator into the indicator chamber,

passing separated low-density flow phase and high-density flow phase through each flow restrictor,

washing out the low-density flow phase and the high-density flow phase with an indicator cloud from the outlet chamber through the outlet ports into the local flow inside the well.

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 collecting samples for analysis in monitoring a multiphase flow well, comprising:

installation of at least one outlet chamber containing:

- flow phase separation section,

- indicator camera,

- one or more outlet ports,

- at least one flow limiter,

- indicator release system with one or more indicators,

dividing the diverted flow in the diverting chamber into a low-density flow phase and a high-density flow phase,

releasing at least one indicator into the indicator chamber,

passing separated low-density flow phase and high-density flow phase through each flow restrictor,

washing out the low-density flow phase and the high-density flow phase with the tracer cloud from the outlet chamber through the outlet ports into the local flow within the well, and

sampling at a location downstream of said at least one outlet chamber.

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 quantitative downhole monitoring of a multiphase flow containing at least two phases of any of oil, water or gas in an oil well,

wherein the well contains at least one outlet chamber containing:

- flow phase separation section,

- delay chamber,

- one or more outlet ports,

- at least one flow limiter,

- indicator release system with one or more indicators,

obtaining samples taken from the production stream at a location downstream of said at least one outlet chamber at a known sampling time,

measuring the indicator concentration for a specified one or more indicators in samples,

Calculation of the characteristic washout time or transit time for the separated phases in the delay chamber based on the concentration of the indicator.

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.

In accordance with a thirteenth aspect of the invention, there is provided a method for quantitative downhole monitoring of multiphase flow, comprising

calculating a characteristic washout time or transit time for the separated phases based on measured indicator concentrations for one or more indicators in samples taken from the production stream at a location downstream of the at least one outlet chamber at a known sampling time.

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

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the invention are described below, solely by way of example, with reference to the following drawings (like reference numerals refer to like features), in which:

Fig. 1 depicts a simplified view of an oil well with production chambers, in accordance with one embodiment of the invention. The drawing shows an embodiment with four outlet chambers located in the horizontal part of the well or in a slightly inclined area,

Fig. 2A is a longitudinal sectional view of a discharge chamber in accordance with one embodiment of the invention.

Fig. 2B-2E are sectional views along lines A-A, B-B, C-C and D-D, respectively, shown in FIG. 2A,

Fig. 3A is a longitudinal sectional view of a discharge chamber, in accordance with another embodiment of the invention, in which flow restrictors are located upstream of the delay chamber,

Fig. 3B to 3E are sectional views along lines A-A, B-B, C-C and D-D, respectively, shown in FIG. 3A,

Fig. 4A is a longitudinal sectional view of a release chamber, in accordance with a further embodiment of the invention, in which the indicator is released at a known location within the delay chamber at a predetermined time or upon a command or occurrence of any other predetermined downhole event,

Fig. 4B to 4E are sectional views along lines A-A, B-B, C-C and D-D, respectively, shown in FIG. 4A,

Fig. 5 is a longitudinal sectional view, in accordance with a further embodiment of the invention, in which the indicator is released at the beginning and end of the delay chamber to create two detectable peaks at the detection point,

Fig. 5B to 5E are sectional views along lines A-A, B-B, C-C and D-D, respectively, shown in FIG. 4A,

Fig. 6 illustrates the functionality of the invention and shows part of the delay chamber and the upper and lower limiter,

Fig. 7 is a photograph of a section of test pipe illustrating the mixture from the main pipe entering the outlet chamber, in accordance with one embodiment of the invention, and separating into two separate phases,

Fig. 8 graphically depicts the pressure distribution in the main pipe and annulus,

Fig. 9A is a perspective view of a flow restriction device in an outlet chamber, in accordance with one embodiment of the invention,

Fig. 9B and 9C show a longitudinal section through additional flow restriction devices in the outlet chambers, in accordance with embodiments of the invention,

Fig. 10 shows a cross-section of a discharge chamber, in accordance with one embodiment of the invention, with several flow restrictors,

Fig. 11 depicts an indicator release system for use in a discharge chamber, in accordance with one embodiment of the invention,

Fig. 12A and 12B depict a longitudinal sectional view of a withdrawal chamber, in accordance with one aspect of the invention, shown, respectively, in an inclined and generally horizontal well,

Fig. 13A, 13B and 13C depict perspective views of a discharge chamber, in accordance with one aspect of the invention,

Fig. 14 shows a longitudinal section of the outlet chamber, in accordance with another embodiment of the invention,

Fig. 15A is a longitudinal sectional view of a discharge chamber containing a mechanical indicator release system, in accordance with one embodiment of the invention,

Fig. 15B is an enlarged view of the mechanical indicator release system shown in FIG. 15A.

Fig. 16A and 16B depict schematic views of a discharge chamber containing a kinematic pressure valve assembly, in accordance with one aspect of the invention.

Fig. 17A and 17B are schematic views of a discharge chamber containing a differential pressure valve assembly in accordance with one aspect of the invention.

Fig. 18A-18C depict schematic views of an outlet chamber containing an outward outlet section, in accordance with one aspect of the invention.

Fig. 19A and 19C depict schematic views of an outlet chamber including an outflow section and an inlet in communication with the annulus, in accordance with one aspect of the invention.

DETAILED DESCRIPTION OF PREFERRED IMPLEMENTATION OPTIONS

Fig. 1 depicts a simplified cross-sectional view of a production well 10. The well contains a central production string 12 surrounded by an annular space 13. Fluid influx volumes enter the well from the formation into the central production string 12 through individual inflow points. Flow outlet chambers 12 are installed in or on the production string and are located next to each inflow point. Indicators are released from the outlet chambers and measured at surface 16 to provide information about where inflow is occurring, its multiphase conditions, and at what flow rate. In this example there are four outlet chambers 12a, 12b, 12c and 12d. However, there may be a different number of inflow zones and/or outlet chambers than that shown in FIG. 1. Each outlet chamber has inlet ports 20 and outlet ports 22.

Fig. 2A depicts an outlet chamber 100 that has indicator material 124 located in the outlet flow path 118. The outlet chamber also includes flow restrictors 126 in the outlet flow path 118. In the example shown in FIG. 2A, flow restrictors 126 are located downstream of the indicator source. However, as discussed below, alternative outlet chamber configurations may be provided. Flow restrictors 126 are configured to be phase dependent, since flow restrictor 126a limits the flow of low density fluids and flow restrictor 126b limits the flow of high density fluids.

Fig. 2B-2E are sectional views along lines A-A, B-B, C-C and D-D, respectively, shown in FIG. 2A. Fig. 2B illustrates that the inlets 120 may be a series of openings around a main pipe, tube, or the like (the inward venting embodiment is illustrated here). The inlet ports 120a, 120b, 120c may be one or more openings such as slots, holes, grilles, etc.

The diverted flow outlet chamber 100 has an elongated, at least partially cylindrical body 100a for housing a phase separation section 130 . This section should provide separation of high and low density phases. In this example, the separation section is at least partially circumferential so that the heavy phase will move to the bottom of the chamber and the lower density fluid will lie on top. The separated phases will then flow under the pressure difference between inlet ports 120 and outlet ports 122 through each additional flow restrictor of known characteristic on its way through the outlet chamber.

Next, with reference to the embodiment of the invention shown in FIG. 2A, the functionality of the invention is first given for simplicity and to introduce terminology for single-phase flow, and then it is extended to two-phase flow. For a single-phase flow it looks like this:

The fluid flow in the main pipe 116 creates a pressure difference between the inlet and outlet positions connecting the main pipe 116 and the outlet chamber 100, which is an annular chamber 114 surrounding the main pipe.

This pressure difference between the inlet and outlet ports moves a portion of the fluids through the outlet chamber 100 between the inlet and outlet ports. The indicator sources 124 are installed in a portion of the outlet chamber called the delay chamber 140. Such a tracer source produces a tracer cloud (a concentration of a given tracer higher than the background concentration) upon the occurrence of a predetermined event, on command or at a specific time, or due to tracer accumulation after a well shut-in if the tracers are installed in a slow-release container. In this example, the delay chamber 140 has an oil indicator source and a water indicator source 124b. Details of such installation methods and restrictions will be discussed below.

