CN109763797B - Underground throttle - Google Patents

Abstract

The application provides a downhole choke, including the center tube the both ends of center tube are equipped with salvage deblocking mechanism and seat seal self-locking mechanism respectively salvage deblocking mechanism and seat seal self-locking mechanism between be equipped with card sealing mechanism, salvage deblocking mechanism includes sleeve pipe, host, slip support and locking ball, the sleeve pipe suit is in on the center tube and with the one end of host cup joints, the other end of host with seat seal self-locking mechanism spacing is connected, slip support suit is in on the host and with the suit is in hanging cap spacing connection on the sleeve pipe, the locking ball is in through the spacing setting of sleeve pipe slip support and make slip support with the host is followed the direction locking of center tube axis, card sealing mechanism suit is in on the lateral wall of host and respectively with slip support with seat seal self-locking mechanism is connected.

Description

Underground throttle

Technical Field

The application relates to the technical field of downhole throttling heat preservation tools for gas well production, in particular to a downhole throttler.

Background

At present, the production of the gas well mainly depends on stratum energy to maintain the production, so that the purpose of saving energy, reducing consumption and improving economic benefit is achieved by avoiding using external energy and power, therefore, for the gas well with higher stratum energy, the underground gas can be completely lifted to the ground by depending on the energy of the gas well, but the ground remote high-pressure transmission cost is high and unsafe, and the gas well terminal cannot be used yet. If the ground is adopted for depressurization and then is conveyed, a great amount of heat energy can be absorbed and taken away by the gas suddenly losing pressure at the wellhead, so that the wellhead absorbs the water vapor and is frozen rapidly, and continuous production cannot be realized.

Therefore, in the prior art, the underground throttle with the throttle air tap and the matched tool thereof are clamped and placed at proper positions in the oil pipe in a steel wire operation mode to form a partition and seal all channels except the air tap, so that the purpose of reducing pressure is achieved after the natural gas is throttled by the air tap of the underground throttle. Although the temperature is reduced simultaneously in the depressurization process, the natural gas can fully absorb the geothermal energy in the shaft when being cooled due to the restriction of the constant temperature of the stratum, when the natural gas with lower pressure reaches the wellhead, the natural gas is thrown to keep higher temperature, the ground does not need throttling and depressurization again, the cooling process can not occur, and the natural gas can be directly transported and utilized remotely.

However, the common problem of the current throttlers in China is that the throttlers cannot be lifted and released when meeting the blockage in the process of descending the well, and the throttlers cannot be lowered to the design position due to the fact that the throttlers are blocked once lifted; the success rate of salvaging and unsealing is low, and a considerable part of the valve can not be fished out for replacement when the air tap of the throttle needs to be replaced. The reason is mainly that the setting principle is that the slips are downwards placed against the inner wall of the oil pipe and set when the oil pipe is lifted, so that the existing throttler can only be downwards placed and cannot be lifted, the slips are required to be loosened firstly when the oil pipe is salvaged and unsealed, the slips are blocked by the slips which are blocked on the inner wall of the oil pipe, and the overall popularization of the throttling and decompression process of the oil exploitation natural gas well is influenced.

Disclosure of Invention

The purpose of the present application is to overcome the drawbacks of the prior art and to provide a downhole choke.

In order to achieve the above purpose, the present application adopts the following technical scheme:

the underground throttle comprises a central pipe 11, wherein a salvaging and unsealing mechanism and a seat seal self-locking mechanism are respectively arranged at two ends of the central pipe 11, a clamping and sealing mechanism is arranged between the salvaging and unsealing mechanism and the seat seal self-locking mechanism, the salvaging and unsealing mechanism comprises a sleeve 4, a supporting pipe 12, a slip support 10 and a locking ball 9, the sleeve 4 is sleeved on the central pipe 11 and sleeved with one end of the supporting pipe 12, the other end of the supporting pipe 12 is in limiting connection with the seat seal self-locking mechanism, the slip support 10 is sleeved on the supporting pipe 12 and in limiting connection with a hanging cap 5 sleeved on the sleeve 4, the locking ball 9 is arranged on the slip support 10 through the sleeve 4 in a limiting manner and enables the slip support 10 and the supporting pipe 12 to be locked along the axis direction of the central pipe 11, and the clamping and sealing mechanism is sleeved on the side wall of the supporting pipe 12 and is respectively connected with the slip support 10 and the seat seal self-locking mechanism.

Optionally, the downhole choke further comprises a connection delivery mechanism and a filtering choke mechanism, one end of the connection delivery mechanism is connected with the central tube 11 through the sleeve 4, the other end of the connection delivery mechanism is connected with a delivery tool of the steel wire working machine, and the filtering choke mechanism is arranged at the end part, far away from one end of the salvaging and unsealing mechanism, of the central tube 11 and is connected with the seat seal self-locking mechanism.

Optionally, the salvaging and deblocking mechanism further includes a lifting hanging ring 7 and a deblocking shear pin 8, the inner circumferential surface of the lifting hanging ring 7 is in threaded connection with the sleeve 4, so that the lifting hanging ring 7 is fixedly installed on the sleeve 4, a shear pin ring groove is formed in the outer circumferential surface of the lifting hanging ring 7, and the deblocking shear pin 8 is arranged on the side wall of the slip support 10 and matched with the shear pin ring groove, so that the sleeve 4 and the limit setting mechanism of the slip support 10 are formed.

