CN220469868U - Back pressure valve and delivery tool for back pressure valve - Google Patents

Abstract

The utility model relates to a back pressure valve and a delivery tool of the back pressure valve, wherein the back pressure valve comprises an upper joint, and the upper end of the upper joint is provided with an external thread structure; the upper joint is internally and fixedly connected with a central rod, the central rod can move upwards relative to the upper joint, the outer part of the central rod is fixedly connected with a valve seat, and a first sealing mechanism is arranged between the valve seat and the upper joint; the valve seat is fixedly connected with a lower joint, a channel extending to penetrate through the central rod, the upper joint and the lower joint along the axial direction of the central rod is arranged on the central rod, an air hole is formed in the side wall of the lower end of the central rod, and a plugging mechanism is arranged in the channel between the central rod and the lower joint. The back pressure valve can realize the blocking of the internal channel of the back pressure valve through the arrangement of the blocking mechanism; the annular space between the back pressure valve and the tubing hanger can be sealed through the first sealing mechanism, so that the effective plugging of the air passage can be realized.

Description

Back pressure valve and delivery tool for back pressure valve

Technical Field

The utility model belongs to the technical field of pressure control valves, and particularly relates to a back pressure valve and a delivery tool of the back pressure valve.

Background

Before the christmas tree is disassembled in well repairing operation, the pressure of a wellhead is required to be isolated, so that the operation safety is ensured; in addition, oil and gas well heads are mined for a long time, problems such as corrosion, ageing of sealing elements, sealing abrasion and the like can occur in the well head control valve, the problems easily cause internal leakage or external leakage of the valve and other well head parts, the production of the oil and gas well is seriously influenced, the maintenance or replacement of the valve parts is required, the pressure of the well head is required to be isolated in the maintenance or replacement process of the valve parts, and the operation safety is ensured.

The conventional process isolates wellhead pressure for valve maintenance or replacement through a well killing process, but the method can cause serious interference to normal production of oil and gas wells and bring about a plurality of adverse factors. Therefore, at present, a simple back pressure valve tool is used when the christmas tree is disassembled or the valve of the christmas tree is damaged, but the existing back pressure valve lacks effective blocking of an air passage, and the risk in the operation process is relatively high.

Disclosure of Invention

In order to solve all or part of the problems, an object of the present utility model is to provide a back pressure valve and a delivery tool for the back pressure valve, which can realize the blocking of the internal channel of the back pressure valve by the arrangement of a blocking mechanism; the annular space between the back pressure valve and the tubing hanger can be sealed through the first sealing mechanism, so that the effective plugging of the air passage can be realized.

According to one aspect of the utility model, there is provided a back pressure valve comprising an upper joint having an upper end provided with an external thread formation for mating with an internal thread on an inner wall of a tubing hanger;

the inner part of the upper joint is fixedly connected with a center rod, the center rod can move upwards relative to the upper joint, the outer part of the center rod is fixedly connected with a valve seat, a first sealing mechanism is arranged between the valve seat and the upper joint, and the first sealing mechanism is used for sealing an annulus between the back pressure valve and the tubing hanger when the center rod moves upwards to a preset position;

the valve seat is fixedly connected with a lower joint, a channel extending to penetrate through the central rod, the upper joint and the lower joint along the axial direction of the central rod is arranged on the central rod, an air hole is formed in the side wall of the lower end of the central rod, a blocking mechanism is arranged in the channel between the central rod and the lower joint and is configured to be pressed on the central rod, and when the central rod moves upwards and the air hole is located in the valve seat, the blocking mechanism and the valve seat are matched to block the channel.

Further, a limiting ring is arranged in the upper joint, the central rod comprises a first section of the central rod above and a second section of the central rod below, the inner diameter of the limiting ring is smaller than the outer diameter of the first section of the central rod, and the first section of the central rod is in threaded connection with the upper joint above the limiting ring.

Further, the first sealing mechanism comprises a sealing rubber sleeve, the sealing rubber sleeve is sleeved on the second section of the central rod, and the sealing rubber sleeve is pressed to deform so as to seal an annulus between the back pressure valve and the tubing hanger.

