CN-117627596-B - Downhole choke, downhole choke system, oilfield gas production system and application thereof

CN117627596BCN 117627596 BCN117627596 BCN 117627596BCN-117627596-B

Abstract

The invention discloses an underground throttle, an underground throttle system, an oilfield gas production system and application thereof, wherein the underground throttle comprises a central pipe, an anchoring assembly and a sealing assembly, wherein the anchoring assembly and the sealing assembly are sleeved outside the central pipe; the anchoring assembly comprises a slip seat, slips, a slip cover, a cone and a slip cover pressing cap, wherein the slip seat and the cone are sleeved outside a central tube, the slip cover is sleeved outside the slip seat and the cone, the slip cover pressing cap is sleeved outside the cone and limited by the cone, the proximal end of the slip cover is detachably connected with the slip cover pressing cap, the slips are installed in the slip cover, the distal end of the slips is limited by the slip seat, the proximal end of the slips is abutted against the conical surface of the cone, the sealing assembly comprises an upper rubber shoulder protector, a rubber cylinder and a lower rubber cylinder shoulder protector, the rubber cylinder is positioned between the upper rubber cylinder shoulder protector and the lower rubber cylinder shoulder protector, and the upper rubber cylinder shoulder protector is detachably connected with the cone.

Inventors

GUO MING
YANG XIAOYONG
WANG YUE
LI MEI
CHENG QI
Bao Zuofan
SUN WEIWEI

Assignees

中国石油天然气集团有限公司
中国石油集团渤海钻探工程有限公司

Dates

Publication Date: 20260508
Application Date: 20220816

Claims (12)

1. The downhole choke is characterized by comprising a central tube, an anchoring assembly and a sealing assembly, wherein the anchoring assembly and the sealing assembly are sleeved outside the central tube; The anchoring assembly comprises a slip seat, slips, a slip cover, a cone, a slip cover pressing cap and an elastic sheet, wherein the slip seat and the cone are sleeved outside the central tube, the slip cover is sleeved outside the slip seat and the cone, the slip cover pressing cap is sleeved outside the cone and limited by the cone, the proximal end of the slip cover is detachably connected with the slip cover pressing cap, a groove is formed in the inner side of the slip cover, the slips are arranged in the groove, so that at least part of areas of the slips are wrapped by the slip cover, the distal end of the slips is limited by the slip seat, and the proximal end of the slips is in butt joint with the conical surface of the cone; the sealing assembly comprises a rubber cylinder upper shoulder pad, a rubber cylinder and a rubber cylinder lower shoulder pad, wherein the rubber cylinder is positioned between the rubber cylinder upper shoulder pad and the rubber cylinder lower shoulder pad, and the rubber cylinder upper shoulder pad is detachably connected with the cone; The elastic sheet is positioned between the slip cover and the slip, and the slip expands to compress the elastic sheet so as to store force; the slips are expanded to anchor the inner wall of the oil pipe of the well to be sealed, the slip cover drives the cone to compress the upper shoulder pad of the rubber cylinder, and the rubber cylinder is extruded under the combined action of the lower shoulder pad of the rubber cylinder so that the rubber cylinder seals the oil pipe to realize the sealing of the well to be sealed; The slips are released from anchoring and return, the slip cover drives the shoulder pad on the rubber cylinder to slide through the cone, and the rubber cylinder returns to realize the deblocking of the well to be sealed.
2. The downhole choke of claim 1, further comprising a launch assembly, a fishing assembly, a locking assembly, and a choke assembly; The fishing assembly is sleeved outside the central tube and detachably connected with the far end of the central tube, and the throwing assembly is connected with a far end rivet of the fishing assembly; the slip seat is sleeved outside the proximal end of the fishing assembly and is detachably connected with the fishing assembly; The locking sleeve of the locking assembly is positioned between the central tube and the anchoring assembly and the sealing assembly, and a preset gap is reserved between the locking sleeve and the salvaging assembly in the axial direction and is used for locking the anchoring assembly and the sealing assembly; the lower shoulder pad of the rubber cylinder is connected with a locking ring cover of the locking assembly; The throttling assembly is located inside the proximal end of the center tube.
3. The downhole choke of claim 2, wherein the locking assembly includes a locking sleeve, a locking ring cap, and a locking ring cover; The locking sleeve is sleeved outside the central tube, and the far end of the locking sleeve is limited by the fishing assembly; the locking ring is sleeved outside the locking sleeve and is detachably connected with the proximal end of the locking sleeve; the lock ring cap is sleeved outside the lock sleeve and the lock ring and is clamped with the lock sleeve; The locking ring cover is sleeved outside the locking ring and the locking ring cap and limits the locking ring cap.
4. A downhole choke according to claim 3, wherein the distal end of the locking sleeve is provided with a spring finger, the inner face of the intermediate sleeve of the fishing assembly is provided with a recess, the locking sleeve being retained in the recess by the spring finger; the proximal end of the locking sleeve is provided with a first barb, the locking ring cap is provided with a second barb matched with the first barb, and the locking ring cap is clamped with the locking sleeve.
5. The downhole choke of claim 2, wherein the fishing assembly comprises a fishing sleeve, a fishing sleeve liner, a fishing shear block, a fishing shear, an intermediate sleeve, and a pressure cap; The fishing sleeve lining is detachably connected with the central tube, the fishing sleeve is sleeved outside the fishing sleeve lining, and the fishing sleeve can be limited by the proximal end of the fishing sleeve lining; The salvaging shear pin seat is sleeved on the salvaging sleeve and is detachably connected with the proximal end of the salvaging sleeve; The middle sleeve is sleeved outside the salvaging shear pin seat and limited by the salvaging shear pin, and the middle sleeve is detachably connected with the slip seat; The pressure cap sleeve is arranged outside the salvaging sleeve and connected with the middle sleeve and used for limiting the salvaging shear pin seat.
6. The downhole choke of claim 5, wherein the launch assembly includes a lost head and a lost shear pin; the releasing head is nested in the fishing sleeve lining and limited by the releasing shear pin.
7. The downhole choke of claim 2, further comprising a connection assembly and a screen, the connection assembly for connecting the screen with the proximal end of the base pipe; The distal end of the screen pipe is abutted with the throttling assembly; the connecting component comprises a transfer sleeve, a lower connecting sleeve, a gasket and a connecting cap; The transfer sleeve and the lower connecting sleeve are sleeved outside the central tube and detachably connected with the proximal end of the central tube, and the distal end of the transfer sleeve is abutted with the lock ring cover of the locking assembly; The gasket is positioned between the transfer sleeve and the lower connecting sleeve; the connecting cap is sleeved outside the lock ring cover and the transfer sleeve, the connecting cap is detachably connected with the lock ring cover, and the connecting cap is clamped with the transfer sleeve.
8. The downhole choke of claim 7, wherein at least two stages of nickel-copper foam alloy filler are disposed within the screen, the nickel-copper foam alloy filler being disposed in a croup configuration.
9. A downhole choke system comprising a launch device and a downhole choke according to any one of claims 1-8; The delivery device is used for setting the downhole choke at a preset position through a delivery assembly.
10. The system of claim 9, further comprising a fishing apparatus for unsealing and fishing the downhole choke by a fishing assembly.
11. An oilfield gas production system comprising an oil pipe and a downhole choke as set forth in any one of claims 1-8; The downhole choke is used for being arranged at a preset position in the oil pipe so as to seal the oil pipe at the preset position.
12. Use of a downhole choke as claimed in any one of claims 1-8 in an oilfield gas production system.