The flow of fluid through the delay chamber moves the tracer cloud from the discharge chamber into the wellbore through the outlets 122. The dispersion of the tracer as it moves along the delay chamber creates a characteristic signal called the washout signal. The washout signal has a peak concentration followed by a decline in concentration. 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 decay slope functions is proportional to the velocity of the fluid within the delay chamber, and thus the velocity of the fluid within the delay chamber can be calculated based on the measured decay curve of the indicator concentration. A steeper curve, that is, a shorter washout time, corresponds to a higher fluid velocity inside the delay chamber.

The flow of fluid through the outlet chamber 100 is proportional to the pressure difference between the inlet 120 and outlet 122 ports in the main pipe 116. The delay chamber 140 and flow limiters 126 are used to obtain the duration of the tracer washout signal, which can be measured at the wellhead with available measurement time resolution or frequency sampling. In addition, the signal must be long enough so that it is not destroyed by dispersion as it travels to the detection point, which may be located downstream of the tophole production equipment and liner extension. Detection is accomplished by monitoring at a detection point, which in one embodiment is in a wellbore. Observation may also or instead be performed at detection point 16 at the wellhead.

Monitoring may be accomplished by inspection and/or probe detection, in-line, in-stream, time-delay measurement, or the like. Such monitoring may be more or less continuous and pick up indicator signals whenever they occur. In embodiments of the invention, monitoring is accomplished by analyzing fluid samples taken. This requires a scheduled tracer release option or an automatic sampling device since manual sampling is resource intensive.

Modification of the signal duration (washout duration) can be performed as follows: increasing the volume of the delay chamber increases the time it takes for the indicators to pass through the delay chamber and, consequently, the duration of the indicators washout. Increased volume can be achieved by increasing the length (L) or cross-sectional area (S) of the delay chamber. The relationship between washout time and delay chamber length can be roughly described as follows:

where L is the length of the delay chamber, V is the average velocity of the fluid in the delay chamber. The relationship between the fluid velocity in the delay chamber and the flow restriction is as follows: V*S=Vr*Sr, where S is the cross-sectional area of the delay chamber, Vr is the flow velocity in the flow restriction node/s, Sr is the effective cross-sectional area of the node/s flow restriction nodes. Thus, increasing the cross-sectional area of the delay chamber leads to an increase in washout time.

In addition to modifying the delay chamber, increasing the indicator transit time in the delay chamber can be achieved by modifying the flow limiter assemblies. Increasing the resistance of the flow restrictor assembly to the fluid flow passing through it results in a lower fluid velocity within the delay chamber corresponding to the pressure difference between the inlet and outlet ports, thus the transit time and washout time are longer for the modified flow restrictor assembly. The flow rate in the delay chamber is used to calculate the pressure difference between the inlet and outlet ports, and the latter is used to calculate the flow rate in the main pipe using known empirical correlations of pressure difference versus fluid flow rate.

Such calculations may not require an exact relationship between pressure difference and flow rate. In the case where several such washout chambers (12a, 12b, 12c, 12d (as shown in FIG. 1)) are installed along a well, the productivity for each location can be obtained from a relative comparison of the washout time for all locations and the known overall productivity of the well.

The pressure difference between the inlet and outlet can be estimated based on the predetermined chamber volume.

Fig. 2A is a longitudinal sectional view of one of the discharge chambers shown in FIG. 1. The outlet chamber 100 is located in the annulus 114 at the periphery of the main pipe 116. The outlet chamber 100 has an outlet flow path 118 having inlet ports 120 and outlet ports 122. In FIG. 2B shows that the outlet chamber has a plurality of inlets through which mixed fluids 19 enter the outlet chamber from the main pipe 116.

In FIG. 2C is an end view of the separation section and shows separated oil 21 and water 23 in the discharge chamber. Fig. 2D and 2E are sectional views showing narrow tube flow restrictors 126a and 126b. The surrounding "annulus" 127 is now a blind pipe or sealed zone, at least at the inlet and outlet ends, preventing flow in the outlet chamber from entering this area, but leading to flow restrictors 126a and 126b.

Fig. 3A depicts an alternative outlet chamber design. The outlet chamber 200 is similar to the outlet chamber 100 described with reference to FIG. 2A, and will be clear from the description of FIG. 2A. However, flow limiters 226a and 226b are located upstream of delay chamber 240. The delay chamber 240 contains indicator sources 224 that are specific to the fluid, that is, water 224a or oil 224b.

Fig. 3B-3E are sectional views along section lines A-A, B-B, C-C and D-D, respectively, shown in FIG. 3A. In FIG. 3B shows that the outlet chamber has a plurality of inlets through which mixed fluids 19 enter the outlet chamber from the main pipe 216. FIG. 2C is an end view of the separation section 230 and shows separated oil 21 and water 23 in the discharge chamber. Fig. 3D is a sectional view showing narrow tube flow restrictors 226a and 226b. In FIG. 3E shows that the individual phases that have passed through the corresponding limiters are in contact with the indicator 224.

Fig. 4A depicts an alternative design of the outlet chamber. The outlet chamber 300 is similar to the outlet chambers 100 and 200 described with reference to FIGS. 2A and 3A, and will be clear from the description of FIG. 2A and 3A. However, the indicator source is released only at a known location 125 within the delay chamber 340 at a predetermined time or after a command, or after the occurrence of any other predetermined downhole event.

Fig. 4B-4E are sectional views along section lines A-A, B-B, C-C and D-D, respectively, shown in FIG. 4A. Fig. 4B through 4E are similar to the cross-sectional views of the outlet chambers 200 shown in FIG. 3A, and will be clear from the description of FIG. 3A.

Fig. 5A depicts an alternative design of the outlet chamber. The outlet chamber 400 is similar to the outlet chambers 100, 200, 300 described with reference to FIGS. 2A, 3A and 4A, and will be clear from the description of FIG. 2A, 3A and 4A. However, the indicator 424a, 424b is issued at two different ends of the delay chamber 440 to create two detectable peaks at the detection point.

Fig. 5B to 5E are sectional views along lines A-A, B-B, C-C and D-D, respectively, shown in FIG. 5A, they are similar to the cross-sectional view of the outlet chambers 200 described with reference to FIG. 3A, and will be clear from the description of FIG. 3A.

Fig. 6 is an enlarged view of a portion of the outlet chamber 500 showing a portion of the delay chamber 540 and the upper and lower restriction assemblies 526a and 526b.

The functionality of the invention for two-phase flow is first described for the simplest case where the well is horizontal at the location of the discharge chamber and the flow in the main pipe is divided. In this case, part of the delay chamber is filled with the first phase, that is, oil 21, and part of the delay chamber is filled with the second phase, that is, water 23. The location of the interface between the two phases 21 and 23 in the outlet chamber is controlled only by static pressure in the vertical direction and is combined with the location interfaces in the main pipe. As a result, the delay chamber flow is divided into two parts 540a and 540b, as shown in FIG. 6.

The washout of each phase can be considered as a washout from an independent delay chamber. The effects of interfacial forces at the interface between the two phases can be neglected since the interface constitutes only a small portion of the phase surface and the main resistance is due to wall friction and resistance in flow restrictors 526a and 526b.

The pressure difference between the inlet and outlet creates a fluid flow in the outlet chamber. If the main pressure drop occurs at restrictor 526a and 526b rather than at delay chamber 540, then the flow rate through the restrictor is proportional to the pressure difference driving the flow ΔP _B . In the case of turbulent flow through a restrictor it looks like this (for laminar flow there is a linear relationship between velocity and pressure drop, but the conceptual functionality is the same):

where ΔP _B is the pressure difference between the inlet and outlet ports in the production string or main pipe, or in the outlet chamber if well fluids flow in the outlet channel before entering the main well flow, ρ _o and ρ _w are the densities, respectively, of oil and water.

The washout time of the oil indicator is proportional to the area occupied by oil in the outlet chamber:

where L is the length of the delay chamber, S _{o is} the cross-sectional area of the delay chamber occupied by the oil phase, and S _R is the cross-section of the flow restriction where k _o (ρ _o , μ _o ) is a proportionality coefficient depending on the properties of the fluid medium and the geometry of the outlet chamber. This coefficient is different for the oil and water phases, since it depends on the density and viscosity of the fluid.

