RU2711522C2 - Circulation sub with activation mechanism and corresponding method - Google Patents

Abstract

FIELD: oil, gas and coke-chemical industries.SUBSTANCE: group of inventions relates to oil and gas industry, in particular to valve devices in circulation systems of drilling mud during well drilling. Activation mechanism comprises at least one sensor to measure the pressure of the drilling fluid in the first fluid pipe in the circulating sub, control unit connected to sensor to monitor received sensor signal. Control unit is configured to electronically activate movement of at least one movable valve element in one direction based on the received signal. Valve element is configured to be positioned relative to at least a second fluid pipe in the circulation adapter and is movable between an open position and a closed position. Fluid medium pipe is communicated via fluid medium with first fluid medium pipe. Valve element comprises at least one end configured to close the second fluid pipe in the closed position and open the second fluid pipe in the open position. Control unit is electrically connected to at least one actuator unit located relative to at least one valve element. Actuator unit is configured to reciprocate at least one valve element between an open position and a closed position an unlimited number of times, wherein control unit is further configured to electronically activate movement of at least one movable valve element in opposite direction an unlimited number of times.EFFECT: simplified design, increased safety, reduced time costs, fast and accurate activation of downhole tool.15 cl, 6 dwg

Description

Field of Invention

The present invention relates to an activation mechanism for activating a circulation sub in a drill string, comprising a sensor measuring at least the pressure of the drilling fluid located in the first fluid pipe in the downhole tool, when a valve element is located relative to the second fluid pipe in the downhole tool when installed, and a control unit connected to the sensor and configured to monitor the received signal and electronically control the escheniem valve member based on the received signal.

The present invention also relates to a circulation sub for installation in a wellbore, comprising a casing having an outer side surface facing the inner wall of the wellbore, a first fluid pipe connected to a first opening at one end and a second opening at the other end, for guiding the drilling solution through the circulation sub, and at least a second fluid pipe in fluid communication with the first fluid pipe, the circulation sub further comprising a tivatsionny mechanism as mentioned.

The present invention finally relates to a method for activating a circulation sub using an activation mechanism, as mentioned above, where the method comprises the steps of installing a circulation sub at a predetermined depth in the wellbore, increasing the pressure of the drilling fluid located in the first fluid pipe of the circulation sub monitor the pressure of the drilling fluid inside the first fluid pipe, and activate the circulation sub when some event using the control unit.

BACKGROUND OF THE INVENTION

Today, various activation systems are used to selectively activate downhole tools, such as circulation sub, drills and other types of downhole tools used during drilling. It is known to dump balls of various sizes into the drilling fluid to activate or deactivate a circulation sub having the corresponding number of ball sockets for receiving these balls. Such an activation system can perform only a limited number of activation / deactivation operations, usually five to seven, which is determined by the size of the ball nests. When the circulation sub is full, it must be raised and the ball nests must be released from the balls before a possible new descent into the wellbore. In addition, the ball can be stopped in the fluid passage by accumulated solid particles, while blocking the circulation of the drilling fluid and causing an increase in pressure above the blockage, which can damage the downhole tool or even technological equipment installed at zero level.

In another activation system, a radio frequency (RF) receiver or transceiver located in a circulation sub for wireless communication with one or more radio frequency identification (RFID) tags discharged into the drilling fluid is used to solve this problem. Within the range of communication with the receiver / transceiver, the RFID device is able to communicate with the circulation sub to activate or deactivate the selected circulation sub. An example solution is disclosed in US 2013/0319767 A1 in which active or passive RFID tags are used to activate the desired function of a circulation sub based on a command received from an RFID tag. Instead, a pressure transmitter can be used in the circulation sub to detect mud pulses or flow signals to activate the circulation sub.

Both types of activation systems provide a slow and time-consuming method, since each ball or RFID tag must first be pumped with a mud pump from zero to the selected downhole tool before being able to activate or deactivate the downhole tool. Often, reaching an RFID tag or ball with a downhole tool installed at a depth of about 3,000 meters takes more than one hour, because the speed of moving the RFID tag or ball depends on the feed rate of the pump and the inner diameter of the drill string.

In another solution, a step-by-step activation system is used in which the configuration of the downhole tool changes each time the mud circulation pumps are turned on and off. The disadvantage of this solution is that the sequence of configurations is determined by the mechanism of stepwise movement, so the operator must follow the sequence of stepwise movement to select the desired configuration. In addition, it is well known that such step-by-step mechanisms have a complex configuration and are susceptible to mechanical failure.

WO 2013/103907 A1 discloses a drill with a pressure activated flow switching mechanism for activating and deactivating a drill. The flow switching mechanism comprises a piston arranged to move between an open position and a closed position based on different pressures. The spring element pushes the piston towards the upper seat of the casing to form a seal in the closed position. When the pressure drop of the passing drilling fluid exceeds the force of the spring, the piston axially moves to the open position where it comes into contact with the lower seat of the casing. At the same time, providing the drilling fluid with an entrance to the upper chamber and the release of drilling fluid from the lower chamber through the external opening. The drilling fluid in the upper chamber additionally acts on another piston, which radially moves the cutting unit out of the casing. The spring element presses the piston back to the closed position when the spring force exceeds the combined forces of the differential pressure and friction of the annular seal installed between the piston and the surrounding casing. This activation mechanism has a complex configuration and requires an actual flow through the drill tool to activate the cutting unit.

There is a need for an improved method that enables fast and accurate activation of a downhole tool, such as a circulation sub, without the use of a ball or RFID tag or a complex communication line in the well.

US 2013/0284424 A1 discloses a circulation sub comprising a housing having a central fluid path in fluid communication with a bypass path in the side wall of the housing. The bypass path has an inlet opening facing the central fluid path and an outlet opening facing the annular space surrounding the sub. The movable piston is located inside the inner chamber relative to this bypass path and contains a plug facing the saddle plugs installed in the bypass path. The controller uses a pressure sensor in the inner chamber to detect an activation signal through mud pulses or downlink signals transmitted through the passage of the mud in the central fluid path. After activation, the controller ignites the flammable agent, while the gaseous products of combustion push the piston into the bypass path until the plug comes into contact with its seat. With this bypass path. tightly closed. This configuration provides a one-time activation after which the circulation sub must be lifted from the wellbore and reconfigured. This activation mechanism can become available and reconfigured as a result of disassembling the sub, which increases the complexity and cost of the sub.

