RU2232248C2 - System for pressure testing wells in operation - Google Patents

Abstract

FIELD: oil and gas extractive industry.

SUBSTANCE: system has hoisting device, power supply with drive of reciprocal movement direction and packer connected through engaging assembly to the drive. Packer has hollow body with several rows of through apertures, fixedly connected to drive flange. Also included is pusher with supporting assembly on free end, fixedly connected to output rod of drive, collar, supporting washers of collar, guiding bushing with slanting grooves and slips with shelves placed in grooves of the latter. Packer additionally has shaft with packing elements on upper end. Shaft is mounted coaxially on the pusher and placed with its upper end in the body. Collar, supporting washers and guiding bushing are placed coaxially on the shaft.

EFFECT: possible use in operation columns with different inner diameter and lesser time required for technological operations.

9 cl, 6 dwg

Description

The invention relates to the oil and gas industry and can be used in the operation of an oil or gas or water well, repair of a production string, uncoupling of well seams.

A known system for crimping wells, containing a lifting device and a packer, including a barrel, a cuff, a telescopic hydraulic actuator with valves and anchor nodes [1].

The disadvantages of this system are the increased complexity of disruption and removal of the packer in the production casing and the complexity of the device for fixing the packer in the working position.

Known electromechanical packer, mounted on a cable rope and consisting of a hollow body with radial channels mounted on the body of an elastic cuff with upper and lower support washers and a pusher, a cone with slips placed on it, installed in the cavity of the barrel body, which forms the circulation channel with the latter communicating through the radial channels of the housing space behind it, above and below the sealing element [2].

This system does not allow to significantly increase the pressure of the crimping from the side of the wellhead due to a decrease in the axial force of the cone on the slips and a decrease in the force of fixation of the latter on the production string due to the effect of the pressure of the crimping on the elastic cuff.

The closest analogue of the same purpose as the claimed technical solution is a system for crimping oil and gas wells, consisting of a lifting device, an energy supply device with a reciprocating drive and a packer connected to the latter through a docking station [3].

The disadvantages of the described system are:

- the possibility of use only for production casing with one inner diameter;

- a lot of time for the maintenance of the packer in the conditions of repair shops, when replacing rapidly wearing parts due to the presence of non-separable joints in its design;

- great damage to the design of the packer installed in the production casing when it is removed to the surface in the event of an accident on hoisting or power supply devices.

The basis of the invention is the solution of the following problems:

- the possibility of multiple installation, reinstallation and removal of the system in the production casing with the same packer;

- the possibility of using a system with the same packer for use in production casing with different inner diameters;

- reduction of time for system maintenance in the field without a special tool when replacing packer wearing parts or changing it to cuffs with other outer diameters;

- reduction of the destruction of the packer parts if it is removed to the surface in the event of an emergency in the system.

The tasks are solved in that the system for crimping the production casing of an oil, or water, or gas well consists of a lifting device, an energy supply device with a reciprocating drive, and a packer connected to the latter through a docking unit, which is provided with an output rod on the drive side and flange. The packer contains a hollow body with several belts of through holes for fluid overflow from the outside into the internal cavity of the latter, fixedly attached to the actuator flange, a bypass valve with sealing elements for communicating or uncoupling the above-packer and under-packer space through the housing openings, a pusher fixedly connected to the output rod of the actuator, a support unit mounted on the free end of the pusher, an elastic cuff with an internal cavity, as well as the upper and lower cuff support washers, guiding a bushing and slips with protrusions arranged in series between the housing and the support assembly.

The guide sleeve has radial, sloping towards the support node, dovetail grooves, and the slips with protrusions are located in the grooves of the latter.

According to the invention, the packer further comprises a stepped barrel with sealing elements of the bypass valve at the upper end, mounted coaxially on the push rod and placed at the upper end in the housing. The elastic cuff, upper and lower support washers and guide sleeve are mounted coaxially on the barrel. The guide sleeve is fastened with threaded locking elements with the latter.

The support assembly includes a lock washer with radial grooves, a centering washer with radial recesses, and a thrust washer fixedly attached to the pusher by means of a detachable connection. Each slip consists of a wedge and a lining fastened together by threaded clamping elements, each wedge on the side facing the guide sleeve provided with a protrusion, and on the side facing the support node with a hook with a jumper, where the protrusions are placed in the grooves of the supporting sleeve, hooks in the grooves of the lock washer, and jumpers in the recesses of the centering washer.