Optionally, the slip support 10 is of a tubular structure with an equal diameter on the outer peripheral surface, and comprises a first inner diameter portion 1001, a second inner diameter portion 1002, a third inner diameter portion 1005 and a fourth inner diameter portion 1006 which are communicated, wherein an internal thread connected with the hanging cap 5 is arranged on the side wall of the first inner diameter portion 1001, radial shear pin threaded holes 1003 for installing the deblocking shear pins 8 are uniformly distributed on the side wall of the second inner diameter portion 1002, an annular locking ball groove 1004 for accommodating the locking balls 9 is arranged on the inner side of the third inner diameter portion 1005, and three inclined grooves 1007 connected with the locking sealing mechanism are uniformly distributed on the end portion, away from one end of the first inner diameter portion 1001, of the fourth inner diameter portion 1006.

Optionally, the seat seal self-locking mechanism comprises a rubber cylinder support 16, a lock ring support 17, a lock ring 18 and a lock ring support sleeve 19, wherein the lock ring 18 is sleeved at the end part of the support tube 12 and is in limit fit with the support tube 12, the lock ring support 17 is sleeved at the outer side of the lock ring 18 and is installed on the inner peripheral surface of one end of the lock ring support sleeve 19, the rubber cylinder support 16 is sleeved on the support tube 12 and is in threaded connection with the outer peripheral surface of one end of the lock ring support sleeve 19, and the other end of the lock ring support sleeve 19 is matched with the inner peripheral surface of the end part of the central tube 11.

Optionally, the pipe 12 includes a pipe expanding section 121 and a pipe body 123, a set of radial through holes 122 for installing the locking balls 9 are provided on a side wall of the pipe expanding section 121, a first unidirectional saw-tooth lock 124 is provided on an outer wall of an end of the pipe body 123 away from the pipe expanding section 121, and a sealing surface is provided on an inner wall of the pipe body 123 away from the pipe expanding section 121.

Optionally, the locking ring 18 has an annular structure, and includes a locking ring body 181, an outer conical surface 182 matched with the locking ring support 17 is disposed on an outer peripheral surface of an end portion of the locking ring body 181, and a second unidirectional sawtooth lock 183 matched with the first unidirectional sawtooth lock 124 is disposed on an inner peripheral surface of the end portion of the locking ring body 181.

Optionally, the locking sealing mechanism comprises a slip 13, a wedge body 14 and a sealing rubber cylinder 15 which are sleeved on the side wall of the supporting tube 12, one end of the slip 13 is connected with the slip support 10, the other end of the slip 13 is slidably connected with one end of the wedge body 14, the other end of the wedge body 14 is abutted with one end of the sealing rubber cylinder 15, and the other end of the sealing rubber cylinder 15 is abutted with the seat seal self-locking mechanism.

Optionally, the connection delivery mechanism includes joint 1, shearing pin 2 and carries string pipe 3, carry string pipe 3's one end cover and establish in the sleeve pipe 4 and with the tip of center tube 11 is connected, carry string pipe 3's the other end through shearing pin 2 with the one end fixed connection who connects 1, the other end that connects 1 with the delivery instrument of steel wire operation machine is connected.

Optionally, the filtering and throttling mechanism includes an adjusting stabilizing pin 20, an air tap 21, a connecting cap 22 and a filter screen cover 23, the air tap 21 is arranged in the central tube 11, the filter screen cover 23 is sleeved on the outer peripheral surface of the end part of the central tube 11 and supports the end part of the air tap 21 so as to limit the air tap 21, one end of the connecting cap 22 is sleeved on the outer peripheral surface of the filter screen cover 23 and is limited by an annular boss arranged on the inner peripheral surface of the connecting cap 22, and the other end of the connecting cap 22 is in threaded connection with a locking ring supporting sleeve 19 of the self-locking mechanism and is adjusted and fixed by the adjusting stabilizing pin 20.

Optionally, the central tube 11 is of a drift diameter structure, a first sealing groove 111 for installing the sealing ring 6, external threads matched with the connection delivery mechanism and a sealing surface are arranged on the outer peripheral surface of one end of the central tube 11, external threads matched with the seat seal self-locking mechanism and a second sealing groove 112 for installing the sealing ring 6 are respectively arranged on the outer peripheral surface and the inner peripheral surface of the other end of the central tube 11, an external convex ring 113 and a third sealing groove 114 which is arranged on the external convex ring 113 and is used for installing the sealing ring 6 are arranged on the outer peripheral surface of the middle part of the central tube 11 and close to one end of the second sealing groove 112.

The downhole choke of this application is before setting down the well, its card sealing mechanism is located all the time in the maximum diameter of downhole choke, and seat seal self-locking mechanism passes through axial compression card sealing mechanism realizes setting, consequently this application's downhole choke has the clearance all the time with oil pipe's pipe wall when down the well, as long as this application's downhole choke can be lifted up wantonly or put down in oil pipe with proper steady speed when meeting blocking and unreeled, and can not appear card sealing mechanism sits and seals the action and can guarantee to put down the position of design, simultaneously, the downhole choke of this application adopts locking ball formula structure, unblock earlier after the deblocking when salvaging, unblock process is simple and the repeatability is high, make this application's downhole choke have that the well is smooth down, seat seal is convenient, sealed reliable, advantage such as being convenient for salvage.