Object of the invention

The objective of the invention is the creation of an activation mechanism that is devoid of the disadvantages of existing technology.

The objective of the invention is the creation of an activation mechanism that provides fast and accurate activation of a downhole tool.

The objective of the invention is the creation of an activation mechanism with the functionality of activating a downhole tool, in fact, in the absence of a flow of drilling fluid.

The objective of the invention is the creation of a downhole tool with an integrated activation mechanism, which reduces the risk of failure of the seal during operation.

Description of the invention

The objective of the invention is solved using the activation mechanism for activating the circulation sub in the drill string, containing:

at least one sensor configured to measure at least the pressure of the drilling fluid located in the first fluid pipe in the circulation sub when installed,

a control unit connected to the sensor and configured to monitor the received signal of at least one sensor, wherein the control unit is configured to electronically activate the movement of at least one movable valve element in one direction based on the received signal,

wherein at least one valve element is arranged to be arranged relative to at least the second fluid pipe in the circulation sub when at least one valve element is arranged to move between the open position and the closed position,

wherein the second fluid pipe is in fluid communication with the first fluid pipe, and the at least one valve element has at least one end configured to close the second fluid pipe in a closed position and open the second fluid pipe in an open position characterized in that the control unit is electrically connected to at least one actuator unit located relative to at least one valve element, at least one execution unit The actuating mechanism is arranged for reciprocating movement of at least one valve element between the open position and the closed position, while the control unit is further configured to electronically activate the movement of at least one movable valve element in the opposite direction.

The term "closed" means that the valve element moves into the pipe and essentially blocks (blocks) the fluid passage so that the drilling fluid cannot pass through the pipe. The term “open” means that the valve element moves out of the pipe so that the drilling fluid can again pass through the pipe.

The above provides a simple and accurate activation mechanism that does not require dropping the ball or RFID tag into the drilling fluid to activate or deactivate the downhole tool. This provides a very quick way to activate / deactivate compared to activation systems using a ball or RFID tag. In the example, this configuration provides the downhole tool installed at a depth of about 3,000 meters, activation after a few minutes, for example, about three minutes. In addition, step-by-step systems are not required to select the operating mode of the downhole tool, since the operating mode can be selected in the commissioning process of the pump system, thus no cycles are required between starting and stopping the pump system to select the operating mode.

This configuration provides an activation mechanism to be integrated into the downhole tool or located as a stand-alone unit configured to connect to the downhole tool. This configuration is well suited for any type of circulation sub, which requires bypass bypass of the main fluid stream. The drilling fluid may be air, oil dust, foam, inert gas, or even any mixture or combination of fluids or gases with different relative densities of any type.

The control unit is configured to control the actuator unit, for example, the first actuator unit, which, in turn, moves the valve element, for example, the first valve element, forward or backward along a predetermined direction. The direction of movement may be parallel and / or orthogonal to the axial / longitudinal direction of the downhole tool. Any type of actuator block may be used to move the valve element, for example, a linear actuator, piston, or other suitable actuator block. The actuator unit may be driven by an electric, mechanical or hydraulic actuator integrated in or connected to the control unit. This provides the control unit with control of the movement and / or speed of the valve element.

In one embodiment, the control unit is further configured to use at least a first time window for the received signal, and to determine whether the received signal remains stable relative to at least the first threshold value of the at least first time window or not, at least at least one valve element is activated if a stable pressure is detected.

The terms “stable”, “stable level” and “stable pressure” are defined by a predetermined threshold level or strip having an upper and lower limit value, centered relative to the threshold value, where a measured parameter, for example, pressure, remains between the upper and lower limit values at least during a time window.

The control unit may be any type of analog, digital or logic electronic circuit suitable for processing and monitoring electrical signals received from sensors, for example, a pressure sensor. Alternatively, another type of sensor may be used to detect a signal representing mud pressure. In a preferred configuration, the control unit comprises a controller, for example, a microprocessor, configured to at least monitor the measured pressure in a given / first time window. The control unit / controller is further configured to compare the measured pressure with at least one / first threshold value defining at least one / first mode of operation. This mode of operation may simply be the activation or deactivation of a downhole tool. The control unit / controller is configured to determine whether the drilling fluid pressure remains stable in the first time window, i.e. within the upper and lower limit values of the corresponding threshold value. If a stable level is detected, then the control unit / controller transmits the specified control signal or command to the downhole tool to activate / deactivate the tool or select its operating mode. The control signal can simply be used to activate the actuator unit, which then moves the valve element forward or backward, depending on the corresponding control signal. The detection of a stable level of the measured parameter provides a simpler and less complicated activation method compared to downhole data transmission systems using mud pulses or flow pulses.

The time window may be selected based on the operating flow rate, operating pressure, or wellbore dimensions. The upper and lower limits can be determined based on the corresponding threshold value and / or tolerances of the pumping system. Operating pressure can be selected between 10 bar and 100 bar. Time windows can be selected between 1 minute and 10 minutes, for example, between 3 minutes and 5 minutes. Upper and lower limits can be selected between ± 1% to ± 10% of the selected activation level / threshold or operating level.

In one embodiment, the control unit is further configured to use at least a second time window for the received signal, and the control unit is further configured to determine whether the received signal remains stable with respect to at least the second threshold value in at least the second time window or not .

In this configuration, the control unit / controller is configured to compare the measured pressure with two or more threshold values, each forming a mode of operation of one downhole tool or an activation level for individual downhole tools. Individual downhole tools can be connected to the same activation mechanism or, alternatively, to individual activation mechanisms, each designed for a selected threshold value. Individual downhole tools may additionally have the same configuration or differing configurations depending on the required operation and / or position in the wellbore. This allows multiple modes of operation and / or downhole tools to be activated or deactivated by an activation mechanism.