Further, the first sealing mechanism further comprises a mandrel in sealing connection with the second section of the central rod, the mandrel is sleeved outside the second section of the central rod, and the mandrel is in threaded connection with the upper joint below the limiting ring; the sealing rubber cylinder is sleeved on the mandrel; the valve seat is fixedly and hermetically connected with a compression sleeve, the upper end of the compression sleeve is contacted with the lower end of the sealing rubber cylinder, and the mandrel is connected with the compression sleeve through a key; the distance between the lower end face of the mandrel and the upper end face of the valve seat is larger than or equal to the distance of the valve seat moving upwards when the first sealing mechanism seals the annulus between the backpressure valve and the tubing hanger.

Further, a compensation sealing gasket is arranged between the sealing rubber cylinder and the upper joint; the second section of the central rod is fixedly connected with the valve seat through a spherical baffle ring.

Further, a second sealing mechanism is arranged outside the upper joint and is used for being in interference fit with a sealing surface of the oil pipe hanger; the second sealing mechanism is a sealing gasket arranged in the groove of the upper joint.

Further, the plugging mechanism comprises a plugging ball and an elastic structure, wherein the diameter of the plugging ball is larger than the inner diameter of the valve seat, one end of the elastic structure is connected with the plugging ball, the other end of the elastic structure is connected with the lower joint, and the elastic structure is configured to press the plugging ball on the central rod or the valve seat; the elastic structure is a spring.

According to another aspect of the present utility model, there is provided a delivery tool of a back pressure valve, the back pressure valve being as described in any one of the above, the delivery tool comprising an outer barrel and a delivery rod located in the outer barrel, the upper end of the outer barrel and the delivery rod being in sealing connection, the lower end of the outer barrel being in sealing connection with the delivery rod by a blowout prevention mechanism, the delivery rod being fixedly connected with a piston which divides the area between the outer barrel, the delivery rod and the blowout prevention mechanism into a first sealing chamber above and a second sealing chamber below, the outer barrel being provided with a crimp hole communicating with the first sealing chamber, the blowout prevention mechanism being for connection with a christmas tree, and the blowout prevention mechanism being capable of decompressing when the pressure in the second sealing chamber is greater; the inner thread of the feeding rod is connected with a hand throwing rod, and the hand throwing rod penetrates through the lower end of the feeding rod to be matched with the upper joint of the back pressure valve; the hand throwing rod is internally connected with a setting rod in a threaded manner, and the lower end of the setting rod is matched with the central rod of the back pressure valve.

Further, the upper end of the outer cylinder is fixedly and hermetically connected with a pressing back cap, a connecting rod is arranged between the pressing back cap and the feeding rod, and the connecting rod is respectively and fixedly connected with the pressing back cap and the feeding rod in a sealing manner.

Further, the blowout prevention mechanism comprises a cylinder body, the upper end of the cylinder body is respectively in sealing connection with the outer cylinder and the feeding rod, a pressure detection port and a pressure release port are arranged on the cylinder body, the pressure detection port is used for detecting the pressure in the second sealing cavity, and the pressure release port is used for being connected with a pressure release valve so as to realize pressure release when the pressure in the second sealing cavity is larger; the lower extreme of barrel is connected with flange, flange is used for with the cooperation of top flange on the christmas tree.

Further, the lower end of the setting rod is provided with a plurality of protruding blocks, and the protruding blocks pass through a traversing groove on the central rod of the back pressure valve and then fall into a ring groove below the traversing groove; the lower end of the releasing rod is in threaded connection with the upper joint of the back pressure valve.

According to the technical scheme, the back pressure valve and the delivery tool of the back pressure valve provided by the utility model have the following beneficial effects:

the back pressure valve can realize the blocking of the internal channel of the back pressure valve through the arrangement of the blocking mechanism; the annular space between the back pressure valve and the tubing hanger can be sealed through the first sealing mechanism, so that the effective plugging of the air passage can be realized;

the delivery tool can be used for placing the back pressure valve into the tubing hanger or taking the back pressure valve out of the tubing hanger, so that the back pressure valve can be conveniently and smoothly plugged in an air passage.