Accurate coefficients for relating washout time to flow rate and delay can be obtained either by flow loop testing and/or empirical correlations, or numerically for known fluid properties.

The washout time can be written in a similar way:

where the ratio between the area occupied by water is the difference between the total cross-section of the outlet chamber ( _Stotal ) and the area occupied by oil.

The washout times of oil (to) and water (tw) are measured at the wellhead and thus, using equations (*) and (**), two unknowns, oil retention in the outlet chamber (So) and pressure drop in the main pipe can be calculated .

The oil retention in the main pipe can be calculated from the oil retention in the outlet chamber from geometric considerations. The pressure difference between the inlet and outlet ports and the delay can be used to calculate the flow of oil and water in the main pipe. It is important to note that the flow restriction area must be constant and not change due to delays, otherwise the required monitoring will not be possible.

Dispersed flow in the main pipe

In the case of a mixed/dispersed flow in the main pipe, the situation is more complex, but fundamentally the same. Fluids after entering the delay chamber in this annular chamber design are quickly separated because the fluid velocity in the annular chamber is much less than in the main pipe. See example of laboratory tests in Fig. 7.

In FIG. 7 is an image of a section of test pipe, illustrating the flow of the mixture from the main pipe into the outlet chamber and the separation of its two separate phases. The flow rate in the main pipe is 350L/min of oil and 150L/min of water, the diameter of the main pipe is 100mm, and the flow is completely dispersed. Image in Fig. 7 shows a short flow path prior to fluid separation along the measuring tape. The dispersed flow is shown at point "M". The pure oil phase is shown at point "O" and the pure water phase at point "W". The boundary between the two phases can be seen at the “O/W” point. The distance at which the phases separate is small, and in this laboratory experiment it was about 5 cm. Thus, the dispersion in the delay chamber is very small and its presence can be neglected. As noted in flow loop testing, there is a correlation between the delay in the annular chamber and the delay of phases in the mixture. However, the relationship between annular chamber delay and phase delay is more complex in the case of segregated flow.

For the case of dispersed flow, the volume balance (which coincides with the mass balance for incompressible fluids, which corresponds to the case under consideration) of each fluid in the outlet chamber is as follows:

where Q _i is the total influx of the mixture from the main pipe into the annular chamber, α _o is the volume fraction of oil in the mixture of the main pipe, Q _Bo is the flow of the separated (clean) oil phase back into the main pipe through the inlet ports, Q _Bw is the flow of the separated (clean) aqueous phase back into the main pipe through the inlet ports.

As can be seen from the above equation, the annulus delay cannot be easily obtained from these equations, the mixture inflow and outflow of each phase are mainly determined by the pressure drop in the main pipe. However, the return flow of the separated oil and water phase depends on the pressure distribution in the main pipe and in the annulus (discharge chamber).

Static pressure, in turn, is directly related to fluid retention, and a typical static pressure distribution is shown in FIG. 8.

Fig. 8 is a graphical representation of the pressure distribution in the main pipe and annulus near the inlet ports. The exact slopes of the curves depend on the flow rate in the main pipe and on the retention of the various fluids.

Arrows “A” indicate the outer diameter of the annulus. The arrows “B” indicate the diameter of the main pipe. Arrow “C” indicates the point where oil exits the annulus. Arrow "D" indicates the pressure of the mixture in the main pipe. Arrow “E” shows the position of the interface in the annulus. Arrow "F" indicates the point at which the mixture in the main pipes enters the annulus. Arrow “G” shows the point where water exits the annulus. The arrow “H” indicates the pressure in the annulus.

When the static pressure in the annular chamber is higher than the pressure in the main pipe, the fluid will flow into the main pipe and vice versa. Therefore, in the case of mixing, the picture is relatively complex. In the case of partially mixed phases or a thick layer of dispersion between two separated phases flowing in the main pipe, the analysis is quite similar to the case of a fully dispersed mixture in the main pipe.

The equations and illustrations shown above in FIG. 7 and 8 show only the direction of analysis and were presented to explain the basic physics. A combination of experimental, analytical and/or numerical process modeling should be used to obtain accurate flow rates for each phase. As shown above, some of the segregated phases may move back into the main pipe through the inlets, and this can be taken into account using numerical simulations. The delay in the annular chamber (discharge chamber) occupied by each phase is not only related to the volume fraction of the incoming fluids, but may depend on the total flow rate in the main pipe, the inclination of the pipe, and the physical properties of the fluid such as viscosity, density, and interfacial tension between two phases.

The specified one or more local multiphase production flows (Fl, F2, F3, shown in Fig. 1) represent the sum of the flow distributed throughout the annulus through the delay chamber and the internal volume of the main pipe, when the outlet chamber is outlet inward, but at the same time the flow through the outlet chamber will be insignificant compared to the flow of the main pipe to cause separation of the fluids. The flow rate in the outlet chamber will be significantly lower.

The outlet chamber indicator may be constructed as a section of production string, meaning that it will be installed as part of the well production equipment. There may be a well production facility with a number of additional flow chambers thus positioned along the main pipe in the well production facility within a formation in the production well.

In one embodiment of the invention, the outlet chamber and/or indicator release devices are designed to be retrofitted, which means that a modified installation tool, such as a hanging tool or installer, can be used. In this case, the outlet chamber will have a fitting according to the diameter inside the pipe, tube, etc., where it is installed, and the pressure drop, etc. must be taken into account when calculating production parameters in accordance with the invention.

Flow paths

Fig. 2-5 depict embodiments of the invention in which the inlet ports (114, 214, 314, 414) are positioned open to flow within the production string. An embodiment of the outlet chamber design in accordance with the invention has inlet ports open to both flow outside the production string and flow inside the production string.

Once the diverted flow has entered the diverter chamber, it must be possible to separate the flow.

Common to all embodiments is that the streams must be separated before entering the flow restrictors, that is, upon entering the inlet ports, the diverted stream is separated into a low density stream phase (hydrocarbon phase) and a high density stream phase (usually an aqueous phase) (or , respectively, gas and oil phase) in the flow phase separation section before entering the flow delay chamber (140, 240, 340, 440) or limiters (126a, 126b, 226a, 226b, 326a, 326b, 426a, 426b). Flow limiters may be located before or after the delay chamber (140, 240, 340, 440).

The indicator (124a, 124b, 224a, 224b, 324a, 324b, 424a, 424b) can be introduced into the split stream or before the split, it will not affect the functionality of the system since the split occurs quickly and in a negligible time compared to the travel time in delay chamber. Indicators can be introduced by slow release from the polymer matrix due to diffusion, dissolution or destruction of the matrix, or by mechanical release.

In the preferred embodiment, the outlet chamber has a cylindrical body (100a, 200a, 300a, 400a) for coaxial placement with the main pipe, production string, casing in the specified well. This is the part enclosing or located outside or inside the specified production string. The discharge chamber then surrounds the pipe and uses a separation section and further measures the flow of water and oil separately.

A neutral indicator can be used for both phases since they can be read out in a concentration measurement based on, for example, the concentration profile, signal duration and knowledge of the limiter for each divided phase.

Separate phase measurement is a necessary condition for solving the above systems of equations.

According to one embodiment of the invention, as shown in FIG. 14, the outlet chamber has inlet ports 1264 open to flow outside the production string, into the annulus 1205, gravel pack, etc. The outlet ports 1266 may also be positioned open to flow from the outside of the pipe, main pipe, or casing, as shown in FIG. 14. The diverted flow is then taken from the annulus outside the main pipe, pipe, etc., separated, marked with indicators, and restricted before being returned back to the annulus. The pressure controlling flow through the outlet chamber is the annulus pressure difference between the inlet and outlet. This may allow analysis of reservoir inflow zones or simply annulus flow as such. In this example, oil and/or water is released into the delay chamber 1240 at a predetermined time or upon command.

Location of Flow Restrictors

The key requirement for flow restrictors is that they function properly and are correctly positioned, i.e. presence of one flow limiter for each phase. In addition, a flow restrictor for the high density phase, i.e. water, should be located at the bottom of the outlet chamber, and the flow limiter for the low density phase, i.e. oil, in the upper part of the outlet chamber, so that monitoring can be carried out even with small delays in one of the phases. Exhaust chambers for oil and gas mixtures can be designed in a similar way.