Drawings

FIG. 1 is a schematic illustration of the overall structure of a downhole choke of an embodiment of the present application;

FIG. 2 is a schematic structural view of a center tube according to an embodiment of the present application;

FIG. 3 is a schematic view of the structure of the connection delivery mechanism according to the embodiment of the present application;

FIG. 4 is a schematic structural view of a salvage decapsulation mechanism according to an embodiment of the present application;

FIG. 5 is a schematic structural view of a sleeve according to an embodiment of the present application;

FIG. 6 is a schematic structural diagram of a host of an embodiment of the present application;

FIG. 7 is a schematic illustration of the construction of a slip bowl according to an embodiment of the present application;

FIG. 8 is a schematic view of the structure of the locking seal mechanism according to the embodiment of the present application;

FIG. 9 is a schematic view of the structure of a wedge according to an embodiment of the present application;

FIG. 10 is a schematic illustration of the construction of a slip according to an embodiment of the present application;

FIG. 11 is a schematic diagram of a seal self-locking mechanism according to an embodiment of the present application;

FIG. 12 is a schematic view of the structure of a locking ring holster according to an embodiment of the present application;

FIG. 13 is a schematic view of the structure of a locking ring according to an embodiment of the present application;

FIG. 14 is a schematic view of a filter restriction mechanism of an embodiment of the present application;

FIG. 15 is a schematic view of the structure of the connection cap of the embodiment of the present application;

FIG. 16 is a schematic of a downhole process of a downhole choke of an embodiment of the present application;

FIG. 17 is a schematic illustration of a seat sealing process for a downhole choke in accordance with an embodiment of the present application;

FIG. 18 is a schematic diagram of a fishing process for a downhole choke in accordance with an embodiment of the present application.

Reference numerals

1-joint, 2-shear pin, 3-hanging tube, 4-sleeve, 5-hanging cap, 6-seal ring, 7-hanging ring, 8-unsealed shear pin, 9-lock ball, 10-slip bracket, 11-center tube, 12-bracket, 13-slip, 14-wedge, 15-sealing rubber, 16-rubber bracket, 17-lock bracket, 18-lock ring, 19-lock ring bracket, 20-adjusting pin, 21-air cock, 22-connecting cap, 23-filter screen cover, 111-first seal groove, 112-second seal groove, 113-outer flange, 114-third seal groove, 101-first joint body, 102-outer flange, 103-second joint body, 301-inner hole upper section, 302-inner hole middle section, 303-inner hole lower section, 401-annular boss, 402-cylindrical plain surface, 403-necking section, 121-bracket diameter section, 122-radial through hole, 123-bracket body, 124-first one-way taper groove, 1001-first inner diameter section, 1002-1003-second lock ring section, 122-radial taper groove, 193-bracket, 133-third taper groove, 133-taper groove, 193-boss, 133-taper groove, 131-taper groove, 193-groove, 131-taper groove, and boss-133-shaped groove-shaped joint, 13-taper groove-shaped, 13-taper joint, 183-second unidirectional sawtooth lock catch, 221-first connecting part, 222-second connecting part, 223-second stabilizing pin hole.

Detailed Description

The following describes specific embodiments of the present application with reference to the drawings.

In this document, "upper", "lower", "front", "rear", "left", "right", and the like are used merely to indicate relative positional relationships between the relevant portions, and do not limit the absolute positions of the relevant portions.

Herein, "first", "second", etc. are used only for distinguishing one another, and do not denote any order or importance, but rather denote a prerequisite of presence.

Herein, "equal," "same," etc. are not strictly mathematical and/or geometric limitations, but also include deviations that may be appreciated by those skilled in the art and allowed by fabrication or use, etc.

Unless otherwise indicated, numerical ranges herein include not only the entire range within both of its endpoints, but also the several sub-ranges contained therein.

The application provides a downhole choke, as shown in fig. 1, including center tube 11 the both ends of center tube 11 are equipped with salvage deblocking mechanism and seat seal self-locking mechanism respectively salvage deblocking mechanism and seat seal self-locking mechanism are equipped with card sealing mechanism between, salvage deblocking mechanism includes sleeve pipe 4, host 12, slips support 10 and locking ball 9, sleeve pipe 4 suit is in on the center tube 11 and with the one end of host 12 cup joints, the other end of host 12 with seat seal self-locking mechanism spacing is connected, slips support 10 suit is in on the host 12 and with the suit is in the spacing connection of hanging cap 5 on sleeve pipe 4, locking ball 9 is through sleeve pipe 4 spacing setting is in slips support 10 and makes slips support 10 with host 12 is followed the direction locking of center tube 11 axis, card sealing mechanism suit is in on the lateral wall of host 12 and respectively with slips support 10 and seat seal self-locking mechanism is connected. When the downhole choke is used for downhole clamping seat sealing operation, the sleeve 4 is impacted and moves along the central pipe 11 to the direction of the seat sealing self-locking mechanism and drives the slip support 10 and the support pipe 12 to act, the slip support 10 and the support pipe 12 enable the clamping sealing mechanism to clamp and expand so as to complete seat sealing of the downhole choke and lock through the locking ball 9, and the end part of the support pipe 12 stretches into the seat sealing self-locking mechanism and limits to ensure that the clamping sealing mechanism reaches and maintains an ideal state required by sealing.

The downhole choke of this application is before setting down the well, its card sealing mechanism is located all the time in the maximum diameter of downhole choke, and seat seal self-locking mechanism passes through axial compression card sealing mechanism realizes setting, consequently this application's downhole choke has the clearance all the time with the pipe wall of oil pipe when down the well, as long as this application's downhole choke can be lifted up wantonly or put down in oil pipe with proper steady speed when meeting blocking and unreeled, and can not appear card sealing mechanism sits and seals the action and thereby can guarantee to put down the position of design, simultaneously, the downhole choke of this application adopts locking ball formula structure, unblock earlier and afterwards uncap when salvaging, unlocking process is simple and the repeatability is high, locking ball formula structure compares with the cable formula structure in the prior art on the reliability of manufacturing and processing and use and has outstanding advantage, make this application's downhole choke have down well smooth, seat seal convenient, sealing reliable, advantage such as being convenient for salvage.