Drawings

FIG. 1 is a cross-sectional view of a back pressure valve according to an embodiment of the present utility model;

FIG. 2 is a cross-sectional view of the back pressure valve blocking the airway;

FIG. 3 is a cross-sectional view of a delivery tool according to an embodiment of the present utility model;

the reference numerals in the drawings are: the sealing device comprises an upper joint 1, a sealing gasket 2, a compensating gasket 3, a sealing rubber cylinder 4, a mandrel 5, a compression sleeve 6, a central rod 7, an air vent 71, a channel 72, an annular groove 73, a crossing groove 74, a spherical baffle ring 8, a valve seat 9, a plugging ball 10, an elastic structure 11, a lower joint 12 and a limiting ring 13;

setting rod 01, bump 011, releasing rod 02, feeding rod 03, connecting rod 04, pressing back cap 05, pressing hole 051, piston 06, outer cylinder 07, cylinder 08, pressure detecting port 081, pressure releasing port 082 and connecting flange 09.

Detailed Description

For a better understanding of the objects, structures and functions of the present utility model, a back pressure valve and a delivery tool for the back pressure valve according to the present utility model will be described in further detail with reference to the accompanying drawings.

As shown in fig. 1-2, the back pressure valve according to the embodiment of the utility model comprises an upper joint 1, wherein the upper end of the upper joint 1 is provided with an external thread structure matched with an internal thread on the inner wall of the tubing hanger, so that the back pressure valve can be fixed inside the tubing hanger through the matching of the external thread structure and the internal thread.

The upper joint 1 is internally and fixedly connected with a central rod 7, the central rod 7 can move upwards relative to the upper joint 1, the outer part of the central rod 7 is fixedly connected with a valve seat 9, a first sealing mechanism is arranged between the valve seat 9 and the upper joint 1, and the first sealing mechanism is used for sealing an annulus between the back pressure valve and the tubing hanger when the central rod 7 moves upwards to a preset position; specifically, when the central rod 7 moves upwards relative to the upper joint 1, the valve seat 9 can be driven to move upwards, and the valve seat 9 moves upwards so that the first sealing mechanism can seal the annulus between the back pressure valve and the tubing hanger.

The valve seat 9 is fixedly connected with the lower joint 12, the central rod 7 is provided with a channel 72 which extends to penetrate through the central rod 7, the upper joint 1 and the lower joint 12 along the axial direction of the central rod 7, the side wall of the lower end of the central rod 7 is provided with ventilation holes, a plugging mechanism is arranged in the channel 72 between the central rod 7 and the lower joint 12 and is configured to be pressed on the central rod 7, and when the central rod 7 moves up to the ventilation holes 71 to be positioned in the valve seat 9, the plugging mechanism is matched with the valve seat 9 to plug the channel 72.

The specific blocking mechanism is arranged in the channel 72 between the central rod 7 and the lower joint 12, and is pressed on the central rod 7, and the communication between the upper part and the lower part of the blocking mechanism is realized through the ventilation holes on the central rod 7; when the central rod 7 moves upwards, the air holes 71 move from the lower end of the valve seat 9 to be blocked by the valve seat 9, and meanwhile, the blocking mechanism is blocked on the valve seat 9, so that the purpose of blocking the channel 72 on the central rod 7 is realized through the blocking mechanism and the valve seat 9.

In this embodiment, the inner channel 72 of the back pressure valve is plugged by the plugging mechanism, and the annulus between the back pressure valve and the tubing hanger can be sealed by the first sealing mechanism, so that the purpose of completely plugging the tubing hanger is achieved, and the complete plugging of the air passage is achieved.

In a specific embodiment, the upper joint 1 is internally provided with a limiting ring 13, the central rod 7 comprises a first section of the central rod above and a second section of the central rod below, the inner diameter of the limiting ring 13 is smaller than the outer diameter of the first section of the central rod, and the first section of the central rod is in threaded connection with the upper joint 1 above the limiting ring 13.

In this embodiment, the inner diameter of the limiting ring 13 is smaller than the outer diameter of the first section of the central rod, and the first section of the central rod is located above the limiting ring 13, and the limiting ring 13 is sleeved outside the second section of the central rod, so that the limiting ring 13 can limit the lower limit position of the central rod 7, and the lower limit position of the central rod 7 is the contact position of the first section of the central rod and the limiting ring 13; the first section of the center rod 7 is screwed to the upper joint 1 above the stopper ring 13, so that when the upper joint 1 is fixed, the center rod 7 can be moved upward relative to the upper joint 1 when the center rod 7 is rotated in the rotational direction for moving the center rod 7 upward.