The implementation of the system with the packer, in which the housing, the barrel and the pusher are used, assembled on the landings with a gap, the placement of the pusher in the stepped barrel, and the latter in the body, the location of the cuff, its support washers, the guide sleeve on the barrel and the slip fastening movably in the lock washer allows :

- reduce packer service time in the field without a special tool;

- increase the available stroke of the pusher to 200 mm, which, in the presence of several flexible interchangeable cuffs of different outer diameters, allows you to overlap the annular gap between the packer and the inner surface of the production casing with an outer diameter of 139.7 ... 168 mm and a wall thickness of 7 ... 11 mm , which reduces the range of packers used;

- to obtain minimal damage to the packer parts if it is removed to the surface in the event of an emergency in the system, which increases its useful life.

Moreover:

- the execution of the barrel in the upper outer part, and the body in the lower inner part with persistent annular collars allows you to fix the barrel from axial movement in the lowest position;

- supplying the outer surface of the pusher with an outer longitudinal groove allows you to communicate the inner cavity of the housing with podpakernym space;

- the location of the lower belt of the through holes of the housing near its lower inner shoulder allows you to exclude locking fluid in the cavity between the shoulders of the housing and the barrel when the latter moves down;

- making in the case of openings of the remaining belts with sockets on the side of its outer surface and installing in them, in addition to the holes of one belt, removable plugs in the presence of a longitudinal groove on the push rod allows informing the packer and subpacker spaces with each other and eliminating the pumping effect when lowering and raising the system in well;

- the execution on the barrel of the outer annular groove, and in the lower support washer of the cuff of the radial stopper, which is placed in the bore of the barrel with a lateral clearance, in the event of an emergency breakdown of the packer prevents the loss of the cuff;

- the implementation in the guide sleeve of the angle of inclination of the grooves to the longitudinal axis within 10 ... 12 ° can reduce the effort to install and remove the packer in the production casing;

- the introduction to the design of the packer spacer sleeve located in the inner cavity of the elastic cuff, and the execution of the end surfaces of the support washers from the side facing the cuff inclined, determines the receipt of the specified law of deformation of the elastic cuff to ensure the tightness of the connection;

- installation of split half rings on the supporting washers and fastening them together using elastic cuffs with a larger diameter than the standard cuff also allows you to get the specified law of deformation of these cuffs.

Thus, the objectives of the invention are solved:

- multiple installation, reinstallation and removal of the system in the production casing with the same packer is possible;

- it is possible to use a system with the same packer for use in production casing with different inner diameters;

- reduced time for maintenance of the packer in the field without the use of a special tool when replacing worn parts or reconfiguring it;

- the destruction of the packer parts is minimal if it is removed to the surface in the event of an emergency in the system.

The present invention will be more clear after further consideration of the detailed description of the implementation of the system for crimping the production casing of an oil, or water, or gas well, which is illustrated by the drawings shown in figures 1-6:

Figure 1 shows a General view of the system in transport position in the production casing; figure 2 is the same in the working position when the packer is installed in the column; figure 3, 4, 5 - embodiments of the inclined end surfaces of the support washers from the sides facing the cuff; figure 6 - installation of split half rings on the supporting washers of the cuff.

The system for crimping the production casing, shown in figures 1 and 2, consists of hoisting and power supply devices with a reciprocating drive, coupled together (not shown) and a packer connected to the drive through the docking unit.

The packer contains a hollow body 1 with several belts 2, 3, 4 through holes for the flow of fluid from the over-packer space into its internal cavity, which is fixedly attached to the flange 5 of the self-braking actuator, a bypass valve formed by the bypass holes of the belts 3, 4 of the housing 1 and sealing elements 6.

In addition, the packer contains a pusher 7, fixedly connected to the thread with a spring washer, with an output rod 8 of the drive, a support assembly mounted on the free lower end of the pusher 7, an elastic sleeve 9 with an internal cavity, and an upper 10 and lower 11 sleeve washers 9, a guide sleeve 12 and slips with protrusions arranged sequentially between the housing 1 and the support assembly, where the guide sleeve 12 has dovetail grooves 13 radially slanted toward the support assembly and the slips are protruded in the grooves 13 last one. The packer further comprises a stepped barrel 14 with sealing elements 6 of the bypass valve at the upper end, mounted coaxially on the follower 7 and placed with the upper end in the housing 1. An elastic sleeve 9, upper 10 and lower 11 support washers and guide sleeve 12 are mounted coaxially on the barrel 14. The guide sleeve 12 is fastened by the threaded locking elements 15 to the barrel 14. The support assembly includes a locking washer 16 with radial grooves, a centering washer 17 with radial recesses and a thrust washer 18, fixedly fastened the pusher 7 by means of a nut 19 and a spring washer 20. Each slip consists of a wedge 21 and a lining 22, fastened together by threaded clamping elements 23. Each wedge 21 from the side facing the support node is equipped with a hook 24 with a jumper 25, where the hooks 24 are located in the radial grooves of the lock washer 16, and the jumpers in the recesses of the centering washer 17. The outer surface of the pusher 7 is provided with a longitudinal groove 26 for communicating the inner cavity of the housing 1 with the locking space. The barrel 14 in the upper outer part and the housing 1 in the lower inner part have persistent annular collars. The lower belt of holes 2 of the housing 1 is located near its inner collar, and the through holes of the remaining belts 3, 4 are provided with sockets 27 on the outer surface of the housing 1 and, in addition to the holes of one belt, removable plugs 28 are installed.