In one embodiment of the present application, as shown in fig. 1, the downhole choke further comprises a connection delivery mechanism, one end of the connection delivery mechanism is connected with the central tube 11 through the sleeve 4, and the other end of the connection delivery mechanism is connected with a delivery tool of the wire working machine, and the delivery tool comprises a jar or a weighting rod. The downhole choke of this application when carrying out downhole clamping seat and sealing the operation, will the downhole choke will connect in can down the jar on, again with the rope cap of steel wire operation machine connection steel wire is connected and is hoisted in well head lubricator, goes into with the lower well speed of normal less than or equal to 60m/min, and at the normal process of going into down the downhole choke need not paste oil pipe's lateral wall, can freely go into, can not meet in the middle and hinder the setting, and the acceleration is transferred when reaching certain height from the preset position, promptly brake under the circumstances that the speed of transfer reaches 250 + -m/min, at this moment downhole choke promptly stands still, and the jar on its upper portion is under the inertial force effect of descending striking sleeve pipe 4, this impact makes the clamping sealing mechanism expansion of downhole choke thereby accomplishes the clamping and sits and seals.

In one embodiment of the present application, as shown in fig. 1, the downhole choke further includes a filtering and throttling mechanism, where the filtering and throttling mechanism is disposed at an end of the central tube 11 away from one end of the salvaging and unsealing mechanism and is connected with the seat seal self-locking mechanism, and the filtering and throttling mechanism can automatically start the downhole operation of throttling, pressure reducing and atomizing.

Optionally, as shown in fig. 2, the central tube 11 is of a drift diameter structure, a first sealing groove 111 for installing the sealing ring 6, an external thread and a sealing surface for matching with the connection delivery mechanism are provided on an outer peripheral surface at one end of the central tube 11, an external thread for matching with the seat seal self-locking mechanism and a second sealing groove 112 for installing the sealing ring 6 are provided on an outer peripheral surface and an inner peripheral surface at the other end of the central tube 11, an external convex ring 113 and a third sealing groove 114 for installing the sealing ring 6 are provided on the external convex ring 113 are provided on an outer peripheral surface at a middle part of the central tube 11 and near one end of the second sealing groove 112.

In the above embodiment, as shown in fig. 3, the connection delivery mechanism includes a joint 1, a shear pin 2, and a hanging pipe 3, one end of the hanging pipe 3 is sleeved in the sleeve 4 and connected with the end of the central pipe 11, the other end of the hanging pipe 3 is fixedly connected with one end of the joint 1 through the shear pin 2, and the other end of the joint 1 is connected with a delivery tool of the wire working machine.

The connector 1 comprises a first connector body 101 and a second connector body 103 which are connected, an outer convex circular ring 102 for accident handling and salvaging is arranged in the middle of the connector 1, an outer thread is arranged on the side wall of the first connector body 101 and used for being connected with a delivery tool of the steel wire working machine, and a first radial shearing pin hole matched with the shearing pin 2 is arranged on the second connector body 103. The lifting and hanging pipe 3 is of a tubular structure with an outer circle, an equal diameter and a hollow reducing, and comprises an inner hole upper section 301, an inner hole middle section 302 and an inner hole lower section 303, wherein a second radial shearing pin hole matched with the shearing pin 2 is formed in the inner hole upper section 301, a necking limit table is arranged on the inner wall of the inner hole middle section 302, and an inner thread used for being connected with the end part of the central pipe 11 and a sealing surface attached to the side wall of the central pipe 11 are arranged on the inner wall of the inner hole lower section 303.

In one embodiment of the present application, as shown in fig. 4, the salvaging and unsealing mechanism further includes a lifting hanging ring 7 and unsealing shear pins 8, where an inner circumferential surface of the lifting hanging ring 7 is in threaded connection with the sleeve 4 so as to fixedly install the lifting hanging ring 7 on the sleeve 4, a shear pin ring groove is formed on an outer circumferential surface of the lifting hanging ring 7, and the unsealing shear pins 8 are disposed on a side wall of the slip support 10 and are matched with the shear pin ring groove to form a limit setting mechanism of the sleeve 4 and the slip support 10.

In the above embodiment, as shown in fig. 5, an annular boss 401 for receiving impact is provided at one end of the sleeve 4, a neck section 403 and an internal thread matched with the lifting hanging ring 7 are provided at the other end of the sleeve 4, and a cylindrical light surface 402 is provided on a side wall of the middle part of the sleeve 4.

In the above embodiment, as shown in fig. 6, the main pipe 12 includes a main pipe expanding section 121 and a main pipe body 123 that are connected, a set of radial through holes 122 for installing the locking balls 9 are provided on the side wall of the main pipe expanding section 121, a first one-way sawtooth lock 124 is provided on the outer wall of the main pipe body 123 at the end far from the main pipe expanding section 121, and a sealing surface is provided on the inner wall of the main pipe body 123 at the end far from the main pipe expanding section 121.

In the above embodiment, as shown in fig. 7, the slip support 10 has a tubular structure with an equal diameter on the outer circumferential surface, and includes a first inner diameter portion 1001, a second inner diameter portion 1002 and a third inner diameter portion 1005 that are connected to each other, an internal thread for connecting to the hanging cap 5 is provided on the side wall of the first inner diameter portion 1001, radial shear pin threaded holes 1003 for mounting the deblocking shear pins 8 are uniformly distributed on the side wall of the second inner diameter portion 1002, an annular lock ball groove 1004 for accommodating the lock balls 9 is provided between the second inner diameter portion 1002 and the third inner diameter portion 1005, three inclined grooves 1007 connected to the locking seal mechanism are uniformly distributed on the end portion of the third inner diameter portion 1005 away from one end of the first inner diameter portion 1001, the inclined grooves 1007 have a stepped shape, and the angle of the inclined surface of the inclined groove 1007 is equal to the angle of the end portion of the inclined groove 1007.