Next, during installation, the center rod 7 is passed through the inner hole of the limit ring 13, and the center rod 7 is rotated to the lower limit position.

In one embodiment, the first sealing mechanism comprises a packing element 4, the packing element 4 being sleeved on the second section of the central rod, the packing element 4 being deformable under pressure to seal the annulus between the back pressure valve and the tubing hanger.

In this embodiment, the first sealing mechanism includes the packing element 4, when the center pole 7 moves up, can drive disk seat 9 and move up, disk seat 9 moves up and compresses packing element 4, thereby packing element 4 is compressed and is out of shape and can seal the annular space between backpressure valve and the tubing hanger.

In a specific embodiment, the first sealing mechanism further comprises a mandrel 5, the mandrel 5 is sleeved on the second section of the central rod, the mandrel 5 is in sealing connection with the second section of the central rod, and the mandrel 5 is in threaded connection with the upper joint 1 below the limiting ring 13; the sealing rubber cylinder 4 is sleeved on the mandrel 5; the valve seat 9 is fixedly and hermetically connected with a compression sleeve 6, the upper end of the compression sleeve 6 is contacted with the lower end of the sealing rubber cylinder 4, and the mandrel 5 is connected with the compression sleeve 6 through a key; the distance between the lower end surface of the mandrel 5 and the upper end surface of the valve seat 9 is larger than or equal to the distance of the valve seat 9 moving upwards when the first sealing mechanism seals the annulus between the backpressure valve and the tubing hanger.

In the embodiment, the mandrel 5 is sleeved on the second section of the central rod, the mandrel 5 is connected with the second section of the central rod in a sealing way, and the mandrel 5 is connected with the upper joint 1 below the limiting ring 13 in a threaded way; the valve seat 9 is in threaded connection with the compression sleeve 6, and the valve seat 9 is in sealing connection with the compression sleeve 6; the lower end of the mandrel 5 and the upper end of the compression sleeve 6 are respectively provided with a boss, and the two bosses are hooked together so that the compression sleeve 6 can only move upwards relative to the mandrel 5; the sealing rubber cylinder 4 is sleeved on the mandrel 5.

Specifically, fig. 1 is a cross-sectional view of the back pressure valve before the back pressure valve seals the airway, at this time, the central rod 7 is at the lower limit position, and the air hole 71 at the lower end of the central rod 7 is located below the valve seat, so that the channel above the sealing mechanism and the channel below the sealing mechanism are communicated through the air hole 71 at this time; when the central rod 7 moves upwards, the central shaft 5 cannot move upwards along with the limiting ring 13 and the upper joint 1; in addition, when the central rod 7 moves upwards, the valve seat 9 is driven to move upwards, the valve seat 9 moves upwards to compress the compression sleeve 6, the compression sleeve 6 is compressed and deformed, meanwhile, the sealing rubber cylinder 4 is compressed, and after the sealing rubber cylinder 4 is compressed, the deformation seals the annulus between the backpressure valve and the tubing hanger, as shown in fig. 2.

Again, in order to allow the valve seat 9 to move up to compress the compression sleeve 6, a gap should be provided between the valve seat 9 and the mandrel 5, which should ensure that the packing element 4 can deform to completely seal the annulus between the back pressure valve and the tubing hanger, i.e. the distance between the lower end surface of the mandrel 5 and the upper end surface of the valve seat 9 is equal to or greater than the distance that the valve seat 9 moves up when the first sealing mechanism seals the annulus between the back pressure valve and the tubing hanger.

Finally, during specific installation, the compression sleeve 6 is sleeved outside the mandrel 5, and the compression sleeve 6 and the mandrel 5 are connected by keys (such as splines); then sleeving the sealing rubber cylinder 4 on the mandrel 5; thirdly, the mandrel 5 passes through the central rod 7, and the mandrel 5 is rotated to enable the external thread of the mandrel 5 to be connected and fastened with the internal thread below the limiting ring 13 of the upper joint 1; sealing the central rod 7 and the mandrel 5 through an O-shaped sealing ring or other sealing structures; finally, the valve seat 9 is sleeved on the central rod 7, the valve seat 9 and the compression sleeve 6 are fastened through threaded connection, and the valve seat 9 and the central rod 7 are fixed through the spherical baffle ring 8.