The second time window may be the same as the first window or have a different length and / or shape. The second threshold value may be the same as the first threshold value or have a value that is higher or lower than the first threshold value. The limit values for the first and second threshold values may be the same, or may differ for each threshold value, for example, defining different spreads of threshold values. This provides activation levels with optimization for each downhole tool and / or each operating mode to provide better control of multiple operating modes and downhole tools.

Two or more thresholds can be used to easily control an actuator unit that selectively extends or retracts the valve element, for example, selectively closes or opens a second fluid pipe, depending on the measured pressure. In this configuration, the controller can monitor the received signal, for example, in another predetermined time window, and selectively activate the actuator unit each time the measured pressure reaches one of the threshold values. The actuator unit in turn performs a reciprocating movement of the valve element according to this selective activation. The control unit may, if necessary, comprise a synchronization unit electrically connected to the controller, and the synchronization unit may be activated when the valve element is moved to the open or closed position. After a predetermined time period, the controller can move the valve element back to the closed or open position through the actuator unit. This allows the circulation sub to be activated at regular intervals, if required, to provide a pulsating fluid flow in the annular space. This pulsating flow can also be used to bias or remove any accumulated cuttings in the annular space.

The control unit / controller may further be configured to detect a temporary drop or decrease in the received signal, for example, a measured pressure. The fall or decrease can be determined by a given amplitude and / or time span. This provides the control unit with confirmation that the selected downhole tool or operating mode is activated or deactivated. A second time window can be applied after detecting a given time drop or decrease, or after increasing or decreasing the discharge pressure to a second threshold value.

In an embodiment, the actuator unit comprises at least one element in the form of a solenoid for inductively moving at least one push rod mechanically connected to at least one valve element.

The actuator unit preferably comprises an element in the form of a solenoid for inductively moving a magnetic or magnetic rod or pipe, i.e. a push rod, which, in turn, is mechanically connected to the valve element. The solenoid type element is positioned relative to the push rod so that the magnetic field is directed into the material, for example, steel or the ferromagnetic material of the push rod. The push rod may form part of the valve member. An external or internal power supply, such as a battery, can be used to power the solenoid. Depending on the direction of the current in the solenoid windings, the solenoid can move the valve element in one or both directions and, thus, to the open and / or closed position. The control unit / controller can control the current in the solenoid, which in turn controls the speed of the valve element. This provides a simple and quick movement of the valve element using a minimum of components. This also provides better movement control compared to other flammable activation mechanisms.

If necessary, the spring element may be positioned relative to the push rod to maintain movement to the closed position. This ensures the fail-safe functioning of the activation mechanism, in which the valve element is held in a closed position so that no drilling fluid is directed to pass through the second fluid pipe.

In one embodiment, at least one sealing element is located on the outer surface of the passage valve, with the outer surface facing the inner surface of the chamber, with at least one sealing element remaining in contact with the inner surface during movement of the passage valve.

The valve element is installed inside the chamber, for example, the first chamber, made in the activation mechanism or in the downhole tool, where the valve element is able to move relative to the chamber when activated. The camera can be made in the side wall of the casing of the downhole tool. The valve element is preferably configured as a check valve, where one end is connected to or forms a part of the push rod mentioned above. The valve element may be a solid or hollow element without internal fluid pipes or openings. The other end of the valve element / check valve is made with a form for contacting the seat, for example, a valve seat mounted relative to the second fluid pipe, for example, its branches. This valve end is configured to substantially close the second fluid pipe when mounted in the seat, for example in the closed position.

The chamber contains at least one inner surface facing the corresponding outer surface of the valve element. The chamber further has a first end facing the second fluid pipe and a second end facing the second fluid pipe. Sealing elements, for example, one, two or more located in the selected outer surface of the valve element / valve passage and are in contact with the selected inner surface of the chamber. The sealing element may be O-rings, stuffing rings or any other suitable sealing element. The above ensures that the sealing elements maintain contact with this inner surface at all stages during movement, thereby forming a permanent seal that prevents the drilling fluid from entering the chamber. This reduces the risk of failure of the sealing element in comparison with conventional well blocks, since no peripheral edges of the valve element move along the sealing elements, just as no sealing elements move along any peripheral edge of the bypass opening in the casing.

In conventional downhole tools, the bypass pipe in the casing is aligned with the corresponding bypass opening provided in the housing and mounted in the center of the valve or coupling. The drilling fluid is guided through a sleeve or valve and exited through this bypass opening and then through the bypass pipe of the casing. Sealing elements mounted on a casing or on a valve or coupling hermetically seal the area between these two blocks. During movement, the valve or sleeve moves relative to the housing so that the peripheral edge of the bypass pipe or bypass opening moves along one or more of the sealing elements. The above increases the risk of failure of the corresponding sealing element due to increased wear; the peripheral edge can squeeze the corresponding sealing element out of the seat. The present invention solves this problem by positioning the activation mechanism and thus the valve element in the side wall of the casing so that no fluid pipes in the valve element are required.

At least a second valve element may be located in the first chamber or at least in the second chamber. The second valve element may be positioned relative to the second fluid pipe, for example, another branch thereof, or at least another / third fluid pipe in fluid communication with the first fluid pipe. If necessary, the second actuator unit may be connected to the second valve element to move the valve element, where the control unit / controller controls this actuator unit. At least two such valve elements and actuator units may have a different configuration or different configurations. Individual valve elements can be activated at the same pressure or at different pressures. This provides an activation mechanism for controlling the bypass of the fluid of two or more fluid pipes, thereby providing improved control of the bypass of the drilling fluid.

Alternatively, the first valve member, as described above, may be positioned relative to two or more branches of the second fluid pipe and / or two or more fluid pipes in fluid communication with the first fluid pipe. This provides increased bypass for drilling fluid bypass. The individual branches and / or fluid pipes used for bypassing the drilling fluid are configured to reduce any “dead ends” between the respective internal and external openings. In the example, the seat can be mounted parallel or perpendicular to the direction of flow in the branch / pipe. The side or sides of the seat can be inclined or curved and / or have a minimum surface area to prevent the accumulation of solid particles on the seat, which otherwise make the valve element inoperative. The inner surfaces of the branch / pipe and, if necessary, the seats are preferably made so that they are not of any significant or large narrowing along the flow path, which otherwise would increase the flow rate and, therefore, accelerate wear.