The barrel 14 has an outer annular groove 29, and the lower support washer 11 is provided with a radial stop 30, which is placed in the groove 29 with a lateral gap. The threaded elements 23, 15 for fastening the plates 22 to the wedges 21 and the guide sleeve 12 to the barrel 14, as well as the thrust washer 18 are made of one material. The cut-off area of the thrust washer 18 exceeds the total cut-off area of the threaded locking elements 15 for fastening the guide sleeve 12 to the barrel 14, and the total cut-off area of the latter exceeds the total cut-off area of the threaded coupling elements 23 for fastening the covers 22 to the wedges 21. The covers 22 from the outer surface have corrugations for better production string hitch. In the guide sleeve 12, the angle of inclination of the grooves to the longitudinal axis is in the range of 10 ... 12 °, which reduces the effort to set and remove the packer in the production casing. The packer may additionally contain a spacer sleeve 31. The end surfaces of the support washers 10, 11 from the side facing the cuff 9, made according to Fig.3, 4, 5 - inclined. The angle of inclination of these washers and the presence of the sleeve 31 is determined by the design and configuration of the sleeve 9. The packer according to Fig.6 for the sleeve 9 with an increased diameter can be equipped with split half rings 32 mounted on the supporting washers 10, 11 and fastened together. This allows you to use a set of cuffs 9 with a larger diameter than the standard cuff for sealing production casing of different internal diameters. The system allows quick complete disassembly of the packer to replace the cuff 9, support washers 10, 11 and other parts in the field with a set of standard tools.

The system according to figures 1 and 2 operates as follows.

A system consisting of a hoisting device, a power supply device with a drive and a packer bonded to the latter is lowered from the wellhead with lateral clearance into the production string to a predetermined depth. In this case, the rod 8 is maximally extended from the drive, the elastic sleeve 9, the supporting washers 10, 11, the guide sleeve 12 and the wedges 21 are located between the housing 1 and the supporting unit of the pusher 7 with axial clearance. Cup 9 is not axially compressed. The outer diameter of the cuff 9 does not protrude beyond the dimensions of the other parts of the packer. The centering of the drive and the packer relative to the production casing is carried out on their protruding outer surfaces. During descent through openings of 3 or 4 belts that do not have removable plugs 28, the longitudinal groove 26 of the pusher 7 and the outer annular gap between the drive, the packer and the inner diameter of the production string, fluid flows from the sub-packer to the over-packer space. After reaching a predetermined immersion depth, a control signal is supplied to the drive causing the drive to operate and retract rod 8 and, together with it, pusher 7. In the process of retracting the push rod 7 towards the drive, the wedges 21 of the slips are pushed into the guide sleeve 12 until the pads contact 22 s the inner surface of the production casing and are fixed on it. Further, since the drive is mounted on a free suspension, it is pulled to the place where the slips are fixed. In this case, the housing 1, fixed on the drive, in contact with the support washer 10, compresses the elastic sleeve 9, which is supported through the support washer 11 on the guide sleeve 12, the wedges 21 and the linings 22 on the production casing. At the end of the compression process of the cuff 9 until the contact with the inner surface of the production casing, the through holes 3 or 4 of the belts not sealed with plugs 28 are closed by the sealing elements 6 of the barrel 14. Thus, the communication channels between the under-packer and over-packer spaces are tightly closed. By increasing the current load on the drive over a predetermined limit, the drive is turned off.

After installing the packer in the column from the wellhead, a test pressure of 80-100 atm is created for 15-20 minutes. If during this period the pressure in the well does not decrease, then the production casing is intact, there is no damage. After that, the test pressure is removed.

The system is removed from the well to the surface. When removing the system installed in the well, the drive and the housing 1 are turned on, moving relative to the rod 8, which is fixedly mounted on the column through the pusher 7, the support unit and the slips, rises up. When this barrel 14 begins to fall relative to the housing 1 down. The axial interference on the cuff 9 is reduced. Next, the pusher 7 through the rod 8 leaves the drive and through the support node pulls down the wedges 21 from the grooves 13 of the guide sleeve 12 and disengages the slip linings 22 from the engagement casing. In this case, the axial interference on the cuff 9 disappears and axial gaps arise between it, the support washers 10, 11 and the guide sleeve 12. An annular gap appears between the cuff 9 and the production string. When pulling the wedges 21 from the grooves 13, their radial movement inward to the axis of the packer is limited by the emphasis on the outer surface of the pusher 7, and then without leaving engagement with the guide sleeve 12 in the grooves 13 they finally push the barrel 14 from the housing 1 to the bottom through the locking threaded elements 15 the emphasis of its outer shoulder in the inner shoulder of the housing 1.

