RU2178513C1 - Subsurface safety valve - Google Patents

Abstract

FIELD: oil and gas producing industry, particularly, devices for cutting-off of producing formation from well. SUBSTANCE: subsurface safety valve includes packer with landing joint and check valve, kelly, stem, flange installed on lift string, and X-mass tree. Packer has fork installed by means of tie-rods into body recesses. Fork tie-rods are connected with bracing member located on body lower stage with seal. Tubular seal with sealing members is installed on seal and connected with body lower stage. Circular sectors with catching shoulders on landing joint are connected by screws with valve installed in its passage channel. Circular sectors are located in bore of body cover. Catching shoulders of sectors are located in windows of body upper stage for their transverse motion with conjugation of sectors with fork tubular part in process of packer fixing in sealing string coupling by joint. Circular sectors fix fork end in its motion by landing joint with internal bypass channels installed concentrically in its cavity. Landing joint and stem are connected in lower parts with joint. Joint has clamps installed in coaxial windows of joint body with possible closing-unclosing of plunger end piece in their engagement with wedge bosses of spring-loaded ring. Kelly is located in case and connected with it by subs for laying of current-supply cable between kelly and case and cable insulating from well medium by seal unit. Flange is installed between casing head and X-mass tree and connected with them by separate connectors and conjugated with kelly case by sealing member installed in flange bore. After packer lowering into well, valve in landing joint is sheared off, circular sectors are unwedged, packer is lowered to some extent. After installation of packer into well, electric centrifugal pump in assembly with liner is lowered. X-mass tree is installed on flange. Circulation windows in liner communicate producing formation of well with pump intake. EFFECT: higher operating reliability of subsurface safety valve in performance of well repairs without its killing by squeezing fluid. 4 cl, 6 dwg

Description

 The invention relates to the oil and gas industry and is intended to disconnect a productive formation from a well while repairing it.

 A well-known packer for closing a wellbore, comprising a cylindrical: a body on which a disk rotary valve, a seal, slips, reaction stops, upper and lower clamps with unbalanced latches, connected by threaded connections to the body, a pusher with spring-loaded stops of the L-shaped profile mounted on a lifting column with the ability to interact with the stops with the grooves of the upper and lower clamp when installing or lifting the packer in the well, a column for controlling the rotary disk valve [1] .

 The disadvantage of this packer is that it does not have a pressure relief valve to equalize the pressure drop above and below the valve when it is opened, which causes a load on the valve axis with the possibility of its deformation and reduces the reliability of the tight shutoff of the wellbore. The sealing surfaces of the seat and valve during well operation are exposed to high-speed fluid flow, this causes wear and tear and reduces the reliability of the tight shutoff of the wellbore. Installing and removing the packer by rotation does not preclude its jamming in the well.

 Known packer-cutter for blocking the wellbore, which is the closest analogue. The packer-cutter contains a sealing element, a unit for fixing it in the well, a hollow core with a magnetic seat for a check valve and a tubular pusher mounted on a lifting column with the possibility of interaction with a check valve [2].

 A disadvantage of the known packer-cutter is that it is possible that iron-containing particles stick to the magnetic saddle, which reduces the reliability of the tight shutoff of the wellbore. Sealing the wellhead while controlling a non-return valve has not been resolved. The absence of an unloading valve to equalize the differential pressure above and below the check valve when it opens causes a large load on the valve when it opens and a high fluid flow rate, this reduces the durability of the check valve. The use of magnetic elements prone to brittleness and demagnetization in the design reduces the reliability of the packer-cutter as a whole.

 The aim of the invention is to increase the reliability of the cutter during the repair of a well without killing it with filling fluid.

 The proposed borehole shutoff device includes a packer, in the passage channel of which an installation pipe is placed that interacts with the elements of the anchor assembly and a check valve when the packer is fixed in the coupling of the production casing of the well, a lead pipe, a liner, a flange mounted on a lifting column and in a fountain valve with the ability to control the return valve when moving the lifting column in a closed volume of the well.