Optionally, as shown in fig. 4, the slip support hanging cap 5 has an annular structure, the inner circumferential surface of the slip support hanging cap 5 has an drift diameter, and the outer circumferential surface of the slip support hanging cap 5 is provided with an external thread and a limiting boss for being matched with the slip support 10; the lifting hanging ring 7 is of an annular structure, a shear pin annular groove is formed in the outer circumferential surface of the lifting hanging ring 7, and an internal thread matched with the sleeve 4 is formed in the inner circumferential surface of the lifting hanging ring 7.

In one embodiment of the present application, as shown in fig. 8, the locking sealing mechanism includes a slip 13, a wedge body 14 and a sealing rubber cylinder 15 that are sleeved on the side wall of the supporting pipe 12, one end of the slip 13 is connected with the slip support 10, the other end of the slip 13 is slidably connected with one end of the wedge body 14, the other end of the wedge body 14 is abutted with one end of the sealing rubber cylinder 15, and the other end of the sealing rubber cylinder 15 is abutted with the seat seal self-locking mechanism.

In the above embodiment, as shown in fig. 9, the wedge 14 has a cylindrical structure and includes a wedge body 141, a plurality of wedge grooves 142 inclined toward the slips 13 are provided on an outer wall of the wedge body 141 near one end of the slips 13, one slip 13 is correspondingly installed in each wedge groove 142, inclined grooves 143 parallel to inclined surfaces of the wedge grooves 142 are provided on both sides of the wedge groove 142, and an inner conical surface 144 for protecting the seal rubber 15 is provided on an inner wall of the wedge body 141 near one end of the seal rubber 15.

In the above embodiment, as shown in fig. 10, a connection part 131 connected with the chute 1007 of the slip holder 10 is provided at one end of the slip 13, a plurality of teeth 132 of a horse tooth type are provided at the other end of the slip 13, and symmetrical bosses 133 engaged with the inclined grooves 143 of the wedge 14 are provided on the side walls of both sides of the other end of the slip 13.

Alternatively, as shown in fig. 8, the axial interface of the packing element 15 may be of an "M" configuration to facilitate a deformed seal.

When the downhole choke of this application is going on downhole card seat and is sealed the operation, the impact of jar makes a plurality of slips 13 constitute slip group and follows wedge 14 motion and inflation thereby interlock are on the inner wall of oil pipe, prevent downhole choke removes, and then continues to lift the steel wire for thereby sealed packing element 15 is compressed and expanded and hugs closely the inner wall of oil pipe and accomplish the seat and seal, and then continue to pull up and lift the steel wire, thereby make shearing pin 2 is sheared thereby the release of downhole choke, play the supporting connecting instrument in pit of tapping operation at last, such as jar etc. accomplish downhole choke's seat seals the process, downhole choke automatic start throttle atomizing work.

In one embodiment of the present application, as shown in fig. 11, the seat seal self-locking mechanism includes a rubber cylinder support 16, a lock ring support 17, a lock ring 18 and a lock ring support sleeve 19, the lock ring 18 is sleeved at the end of the support tube 12 and is in limit fit with the support tube 12, the lock ring support 17 is sleeved at the outer side of the lock ring 18 and is mounted on the inner peripheral surface of one end of the lock ring support sleeve 19, the rubber cylinder support 16 is sleeved on the support tube 12 and is in threaded connection with the outer peripheral surface of one end of the lock ring support sleeve 19, and the other end of the lock ring support sleeve 19 is matched with the inner peripheral surface of the end of the central tube 11.

In the above embodiment, as shown in fig. 12, the locking ring support sleeve 19 has a tubular structure, and includes a first support sleeve section 191, a second support sleeve section 192 and a third support sleeve section 193 that are connected, the locking ring support 17 and the locking ring 18 are sequentially sleeved on the inner peripheral surface of the first support sleeve section 191, the rubber cylinder support 16 is in threaded connection with the outer peripheral surface of the first support sleeve section 191, the second support sleeve section 192 and the central tube 11 are spaced to form a space for accommodating the supporting tube 12, and the outer peripheral surface of the third support sleeve section 193 is provided with an external thread and a first stabilizing pin hole 194 that are matched with the filtering and throttling mechanism.

In the above embodiment, as shown in fig. 13, the locking ring 18 has a ring structure, and includes a locking ring body 181, an outer conical surface 182 matching with the locking ring support 17 is provided on an outer circumferential surface of an end portion of the locking ring body 181, a second unidirectional sawtooth lock 183 matching with the first unidirectional sawtooth lock 124 is provided on an inner circumferential surface of an end portion of the locking ring body 181, and an opening with a proper width is provided along one of generatrixes of the locking ring 18 so that the locking ring 18 has circumferential elasticity.

Alternatively, as shown in fig. 11, the rubber cylinder support 16 has a circular ring structure, the outer circumferential surface of the rubber cylinder support 16 is an equal diameter circle, one end of the inner circumferential surface of the rubber cylinder support 16 is a circular ring, and the other end is an expanded diameter and is provided with an internal thread for matching with the lock ring support sleeve 19; the lock ring support 17 has an annular structure, the outer circumferential surface of the lock ring support 17 is an equal diameter circle, one end of the inner circumferential surface of the lock ring support 17 is an equal diameter circle, and the other end is a reduced diameter circle to form a conical surface.