In this case, through holes 3 or 4 of the housing belts 1, which are not closed by plugs 28, are opened. Through these holes and the groove 26, the spaces above the packer and under the packer communicate with each other with equalization of pressure. The system is ready for relocation.

If the column above the packer is damaged and the test pressure level is not established, then the packer is removed from the column, the system rises above the set level and the cycle repeats. Moving up the system determines the place of destruction of the column.

Thus, this system allows you to test production casing without interval, without removing it to the surface from the well.

In the event of an emergency failure of the drive with the help of a lifting device, an axial force is generated on the drive up to the wellhead. This axial force is transmitted through the flange 5 and the rod 8 of the self-braking drive to the housing 1 and the pusher 7. From the pusher 7, the axial force is transmitted through the lock washer 16 and the hooks 24 to the wedges 21, cuts the threaded coupling elements 23, freeing the packer from the linings 22. This allows loosen the axial and radial interference of the cuff 9 with the column and other mating parts and remove the system with the packer up to the wellhead.

Using the proposed system allows you to provide a continuous multiple process of interval testing the production casing with test pressure without lifting it to the surface, which increases the productivity and reduces their complexity.

The economic effect of using the proposed system is achieved by reducing the number and time of execution of technological operations.

Used sources

1. SU, copyright certificate, 775291, cl. E 21 B 33/12.

2. US Patent, 3,542,126, cl. E 21 B 43/00.

3. RU, patent, 2144606, cl. E 21 B 33/12.

Claims (9)

1. System for crimping the production casing of an oil, or water, or gas well, consisting of a lifting device, a power supply device with a reciprocating drive, and a packer connected to the latter through a docking unit, which is provided with an output rod and a flange on the drive side, and the packer contains a hollow body with several belts of through holes for fluid flow, fixedly attached to the actuator flange, a bypass valve with sealing elements for communication overpacker space under the openings of the casing, a pusher fixedly connected to the output rod of the drive, a support assembly mounted on the free end of the pusher, an elastic cuff with an internal cavity, as well as upper and lower cuff support washers, a guide sleeve and slips with protrusions placed in series between the case and the support node, where the guide sleeve has radial slanting dovetail grooves, and the slips are protrusions located in the grooves of the latter, characterized in that о the packer further comprises a stepped barrel with sealing elements of the bypass valve at the upper end, mounted coaxially on the push rod and placed with the upper end in the housing, the elastic cuff, upper and lower support washers and the guide sleeve mounted coaxially on the barrel and the guide sleeve fastened with threaded locking elements with Lastly, the support assembly includes a lock washer with radial grooves, a centering washer with radial recesses, and a thrust washer fixedly attached to the pusher by means of a detachable connection, each slip consists of a wedge and a lining fastened together by threaded clamping elements, each wedge on the side facing the support node is equipped with a hook with a jumper, where the hooks are placed in the grooves of the lock washer, and the jumpers are in the recesses of the centering washer . 2. The system according to claim 1, characterized in that the outer surface of the pusher is provided with a longitudinal groove. 3. The system according to claim 1, characterized in that the barrel in the upper outer part and the body in the lower inner part have persistent annular collars, where the lower belt of the housing openings is located near its collar, and the holes of the remaining belts are provided with sockets on the outer surface of the housing , in addition to the holes of one belt, removable plugs are installed in them. 4. The system according to claim 1, characterized in that the barrel has an outer annular groove, and the lower support washer is equipped with a radial stopper, which is placed in the groove with a lateral gap. 5. The system according to claim 1, characterized in that the threaded fastening elements of the pads to the wedges and the guide sleeve to the barrel, as well as the thrust washer are made of one material, and the cut-off area of the thrust washer exceeds the total cut-off area of the threaded locking elements of the fastening of the guide bush to the barrel and the total cutting area of the latter exceeds the total cutting area of the threaded coupling elements for attaching the plates to the wedges. 6. The system according to claim 1, characterized in that in the guide sleeve the angle of inclination of the grooves to the longitudinal axis is within 10 ... 12 °. 7. The system according to claim 1, characterized in that the packer further comprises a spacer sleeve located in the inner cavity of the elastic cuff. 8. The system according to claim 1, characterized in that the end surfaces of the thrust washers of the cuff on the side facing it are made inclined. 9. The system according to claim 1, characterized in that the packer is additionally equipped with split half rings mounted on cuff support washers and fastened together.

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