In practice, the orientation of the diverter chamber in a well is unknown and cannot be adjusted on demand, so there are several ways to overcome this problem, which are described below.

Heavy rotating disk or length of pipe

According to one embodiment of the invention, before a portion of the local flow enters the outlet chamber, at least the restriction assemblies (126a, 126b, 226a, 226b, 326a, 326b, 426a, 426b) are aligned according to the low density phase and high-density phase, which must be separated in the outlet chamber.

Fig. 9A and 9B depict a diverter chamber flow restriction device configured in accordance with one embodiment of the invention. The device has a stationary outer pipe 715 and a stationary main pipe 716. Between the outer pipe 715 and the main pipe 716 there is an annular insert 717, which is mounted on bearings 719 and can move relative to the outer pipe 715 and the main pipe 716.

The combining device has an upper flow restrictor 726a for the low-density phase and a lower flow restrictor 726b for the high-density phase mounted on a rotating ring insert 717. The rotating ring insert 717 is controlled by gravity.

In this example, the flow restrictors are a rotating ring insert. However, flow restrictors may be a pipe-style insert that is free to move/rotate independently of the pipe or section of pipe in which the discharge chamber is installed. Free movement of the flow restrictors can be achieved by installing bearings 719 between the insert and the stationary parts of the outlet chamber. The center of mass of the insert 717 is shifted from the center to its edge using weights or weights 721, etc. The insert 717 occupies a position where the weights or plumbs 721 are at the bottom, as best illustrated in FIG. 9A.

To avoid unnecessary rotation during drilling, the space 723 between the main pipe and the rotating insert 717 can be filled with a non-Newtonian fluid that does not respond to rapid movements but is amenable to slow movements.

In FIG. 9B shows another embodiment of the orientation of flow restrictors using a rotating insert containing flow restrictors in the middle of two longitudinally oriented stationary sections of the outlet chamber. The outlet chamber has inlet ports 720, outlet ports 722, a separation chamber 730, flow restrictors 726a, 726b, and a delay chamber 740. Bearings 723 may be located between the rotating insert 717 and the stationary parts, that is, the separation chamber and the delay chamber.

In FIG. 9C shows an alternative outlet chamber design 800 and illustrates another embodiment of the orientation of flow restrictors due to the presence of a rotating section of pipe with an outlet chamber. The outlet chamber has a movable section 817 with bearings 823 on the periphery of the pipe located between the outlet chamber and the main pipe, which allows the outlet chamber to rotate relative to the stationary main pipe 816.

In FIG. 9B and 9C show the simultaneous release of oil and/or water indicators near the start 725a, 825a and end 725b, 825b of the delay chamber.

Several connected channels

Fig. 10 is an end view of the outlet chamber 900, in which several flow restrictor channels 926 are located around the periphery of the outlet chamber. When the flow chamber is installed in the well, all flow restrictor channels will be plugged with plugs 927 except one that has the highest position 926a and one that has the lowest position 926b in the holder. This design avoids the use of a moving element, but requires the installation of several flow restrictors.

The connection of flow restrictors can be done using an electromechanical system that will determine the positions of the holder and plug of the required restrictors. The system can open the limiters if they are all connected initially. There are several implementation options, including gyroscopes, accelerometers, or the use of spring systems that balance and hold the limiters open only when they are in the up or down positions.

In one embodiment of the invention, the outlet chamber may have multiple flow restrictors that are located around the periphery of a portion of said outlet chamber, wherein said flow restrictors also have connection means and an activator (gyroscope or the like) for aligning and activating said connection means to maintain a restrictor located at the uppermost position and a restrictor located at the lowest position in the holder as said flow restrictors.

To avoid the flow restrictors being blocked in the partially open position due to particles or clogging, the entrance to the flow restrictors can be made of rubber, which will be pressed by the closing control mechanism. In this case, there will be no unwanted open channels.

A method for quantitatively monitoring multiphase flow (F) in a well in accordance with the invention includes, before a portion of the local flow enters the outlet chamber, activating the opening of the sealing device of the inlet and outlet ports (if they are initially blocked).

Flow restrictor design

Flow restrictors may be elongated tubes. In one embodiment, the flow restrictor may be a flow port or flow channel or passage for a porous medium. The simplest way to create a flow restrictor is to use a narrow tube, which will create a significant pressure drop across it due to wall friction.

In one embodiment, the flow restrictors consist of nozzles. However, nozzles can become clogged with fine particles present in wellbore fluids. Installing a filter to protect the nozzles may create additional flow resistance in a multiphase environment due to interfacial forces.

The limiting efficiency (property) of low-density flow phase limiters may differ from the limiting efficiency (property) of high-density flow phase limiters. This means that the behavior of each phase inside the outlet chamber is known and the velocity will be proportional to the pressure drop from the inlet to the outlet of the outlet chamber within the pipe, the main pipe, that is, in the production stream. The pressure difference is what drives the separated flows through the outlet chamber. The amount of each separated phase within the chamber and the design of the limiter will determine the duration of the trace at the monitoring point, which is considered the concentration value. A long-lived trace signal can be obtained. Implementation of the indicator

In one embodiment of the invention, the tracer release system is a dissolution or diffusion-based polymer matrix system for slowly releasing a dose of tracer.

The indicators can be installed inside a polymer matrix or a degradable container inside the well, from which the indicators will be slowly released. In the previous examples it was described that the well is paused to create an indicator cloud. However, in further embodiments, said at least one outlet chamber is suspended to create a high concentration tracer cloud which, when released, creates a detectable high amplitude peak signal.

In one embodiment of the invention, controllable valves may be located at or in the bleed chamber to control the flow of fluid into or out of the bleed chamber in response to a signal from the surface, a change in the velocity of the produced fluid, and/or a pressure difference between the bleed chamber and production column.

Fig. 16A and 16B depict an embodiment of the invention in which the outlet chamber 1400 is located in an annulus 114 having a kinematic valve located at the outlet of the outlet chamber 1400. For clarity, the kinematic valve arrangement is shown for only one outlet.

The outlet chamber 1400 has an outlet flow path 1418 having inlets 1420, a flow restrictor 1426, and outlets 1422. The arrows in FIG. 16A and 16B indicate the direction of movement of the fluid. The outlet chamber 1400 has an outlet flow channel 1418, which contains a phase separation section 1430. The outlet chamber includes flow restrictors 1426a and 1426b and a delay chamber 1440 that contains indicator material 1421. This indicator material is located in the delay chamber to allow fluid to contact the indicator material and flow around the indicator material 1421 in the delay chamber. The indicator material 1421 is configured to release indicator molecules when exposed to a target downhole fluid, ie, oil, gas or water.

Fig. 16A and 16B depict a kinematic valve assembly 1450 located at the outlet 1422 of the discharge chamber 1400. The kinematic valve assembly is located in the inner diameter of the production string. The kinematic valve has an actuating spool element 1460, which is offset in FIG. 16A to the closed position by means of a bias mechanism, in this case a compression spring 1462, located between a projection 1463 on the valve body 1455 and a projection 1461 on the spool member 1460.

The valve body 1455 has a port 1456 extending through the body wall that is aligned with the outlet chamber outlet 1422. Spool member 1460 is supported by a valve body with seals 1471 and 1473 at each end. The spool element can move axially relative to the valve body. Spool member 1460 has a port 1467. The spool member is movable from a closed position in which its port 1467 is not aligned with port 1456 and outlet 1422, as shown in FIG. 16A to an open position in which spool port 1467 is aligned with port 1456 and outlet 1422, as shown in FIG. 16V.

In the closed valve device shown in FIG. 16A, spring 1462 is a spring biased to the fully closed position at low capacity. This prevents the fluid in the shunt flow path 1418 and the delay chamber 1440 from leaving the outlet chamber due to the pressure spool member 1460 closing the outlet 1422. The indicator material 1421 remains open to the volume of fluid for a period of time when the valve assembly is closed, accumulating a high concentration of indicator particles 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, the level of enrichment of a fixed volume of fluid with the indicator is determined.

Once suspended to release the accumulated high concentration of tracer, a throttling assembly connected to the production string is used to increase the production flow above a preset valve threshold.