 This goal is achieved by the fact that, in contrast to the known devices, the packer in the borehole cutter has a plug installed by rods in the housing grooves located between its steps, the fork rods are connected to a spacer element located on the lower stage of the housing with a sealant, a tubular seat with sealing elements, mounted on the seal and connected to the lower stage of the casing, annular sectors with hook shoulders located on the installation pipe and connected by screws to the valve installed in its passage the bottom channel, the hook shoulders of the sectors are placed in the windows of the upper stage of the housing with the possibility of lateral movement when pairing the sectors with the tubular part of the plug during fixation of the packer in the coupling of the production casing, ring sectors installed in the bore of the housing cover with the ability to fix the end of the fork when moving the installation branch pipe. The non-return valve is made in the form of a hollow cylinder and is equipped with a plunger with internal bypass channels mounted concentrically in its cavity with the possibility of communicating the non-return valve cavity with the packer through passage during the interaction of the plunger with the shank. The installation pipe, the shank is connected in the lower part to the lock, which has brackets installed in the coaxial windows of the lock case with the possibility of closing-opening the tip of the plunger when they interact with the wedge protrusions of the spring-loaded ring installed in the lock case, or when they interact with the wedge protrusions spring-loaded ring and with a conical bore of the tubular saddle. The lead pipe is placed in the casing and connected to it by adapters with the possibility of wiring between the pipe and the casing of the current supply cable with its isolation from the borehole medium by the gland packing unit. The flange is installed between the pipe head and the Christmas tree, connected to them by independent connections, mated to the casing of the drive pipe with a sealing element installed in the bore of the flange.

 The goal is also achieved by the fact that the fork has free travel relative to the spacer element and inclined flats are made between its rods.

 The goal is also achieved as a result of the fact that the non-return valve is sealed in the tubular seat on the sealing surfaces of the second, third order, coupled by the type of metal-elastic, metal-metal.

 As well as the fact that the circulation of the borehole medium through the packer is limited by the surfaces of the side windows at the ends of the liner and its internal passage channel.

 The combination of these signs determines the achievement of the goal.

 The use of a tubular plug in the packer, sequentially interacting with the annular sectors, with a spacer element, ensures its reliable installation in the well, since the fork wedges the sectors during free running and presses their hook shoulders against the wall of the production casing of the well with guaranteed installation of the shoulders in the production casing coupling and closure them between the ends of the pipes with a fork, and the subsequent movement of the plug with an installation pipe ensures: the sealant overlays the annulus of the well We, coupling the plug with the annular sectors, securing the packer in the coupling of the production casing of the well with a lock connection.

 The execution of the check valve in the form of a hollow cylinder allows it to be reliably sealed in the tubular seat and increase the durability of its operation, since it is sealed with cuffs on the cylindrical surface and forms a highly tight spherical conical connection with the end surface. Placing a plunger in the cavity of the check valve with internal bypass channels allows you to equalize the pressure drop across the check valve when it is opened.

 Equipped with an interchangeable lock of the installation nozzle and shank, it is possible to provide reliable mechanical control of the check valve, since when moving the lock in the packer passage channel, it passes the plunger tip into itself and rigidly fixes it when the check valve exits the tubular seat, and when the check valve is installed in the saddle, the lock releases the tip of the plunger and exits the packer through passage.

 Equipping the lead pipe with a casing allows you to place the current lead cable in an autonomous cavity on the lifting column, and the seal of the casing in the flange mounted on independent connections between the pipe head and the tree of the fountain reinforcement allows reliable sealing of the wellhead during the control of the non-return valve.

 The circulation of the borehole medium through the side windows and the passage channel of the liner eliminates the impact of high-speed fluid flow on the seat and its sealing elements, thereby increasing the durability of the check valve and improving the reliability of the shutoff as a whole.

 The proposed design of the downhole shutoff device is illustrated by drawings, where: in FIG. 1, 2 - the upper and lower parts of the cutter in the working position; in FIG. Figure 3-6 shows a packer with cuts: aa - along the brackets of the lock, bb - along the annular sectors with hook shoulders, c-c - along the annular sectors in the housing cover.

 The downhole shutoff in FIG. 1 includes a packer in FIG. 2 with a non-return valve 1 and an installation pipe 2 for securing the packer in the coupling 3 of the production casing of the well, the lead pipe 4, the shank 5 mounted on the lifting casing 6, a flange 7 mounted in the fountain between the pipe head 8 and the Christmas tree 9.