In one embodiment, the valve housing is located within the chamber, the passage valve extending at least partially into the valve housing through an opening at one end of the valve housing.

The camera may contain a narrow section and a large section. A narrow section, for example, an internal hole, is located at one end in communication with the second fluid pipe. A narrow section is located at the other end in communication with a large section. The internal dimensions of the narrow portion substantially correspond to the external dimensions of the valve element, thereby forming a relative tight fit around the valve element. This increases the structural strength of the side wall of the casing near the second fluid pipe, since only a minimal amount of material is removed. A large area, for example, a cavity having an opening located in the outer lateral surface of the side wall, is configured to receive and hold the remaining components of the activation mechanism.

The valve housing or stopper may be located in the chamber, for example, in a large area, and contains one end facing the second fluid pipe and the other end facing the actuator unit. The push rod may extend, at least partially, into the valve housing through an opening at this other end. This opening may be hermetically sealed using suitable sealing means. The valve element / check valve may also extend, at least in part, into the valve housing through an opening at this one end. This opening may also be hermetically sealed using suitable sealing means. The valve cover may be partially or completely filled with grease, such as oil. This reduces the amount of air inside the valve housing and reduces the energy required to move the valve element. This also keeps the sealing elements intact.

The valve housing may include guide means, such as a bearing, for guiding the valve element as it moves relative to the valve housing. When installed in the closed position, the contact surface on the valve element, for example, a thickened or thinned section, if necessary, is brought into contact with the corresponding contact surface on the valve housing, for example, a protrusion. Similarly, when installed in the open position, the contact surface on the valve element, for example, a thickened or thinned section, if necessary, is brought into contact with the corresponding contact surface on the valve housing, for example, a protrusion. This limits the movement of the valve element relative to the valve housing.

Alternatively, the push rod may be connected to this other end of the valve housing, and thus the valve housing can be moved relative to the chamber. When the valve housing moves to the second fluid pipe, the contact surface on the valve housing can be brought into contact with the corresponding contact surface on the valve element. The valve housing and valve member are then moved together toward the closed position. Similarly, when the valve housing is moved away from the second fluid pipe, another contact surface on the valve housing can be brought into contact with another corresponding contact surface on the valve element. The valve housing and valve element are then moved together to an open position.

In one embodiment, the control unit is further connected to an activation circuit, for example, a membrane switch, which is configured to activate the control unit at a given pressure.

The control unit is electrically connected to the activation circuitry to reduce the power consumption of the electrical components. The activation circuitry is configured to bring the control unit out of sleep state, for example, by turning on the power when the pressure inside the first fluid pipe exceeds a predetermined / third threshold. Any suitable activation circuitry may be used to wake up the control unit, such as a simple membrane switch. The control unit / controller then monitors the internal pressure of the drilling fluid in the first fluid pipe and activates the desired operating mode or downhole tool or actuator unit, as described above, if a stable pressure is detected. When the activation circuitry is determined, for example, simply by detecting that the pressure falls below a third threshold value, the control unit enters a sleep state, for example, the power is turned off. This provides the control unit with activation only when the internal pressure of the drilling fluid reaches a predetermined pressure value, therefore, energy consumption is reduced and operating time is increased.

The control unit may also be configured to enter sleep mode after completing one or more operations, such as activating a selected operating mode or downhole tool and, if necessary, confirming activation, as described above. The control unit may further be configured to activate a downhole tool or actuator unit when a case is detected, such as excessive vibrations or failure of cocking of the jar.

In one embodiment, the activation mechanism is configured to be implemented in a cavity located in the outer side surface of the casing of the circulation sub.

The activation mechanism according to the invention has a sufficiently small configuration for execution or installation in an external cavity located in the casing of the downhole tool, although most conventional activation mechanisms are designed for execution / installation in the central cavity of the downhole tool. The specified provides a more optimal passage of the fluid flow in the Central through hole, i.e. a first fluid pipe, a downhole tool, since there are no flow restrictors or at least a reduced number of flow restrictors in the downhole tool. Also, this provides quick and easy access to various components of the activation mechanism, while other activation mechanisms become available only as a result of complete disassembly of the downhole tool.

In one embodiment, at least one sensor comprises a first sensor configured to measure a first drilling fluid pressure in a first fluid pipe, and a second sensor configured to measure a second drilling fluid pressure in a returning drilling fluid when installed, wherein the control is configured to determine the differential pressure using the first and second pressures.

The activation mechanism may include at least two pressure sensors electrically connected to the control unit / controller. The first pressure sensor is located relative to the first fluid pipe for measuring the internal / first pressure of the drilling fluid, for example, through an opening in the inner surface of the through hole. The second pressure sensor is located relative to the annular space for measuring the external / second pressure of the returning drilling fluid, for example, through an opening in the outer side surface of the casing or in a removable cover. The control unit may be configured to detect a differential pressure using pressure signals from the first and second pressure sensors. The pressure drop can be compared with a predetermined threshold value, for example, between 40 bar and 60 bar, for example, 50 bar. If the measured pressure drop exceeds this threshold, then the control unit can activate the downhole tool or just a valve element. This ensures that the downhole tool maintains a given pressure drop regardless of the operating depth, hydrostatic pressure and weight of the drilling fluid. This pressure drop can also be used to determine if there is actual flow through the drill string, for example, by detecting whether the first pressure is greater than the second pressure.

The objective of the invention is also solved using a circulation sub for installation in the wellbore, containing:

a casing having an outer side surface facing the inner wall of the wellbore, where the casing is configured to be installed inside the wellbore,

a first fluid pipe connected to a first opening at one end of the circulation sub and a second opening at the other end of the circulation sub to guide the drilling fluid through the circulation sub,

at least a second fluid pipe in fluid communication with the first fluid pipe through at least one internal opening, and connected to at least one external opening located in the outer side surface of the casing,

characterized in that

at least one cavity is provided in the outer side surface of the casing in which at least one activation mechanism is located, as described above.