In one embodiment of the present application, as shown in fig. 14, the filtering and throttling mechanism includes an adjusting stabilizing pin 20, an air tap 21, a connecting cap 22 and a filter screen cover 23, the filter screen cover 23 is sleeved on the outer peripheral surface of the end portion of the central tube 11 and supports the end portion of the air tap 21 so as to limit the air tap 21, one end of the connecting cap 22 is sleeved on the outer peripheral surface of the filter screen cover 23 and is limited by an annular boss arranged on the inner peripheral surface of the connecting cap 22, and the other end of the connecting cap 22 is in threaded connection with a locking ring support sleeve 19 of the self-locking mechanism and is adjusted and fixed by the adjusting stabilizing pin 20.

In the above embodiment, as shown in fig. 15, the connecting cap 22 has a circular ring structure, and includes a first connecting portion 221 and a second connecting portion 222 that are connected, the first connecting portion 221 is provided with an internal thread that mates with the end of the lock ring supporting sleeve 19 of the seat seal self-locking mechanism, the side wall of the first connecting portion 221 is provided with a second stabilizing pin hole 223 for installing the adjusting stabilizing pin 20, the inner peripheral surface of the second connecting portion 222 is smaller than the inner peripheral surface of the first connecting portion 221, and the end of the filter screen cover 23 is sleeved in the first connecting portion 221 and is clamped with the second connecting portion 222.

Alternatively, as shown in fig. 14, the outer circumferential surface of the air tap 21 is a sealing surface, and the inner circumferential surface of the air tap 21 is a small through hole with inner cones at two ends; the connection cap 22 is of a ring-shaped structure, an inner thread connection buckle and a protruding ring for being clamped with the connection cap 22 are respectively arranged on the outer circumferential surface and the inner circumferential surface of one end of the filter screen cover 23, a plurality of gaps for ventilation are arranged at the other end of the filter screen cover 23, and a reducing ring for being abutted with the central tube 11 is arranged in the middle of the connection cap 22.

When the downhole choke is replaced, the fishing and unsealing operation is carried out, the fisher is placed to be at a proper height from the downhole choke at a normal speed in steel wire operation, then the fisher is quickly placed down to collide with the downhole choke, the downhole choke can be grabbed, the steel wire is lifted up, the jarring is started to jarring, the unsealing shear pin 8 is sheared, the locking sealing mechanism is unsealed, the lifting steel wire is continued, the unsealed downhole choke is lifted out of a wellhead, and finally, after inspection and maintenance are carried out by a worker, the air tap 21 is replaced according to requirements, and the operation is completed by being placed down again.

The assembly process of the downhole choke of the application is as follows: sleeving the sleeve 4 on the outer peripheral surface of the lifting and hanging pipe 3 from the lower end, sleeving the hanging cap 5 on the outer peripheral surface of the middle part of the sleeve 4 according to the assembly direction, connecting the internal thread of the lifting and hanging ring 7 on the external thread of the fishing sleeve 4, installing the sealing ring 6 on the central pipe 11, coating sealing grease, connecting the central pipe 11 with the thread of the lifting and hanging pipe 3 through the inner peripheral surface of the lower end of the sleeve 4, and sealing the sealing surface in a matched manner; inserting the lower end (one end with a lock catch) of the supporting tube 12 from the upper end of the slip support 10, aligning the radial through holes 122 of the supporting tube 12 with the annular lock ball grooves 1004 in the middle of the slip support 10, placing one lock ball 9 in each radial through hole 122 of the upper end of the supporting tube 12, restricting the lock ball 9 in the annular lock ball grooves 1004 of the slip support 10 by using sealing grease, integrally sleeving the assembly of the slip support 10, the supporting tube 12 and the lock ball 9 from the lower end of the central tube 11, adjusting the sleeving position to align the radial shear pin threaded holes 1003 on the slip support 10 with the shear pin annular grooves on the hanging rings 7, installing the deblocking shear pins 8, and connecting the external threads of the hanging cap 5 with the internal threads of the slip support 10; sequentially and correspondingly mounting the slips 13, the wedge body 14 and the sealing rubber cylinder 15 on the outer peripheral surface of the support tube 12; the method comprises the steps of sleeving a lock ring 18 in a lock ring support 17, placing the lock ring support 17 in a first support sleeve section 191 of a lock ring support sleeve 19, integrally sleeving the lower end of a support tube 12 after connecting an internal thread of a rubber cylinder support 16 with an external thread of the lock ring support sleeve 19, connecting the internal thread of the bottom of the lock ring support sleeve 19 with an internal thread of the bottom of a central tube 11, adjusting the position to enable the top of the rubber cylinder support 16 to abut against the lower end of a sealing rubber cylinder 15, installing an air tap 21 (the size of the internal hole of the air tap is adjusted according to the requirement of a gas well) at the bottom of the central tube 11, penetrating and hanging a filter screen cover 23 from the top of a connecting cap 22 at a second connecting part 222 at the bottom of the connecting cap 22, connecting the internal thread at the upper end of the connecting cap 22 with the external thread of the lower end of the ring support sleeve 19, installing an adjusting stabilizing pin 20, and finally inserting the lower end of the joint 1 into an inner hole 301 at the upper end of the lifting tube 3 and installing a throttling pin 2 of the downhole shear pin.