In a specific embodiment, a compensating sealing gasket 3 is arranged between the sealing rubber cylinder 4 and the upper joint 1; the second section of the central rod is fixedly connected with the valve seat 9 through the spherical baffle ring 8.

In a specific embodiment, a second sealing mechanism is arranged outside the upper joint 1 and is used for being in interference fit with a sealing surface of the tubing hanger; the second sealing means is a sealing gasket 2 arranged in a groove of the upper joint 1.

In this embodiment, there is a second seal between the back pressure valve and the tubing hanger, i.e., a second seal mechanism disposed outside the upper joint 1, by which the reliability of the seal is improved.

Specifically, an annular groove is formed in the upper joint 1, and the second sealing mechanism is a sealing gasket 2 arranged in the groove of the upper joint 1.

In a specific embodiment, the plugging mechanism comprises a plugging ball 10 and an elastic structure 11, wherein the diameter of the plugging ball 10 is larger than the inner diameter of the valve seat 9, one end of the elastic structure 11 is connected with the plugging ball 10, the other end of the elastic structure 11 is connected with the lower joint 12, and the elastic structure 11 is configured to press the plugging ball 10 on the central rod 7 or the valve seat 9; the elastic structure 11 is a spring.

In this embodiment, the plugging mechanism includes a plugging ball 10 and an elastic structure 11, where the inner diameter of the plugging ball 10 is larger than the inner diameter of the valve seat 9, so that the plugging ball 10 can plug the valve seat 9, and the purpose of isolating the channel 72 is achieved; secondly, the elastic structure 11 is used for pressing the plugging ball 10 on the valve seat 9, when the central rod 7 is in the initial state, the air holes 71 at the lower end of the central rod 7 extend to the lower part of the valve seat 9, and the plugging ball 10 plugs on the central rod 7 under the action of the elastic structure 11, but due to the existence of the air holes 71, the channel 72 is in the conducting state at this time.

Secondly, in the concrete installation, the elastic structure 11 and the plugging ball 10 are arranged in the inner cavity of the lower joint 12, the lower joint 12 and the valve seat 9 are fastened through threads, and the plugging ball 10 is attached to the central rod 7 under the thrust of a spring.

Again, the resilient structure 11 may be provided as a spring, or other structure capable of pressing the occlusion ball 10 against the central stem 7 or the valve seat 9, if specifically provided.

In order to facilitate understanding of the working principle of the back pressure valve according to the embodiment of the present utility model, the following description is given according to the use procedure of the back pressure valve:

when the production line is put down, the back pressure valve is delivered to a preset position through the delivery tool, and the external thread structure on the upper joint 1 of the back pressure valve is connected with the internal thread of the production tree tubing hanger through the operation of the delivery tool; when the back pressure valve is completely connected with the tubing hanger, the sealing washer 2 is in interference fit with a sealing surface on the tubing hanger to realize the first sealing between the back pressure valve and the tubing hanger; operating the feeding tool again to enable the center rod 7 of the back pressure valve to move upwards, enabling the center rod 7 to move upwards to sequentially drive the valve seat 9 and the compression sleeve 6 to move upwards, enabling the center rod 7 to move upwards to compress the sealing rubber cylinder 4 through screw pretightening force so as to expand the sealing rubber cylinder 4, and enabling the sealing rubber cylinder 4 to expand to be tightly attached to the inner wall of the tubing hanger after the center rod 7 moves upwards to a preset position so as to achieve second sealing between the back pressure valve and the tubing hanger; meanwhile, after the central rod 7 moves up to the air holes 71 and is positioned in the valve seat 9, the blocking ball 10 is blocked on the valve seat 9, so that the blocking of the internal channel 72 of the back pressure valve is realized; finally, taking out the delivering tool.