This provides the downhole tool with a simple and accurate activation mechanism that does not require ball narrowing to receive one or more dropped balls, or an RF transceiver or receiver to communicate with the reset RFID tag. This reduces the complexity and number of components required to activate the downhole tool. The activation mechanism described above enables activation of the downhole tool or bypass function using the internal pressure of the drilling fluid; no fluid flow required. The downhole tool is activated using drilling fluid pressure, which provides much faster activation compared to a conventional step-by-step system and systems with balls or RFID tags.

The downhole tool comprises a central through hole, for example, a first fluid pipe extending from the first end, for example, the upper end, to the second end, for example, the lower end, for guiding the drilling fluid pumped into the drill string through the downhole tool. The casing has a diameter smaller than the inner diameter of the wellbore, so that an annular gap is formed along the outer surface to direct the drilling fluid and cuttings back to zero. At least one bypass pipe, for example, a second fluid pipe, is provided in the casing and connected to the outer opening and the inner opening to bypass at least some portion of the drilling fluid.

In the outer side surface, a cavity is made in which an activation mechanism is installed. The valve member is relative to the second fluid pipe, and a saddle is mounted on the second fluid pipe. The seat and the second fluid pipe are arranged so that the valve element, when installed in the seat, closes the fluid pipe so that essentially no drilling fluid is directed through the second fluid pipe. Due to the installation of the activation mechanism in the casing of the downhole tool, for example, between the inner and outer side surfaces, the number of elements that throttle the flow in the fluid channel can be reduced or reduced to zero, while an essentially full bore channel can be obtained, i.e. operating at maximum power or operating speed.

In one embodiment, a removable cover is mounted on an opening of at least one cavity to seal at least one cavity, while it is possible to provide a seal between the cover and the casing.

The cavity is hermetically sealed by means of a cover or hatch to prevent the entry of drilling fluid or cuttings into the activation mechanism and create the cause of a possible failure in the activation mechanism. The lid and surface of the cavity form a chamber in which the activation mechanism is installed. The cover / hatch may be secured to the outer side surface with suitable fastening means, such as bolts, screws, snap-on connectors or other device. A seal or a sealing element, for example, a rubber element, an O-ring or other suitable seal, may be installed between the cover / flap and the housing to seal the chamber. This provides easy access to the activation mechanism in the event of maintenance or replacement of the activation mechanism. This also provides quick and easy installation of the activation mechanism, since the activation mechanism can be assembled and mounted as a monoblock. In addition, no sealing elements need to be directed and then installed inside the inner hole in which the valve element is located. This significantly reduces installation time and its complexity. This also eliminates the need for a special mounting tool to install the sealing elements inside the inner hole.

One or more balancing devices, for example, balancing pistons, may be installed at the upper end or lower end of the downhole tool. The balancing device may be configured to adjust or balance the pressure inside the downhole tool relative to the pressure of the drilling fluid above or below the downhole tool.

In one embodiment, at least one of the inner and outer openings of the second fluid pipe comprises a nozzle configured to control the speed of the drilling fluid entering or leaving the second pipe.

Two or more external openings may be located on the outer side surface to distribute the bypassed fluid and / or optimize the bypass of the drilling fluid. Outer openings may form branches of the same fluid pipe or different fluid pipes, as described above. Alternatively, two or more cavities may be located on the outer surface to accommodate and hold two or more activation mechanisms, each located relative to at least a second or third fluid pipe.

A nozzle is provided to control the speed of the drilling fluid in the inner and / or outer opening of the second fluid pipe. The inner / first nozzle may be configured to increase the speed of the drilling fluid entering the pipe. The outer / second nozzle may be configured to further increase the speed of the drilling fluid exiting the pipe. The nozzles can be installed at a predetermined angle relative to the longitudinal direction of the downhole tool, for example, at an angle of 90 degrees or an acute angle when the nozzle is at least partially facing the first / upper end of the downhole tool. Nozzles can be mounted on openings or integrated into openings. The nozzles may be made of a wear resistant material such as tungsten carbide or other suitable material. This provides a decrease in drilling fluid pressure inside the drill string, as well as an increase in the flow rate of circulating drilling fluid, if required. An increase in the flow rate in the annular space can be used to dissolve or destroy any filled areas or to remove accumulated cuttings from such areas for which filling or blocking of cuttings is predicted, such as a transition area between two different shanks.

The inner / first nozzle can be accessed and mounted externally through a selective tube in the casing. This selective pipe may be a separate pipe or one of the fluid pipes to bypass the first fluid pipe. The selective tube can be hermetically sealed with a stopper mounted on the outer opening. Alternatively, a nozzle for controlling the speed of the drilling fluid exiting a given fluid pipe may be mounted on an external opening. This further simplifies installation and maintenance methods, since all nozzles may be accessible from outside the downhole tool. One or more of these bypass pipes can thus be used for many purposes.

The downhole tool can be a circulation sub or a sealing assembly (active sealant) of any type used in drilling operations where a bypass function is required. The circulation sub or sealing arrangement can preferably be installed in positions along the wellbore where clogging is likely to occur, for example, in areas where the diameter of the wellbore changes, for example, in the transition region between different shanks. Alternatively, the activation mechanism described above can be coupled to or integrated into the jar to release a stuck or stuck downhole tool, such as the jar described in US 2012/0227970 A1.

The objective of the invention is finally solved by the method of activating the circulation sub using the activation mechanism described above, where the method comprises the steps in which:

set the circulation sub at a given depth in the wellbore,

increase the pressure of the drilling fluid located in the first fluid pipe of the circulation sub,

monitoring the pressure of the drilling fluid inside the first fluid pipe using at least one pressure sensor,

activate the circulation sub when an event is detected using the control unit,

characterized in that

the step of activating the circulating sub includes moving the valve member located in the chamber of the activation mechanism from the closed position to the open position so that at least the second fluid pipe is open to direct at least a portion of the drilling fluid through the second fluid pipe.