 The packer in FIG. 2 has a tubular plug 10 installed in the grooves of the housing 11, located between its lower stage 12 and the upper stage 13. On the rods of the fork 10 are made threaded protrusions for its connection with the spacer element 14. An internal thread with a bore is made in the upper part of the spacer element 14, ensuring the free movement of the fork 10 in the spacer element 14 under the action of the spring 15. The spacer element 14 is installed on the lower stage of the housing 12 and is mated on a conical surface with a seal 16. On the lower stage of the housing 12 on a tapered thread A tubular seat 17 is mounted on the seal 16. Conical bores are made in the seat 17 and cuffs are installed in the inner grooves to seal the check valve 1, shank 5. The annular sectors 18 have hook shoulders and are placed on the mounting pipe 2 between the yoke rods 10. The annular sectors 18 are connected screws 19 with a valve 20 installed in the passage channel of the mounting pipe 2, while the hook shoulders of the sectors 18 are placed in the windows of the upper stage of the housing 13 and form a wedge pair with the tubular part of the plug 10. Ring sector 21 have an outer groove under the spring ring 22 and mounted together with it in the bore of the housing cover 23. In the initial position the spring ring 22 presses the annular sectors 21 to the tubular part of the fork 10.

 The check valve 1 is made in the form of a hollow cylinder and consists of two parts, screwed with an emphasis end to end. In one of them, with a spherical end surface, a bore with grooves for sealing rings is made, in the other, through holes are made on the side of the end for communicating the non-return valve cavity with the borehole medium. In the cavity of the check valve 1, a plunger 24 with internal bypass channels, a conical protrusion for restricting the output of the tip 25 of the plunger 24 under the action of the spring 26 is installed in the bore with the o-rings. The geometry of the cavity of the check valve 1 and the distance between the inlet and outlet bypass channels of the plunger 24 provide a message to the cavity the valve with the packer through passage during the interaction of the shank 5 with the plunger 24. The tip of the plunger 25 is connected by a threaded connection to the plunger 24 and has an inlet conical head ku.

 The installation pipe 2, the shank 5 are connected at the bottom with a lock 27, which has brackets 28 installed in coaxial windows of the lock case 27 with the possibility of their closure - opening the tip of the plunger 25 when interacting with the wedge protrusions of the ring 29 and with the conical bore of the seat 17. Ring 29 with a spring 30 installed in the lock housing 27, while the wedge protrusions of the ring 29 interact with the brackets 28.

The lead pipe 4 is concentrically placed in the casing 31 and connected to it by sub. The sub on the outer surface have three threaded protrusions for connection with the casing 31, the protrusions of the sub in the assembled lead pipe 4 are located opposite each other. The protrusions on the sub are located through 120 ^o , the width of the protrusions is based on the calculation of the wiring of the current supply cable 32 between them. The cable 32 is disconnected from the borehole medium in the lead pipe 4 by the packing gland 33, which seals the annular space and the cable cores with pressure cuffs. The internal threads in the casing are made long enough for reciprocating movement of the casing 31 relative to the lead pipe 4 when the current lead cable 32 is wired between them. The flange 7 is connected by independent studs (not shown) to the pipe head 8 and the fountain tree 9, in the bore of the flange 7 a cuff 34 is installed for sealing the casing 31. In the shank 5, circulation windows and connecting threads are made at the ends for connecting the shank 5 to the lock 27 and the downhole pump 35.

 Downhole cutter is installed and operates as follows.

 A packer with a check valve 1 on the installation pipe 2 is lowered into the well on the lifting column 6, which is connected to the anchor assembly elements 18 with screws 19 and the lock 27 with the check valve 1. When the packer approaches the set installation interval, the descent stops and a pressure drop is created in column 6 required for cutting the screws 19. When cutting the screws 19, the valve 20 moves down, the annular sectors 13 are released and due to the free movement of the fork 10 under the action of the spring 15, the annular sectors 18 are wedged and pressed by the hooked shoulders to the st nke production well of the column. When the packer is subsequently lowered into the well, the hooked shoulders of the sectors 18 are guaranteed to be installed in the coupling 3 between the ends of the production string pipes, closed with a fork 10, which, under the action of the mounting pipe 2 from the discharge of the string 6 to the sectors 18, moves down and interacts with the spacer element 14. Spacer the element 14 presses the seal 16 against the production casing 6 and hermetically closes the annulus of the well. At the end of the stroke of the yoke 10, the annular sectors 21 under the action of the spring ring 22 fix the end of the yoke 10 in the housing cover 23. When lifting the column 6, the check valve 1 moves in the seat 17 until the brackets 28 interact with the conical bore of the seat 17 and with the wedge The protrusions of the ring 29 will not release the tip 25 of the plunger 24, after which the pipe 2 exits the packer passage channel. The well is divided into two autonomous zones. An electric centrifugal pump 35 is assembled with a shank 5, lock 27 in front of the well. Before entering the shank 5, a flange 7 is installed on the packer passage channel 8, a lead pipe 4 is assembled with a Christmas tree 9 on a lifting column 6, a current lead cable 32 is passed between the lead pipe 4 and its casing 31, remove it from the cable entry of the fountain tree 9, install the stuffing box seal 33, sealing cable cores 32 therein. Install the fountain tree 9 on the flange 7, while the shank 5 leads the check valve 1 out of the seat 17, fixer I 27 lock the plunger tip 25, and communicates with the productive formation of the well 35 through the intake pump circulation box and the inner passageway of the shank 5. equip wellhead under operation and launch it into work. If it is necessary to change the pump 35, disconnect the power supply cable 32, disconnect the fountain tree 9 from the flange 7, dismantle the ground pipelines, raise the fountain tree 9 to a fixed height, while the check valve 1 is installed in the seat 17 and is disconnected from the shank 5, the casing 31 is hermetically connected to cuff 34, bleed overpressure in the above-packer zone of the well, raise the pump 35 in the Assembly with the shank 5 from the well.