When the plugging ball is taken out, the taking tool is firstly in butt joint with the back pressure valve, the central rod 7 of the back pressure valve is rotated and moved downwards by operating the taking tool, the central rod 7 is moved downwards to push the plugging ball 10 to be separated from the valve seat 9, so that the upper channel 72 and the lower channel 72 are communicated, and the pressure balance of the upper channel 72 and the lower channel 72 is realized; the central rod 7 moves downwards to enable the valve seat 9 to move downwards so that the compression sleeve 6 and the sealing rubber cylinder 4 are gradually reset to release the sealing; and finally, operating the delivery tool to separate the back pressure valve from the tubing hanger, and recovering the back pressure valve through the delivery tool.

Embodiments of the present utility model also provide a back pressure valve running tool for running back pressure valves into a tubing hanger or for running back pressure valves located in tubing hangers, wherein the back pressure valve is as described in any of the above embodiments.

Specifically, as shown in fig. 3, the delivering tool of the embodiment includes an outer barrel 07 and a delivering rod 03 positioned in the outer barrel 07, wherein the upper end of the outer barrel 07 is in sealing connection with the delivering rod 03, the lower end of the outer barrel 07 is in sealing connection with the delivering rod 03 through a blowout prevention mechanism, the delivering rod 03 is fixedly connected with a piston 06, the piston 06 divides a region among the outer barrel 07, the delivering rod 03 and the blowout prevention mechanism into a first sealing cavity above and a second sealing cavity below, a pressing hole 051 communicated with the first sealing cavity is arranged on the outer barrel 07, the blowout prevention mechanism is used for being connected with a christmas tree, and the blowout prevention mechanism can release pressure when the pressure in the second sealing cavity is large; the inner thread of the feeding rod 03 is connected with a releasing rod 02, and the releasing rod 02 penetrates through the lower end of the feeding rod 03 to be matched with the upper joint 1 of the back pressure valve; the hand throwing rod 02 is internally connected with a setting rod 01 in a threaded manner, and the lower end of the setting rod 01 is matched with the central rod 7 of the back pressure valve.

In this embodiment, this send and get instrument includes the hand throwing pole 02, the hand throwing pole 02 with send into pole 03 threaded connection, send into pole 03 and be connected with piston 06, therefore when beating the pressure in to first sealed intracavity through beating hole 051, first sealed intracavity pressure increase promotes piston 06 and moves down, piston 06 moves down and drives send into pole 03 and move down, send into pole 03 move down make with send into pole 03 threaded connection's hand throwing pole 02 move down, the lower extreme of hand throwing pole 02 and the upper joint 1 threaded connection of backpressure valve, consequently hand throwing pole 02 moves down can drive the backpressure valve and move down, thereby can realize sending into the backpressure valve with preset position. The pressing hole 051 is used for connecting a pressing pipeline, and the other end of the pressing pipeline is connected with a manual pressing pump.

After the back pressure valve is sent to the preset position of the tubing hanger, the hand throwing rod 02 and the back pressure valve can be driven to rotate by rotating the sending rod 03, so that when the sending rod 03 rotates according to the preset rotation direction (the rotation direction of the sending rod 03 is anticlockwise in the process of setting sending for convenience of description), the back pressure valve rotates, the external thread structure on the joint 1 on the back pressure valve and the internal thread of the tubing hanger gradually rotate, and connection between the back pressure valve and the tubing hanger is achieved.

Again, in this embodiment, the hand throwing rod 02 is in threaded connection with the setting rod 01, and the lower end of the setting rod 01 extending out of the hand throwing rod 02 is in fit connection with the upper end of the center rod 7. Therefore, after the back pressure valve and the tubing hanger are completely connected, the upper joint 1 cannot rotate according to the previous rotation direction due to the existence of the tubing hanger, and the releasing rod 02 and the feeding rod 03 cannot rotate; setting up when the central rod 7 rotates anticlockwise, rotating the setting rod 01 anticlockwise, and driving the central rod 7 to rotate by the setting rod 01 to enable the central rod 7 to move up, wherein the upward movement of the central rod 7 enables the plugging mechanism to gradually plug the channel 72 inside the back pressure valve on one hand, and enables the first sealing mechanism to start to seal the annulus between the back pressure valve and the tubing hanger on the other hand, so that the back pressure valve gradually plugs the air passage inside the tubing hanger. After the back pressure valve completely seals the air passage, the feeding rod 03 is fixed, the hand throwing rod 02 is rotated anticlockwise, the hand throwing rod 02 and the upper joint 1 are separated, and then the feeding tool is taken out completely.