The above provides a method for quickly and accurately activating or deactivating a downhole tool without using RFID balls or tags dropped into the drilling fluid. This method provides a very quick action in comparison with activation systems using balls or RFID tags. As an example, a process for activating a downhole tool at a depth of about 3,000 meters takes several hours, for example, more than one hour, and the present invention provides a process for activation that takes minutes, for example, three minutes. In addition, the complexity as well as the number of components required to activate the downhole tool can be reduced in comparison with conventional activation systems, therefore, costs are reduced.

This configuration enables activation of the downhole tool that does not require the actual passage of the flow through the downhole tool, thereby ensuring its use in plugged wellbores or situations where no circulation flow can be established.

In one embodiment, the measured pressure is monitored in at least one time window, and the control unit activates the circulation sub if it is determined that the measured pressure has remained stable relative to at least one threshold value in at least one time window.

This provides activation of the downhole tool when the pressure reaches the specified activation value for the downhole tool or its operating mode. When the control unit determines that a stable pressure is detected, a control signal is transmitted to the actuator unit to initiate movement of the valve element. The actuator unit then moves the valve element from the closed position where the second fluid pipe is closed to the open position where the second fluid pipe is open, or vice versa if the configuration or tool is deactivated. This provides at least a portion of the drilling fluid bypass from the first fluid pipe to the pressure chamber located inside the downhole tool or into an annular gap located on the outer surface of the casing of the downhole tool. This also provides an unlimited number of activations or deactivations without the need to lift the downhole tool to unload the ball seats or reinstall the activation mechanism.

The control unit may continue monitoring the measured pressure to detect a change, for example, a pressure drop that indicates that the downhole tool or the selected operating mode has been activated. The pressure of the injected drilling fluid can then be increased to a working level or a different activation pressure for another configuration or downhole tool.

In one embodiment, the measured pressure is monitored in at least a second time window, and the control unit activates a second downhole tool or another mode of operation of the first downhole tool if it is determined that the pressure has remained stable relative to at least a second threshold value, at least at least second time window.

This provides a simple and accurate way of activating or deactivating multiple downhole tool operating modes and / or multiple downhole tools using the same activation mechanism or individual activation mechanisms. This configuration allows multiple operating modes and / or multiple downhole tools to be activated / deactivated by simply adjusting the pressure of the drilling fluid; no step-by-step movement system is required. In addition, operating modes and / or downhole tools can be activated or deactivated using different threshold levels, as described above. Activation levels or threshold levels can be chosen so that they do not interfere with the operation of other downhole drill string tools.

The control unit can monitor the vibrations measured by at least one vibration sensor and activate the downhole tool if excessive vibrations are detected, and / or monitor the measured pressure to determine if the jar is cocked and not activate the jar when some event is detected.

In this configuration, the downhole tool further comprises at least one vibration sensor connected to a control unit that monitors the vibration of the downhole tool and, in part, the drill string. The control unit compares the measured vibrations with one or more threshold parameters, for example, a reference frequency, profile, amplitude, or any other relevant parameters. If the measured vibrations exceed the threshold parameters, then the control signal is transmitted to the actuator unit to move the valve element so that the second fluid pipe opens. This provides a decrease in the pressure of the injected drilling fluid with an increase in flow rate. This indicates to the operator at zero that the vibration of the drilling has exceeded normal limits without the use of measurement signals during (MWD).

In another configuration, the downhole tool is configured as a jar or connected to the jar. The control unit compares the measured pressure with one or more reset levels to determine if the jar is cocked or not. The control unit may generate another control signal when the pressure reaches the selected reset level or if the measured pressure remains stable at the reset level in another time window. The control unit may be configured to detect a drop in a predetermined amplitude and / or time span which indicates that the jar is cocked.

In one embodiment, the operating circuitry activates the control unit when the drilling fluid pressure exceeds a predetermined pressure.

Electrical components are powered by an external or internal source of electrical energy, such as a battery. The power supply of the electrical components is controlled by a possible activation electric circuit, for example, a membrane switch, which turns on the power when the drilling fluid pressure exceeds the activation level / third threshold value. The control unit then switches from sleep mode to normal operation, in which it monitors the pressure of the drilling fluid in the first fluid pipe. The control unit activates or deactivates the selected operating mode or downhole tool if a stable pressure level is detected as described above. The control unit enters sleep mode again and the power turns off when the activation or deactivation process is completed or if the measured pressure falls below the activation level / third threshold level. At the same time, energy is saved, since the downhole tool is activated only at a given pressure, while reducing energy consumption and increasing operating time.

Description of drawings

The invention is described only as an example and with reference to the drawings, which show the following.

In FIG. 1, an activation mechanism of the present invention integrated into a downhole tool is shown from the upper end.

In FIG. 2 shows a downhole tool with three activation mechanisms from the upper end.

In FIG. 3 shows a longitudinal section of the activation mechanism of FIG. 1 in the closed position.

In FIG. 4 shows a longitudinal section of the activation mechanism of FIG. 1 in the open position.

In FIG. Figure 5 shows an example of the use of a downhole tool placed in a wellbore in a deactivated state.

In FIG. 6 shows the downhole tool of FIG. 5 in the activated state.

In the following text, the figures are described one after another, and the same parts and positions should be denoted by the same numbers in different figures, not all parts and positions indicated on a particular figure are considered together with the figure.

List of Reference Items

1 Activation mechanism

2 Downhole tool

3 Casing

4 Outer side surface

5 cavity

6 First fluid pipe, first hole

7 Second fluid pipe

8 Inner opening

9 Inner surface

10 Inner wall of the wellbore

11 pressure sensor

12 control unit

13 Membrane Switch

14 Actuator block

15 valve element

16 push rod

17 Camera

18 valve cover

19 Valve seat

20 Sealing elements

21 annular space

22 Upper end

23 lower end

24 External opening

25 Cork

26 cover

27 drill string

28 Wellbore

29 Drill

30 Transitional area

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

In FIG. 1 shows an example embodiment of an activation mechanism 1 of the present invention. The activation mechanism 1 is integrated into the downhole tool 2 in the form of a circulation sub. The downhole tool 2 and the activation mechanism 1 are shown from the upper end (shown in Fig. 3-4), where the upper end, lower end (shown in Fig. 3-4) and other components of the downhole tool 2 are excluded for illustrative purposes.