 Thus, the proposed design of the borehole cutter increases its reliability of disconnecting the reservoir from the well for the duration of the repair.

 Downhole shutoff can be made by known means and used to work with existing equipment.

 All this indicates the availability of industrial applicability of the proposed design of the borehole cutter.

Sources of information
1. Auth. St. USSR N 1543046 dated 10.10.87 B.A. Kirsh, M.R. Aliev. All-Union Petroleum Research Institute for Safety Engineering. Packer.

 2. Auth. St. USSR N 1221324 dated January 11, 83 M.N. Romashev, V.A. Khrolikov, V.V. Korelyakov. Central laboratory of research and experimental work. Production Association Kuibyshevneft. Packer cutter.

Claims (4)

 1. A borehole shutoff device, including a packer, in the passage channel of which an installation pipe is placed that interacts with the elements of the anchor assembly and a check valve when the packer is fixed in the coupling of the production casing of the well, the lead pipe, liner, flange mounted on the lifting column and in the fountain fittings control the check valve when moving the lifting column in a closed volume of the well, characterized in that, in order to increase its reliability in the work during the repair of the well without drowned As a filling liquid, the packer has a fork installed by rods in the grooves of the housing located between its steps, the rod traction is connected to a spacer element located on the lower stage of the housing with a seal, a tubular seat with sealing elements mounted on the seal and connected to the lower stage of the housing, annular sectors with hooked shoulders placed on the mounting pipe and connected by screws with a valve installed in its passage channel, hooked shoulders of sectors placed in the windows of the upper the case with the possibility of their lateral movement when mating sectors with the tubular part of the fork during the fixation of the packer in the coupling of the production casing, ring sectors installed in the bore of the cover of the housing with the ability to fix the end of the fork when moving the installation pipe, the check valve is made in the form of a hollow cylinder and equipped with a plunger with internal bypass channels mounted concentrically in its cavity with the possibility of communicating the cavity of the check valve with the passage channel of the packer when at the interaction of the plunger with the shank, the mounting pipe, the shank are connected at the bottom with a lock that has brackets installed in the coaxial windows of the lock case with the possibility of closing-opening the tip of the plunger when they interact with the wedge protrusions of the spring-loaded ring installed in the lock case, or when their simultaneous interaction with the wedge protrusions of the spring-loaded ring and with the conical bore of the tubular saddle, the lead pipe is placed in the casing and connected to it by adapters with the possibility of vodka between the pipe and the casing of the current supply cable with its isolation from the borehole medium by the stuffing box, the flange is installed between the pipe head and the Christmas tree, connected with them by independent connections, mated with the casing of the lead pipe by a sealing element installed in the flange bore.  2. The borehole cutter according to claim 1, characterized in that the fork has a free movement relative to the spacer element and inclined flats are made between its rods.  3. The downhole shut-off device according to claim 1, characterized in that the non-return valve in the tubular seat is sealed by sealing surfaces of the second and third order, conjugated by metal-elastic, metal-metal type.  4. The borehole cutter according to claim 1, characterized in that the circulation of the borehole medium through the packer is limited by the surfaces of the side windows at the ends of the liner and its internal passage channel.

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