As shown in fig. 16 to 17, the downhole locking seat sealing process of the downhole choke of the present application is that the jar in the delivery tool of the wire work is violently impacted on the annular boss 401 of the sleeve 4 under the action of inertia, and under the action of the hanging ring 7 and the locking ball 9, the sleeve 4 is impacted to push the supporting pipe 12, the slip support 10 and the hanging cap 5 to move downwards together, so that the slip 13 moves downwards and expands along the inclined plane of the wedge body 14 to be clamped on the inner wall of the oil pipe; meanwhile, the sealing rubber cylinder 15 is compressed axially and expanded radially to seal the annulus of the pipe 12 and the oil pipe, the pipe 12 is inserted into the lock ring supporting sleeve 19 due to the seat seal self-locking mechanism consisting of the rubber cylinder supporting 16, the lock ring supporting 17, the lock ring 18 and the lock ring supporting sleeve 19, and the pipe can only enter under the action of the first unidirectional sawtooth lock catch 124 and the second unidirectional sawtooth lock catch 183 to realize self-locking, if the sealing rubber cylinder 15 is not compressed to an ideal state of a sealing requirement, the slip group 13 is pulled more tightly by lifting the joint 1 and the sealing rubber cylinder 15 is compressed continuously through the lock ring supporting sleeve 19, so that the sealing capability is stronger and stronger, and under the condition that the tensile force reaches the optimal value of the design seat seal, the shearing pin 2 is sheared, so that the downhole choke realizes releasing and the seat seal.

In the process of clamping and setting, the outer peripheral surface of the downhole choke of the application is smaller than the inner peripheral surface of an oil pipe, and before setting, the slip group 13 is contracted in the maximum outer peripheral surface of the downhole choke, the sealing rubber cylinder 15 adopts a compression rubber cylinder and seals an annular gap between the downhole choke and the oil pipe by axial compression and radial expansion, so that all parts are ensured to be in the maximum outer peripheral surface of the downhole choke before setting, the slip group 13 and the slip support 10 cannot relatively displace when being lifted and lowered stably in any section in the oil pipe, the slip group 13 cannot radially expand, and the downhole choke is ensured to be lowered to a design position.

In the prior art, the slip structure of the existing clamping sealing mechanism is provided with a self-hanging slip, a throttle adopting the self-hanging slip structure naturally sags to be in an expansion state in the underground vertical well descending process, a descending stopper can automatically move back upwards to retract but not integrally lift and release the stopper, the existing clamping sealing mechanism also generally adopts a rubber cup type sealing rubber cylinder, the outer peripheral surface of the existing clamping sealing mechanism is the same as the inner peripheral surface of an oil pipe, the setting principle of the throttle adopting the structure is that the self-hanging slip clamps the inner wall of a main oil pipe, the main body slip is lifted to continuously expand and embed into the inner wall of the oil pipe to complete the clamping, and the sealing is realized by pushing a rubber cup to expand again by using the pressure difference generated by the throttling of the rubber cup type sealing rubber cylinder.

As shown in fig. 18, in the process of salvaging and unsealing the downhole choke of the present application, the salvaging device is lowered to a proper height from the downhole choke at a normal speed, the salvaging device is quickly lowered to strike and grasp the annular boss 401 at the upper end of the casing 4, the lifting wire starts the jar and cuts off the unsealing shear pin 8, the lifting wire continues to lift the casing 4 to lift the lifting ring 7 and hang the hanging cap 5, the lower end of the casing 4 is separated from the inner circle at the upper end of the supporting tube 12 to form an annulus so as to lose the locking effect, the lifting ring 7 continues to lift the hanging cap 5 and the slip support 10, the slip support 10 is lifted upwards, the slip 13 is lifted upwards to be completely contracted to the unsealing position, and the symmetrical boss 133 of the slip 13 is matched with the inclined groove 143 of the wedge 14 so as to pull the wedge 14 upwards to form a sealing rubber cylinder 15 to restore the original space, thereby completing the unsealing of the downhole choke 15 and the downhole choke 15. Finally, the necking section 403 of the sleeve 4 hooks the lower section 303 of the inner hole of the hanging pipe 3, so that the hanging pipe 3 drags the whole underground throttle to lift the wellhead through the central pipe 11, and a worker replaces the air tap 21 to drop into the well again according to the requirement after maintenance.

The preferred embodiments and examples of the present application have been described in detail with reference to the accompanying drawings, but the present application is not limited to the embodiments and examples described above, and various changes may be made within the knowledge of those skilled in the art without departing from the spirit of the present application.

Claims (6)

1. A downhole choke, comprising: the automatic sealing device comprises a central tube (11), wherein a salvaging deblocking mechanism and a seat sealing self-locking mechanism are respectively arranged at two ends of the central tube (11), a clamping sealing mechanism is arranged between the salvaging deblocking mechanism and the seat sealing self-locking mechanism, the salvaging deblocking mechanism comprises a sleeve (4), a supporting tube (12), a slip support (10) and a locking ball (9), the sleeve (4) is sleeved on the central tube (11) and is sleeved with one end of the supporting tube (12), the other end of the supporting tube (12) is in limiting connection with the seat sealing self-locking mechanism, the slip support (10) is sleeved on the supporting tube (12) and is in limiting connection with a hanging cap (5) sleeved on the sleeve (4), the locking ball (9) is arranged on the slip support (10) in a limiting manner through the sleeve (4) and enables the slip support (10) and the supporting tube (12) to be locked along the axis direction of the central tube (11), and the clamping sealing mechanism is sleeved on the side wall of the supporting tube (12) and is respectively connected with the slip support (10) and the seat sealing self-locking mechanism;

