Repair check valve

Abstract

The utility model relates to the field of oil and gas equipment, in particular to devices for diagnosing well tubing strings and ensuring their safe operation, and is intended to duplicate a standard check valve. The repair check valve (RCV) comprises five main coaxial units, namely, a sealing unit (A), a transport unit (B), a hydraulic drive (V), a check valve unit (G), and a limiter (D). The sealing unit (A) is designed to seal the annular space of the tubing. It comprises a barrel (1) with a funnel (2) fixed on top and a swelling rubber (3) installed on it. The transport unit (B) serves for the autonomous movement of the entire device within the tubing string. The hydraulic drive (V) is designed to fix the device in the tubing string when excess pressure is created in the internal cavity of the device, exceeding a predetermined response threshold.The check valve (G) is located at the bottom of the device and consists of a housing (26) containing a valve pair comprising a ball (27) and a seat (28). A limiter (D) is installed at the bottom of the device and serves to prevent the drain valve from opening accidentally while the device is being lowered into the well. This results in improved tubing safety due to the ability to quickly install the device, which combines autonomous movement along the string to the leaking check valve, automatic stopping and locking onto it, and subsequent operation of the check valve. 6 fig.

Description

[0001] The utility model relates to the field of oil and gas equipment, namely to devices for diagnosing well tubing strings and ensuring their safe operation, and is intended to duplicate a standard check valve.

[0002] Check valves installed in the tubing string are known. Their installation at a given depth requires separate tripping operations.

[0003] There are devices for well diagnostics that are lowered on a cable or pipes.

[0004] The disadvantages of such devices include dependence on lifting equipment and cable lines, limited diagnostic range, and the need for a separate operation to install the valve device after a defect is detected.

[0005] A check valve for an electric centrifugal unit is known (RU No. 141160 U1, IPC E21B 34 / 06, F04D 13 / 10, F04B 47 / 06, published on 05 / 27 / 2014), containing a stepped seat, a sleeve with windows and a spring, the design of which allows for backwashing of the receiving part of the pump.

[0006] The disadvantage is the lack of the ability to duplicate the standard check valve.

[0007] The closest analogue is a packer system for isolating an inactive perforation interval or a leaky section of a wellbore (RU No. 2387802 C1, IPC E21B 33 / 12, E21B 43 / 00, published on April 27, 2010), comprising two packers lowered into the well on a pipe string, each equipped with a barrel, sealing cuffs, a hydraulic anchor above them, an anchoring unit in the form of a cone and a ram holder with rams below them, and a stopper fixing the position of the packers. A disconnector-connector for the pipe string is located above the upper packer. The upper hydraulic packer, configured with a double anchor, is lowered above the leaky section or the inactive perforation interval, while the lower, configured with a single anchor, is lowered below the leaky section or the inactive perforation interval. A shear shoe valve or a landing nipple for a removable check valve, or one or more well chambers with removable elements, are installed beneath or between the packers.Below the upper packer or its sealing cuffs, an unpacking and circulation unit with a mechanically operated sliding sleeve is installed. A telescopic connection can be installed between the packers.

[0008] The disadvantage is the complexity of the design, and the valve design is sensitive to clogging, even small particles can lead to valve failure and lack of tightness, requiring frequent cleaning.

[0009] The technical problem that the utility model is aimed at solving is the creation of a device that duplicates a check valve, which is automatically placed above it and allows, in one release operation, to install a safety valve device on it that holds the liquid column located above.

[0010] The technical result consists in increasing the safety of tubing operation due to the possibility of quickly installing a device that combines the capabilities of autonomous movement along the column to a leaky check valve, automatic stopping and fixation on it, and then performing the functions of a check valve.