In response to the higher performance, the flow force acting on the spool element 1460 is sufficient to compress the spring 1462, moving the spool element 1460 to a fully open position in which the spool element port 1467 is aligned with the port 1456 and the outlet 1422, as shown in FIG. . 16V.

A high concentration of tracer, also known as a tracer cloud, exits the outlet chamber and is carried to the surface where it is detected as a high amplitude tracer response.

The pressures 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 should be understood that an extension spring can be used. Although in this example the spool element bias mechanism is a spring, it should be understood that other bias mechanisms can be used, such as a pressure chamber containing a gas such as nitrogen. The spool element bias mechanism spring may be adjustable, and may be adjusted, for example, in in the case of a spring, by changing the type, length or tension of the spring.

Fig. 17A and 17B depict a longitudinal sectional view of a discharge chamber 1500 located in the annulus 114, in accordance with one embodiment of the invention in which a differential pressure valve is located at an outlet 1522 of the discharge chamber 1500.

The outlet chamber 1500 has an outlet flow path 1518 having inlets 1520, a phase separation chamber 1530, flow restrictors 1526, and outlets 1520. Arrows in FIG. 17A and 17B indicate the direction of movement of the fluid.

The outlet chamber 1500 has a delay chamber 1540 that contains indicator material 1521. The indicator material is located in the delay chamber to allow fluid to contact the indicator material and pass around the indicator material 1521 in the channel. The indicator material 1521 is configured to release indicator molecules when exposed to a target downhole fluid, ie, oil, gas or water.

Fig. 17A and 17B depict a differential pressure valve assembly 1550 located at the outlet 1520 of the discharge chamber 1500. The differential pressure valve assembly is located in the inner diameter of the production string.

The valve assembly 1550 is located within the outlet chamber so that it is not constrained by the internal diameter of the production string. However, it should be understood that it may be located within the outlet chamber. Other components of the device are not shown for clarity.

Valve assembly 1550 has a body 1510 with an outlet port 1512 extending through the wall of the valve body, which is aligned with the outlet chamber outlet 1520. The spool element 1514 is movable axially relative to the valve body. Valve body 1510 has an inlet port 1517 in fluid communication with valve seat 1519. In the closed valve position, the spool element is located in the valve seat 1509, and the spool element closes the outlet port 1512 and the outlet 1520, as shown in FIG. 17A. In the open state of the valve, the spool element moves axially from the valve seat, and the outlet port 1512 and outlet 1520 are in fluid communication with the internal volume within the outlet chamber, as shown in FIG. 17V. The spool element bias mechanism, in this case a spring 1519, is located between a lug 1521 on the valve body and a lug 1523 on the spool element.

In this example, the spool element bias mechanism is a spring 1521, however, it should be understood that other bias mechanisms, such as a pressure chamber containing a gas such as nitrogen, can be used.

The spool element 1514 acts as a piston that can move axially due to the pressure difference between the discharge chamber and the production string. Pressure from the outlet chamber is applied to the spool element 1514 through the inlet port 1517. Pressure from the production string is applied to the spool element 1514 through the outlet port 1512 and outlet port 1520. When the pressure applied to the inlet port 1517 reaches a predetermined value, the pressure force compresses the spring 1514 to move the spool element axially away from the valve seat 1509 so that the spool element opens the outlet port 1512 and the outlet port 1520.

The spool element will remain in the open position as shown in FIG. 17B until the pressure difference between the flow chamber device and the production string is sufficient to keep the spring 1514 compressed.

As soon as the pressure difference between the flow chamber device and the production string decreases below a preset value, the spring force can overcome the pressure force acting on the spool element. The spool element moves to a closed position where it rests in the valve seat 1509.

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 should be understood that an extension spring can be used.

In the above embodiments, only one outlet valve for the outlet chamber is described. However, it should be understood that the outlets for each phase or the outlets for each sub-chamber in the outlet chamber may have a valve.

In the above embodiments, the valves are located at the outlet and are configured to selectively open and close the outlet based on the local fluid velocity in the main pipe and/or the pressure difference between the main pipe and the outlet chamber. However, alternatively or additionally, valves may be located at the inlet and may be configured to selectively open and close the inlet based on the local fluid velocity in the main pipe and/or the pressure difference between the main pipe and the outlet chamber.

The valves described with reference to FIGS. 16A, 16B, 17A and 17B may be closed for a period of time to pause the outlet chamber to increase the concentration of indicator molecules in the outlet chamber. When the outlet chamber is suspended, the concentration of indicator molecules released from the indicator material into the target fluid increases until the volume of fluid in the outlet chamber becomes enriched in indicator molecules.

While the above examples describe control and actuation of the 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 via wired and/or wireless communication.

After pausing the outlet chamber and increasing the tracer concentration in the outlet chamber to create an indicator cloud, the valve can be opened to release the indicator cloud by adjusting the production flow and/or creating a pressure difference between the fluid in the outlet chamber and the production stream.

High concentrations of tracer or tracer cloud are released as needed into the production string, carried to the surface and detected as high amplitude peak signals.

The valve can be closed to stop the discharge chamber. The retraction chamber can be paused for a certain period of time. The time period can vary from hours to months. The outlet chamber may be suspended for a period of time necessary to create a sufficiently high or elevated local concentration of the tracer, also known as an indicator cloud, that is detected on the surface upon release from the outlet chamber. The diverter chamber can be paused for less than 24 hours to pause the diverter chamber. The valve can be closed for more than 24 hours to stop the discharge chamber.

The valves described above can be adjusted to vary the rate of release of the tracer into the production string to adjust the amplitude and/or duration of the tracer response peak at the point of detection.

The tracer release system can be controlled by downhole conditions or conditions such as pressure, temperature, flow rate, conductivity, salinity, viscosity, etc. This may cause activation of the signal receiver or may chemically or physically open the flow through the outlet chamber and thus activate the release system to release the tracers.

When the release system is activated, the indicator may be released from a polymer matrix, an indicator liquid, or a solid particle release system that releases the indicators from the matrix. The indicator can be released by introducing the indicators using an injector or releasing the indicators from a container. You can use degradable indicators or indicator containers that can create indicator peaks in the chamber. Such containers can be made of water-soluble alloys and water- and oil-soluble polymers.

In one embodiment of the invention, the indicator release system includes a mechanism for releasing the indicator. In one embodiment of the invention, by controlling the outlet or inlet valves from the outlet chamber, the onset of flow through the outlet chamber is controlled. An indicator cloud can be created inside the chamber by pausing the outlet chamber.

The method may enable the indicator release system to simultaneously release a first dose of at least one of the indicators into a first end of the delay chamber and a second dose of at least one of the indicators into a second end of the delay chamber. In this case, the indicator exhaust system has two injectors and injector positions for each phase. This results in a double concentration peak for each phase of each diverted stream in the analyzed fluid.

The concentration of the indicator in the resulting indicator cloud should be 2 times higher than the background concentration, almost 5-1000 times higher than the specified background concentration.

The use of a withdrawal chamber that can be paused allows for the selective generation and release of high concentrations of tracer molecules without requiring the well to be paused. The withdrawal chamber may be configured to be suspended during production in the well. By using a device with an outlet chamber with at least one valve configured to selectively control the flow of fluid through the at least one outlet, it is possible to suspend the device to increase the concentration of indicator molecules in the fluid volume of the device. Subsequent opening of the valve to release an increased concentration of tracer may cause an tracer transient. The increased concentration of tracer molecules travels downstream with the produced stream as a tracer cloud, slug or charge, which can be detected downstream of the device and/or upstream as a tracer response signal or peak at the downstream detection point.

The advantage of suspending the outlet chamber is that accurate flow analysis can be performed in a multiphase system because it captures a point in time in the produced flow and allows the different phases to contact their respective phase indicators, increasing the confidence of the multiphase analysis.

Mechanical release by timer

Fig. 15A depicts a discharge chamber 1300 with a tracer release system 1301 including a mechanical release system for releasing a dose of tracer. Fig. 15B is an enlarged view of the indicator release system 1301.

The indicator release system 1301 includes a timer 1302, a relay 1304, and a battery 1306 for controlling the release of the indicator. The system also includes a spring 1308, a spring tension nut 1310, a melting ring 1312, clamps 1314, an ejector piston 1316, a fluid compensated chamber 1318, and a rupture disk 1320.