Finally, it should be noted that: after the back pressure valve and the tubing hanger are completely connected, the back pressure valve and the tubing hanger are sealed through a second sealing mechanism.

When the back pressure valve is taken out by using the feeding tool of the present embodiment, the hand throwing lever 02 is rotated first to connect the hand throwing lever 02 with the back pressure valve by screw thread, and the setting lever 01 is rotated to fit the setting lever 01 with the center lever 7; the setting rod 01 is rotated clockwise again, so that the setting rod 01 drives the center rod 7 to move downwards, the center rod 7 moves downwards to enable the upper channel 72 and the lower channel 72 to be communicated, and the center rod 7 moves downwards to enable the compression sleeve 6 and the sealing rubber cylinder 4 to reset gradually to release sealing; the feeding rod 03 is rotated clockwise again, the feeding rod 03 drives the hand throwing rod 02 and the upper connector 1 to move upwards, and the upper connector 1 moves upwards to leave the tubing hanger and then the backpressure valve and the feeding tool are taken out.

In an embodiment, the upper end of the outer cylinder 07 is fixedly and hermetically connected with a pressing back cap 05, a connecting rod 04 is arranged between the pressing back cap 05 and the feeding rod 03, and the connecting rod 04 is respectively and fixedly connected with the pressing back cap 05 and the feeding rod 03 in a sealing manner.

In one embodiment, the blowout prevention mechanism comprises a cylinder 08, the upper end of the cylinder 08 is respectively in sealing connection with the outer cylinder 07 and the feeding rod 03, a pressure detection port 081 and a pressure release port 082 are arranged on the cylinder 08, the pressure detection port 081 is used for detecting the pressure in the second sealing cavity, and the pressure release port 082 is used for connecting a pressure release valve so as to realize pressure release when the pressure in the second sealing cavity is larger; the lower extreme of barrel 08 is connected with flange 09, and flange 09 is used for cooperating with the top flange on the christmas tree.

In this embodiment, the blowout prevention mechanism includes a cylinder 08, a pressure detecting port 081 and a pressure releasing port 082 are provided on the cylinder 08, the pressure detecting port 081 is used for connecting a pressure gauge and the like, so that the pressure in the second sealing cavity is detected by the pressure gauge, and the pressure releasing port 082 is used for connecting a pressure releasing valve, so as to realize pressure release when the pressure in the second sealing cavity is larger. The connection flange 09 at the lower end of the barrel 08 is adapted to mate with a top flange on the tree.

In one embodiment, as shown in fig. 2-3, the lower end of the setting rod 01 is provided with a plurality of protruding blocks 011, and the protruding blocks 011 pass through the through groove 74 on the central rod 7 of the back pressure valve and then fall into the annular groove 73 below the through groove 74; the lower end of the hand throwing rod 02 is in threaded connection with the upper joint 1 of the back pressure valve.

It is noted that unless otherwise indicated, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this utility model pertains.

Furthermore, the terms "a," "an," "the" and the like are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. In the description of the present utility model, the meaning of "plurality" is two or more unless specifically defined otherwise.

In this application, unless specifically stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model, and not for limiting the same; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the utility model, and are intended to be included within the scope of the appended claims and description. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present utility model is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims (11)

1. The back pressure valve is characterized by comprising an upper joint, wherein the upper end of the upper joint is provided with an external thread structure matched with an internal thread on the inner wall of the tubing hanger;

the inner part of the upper joint is fixedly connected with a center rod, the center rod can move upwards relative to the upper joint, the outer part of the center rod is fixedly connected with a valve seat, a first sealing mechanism is arranged between the valve seat and the upper joint, and the first sealing mechanism is used for sealing an annulus between the back pressure valve and the tubing hanger when the center rod moves upwards to a preset position;

the valve seat is fixedly connected with a lower joint, a channel extending to penetrate through the central rod, the upper joint and the lower joint along the axial direction of the central rod is arranged on the central rod, an air hole is formed in the side wall of the lower end of the central rod, a blocking mechanism is arranged in the channel between the central rod and the lower joint and is configured to be pressed on the central rod, and when the central rod moves upwards and the air hole is located in the valve seat, the blocking mechanism and the valve seat are matched to block the channel.