[0011] The technical result is achieved due to the fact that the repair check valve, containing sealing cuffs, supports with dies and the check valve assembly consists of a series of coaxially connected sealing unit, a transport unit, a hydraulic drive, a check valve assembly and a limiter, wherein the sealing unit includes a barrel with a funnel fixed on top and swelling rubber installed on it, the transport unit contains a barrel connected to the barrel of the sealing unit, with sealing cuffs fixed on it, spacer bushings are installed between the cuffs, and a thrust washer is installed in the lower part of the barrel of the transport unit, the hydraulic drive contains a barrel connected to the barrel of the transport unit, a cylinder is installed on the barrel of the hydraulic drive, fixed from axial displacement by screws, the cylinder encircles the piston with the formation of a sealed annular chamber between the inner surface of the cylinder, the outer surface of the barrel and the piston,wherein radial holes are made in the wall of the barrel, hydraulically connecting its internal cavity with the annular chamber, and the piston is fixed relative to the barrel of the hydraulic drive with shear screws designed to break upon reaching a threshold force, a cone is attached to the front end of the piston with the possibility of interaction with dies mounted on a support secured to the barrel of the hydraulic drive, a ratchet bushing is installed in the lower part of the cylinder, connected to the cylinder by a threaded connection, a ratchet is placed in the internal bore of the ratchet bushing, pressed in the radial direction by a spring, and a mating ratchet thread is made on the outer cylindrical surface of the piston, with which the ratchet has the possibility of interaction, through a coupling the hydraulic drive is further connected to the check valve assembly consisting of a housing, inside which a valve pair is located, including a ball and a seat, and above the valve pair a cage is installed with the possibility of limiting the travel of the ball,further, a limiter body is attached to the body of the check valve assembly, a piston is located inside the limiter body, installed with the possibility of axial movement, a sleeve is fixedly fixed in the upper part of the limiter body, enclosing the piston, while a sealed chamber with atmospheric pressure is formed between the inner surface of the limiter body, the outer surface of the piston and the lower end of the sleeve.

[0012] The essence of the utility model is explained by the following drawings:

[0013] Fig. 1 shows a general view of the assembled repair check valve (device diagram);

[0014] Fig. 2 shows the sealing unit A;

[0015] Fig. 3 shows transport hub B;

[0016] Fig. 4 shows hydraulic drive B;

[0017] Fig. 5 shows the check valve assembly G;

[0018] Fig. 6 shows limiter D.

[0019] The repair check valve (RCV) contains five main coaxial units, namely: sealing unit A, transport unit B, hydraulic drive B, check valve unit G and limiter D.

[0020] Sealing unit A is designed to seal the annular space of tubing. It consists of a barrel (1) with a funnel (2) attached to it and a swelling rubber (3) installed on it.

[0021] Transport unit B is used for autonomous movement of the entire device within the tubing string. It comprises a barrel (4) with sealing cuffs (5) attached to it. Spacer bushings (6) are installed between the cuffs. The cuffs are sealed along the barrel (4) by O-rings (7). When fluid is pumped into the string from above, a pressure differential is created across these cuffs, forcing the device to move down the string like a piston. A thrust washer (8) is installed on the barrel (4), contacting the end of the outermost cuff. When a pressure differential is created, the cuffs tend to move along the barrel and rest against the washer (8), which, in turn, transmits axial force to the subsequent barrel (9), thereby ensuring combined movement.

[0022] Hydraulic drive B is designed to fix the device in the tubing string when excess pressure is created in the internal cavity of the device, exceeding the specified response threshold.

[0023] Hydraulic drive B comprises a barrel (9) on which a cylinder (10) is mounted, fixed against axial displacement by screws (11). The cylinder (10) encloses a piston (12) to form a sealed annular chamber between the inner surface of the cylinder, the outer surface of the barrel (9) and the piston (12). To seal said chamber, the piston (12) is sealed relative to the cylinder (10) by a rubber ring (13), and relative to the barrel (9) by a rubber ring (14). Radial holes are made in the wall of the barrel (9), hydraulically connecting its internal cavity with the annular chamber.

[0024] In the transport position, the piston (12) is fixed relative to the barrel (9) or cylinder (10) by shear screws (15), designed to fail upon reaching the threshold force. A cone (17) is attached to the front end of the piston by means of screws (16). The cone (17) interacts with rams (18), which are mounted on a support (19). The support (19) is fixedly attached to the barrel (9) via a coupling (20) and screws (21). The rams (18) in the initial state are pressed to the outer surface of the barrel (9) by elastic rubber rings (22).