the salvaging and deblocking mechanism further comprises a lifting hanging ring (7) and deblocking shear pins (8), wherein the inner circumferential surface of the lifting hanging ring (7) is in threaded connection with the sleeve (4) so as to fixedly install the lifting hanging ring (7) on the sleeve (4), shear pin ring grooves are formed in the outer circumferential surface of the lifting hanging ring (7), and the deblocking shear pins (8) are arranged on the side wall of the slip support (10) and are matched with the shear pin ring grooves to form a limiting mechanism of the sleeve (4) and the slip support (10);

the slip support (10) is of a tubular structure with the same diameter on the outer peripheral surface, and comprises a first inner diameter part (1001), a second inner diameter part (1002), a third inner diameter part (1005) and a fourth inner diameter part (1006) which are communicated, wherein the side wall of the first inner diameter part (1001) is provided with internal threads connected with the hanging cap (5), the side wall of the second inner diameter part (1002) is uniformly distributed with radial shear pin threaded holes (1003) for installing the deblocking shear pins (8), the inner side of the third inner diameter part (1005) is provided with an annular locking ball groove (1004) for accommodating the locking balls (9), and the end part of the fourth inner diameter part (1006) far away from one end of the first inner diameter part (1001) is uniformly distributed with three chute (1007) connected with the locking sealing mechanism;

the seat seal self-locking mechanism comprises a rubber cylinder support (16), a lock ring support (17), a lock ring (18) and a lock ring support sleeve (19), wherein the lock ring (18) is sleeved at the end part of the support tube (12) and is in limit fit with the support tube (12), the lock ring support (17) is sleeved at the outer side of the lock ring (18) and is arranged on the inner peripheral surface of one end of the lock ring support sleeve (19), the rubber cylinder support (16) is sleeved on the support tube (12) and is in threaded connection with the outer peripheral surface of one end of the lock ring support sleeve (19), and the other end of the lock ring support sleeve (19) is matched with the inner peripheral surface of the end part of the central tube (11);

the pipe support (12) comprises a pipe support expanding section (121) and a pipe support body (123), a group of radial through holes (122) for installing lock balls (9) are formed in the side wall of the pipe support expanding section (121), a first one-way sawtooth lock catch (124) is arranged on the outer wall of the pipe support body (123) away from one end of the pipe support expanding section (121), and a sealing surface is arranged on the inner wall of the pipe support body (123) away from one end of the pipe support expanding section (121);

the locking ring (18) is of an annular structure and comprises a locking ring body (181), an outer conical surface (182) matched with the locking ring support (17) is arranged on the outer peripheral surface of the end part of the locking ring body (181), and a second unidirectional sawtooth lock catch (183) matched with the first unidirectional sawtooth lock catch (124) is arranged on the inner peripheral surface of the end part of the locking ring body (181).

2. The downhole choke according to claim 1, further comprising a connection delivery mechanism and a filtering choke mechanism, wherein one end of the connection delivery mechanism is connected to the central tube (11) through the sleeve (4), the other end of the connection delivery mechanism is connected to a delivery tool of a wire working machine, and the filtering choke mechanism is arranged at an end of the central tube (11) far from one end of the fishing and unsealing mechanism and is connected to the seat seal self-locking mechanism.

3. The downhole choke according to claim 1, wherein the locking sealing mechanism comprises a slip (13) sleeved on the side wall of the supporting pipe (12), a wedge body (14) and a sealing rubber cylinder (15), one end of the slip (13) is connected with the slip supporting pipe (10), the other end of the slip (13) is slidably connected with one end of the wedge body (14), the other end of the wedge body (14) is abutted with one end of the sealing rubber cylinder (15), and the other end of the sealing rubber cylinder (15) is abutted with the seat seal self-locking mechanism.

4. The downhole choke according to claim 2, characterized in that the connection delivery mechanism comprises a joint (1), a shear pin (2) and a hanging pipe (3), one end of the hanging pipe (3) is sleeved in the sleeve (4) and connected with the end of the central pipe (11), the other end of the hanging pipe (3) is fixedly connected with one end of the joint (1) through the shear pin (2), and the other end of the joint (1) is connected with a delivery tool of the wire working machine.

5. The downhole choke according to claim 2, wherein the filtering and throttling mechanism comprises an adjusting stabilizing pin (20), an air tap (21), a connecting cap (22) and a filter screen cover (23), wherein the air tap (21) is arranged in the central tube (11), the filter screen cover (23) is sleeved on the outer peripheral surface of the end part of the central tube (11) and supports the end part of the air tap (21) so as to limit the air tap (21), one end of the connecting cap (22) is sleeved on the outer peripheral surface of the filter screen cover (23) and is limited by an annular boss arranged on the inner peripheral surface of the connecting cap (22), and the other end of the connecting cap (22) is in threaded connection with a locking ring support sleeve (19) of the self-locking mechanism and is adjusted and fixed by the adjusting stabilizing pin (20).

6. The downhole choke according to claim 2, wherein the central tube (11) has a drift diameter structure, a first sealing groove (111) for installing a sealing ring (6) is provided on an outer circumferential surface of one end of the central tube (11), an external thread and a sealing surface which are matched with the connection delivery mechanism are provided on an outer circumferential surface and an inner circumferential surface of the other end of the central tube (11), an external thread matched with the seat seal self-locking mechanism and a second sealing groove (112) for installing the sealing ring (6) are provided on the outer circumferential surface which is arranged in the middle of the central tube (11) and is close to one end of the second sealing groove (112), and a third sealing groove (114) for installing the sealing ring (6) is provided on the external convex ring (113).