Description

Downhole choke, downhole choke system, oilfield gas production system and application thereof Technical Field The invention relates to the technical field of oilfield gas exploitation, in particular to an underground throttle, an underground throttle system, an oilfield gas production system and application thereof. Background At present, the underground throttling technology is widely adopted to convert the traditional ground throttling depressurization into underground throttling depressurization, geothermal heating is fully utilized, so that the temperature of air flow after underground throttling is higher than the critical temperature of air-water mixture formation under the pressure condition after throttling, and therefore the purposes of inhibiting the generation of hydrate and reducing the pressure of ground pipelines in the production process of a gas well are achieved. The underground throttling process realizes throttling and depressurization of a well shaft of a gas well by means of an underground throttling nozzle, and well shaft hydrate is not formed while the pressure is reduced, so that the blockage caused by ground equipment is avoided. Disclosure of Invention The inventor finds that the underground throttle has the following problems in the field application process due to the fact that the anchoring and sealing of slips and rubber drums in the structural design cannot realize linkage, so that the slips and the rubber drums cannot be synchronously recovered in the salvage process, and the throttle is difficult or even impossible to salvage, and (2) the conventional throttle has poor sand prevention performance, so that sand at the top of the throttle is buried, and the salvage is difficult. The present invention has been made in view of the above problems, and it is an object of the present invention to provide a downhole choke, a downhole choke system, an oilfield gas production system and applications thereof, which overcome or at least partially solve the above problems. In a first aspect, embodiments of the present invention provide a downhole choke that may include a base pipe and an anchor assembly and a seal assembly disposed outside the base pipe; the anchoring assembly comprises a slip seat, slips, a slip cover, a cone and a slip cover pressing cap, wherein the slip seat and the cone are sleeved outside the central tube, the slip cover is sleeved outside the slip seat and the cone, the slip cover pressing cap is sleeved outside the cone and limited by the cone, the proximal end of the slip cover is detachably connected with the slip cover pressing cap, the slips are installed in the slip cover, the distal end of the slips is limited by the slip seat, and the proximal end of the slips is in butt joint with the conical surface of the cone; the sealing assembly comprises a rubber cylinder upper shoulder pad, a rubber cylinder and a rubber cylinder lower shoulder pad, wherein the rubber cylinder is positioned between the rubber cylinder upper shoulder pad and the rubber cylinder lower shoulder pad, and the rubber cylinder upper shoulder pad is detachably connected with the cone; the slips are expanded to anchor the inner wall of the oil pipe of the well to be sealed, the slip cover drives the cone to compress the upper shoulder pad of the rubber cylinder, and the rubber cylinder is extruded under the combined action of the lower shoulder pad of the rubber cylinder so that the rubber cylinder seals the oil pipe to realize the sealing of the well to be sealed; The slips are released from anchoring and return, the slip cover drives the shoulder pad on the rubber cylinder to slide through the cone, and the rubber cylinder returns to realize the deblocking of the well to be sealed. Optionally, a groove is formed in the inner side of the slip cover, and the slips are arranged in the groove, so that at least part of areas of the slips are wrapped by the slip cover. Optionally, the anchor assembly may further comprise a spring positioned between the slip cover and the slip, the slip expanding to compress the spring such that the spring stores force, the slip de-anchoring, the spring acting on the slip to return the slip. Optionally, the downhole choke can further comprise a throwing component, a salvaging component, a locking component and a choke component; The fishing assembly is sleeved outside the central tube and detachably connected with the far end of the central tube, and the throwing assembly is connected with a far end rivet of the fishing assembly; the slip seat is sleeved outside the proximal end of the fishing assembly and is detachably connected with the fishing assembly; The locking sleeve of the locking assembly is positioned between the central tube and the anchoring assembly and the sealing assembly, and a preset gap is reserved between the locking sleeve and the salvaging assembly in the axial direction and is used for locking the anchoring assembly and the sealing assembl