[0025] A ratchet sleeve (23) is installed at the rear of the cylinder (10), connected to the cylinder by a threaded connection. A ratchet (24), pressed radially by a spring (25), is located in the inner bore of the ratchet sleeve (23). A mating ratchet thread is made on the outer cylindrical surface of the piston (12), with which the ratchet (24) interacts.

[0026] Hydraulic drive B operates as follows. The internal cavity of the barrel (9) is connected to a source of excess pressure. Pressurized fluid enters the annular sealed chamber through radial openings in the barrel (9) and acts on the effective area of ​​the piston (12). When the pressure differential increases to the calculated value, the axial force on the piston exceeds the shear force of the shear screws (15). The screws (15) break, and the piston (12) moves forward, extending the cone (17) attached to it. The cone (17), interacting with the inclined surfaces of the rams (18), moves them apart in the radial direction. The rams (18) engage with the inner wall of the tubing string, securing the device from longitudinal movement.

[0027] Simultaneously with the movement of the piston (12), the ratchet (24), under the action of the spring (25), jumps along its ratchet thread and blocks the possibility of the piston (12) returning after the pressure is released, maintaining the wedged state of the dies and reliable fixation of the device in the column.

[0028] Check valve G is located in the lower part of the device and consists of a housing (26), inside which a valve pair is placed, including a ball (27) and a seat (28). The seat (28) is sealed relative to the housing (26) by a sealing ring (29), installed in an annular groove made in the housing. A cage (30) is installed above the valve pair, limiting the travel of the ball (27) and fixed from axial movement by a nut (31), which is screwed into a thread made in the upper part of the housing (26). The housing (26) of check valve G is connected to the coupling (20) of the hydraulic drive B.

[0029] The check valve is designed to ensure continued well operation after the device has been activated. After the device is secured in the tubing string by the hydraulic drive rams, when the downhole pump (e.g., ESP) is started, the upward flow of produced fluid acts on the ball (27), lifting it from its seat (28). The ball is held in place by a cage (30), opening the full flow channel (e.g., 31 mm in diameter) for production or injection. When the pump stops or a reverse pressure drop occurs, the ball (27) seats in the seat (28), closing the channel and preventing reverse circulation. Thus, the device, secured at the fault location, additionally functions as a check valve, duplicating the standard check valve.

[0030] The D limiter is installed at the bottom of the device and serves to prevent the unintentional opening of the drain valve during the process of lowering the device into the well.

[0031] The limiter comprises a housing (32) connected by a threaded connection to the lower end of the body (26) of the check valve. Inside the housing (32) is a piston (33) mounted so as to be able to move axially. The piston (33) is sealed relative to the housing (32) by sealing rings (34). In the upper part of the housing (32) a sleeve (35) is fixedly fixed, enclosing the piston (33) and sealed relative to it by a sealing ring (36). Between the inner surface of the housing (32), the outer surface of the piston (33) and the lower end of the sleeve (35) a sealed chamber with atmospheric pressure is formed.

[0032] The housing wall (32) contains radial grooves in which keys (37) are installed with the ability to move radially. The piston (33) has an angled surface at the area where it interacts with the keys.

[0033] When the device is lowered into a fluid-filled well, increasing hydrostatic pressure acts on the piston (33) from below, creating a pressure differential relative to the sealed chamber at atmospheric pressure. Under the influence of axial force, the piston (33) moves, its surface interacting with the keys (37), pushing them radially outward from the grooves of the housing (32). The extended keys form a stop with an outer diameter exceeding the inner diameter of the drain valve passage. Due to this, the extended keys of the housing (32) rest against the end of the drain valve, limiting further downward movement of the device and reliably eliminating contact with the drain valve locking pin. This prevents the drain valve from being knocked off during tripping operations.

[0034] The device is installed at the wellhead using a trigger. Fluid is pumped into the tubing string using a pumping unit. Under the pressure differential created across the sealing cuffs (5) of transport unit B, the device, like a piston, begins to move down the string.