In the case where indicators are released on a timer, the timer does not need to be very accurate. As long as the indicator signal is picked up at the detection point (D), the exact release time is not important. In addition, the insertion of the indicator into the camera does not have to be strong or fast. For example, the measurement accuracy will be 30% if the time of dissolution of indicators, reaching the target phase or distribution takes 30% of the total time of passage in the delay chamber. If the transit time is 20 minutes, it is acceptable for the indicators to reach the target phase in 6 minutes.

Fig. 11A and 11B depict a mechanical release system implemented in accordance with one embodiment of the invention. The mechanical release system 1000 consists of several modules 1010a, 1010b, 1010c, 1010d... 1010n connected to each other, which ensures fairly accurate release of the indicator. In this case, the release chamber would have an indicator release system 1000 with two or more release modules connected in series, each containing a release controller 1011 and an indicator chamber 1012 for the indicator 1024.

The release controller also includes a signal transmitting means 1025 for transmitting a signal to a signal receiving means 1027 in the sequential release modules to activate an indicator release delay mechanism 1029 in the sequential releasing modules 1010a, 1010b, 1010c, 1010d... 1010n to release a dose of said indicator after a predetermined time. Each release module 1010a, 1010b, 1010c, 1010d... 1010n includes an indicator chamber 1012 and a release controller 111.

The release controller 1011 and delay mechanism 1029 may be a mechanical clock or the like, that is, based on a harmonic oscillator and a spring, in addition to a set of gears for controlling the rate of energy release. The frequency of the harmonic oscillator can change under the influence of well temperature, and if such an effect can be assessed, this is sufficient for measurements. Indicators can be released even an hour or a day later than planned if the indicator signal is measured at the detection point. The indicator release delay means for various embodiments may be a mechanical timer, a dissolving wall actuated (by a signal transmitter) to release the indicator by a pre-released indicator, or an electronic timer. When the indicator is released by the first module 1010a, the module sends a signal to the next module 1010b to start its timer. Such a mechanism can be implemented purely mechanically. A complete system of several modules can provide monitoring for many years.

The advantage of a mechanical system is its simplicity of design and the absence of the danger of self-discharge of batteries at high temperatures in the well, as is the case with electronic timers. However, a similar implementation in one embodiment would be done with electronic timers as the delay mechanism. If a liquid form of indicators is used, the indicators can be released by opening the indicator chamber or by having a piston that pushes the indicators into the delay chamber. For example, a low energy spring can be used to push the piston. The exact time of release of the indicators will shift, however the expected arrival of the indicator at the detection point may be adjusted depending on the time the previous signal was measured.

Indicators in powder form can also be used for monitoring if they reach the target phase by gravity or buoyancy and dissolve into the target phase directly without any intervening solvent. The modules may be placed along the delay chamber, along the periphery, or in any other suitable manner.

Instead of a timer between the indicator chambers, dissolvable plugs can be used to act as a means of delaying the release of the indicator. The dissolution time of each plug will act as a timer between successive releases of the indicator. However, such a plug must completely open the indicator chamber so that the indicator release does not spread over too long a period of time. Electronic timers can also be used.

The mechanism that controls the release of the indicator may be a chemical reaction, dissolution of plugs, or an electrical or mechanical clock. It is important that the control mechanism for the next exhaust system is activated only after the previous exhaust system.

The release of the indicator by the indicator system can be controlled by a downhole timer. It may be pre-installed or contain a signal receiver.

The release of the indicator by the indicator release system can be controlled by a command from the surface, the command being transmitted either wirelessly or by wire and connected to a signal receiver. These systems can be combined with both chemical, physical, and clock systems. The outlet chamber indicator release device, in accordance with one embodiment of the invention, may have inlet and/or outlet ports with a sliding spool port for opening and closing the inlet ports. It can be used as an indicator release activator or also as a trigger protection device to prevent contamination during the installation and completion phase. The inlet and outlet openings may have means for temporarily closing the openings for installation purposes.

The inlet ports can be opened to allow diverted flow to enter the diverter chamber, and closed to activate an indicator release signal to form an indicator cloud, keeping the ports closed for a preset time. Subsequently, the holes can be opened to direct the diverted flow through the diverter chamber due to the pressure difference. The ports can act on a signal coming from the surface. Ports can also act as a result of physical or chemical changes in the well.

Simultaneous injection of indicators at each end of the delay chamber

As an alternative to creating a washout signal, another approach can be used. In this case, the same indicators or different indicators are released simultaneously near the start of the delay chamber and near the end of the delay chamber, as best shown in FIG. 4. The distance between release points must be known, and the release of indicators must be carried out either simultaneously or after a known time interval. Each release of tracers creates a detectable peak in tracer concentration at the point of detection. The difference between the arrival times of these two peaks is then used to calculate the fluid velocity in the delay chamber and thus the delay and flow rates of the two phases flowing in the production string.

Holder design for high productivity or inclined wells.

The technology cannot be applied to vertical or highly inclined wells because gravity is used to separate the fluid. This technology can only be applied to horizontal and slightly inclined wells, however, even for slightly inclined wells, a shorter holder should be considered due to the problem of well inclination, as shown in FIG. 12A and this shows the importance of considering the design of the holder/discharge chamber. As shown in FIG. 12A, long holder/discharge chamber 1112, where 1150 is the oil-water interface. The long holder/outlet chamber 1112 cannot provide the required functionality because the water does not reach the flow restrictors 1126 unless an improved embodiment of the invention is used. In FIG. 12B shows a short holder/outlet chamber 1162, configured in accordance with one embodiment of the invention, in which water can reach the flow restrictor 1126b.

Fig. 13A depicts a complete holder 1121. FIG. 13B and 13C depict a discharge chamber configured in accordance with one embodiment of the invention. The delay chamber 1140 is located downstream of the flow restrictors 1126a, 1126b. The outlet chamber has a separation chamber, which is a fluid separation space 1129 before entering the flow restrictors. The invention is adapted for deviated wells, the flow restrictors 1126a, 1126b and the delay chamber 1140 related to the direction of the produced flow (F) extend downstream from one or more outlet ports 1122, but are associated with the direction of the diverted flow through the diverter chamber and are designed as downstream channels, see Fig. 13.

In FIG. 12A and 12B show how important it is to consider well inclination when designing a support structure. There are two problems with the shorter holder. One of them is a limitation on the number of installed indicators and, as a result, on the system resource. However, this can easily be corrected by installing several short holders that can accommodate the same number of indicators as a long holder.

The second problem is the limited space for the flow restrictor and delay chamber, and if the well flow rate is very high, it is difficult to achieve the required pressure drop by restricting the flow. In one embodiment of the invention, to overcome this problem, the inlet and outlet ports are located close together and direct the fluid back and forth relative to the direction of flow in the main pipe. This reduces the pressure controlling fluid flow in the outlet chamber and, therefore, the volume (length) requirements of the outlet chamber and the length of the flow restrictor modules if they are in the form of tubes. One possible embodiment is shown in FIG. 13. The fluid mixture enters the outlet chamber (position A in Fig. 13). The fluids separate due to segregation and enter the flow restrictors (position B in FIG. 13), which are long narrow tubes installed inside the delay chamber and opening into the delay chamber at point C in FIG. 13. The fluids then move to point D in FIG. 13, where they return to the main pipe. The main advantage is that the length of the delay chamber is greater than the distance between the inlet ports 1120 and the outlet ports 1122.

The invention provides an interpretation method for quantitative multiphase downhole monitoring for an oil well with a production flow in the well. This means the presence

- obtained data on a production well having at least one outlet chamber with separated phase flows through separate flow restrictors of a known design,

- one or more indicator injection positions,

- one or more local multiphase production flows,

- data containing measurements of tracers in the produced stream at a detection point (D) downstream of said at least one outlet chamber to determine indicator concentration values for said one or more tracers, and

- calculating the characteristic washout time or transit time for the separated phases in the at least one outlet chamber based on the indicator concentration values.

The method may include calculating a characteristic washout time or transit time for the separated phases in the at least one delay chamber in the outlet chamber based on the indicator concentration values.