The downhole tool 2 includes a casing 3, configured to be placed in the wellbore, where the outer side surface 4 of the casing 3 is facing the inner wall (shown in Fig. 3-4) of the wellbore. A cavity 5 is made in the outer surface 4 to accommodate and hold the activation mechanism 1. The cavity 5 is closed by a lid (shown in Figs. 3-4) so that the drilling fluid in the wellbore does not come into contact with electrical components.

Inside the casing 3 is formed in the center, the first hole 6 extending in the longitudinal direction of the downhole tool 2. The first hole 6 forms a first fluid pipe for directing drilling from the upper end, through the downhole tool 2 and outward from the lower end.

In the wall of the casing 3 is made and forms a second fluid pipe, a second hole 7 for bypassing at least some part of the drilling fluid. The second fluid pipe 7 is in fluid communication with the first fluid pipe 6 passing through the internal opening 8 and with an annular gap (shown in FIG. 3-4) through the external opening (shown in FIG. 3-4). The activation mechanism 1 is positioned relative to the second fluid pipe 7 so that the valve element (shown in FIGS. 3-4) is able to control the flow rate of the fluid passing through the second fluid pipe 7.

In FIG. 2 shows another exemplary embodiment of a downhole tool 2ʹ having three activation mechanisms 1, 1ʹ, 1ʹʹ located in individual cavities 5, 5ʹ, 5ʹʹ in the outer surface 4. Each of the activation mechanisms 1, 1ʹ, 1ʹʹ is located relative to the second fluid pipe 7 , 7ʹ, 7ʹʹ for bypassing at least some of the drilling fluid in the first fluid pipe 6. The activation mechanisms 1, 1ʹ, 1ʹʹ can each have the same or different configurations, for example, they can be activated simultaneously or individually.

In FIG. 3 shows a longitudinal section of the activation mechanism 1 in a deactivated state. The activation mechanism 1 is installed in the side wall of the casing 3 between the outer surface 4 and the inner surface 9. The inner surface 9 is facing the first pipe 6 of the fluid. The outer surface 4 faces the inner wall 10 of the wellbore.

The activation mechanism 1 includes a pressure sensor 11, configured to measure the pressure of the drilling fluid in the first pipe 6 of the fluid. The pressure sensor 11 is electrically connected to a control unit 12 containing a controller, for example, a microprocessor, a storage unit, a communication interface for communicating with other downhole tools 2 or other outdoor devices or tools, as well as other components for controlling internal communication between the individual activation components mechanism 1. The pressure switch 13, configured to measure the pressure of the drilling fluid in the first pipe 6 of the fluid, optionally connected nen with control unit 12, such as its power supply. The pressure switch 13 is configured to turn on or off the power of the electrical components of the activation mechanism 1.

The actuator unit 14 in the form of a solenoid is electrically connected to the control unit 12. The actuator unit 14 is arranged to control the movement of the valve element 15 by generating a magnetic field in its wires that affects the push rod 16 mechanically connected to the valve element 15. The push rod 16 is made of a magnetic material, for example steel or ferromagnetic material. The valve element 15 is movable inside the chamber 17, for example, made in the activation mechanism or the casing 3. One end of the valve element 15 is installed inside the valve casing 18, which forms a stopper for the valve element 15. The valve casing 18 is connected to the push rod 16. Another the end of the valve member 15 is configured to abut against a seat 19 located relative to the second fluid pipe 7 in the closed position as shown in FIG. 3, thus closing the second fluid pipe 7 so that no drilling fluid is bypassed over the pipe. This allows the drilling fluid to pass from the upper end 22 of the downhole tool 2 and exit through the lower end 23 of the downhole tool 2 through the first pipe 6 of the fluid.

One or more sealing elements 20, two shown here, are located on the outer surface of the valve element 15 as shown in FIG. 3-4, a seal is formed between the chamber 17 and the second fluid pipe 7. The sealing elements 20, for example, O-rings, remain in contact with the inner surface of the chamber 17 at all stages of the movement of the valve element 15. Thus, no bypass openings or peripheral edges move along any of the sealing elements 20, thereby decreasing the risk of extrusion of the sealing elements 20 from their seats or other damage.

Another pipe connected to another external opening 24 in the outer side surface 4 is located in the side wall of the casing 3. The external opening 24 of this pipe is aligned with the internal opening 8. Here, this pipe is sealed by a lid 25. This pipe provides access to the internal opening 8 and provides nozzle installation as shown in FIG. 3-4. The plug 25 can be replaced by another nozzle, thus providing the action of this pipe as another second fluid pipe 7 to bypass the fluid from the first pipe 6.

The chamber 17 is sealed with a removable cover 26, which is fastened to the casing 3. The cover 26 is hermetically sealed using suitable sealing means to prevent the drilling fluid from entering the chamber 17.

In FIG. 4 shows the activation mechanism 1 in the activated state, where the actuator unit 14 is activated to move the valve element, for example, in the longitudinal direction, from the closed position shown in FIG. 3 to the open position shown in FIG. 4.

The actuator unit 14 is adapted to retract the valve element 15 further into the chamber 17 so that the other end of the valve element 15 is brought out of contact with the seat 19. This opens the second fluid pipe 7, thus providing at least some of the drilling fluid bypassing the first fluid pipe 6 and entering the annular gap 21. This allows the drilling fluid to pass from the upper end 22 of the downhole tool 2 and partially bypassing the first fluid pipe 6 the second pipe 7 of the fluid.

In FIG. 5-6 shows an example of the use of a downhole tool 2 with an activation mechanism (shown in Figs. 3-4) installed in the drill string 27 or the layout of the bottom of the drill string (BHA), which is installed in the wellbore 28. In an exemplary embodiment of the invention, the downhole tool 2 is installed above the drill and / or drill bit, which are configured to expand the wellbore and / or deepen the wellbore.

Drilled rock 29 is directed to the top of the wellbore 28 through the annular gap 21 between the drill string 27 and the wall 10 of the wellbore (indicated by dashed lines here). Drilled rock 29 accumulates in the transition region 30, in which the speed of the returning drilling fluid containing drill bit 29 is slowed down, for example, due to the expansion of the diameter of the wellbore 28. This causes clogging of the cuttings 29, as shown in FIG. 5.