2. The back pressure valve of claim 1 wherein a stop collar is provided in the upper fitting, the center rod including an upper center rod first section and a lower center rod second section, the stop collar having an inner diameter less than an outer diameter of the center rod first section, the center rod first section threadably engaging the upper fitting above the stop collar.

3. The backpressure valve of claim 2, wherein the first sealing mechanism comprises a packing element that is sleeved on the second section of the central rod, the packing element being deformable under pressure to seal an annulus between the backpressure valve and a tubing hanger.

4. The back pressure valve of claim 3 wherein said first sealing mechanism further comprises a mandrel sealingly connected to said second section of said central rod, said mandrel being sleeved outside said second section of said central rod, said mandrel being threadably connected to said upper fitting below said stop collar; the sealing rubber cylinder is sleeved on the mandrel; the valve seat is fixedly and hermetically connected with a compression sleeve, the upper end of the compression sleeve is contacted with the lower end of the sealing rubber cylinder, and the mandrel is connected with the compression sleeve through a key; the distance between the lower end face of the mandrel and the upper end face of the valve seat is larger than or equal to the distance of the valve seat moving upwards when the first sealing mechanism seals the annulus between the backpressure valve and the tubing hanger.

5. The back pressure valve of claim 4 wherein a compensating gasket is disposed between the packing element and the upper fitting; the second section of the central rod is fixedly connected with the valve seat through a spherical baffle ring.

6. The back pressure valve of claim 1, wherein a second sealing mechanism is provided on the exterior of the upper fitting for interference fit with a sealing surface of the tubing hanger; the second sealing mechanism is a sealing gasket arranged in the groove of the upper joint.

7. The back pressure valve of claim 1, wherein the blocking mechanism comprises a blocking ball having a diameter greater than an inner diameter of the valve seat and an elastic structure having one end connected to the blocking ball and the other end connected to the lower joint, the elastic structure being configured to press the blocking ball against the central stem or valve seat; the elastic structure is a spring.

8. A delivery tool of a back pressure valve, characterized in that the back pressure valve is as claimed in any one of claims 1 to 7, the delivery tool comprises an outer cylinder and a delivery rod positioned in the outer cylinder, the upper end of the outer cylinder is in sealing connection with the delivery rod, the lower end of the outer cylinder is in sealing connection with the delivery rod through a blowout prevention mechanism, the delivery rod is fixedly connected with a piston, the piston divides a region among the outer cylinder, the delivery rod and the blowout prevention mechanism into a first sealing cavity at the upper part and a second sealing cavity at the lower part, a punching hole communicated with the first sealing cavity is formed in the outer cylinder, and the blowout prevention mechanism is used for being connected with an oil extraction tree;

the inner thread of the feeding rod is connected with a hand throwing rod, and the hand throwing rod penetrates through the lower end of the feeding rod to be matched with the upper joint of the back pressure valve; the hand throwing rod is internally connected with a setting rod in a threaded manner, and the lower end of the setting rod is matched with the central rod of the back pressure valve.

9. The back pressure valve delivering tool according to claim 8, wherein the upper end of the outer cylinder is fixedly and hermetically connected with a pressing back cap, a connecting rod is arranged between the pressing back cap and the delivering rod, and the connecting rod is respectively and fixedly connected with the pressing back cap and the delivering rod in a sealing manner.

10. The back pressure valve delivering tool according to claim 8, wherein the blowout preventing mechanism comprises a cylinder, the upper end of the cylinder is respectively in sealing connection with the outer cylinder and the delivering rod, a pressure detecting port and a pressure releasing port are arranged on the cylinder, the pressure detecting port is used for detecting the pressure in the second sealing cavity, and the pressure releasing port is used for connecting a pressure releasing valve; the lower extreme of barrel is connected with flange, flange is used for with the cooperation of top flange on the christmas tree.

11. The back pressure valve delivering tool according to claim 8, wherein the lower end of the setting rod is provided with a plurality of protruding blocks, and the protruding blocks pass through the traversing groove on the central rod of the back pressure valve and then fall into the annular groove below the traversing groove; the lower end of the releasing rod is in threaded connection with the upper joint of the back pressure valve.