Embodiments of the interpretation method may use production data obtained from a well. One or more of the following production data may be combined with the concentration data above, including total production, individual water, oil and gas production rates, downhole and/or wellhead pressure, choke settings and wellbore temperatures and/or at the wellhead.

Interpretation is not required on site. Samples may be collected for analysis later and/or at a different location. Interpretation may take place later and/or at a different location than the sampling and/or analysis steps.

Fig. 18A-18C are enlarged cross-sectional views of a discharge chamber device 1600 in accordance with one embodiment of the invention. The outlet chamber device is mounted on the production string 12. The outlet chamber device 1616 has an outflow section 1616a with an inlet 1618a in fluid communication with the production string, and an outlet 1620a in fluid communication with the annulus 11. The outflow section 1616a has an annular chamber. 1621a surrounding the production string, with a fluid volume 1622a between inlet 1618a and outlet 1620a.

The outlet chamber device 1600 has an inward outlet section 1616b with an inlet 1618b in fluid communication with the annulus 11 and an outlet 1620b in fluid communication with the production string 12. Arrows indicate the direction of fluid movement. The inward discharge section 1616b has a phase separation section 1625 and a delay chamber 1621b surrounding a production string containing a fluid volume 1622b. The delay chamber contains indicator material 1624a and 1624b. The outlet chamber also includes flow restrictors 1626a and 1626b. The indicator material may be located in the delay chamber to allow the fluid to contact the indicator material and flow around the indicator material in the fluid volume 1622b. Tracer materials 1624a and 1624b are configured to release tracer molecules or particles when exposed to a target well fluid, ie, oil, gas, or water.

Valve assembly 1628 is secured by a movable closure member to selectively open and close outlet 1620b to control the flow of fluid from delay chamber 1621b into the production string.

In this example, valve assembly 1628 is a differential pressure valve configured to open and close in response to changes in the pressure difference between the production string and the plenum device. In this case, the change in pressure difference is controlled by regulating the produced flow. The valve assembly is configured to open above a preset production flow threshold and close below a preset threshold.

During normal production, as shown in FIG. 18A, the production flow rate is below a preset flow rate threshold and therefore the valve assembly remains closed. The fluid flows from the production string through the outlet 1618a into the fluid volume 1622a of the annular chamber 1621a and through the outlet 1620a of the outflow section 1616a into the annulus 11. The fluid enters the fluid volume 1622b of the inward section 1616b from the annulus 11 through the inlet hole 1618b.

The high and low density phases are separated in a phase separation section 1625. The heavy phase moves to the bottom of the chamber, and the fluid with a lower density lies on top.

In fluid volume 1622b, the indicator material is exposed to the target fluid, releasing indicator molecules into the fluid. The tracer material 1624 in the fluid volume remains exposed to the fluid volume in the fluid volume 1622 for a period of time while the valve 1626 is closed, creating a high concentration of tracer particles in the internal fluid volume of the outlet chamber device.

When a tracer release operation is required, the throttling assembly is temporarily adjusted to increase the production flow to a second flow rate that is higher than a preset flow threshold for valve 1626, valve 1626 opens outlet 1620b, releasing fluid and a high concentration of tracer cloud into production. column 12. The high density phase flows through the lower flow restrictor 1626b, and the low density phase flows through the upper flow restrictor 1626a through the outlet chamber.

The indicator-rich fluid is gradually washed out of the outlet chamber through flow restrictors 1626a, 1626b into the production string. The tracer cloud produces a high amplitude peak signal at the point of detection, followed by a tracer signal decay curve that describes the gradual displacement and washout of tracer from the outlet chamber device.

Fig. 19A-19C depict enlarged cross-sectional views of the outlet chamber device 1700. The outlet chamber device is mounted on the production string 12. The outlet chamber 1716 has an outflow section 1716a with inlets 1718a and outlets 1720a in fluid communication with the annulus 11. The outlet chamber 1716 of the outflow section 1716a has an annular delay chamber 1721a surrounding the production string. with a fluid volume 1722a that contains indicator materials 1724a and 1724b. The indicator materials are located in the indicator chamber to allow the fluid to contact the indicator material and pass around the indicator material in the fluid volume 1722a. Tracer materials 1724a and 1724b are configured to release tracer molecules when exposed to a target downhole fluid, ie, oil, gas, or water.

The outlet chamber device 1700 has an inward outlet section 1716b with inlets 1718b in fluid communication with the annulus 11 and outlets 1720b in fluid communication with the production string 12. Arrows indicate the direction of fluid movement. The inward discharge section 1716b has an annular chamber 1721b surrounding a production string with a fluid volume 1722b between the inlet 1718b and the outlet 1720b. The inward discharge section 1716b has a phase separation section 1725 and flow restrictors 1726a and 1726b.

The valve assembly 1728 is supported by a movable closure member to selectively open and close the outlets 1720b to control the flow of fluid from the annular chamber 1721b into the production string.

In this example, valve assembly 1728 is a differential pressure valve configured to open and close in response to changes in the pressure difference between the production string and the plenum device. In this case, the change in pressure difference is controlled by regulating the flow rate of the produced flow. The valve assembly is configured to open above a preset production flow threshold and close below a preset threshold.

During normal production, as shown in FIG. 19A, the production flow rate is below a preset flow threshold and therefore the valve assembly remains closed. Fluid flows from the annulus through outlet 1718a into fluid volume 1722a of annulus indicator chamber 1721a and through outlet 1720a of outflow section 1716a into annulus 11.

In fluid volume 1722a, the indicator materials are exposed to the respective target fluids, releasing indicator molecules into the fluid.

The fluid enters the fluid volume 1722b of the inward bleed section 1716b from the annulus 11 through the inlet 1718b. Fluid containing indicator molecules cannot enter the production string while valve 1726 is closed. The high and low density phases are separated in a phase separating section 1725. The heavy phase moves to the bottom of the chamber, and the fluid with a lower density lies on top.

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 1726, valve 1726 opens outlet 1720b, releasing fluid and tracer molecules into the production string. 12. The high density phase flows through the lower flow restrictor 1626b, and the low density phase flows through the upper flow restrictor 1726a through the outlet chamber.

The indicator-rich fluid is gradually washed out of the outlet chamber through flow restrictors 1726a, 1726b into the production string. The released tracer produces a high amplitude peak signal at the detection point, followed by a tracer signal decay curve that describes the gradual displacement and washout of the tracer from the discharge chamber device.

In the above example, the indicator materials are located in the annular chamber 1721a of either the outward venting section 1716a or the inward venting section 1716b. However, it should be understood that the indicator material may, alternatively or additionally, be located on both the inward and outward outlet sections. In examples in which the indicator material is located in the outward outlet section 1716a and in the inward outlet sections, the indicator material in the inward outlet section may be the same or different from the indicator material in the outward outlet section.

In the above examples described with reference to FIGS. 18A-19C, the outlet chamber device is configured to close the outlet chamber device during normal low production and release a high concentration of tracer by temporarily increasing the flow rate of the production stream. However, it should be understood that the outlet chamber device may alternatively be configured to pause during normal high production in high production wells and release the tracer by temporarily reducing the flow rate of the produced stream.

In the above examples described with reference to FIGS. 18A-19C, flow restrictors are located downstream of the indicator materials. However, it should be understood that flow restrictors may be located upstream of the indicator materials. It should also be understood that the flow phases may be separated before or after the fluid contacts the indicator material.

It should also be understood that the outlet chamber device may be configured to release the tracer during normal production and be 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. 18A-19C have a valve located at the outlet 1720b for the indicator release operation, it will be understood from the above examples that the valves may be located at any and/or all of the inlets and/or outlets of the outlet chamber device. For example, valve assemblies may control the flow of fluid through outlets 1720a and/or 1720b. Alternatively or additionally, valve assemblies may control fluid flow through inlet ports 1718a and/or 1718b.

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 indicator locations may be known in the well geometry.

When a single tracer is released from two or more outlet chamber devices to the surface, their arrival at the surface is monitored and analyzed to determine the distribution of the influx. The volume between the arrival of each indicator peak is proportional to the inflow 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 production well geometry, which assumes a specific inflow distribution scenario, simulates the arrival times of the tracer peaks, and compares the modeled results with the actual peak arrival times. 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.