[0035] When immersed in the fluid filling the well, limiter D is activated. Under the influence of increasing hydrostatic pressure, the piston (33) moves, and its beveled surface pushes the keys (37) radially outward from the grooves in the housing (32). The extended keys form a stop, the diameter of which exceeds the drain valve passage, preventing unintentional impact on its locking pin during lowering. The device continues downward movement with the limiter now activated.

[0036] When the device reaches the drain valve, the extended keys (37) press against its end, creating a rigid stop and stopping further downward movement. The pump unit continues pumping, causing the pressure inside the device to increase. Since axial movement is blocked, the increasing pressure through the radial holes of the barrel (9) acts on the piston (12) of the hydraulic drive B.

[0037] When the force on the piston (12) exceeds the tensile strength of the brass shear screws (15), the screws fail. The piston (12) moves forward, extending the cone (17) attached to it. The cone, interacting with the slips (18), pushes them apart radially and engages them with the inner wall of the tubing string. The ratchet (23) engages the ratchet thread of the piston (12) and securely blocks its return stroke, maintaining the wedged position of the slips. The device is then secured in the tubing string.

[0038] The triggering moment is recorded by the operator at the surface based on a characteristic change in pumping parameters—an increase in pressure and a change in flow rate. The device's stop depth, determined by the known installation depth of the drain valve, indicates the location of the planned stop point.

[0039] After the well is secured, it can be put into production. The upward flow of produced fluid opens the check valve G, lifting the ball (27) from its seat (28). Unrestricted production is ensured through the open flow channel. When the pump stops or a reverse pressure drop occurs, the ball (27) drops into the seat (28), closing the flow channel. Thus, the secured device functions as a check valve.

[0040] Within 24 hours, the swelling rubber (3) becomes operational and seals the space around it. A unique feature of this material is its ability to expand over time, allowing the device to be installed within the test column within the required time.

[0041] The outer diameter of the device is made less than 58 mm to pass inside the 73×5.5 mm tubing, and the diameter of the passage channel is not less than 31 mm.

Claims

A repair check valve comprising sealing cuffs, supports with dies and a check valve unit, characterized in that it consists of a sealing unit, a transport unit, a hydraulic drive, a check valve unit and a limiter connected in series in a coaxial manner, wherein the sealing unit includes a barrel with a funnel fixed on top and swelling rubber installed thereon, the transport unit includes a barrel connected to the barrel of the sealing unit, with sealing cuffs fixed thereon, spacer bushings are installed between the cuffs, and a thrust washer is installed in the lower part of the barrel of the transport unit, the hydraulic drive includes a barrel connected to the barrel of the transport unit, a cylinder is installed on the barrel of the hydraulic drive, fixed from axial displacement by screws, the cylinder encircles the piston with the formation of a sealed annular chamber between the inner surface of the cylinder, the outer surface of the barrel and the piston, wherein radial holes are made in the wall of the barrel,hydraulically connecting its internal cavity with the annular chamber, and the piston is fixed relative to the hydraulic drive barrel with shear screws designed to break upon reaching a threshold force, a cone is attached to the front end of the piston with the ability to interact with dies mounted on a support secured to the hydraulic drive barrel, a ratchet bushing is installed in the lower part of the cylinder, connected to the cylinder by a threaded connection, a ratchet is placed in the internal bore of the ratchet bushing, pressed in the radial direction by a spring, and a mating ratchet thread is made on the outer cylindrical surface of the piston, with which the ratchet has the ability to interact, through a coupling the hydraulic drive is further connected to the check valve assembly consisting of a housing, inside which a valve pair is located, including a ball and a seat, and above the valve pair a cage is installed with the ability to limit the travel of the ball,further, a limiter body is attached to the body of the check valve assembly, a piston is located inside the limiter body, installed with the possibility of axial movement, a sleeve is fixedly fixed in the upper part of the limiter body, enclosing the piston, while a sealed chamber with atmospheric pressure is formed between the inner surface of the limiter body, the outer surface of the piston and the lower end of the sleeve.

Images