The activation mechanism 1 and thus the downhole tool 2 remains inoperative until the switch 13 for supplying pressure to the electrical components, including the control unit 12, is turned on. The drilling fluid is then directed through the first fluid pipe 6 and back up through the annular gap 21, as indicated by the arrows in FIG. 3-4.

The pressure switch 13 is activated when the internal pressure inside the first fluid pipe 6 exceeds a predetermined pressure. The control unit 12 then wakes up and monitors the pressure inside the first fluid pipe 6 in one or more predetermined time windows. If the control unit 12 determines that the pressure remains stable in at least one time window, a control signal is generated and transmitted to the actuator unit 14. The actuator unit 14 then moves the valve member 15 from the closed position to the open position, thereby allowing at least some of the drilling fluid to bypass the first fluid pipe 6. The specified activates the downhole tool 2, and the drilling fluid is directed through the second fluid pipe 7 (indicated by arrows in Fig. 6) and into the annular gap 21. The indicated increases the speed of the returning drilling fluid, while blockage is made, so that circulation of the drilling fluid can to be restored.

The present invention is not limited to the illustrated embodiment or the embodiments described herein, and may be modified or adapted without departing from the scope of the present invention defined in the claims below.

Claims (31)

1. An activation mechanism for activating a circulation sub in a drill string, comprising: at least one sensor configured to measure at least the pressure of the drilling fluid located in the first fluid pipe in the circulation sub when installed, a control unit connected to the sensor and configured to monitor the received signal of at least one sensor, while the control unit is configured to electronically activate the movement of at least one movable valve element in one direction based on the received signal, wherein at least one such valve element is arranged to be arranged relative to at least the second fluid pipe in the circulation sub when at least one such valve element is arranged to move between the open position and the closed position, wherein the second fluid pipe is in fluid communication with the first fluid pipe, and the at least one valve element has at least one end configured to close the second fluid pipe in a closed position and open the second fluid pipe in an open position characterized in that the control unit is electrically connected to at least one actuator unit interconnected with at least one valve element, and at least one such actuator unit is arranged for reciprocating movement of at least one valve element between the open position and the closed position an unlimited number of times, while the control unit is additionally configured to electronically activate the movement of at least one movable of the valve member in the forward or backward an unlimited number of times. 2. The activation mechanism according to claim 1, characterized in that the control unit is configured to use at least a first time window for the received signal and determine that the received signal remains stable relative to at least the first threshold value at least in the first time window or no, with at least one valve element being activated if a stable pressure is detected. 3. The activation mechanism according to claim 1 or 2, characterized in that the actuator unit comprises at least one solenoid-type element for inductively moving at least one push rod mechanically connected to at least one valve element. 4. The activation mechanism according to any one of paragraphs. 1-3, characterized in that at least one valve element is a check valve located inside the chamber of the activation mechanism, while the check valve is arranged to move relative to the camera when activated. 5. The activation mechanism according to claim 4, characterized in that at least one sealing element is located in the outer surface of the check valve, the outer surface facing the inner surface of the chamber, while at least one sealing element remains in contact with the inner surface in valve travel time. 6. The activation mechanism according to claim 4 or 5, characterized in that the valve housing is located inside the chamber, while the check valve passes at least partially into the valve housing through an opening at one end of the valve housing. 7. The activation mechanism according to any one of paragraphs. 1-6, characterized in that the control unit is additionally connected to the activation circuitry, for example, a membrane switch, which is configured to activate the control unit at a given pressure. 8. The activation mechanism according to any one of paragraphs. 1-7, characterized in that the activation mechanism is made with the possibility of execution in the cavity located in the outer side surface of the casing of the circulation sub. 9. The activation mechanism according to any one of paragraphs. 1-8, characterized in that at least one sensor comprises a first sensor configured to measure a first drilling fluid pressure in a first fluid pipe, and a second sensor configured to measure a second drilling fluid pressure in a returning drilling fluid when installed while the control unit is configured to determine the differential pressure using the first and second pressures. 10. A circulation sub for installation in a wellbore, comprising: a casing having an outer side surface facing the inner wall of the wellbore, where the casing is configured to be installed inside the wellbore, a first fluid pipe connected to a first opening at one end of the circulation sub and a second opening at the other end of the circulation sub to guide the drilling fluid through the circulation sub, at least a second fluid pipe in fluid communication with the first fluid pipe through at least one inner opening and connected to at least one outer opening located in the outer side surface of the casing, characterized in that at least one cavity is made in the outer side surface of the casing, in which at least one activation mechanism according to any one of paragraphs is located. 1-9. 11. The circulation sub according to p. 10, characterized in that the removable cover is located on the opening of at least one cavity for hermetically closing at least one cavity, while it is possible to provide a seal between the cover and the casing. 12. The circulation sub according to claim 10 or 11, characterized in that at least one of the inner and outer openings of the second fluid pipe comprises a nozzle adapted to control the speed of the drilling fluid entering or leaving the second pipe. 13. A method for activating a circulation sub using an activation mechanism according to any one of paragraphs. 1-9, which includes stages in which: set the circulation sub at a given depth in the wellbore, increase the pressure of the drilling fluid located in the first fluid pipe of the circulation sub, monitoring the pressure of the drilling fluid inside the first fluid pipe using at least one pressure sensor, activate the circulation sub when an event is detected using the control unit, characterized in that the step of activating the circulating sub includes moving the valve member located in the chamber of the activation mechanism from the closed position to the open position, wherein at least the second fluid pipe is open to guide at least a portion of the drilling fluid through the second fluid pipe. 14. The method of activating the circulation sub according to claim 13, characterized in that the measured pressure is monitored in at least one time window and the control unit activates the circulating sub if it is determined that the measured pressure has remained stable with respect to at least one threshold value of at least at least one time window. 15. The method of activating the circulation sub according to claim 13 or 14, characterized in that the working electric circuit activates the control unit when the measured drilling fluid pressure exceeds a predetermined pressure.

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