When tracer is washed out of a vent chamber device, zones with high influx rates wash out the indicator faster than zones with low influx rates, thereby maintaining a high concentration of tracer 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 present invention provides an apparatus and method for quantitative multiphase downhole oil monitoring. The device contains a discharge chamber for the diverted flow. The flow outlet chamber includes one or more inlet openings and one or more outlet openings located, respectively, in the front part and the bottom part of the outlet indicator chamber. The flow shunt chamber also contains a flow phase separation section, an indicator delay chamber, an indicator release system for at least one indicator, and at least one flow restrictor in fluid communication with the delay chamber.

The advantage of the invention is that it allows the phases to be separated within the outlet chamber, exposed to the indicator and allows each phase to pass through a known limiter designed for each phase. This means that the behavior of each phase inside the outlet chamber is known and the velocity will be proportional to the pressure difference between the inlet and outlet of the outlet chamber within the pipe, the main pipe, that is, in the production stream.

The pressure difference is what drives the separated flows through the outlet chamber. The amount of each separated phase within the chamber and the design of the limiter will determine the duration of the trace at the monitoring point, which is considered the concentration value. A long-lived trace signal can be obtained.

The present invention provides a diverter chamber device capable of improving quantitative multiphase downhole oil surveillance by measuring the produced flow of each phase in a two-phase flow.

The use of a withdrawal chamber that can be paused allows for the selective generation and release of high concentrations of tracer molecules without requiring the well to be paused.

An advantage of the present invention is that accurate flow analysis can be performed on a multiphase system because it captures a point in time in the produced stream and allows the different phases to contact their respective phase indicators, increasing the confidence of the multiphase analysis.

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,” “upstream,” “downstream,” and the like 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 is 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 (60)

1. A method for quantitative downhole monitoring of a multiphase flow containing at least two phases of any of oil, water or gas in an oil well, the method comprising: using at least one outlet chamber containing: flow phase separation section, delay chamber, one or more outlet ports, at least two flow limiters, indicator release system with one or more indicators, dividing the diverted flow in the diverting chamber into a low-density flow phase and a high-density flow phase, releasing at least one indicator into said delay chamber, passing the separated phase of the low density flow through at least the first flow restrictor, and the phase of the high density flow through at least the second flow restrictor, washing out the low-density flow phase and the high-density flow phase with an indicator from the outlet chamber through the outlet ports into the local flow inside the well, monitoring said at least one indicator in the production stream at a detection point downstream of the outlet ports, measuring the concentration of said one or more indicators in a controlled stream. 2. The method according to claim 1, in which the multiphase flow in a horizontal and/or inclined well is monitored. 3. The method according to claim 1 or 2, in which the characteristic time of leaching of each indicator from the delay chamber or the time of passage of each indicator through the outlet chamber is calculated based on the concentration of the specified one or more indicators in the controlled flow. 4. Method according to any one of paragraphs. 1-3, wherein the diverted stream is separated into a low-density stream phase and a high-density stream phase in a flow phase separating section before releasing an indicator or exposing the stream to said one or more indicators. 5. Method according to any one of paragraphs. 1-3, wherein one or more indicators are released into the diverted stream or the stream is exposed to the indicator before separating the diverted stream into a low density flow phase and a high density flow phase in a flow phase separating section. 6. The method according to any of the preceding paragraphs, in which the specified at least one outlet chamber is suspended by changing the flow rate of the produced flow in the well. 7. A method according to any of the preceding claims, wherein said at least one indicator is released into a delay chamber to form an indicator cloud or several separate clouds in one chamber. 8. The method according to claim 7, in which said at least one outlet chamber is suspended and an indicator cloud is formed in it. 9. The method according to claim 7 or 8, in which the low-density flow phase and the high-density flow phase with the indicator cloud are washed out from the outlet chamber through the outlet ports into the local flow inside the well. 10. Method according to any one of paragraphs. 7-9, wherein a pressure difference between the inlet ports and the outlet ports is used to flush out the indicator cloud from the at least one outlet chamber, the inlet ports being located upstream of the outlet ports. 11. The method of any one of the preceding claims, wherein a predetermined chamber volume is used and the pressure drop in the well between the inlet ports and the outlet ports is estimated, the inlet ports being located upstream of the outlet ports. 12. Method according to any one of paragraphs. 3-12, which calculates the delay and/or cost for each phase of local multiphase flows. 13. The method as claimed in any one of the preceding claims, wherein the flow rates of the produced flow of each of the two phases are calculated based on the measured washout time of the indicators from the delay chamber or the transit time of the indicator in the delay chamber and the known throughput of the specified at least two flow limiters for a given pressure difference between the inlet ports and the outlet ports, the inlet ports being located upstream of the outlet ports. 14. The method of any one of the preceding claims, wherein a pressure difference is provided between the inlet ports and the outlet ports to cause a portion of the well fluids to pass through the delay chamber and said at least two flow restrictors, the inlet ports being located upstream of the outlet ports . 15. A method as claimed in any one of the preceding claims, wherein indicators with similar properties to the target two phases are used, which can be detected either online or by post-sampling fluid analysis. 16. The method as claimed in any one of the preceding claims, wherein the diverted flow is directed into the diverter chamber from the annulus of the production string in the well or from inside the production string in the well. 17. A method as claimed in any one of the preceding claims, wherein said at least two flow restrictors are aligned with an upper position of the low-density phase and a lower position of the high-density phase in the diverter chamber before a portion of the diverted flow enters the diverter chamber. 18. The method according to any one of the preceding claims, wherein the opening of the sealing device of the inlet ports and/or outlet ports is activated, the inlet ports being located upstream of the outlet ports. 19. The method of any one of the preceding claims, wherein a first dose of at least one of the indicators is released from the indicator release system into the first end of the delay chamber and simultaneously a second dose of at least one of the indicators is released into the second end of the delay chamber. 20. A method as claimed in any one of the preceding claims, wherein monitoring is carried out by in-stream detection, probe detection, delayed measurement or physical sampling. 21. An indicator device with a discharge chamber for quantitative multiphase monitoring of oil in a well, which contains: a flow-through outlet chamber for the diverted flow, containing: one or more outlets, a flow phase separating section for separating the diverted flow into a low density flow phase and a high density flow phase, delay chamber, an indicator release system for at least one indicator and at least two flow limiters in fluid communication with the delay chamber. 22. The indicator device according to claim 21, wherein said at least one indicator is one or more of the following indicators: a water indicator, an oil indicator or a neutral indicator. 23. An indicator device according to claim 21 or 22, wherein said at least two flow limiters are phase dependent. 24. Indicating device according to any one of paragraphs. 21-23, in which the flow restrictors have a given restriction efficiency. 25. Indicating device according to any one of paragraphs. 21-24, wherein the indicator release system is an indicator injection system or an indicator carrier matrix system. 26. Indicating device according to any one of paragraphs. 21-25, comprising at least one valve configured to selectively control the flow of fluid through said one or more outlets. 27. Indicating device according to any one of paragraphs. 21-26, wherein said at least one valve is configured to selectively open and/or close in response to a signal from the surface or in response to a change in temperature, fluid velocity and/or fluid pressure in the wellbore. 28. An interpretation method for quantitative multiphase downhole observation for an oil well with a production flow in the well, comprising: obtaining data from a production well having at least one outlet chamber, wherein the data comprises measurements of tracers in the production stream at a detection point (D) downstream of said at least one outlet chamber to determine tracer concentration values for said one or more tracers, and calculating a characteristic washout time or transit time of the separated phases in the at least one outlet chamber based on the concentration of the indicator. 29. Method of sampling for analysis when monitoring a well with a multiphase flow containing: at least one outlet chamber containing: flow phase separation section, delay chamber, one or more outlet ports, at least two flow limiters, an indicator release system with one or more indicators, wherein said at least one outlet chamber is configured to: dividing the diverted flow in the outlet chamber into a low-density flow phase and a high-density flow phase, releasing at least one indicator into the delay chamber, passing the separated phase of the low-density flow through at least the first restrictor, and the phase of the high-density flow through at least the second flow restrictor, washing out the low-density flow phase and the high-density flow phase with an indicator from the outlet chamber through the outlet ports into the local flow inside the well, wherein the method includes taking samples at a location downstream of said at least one outlet chamber.

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