Hydraulic wellhead sealing tools, auxiliary hydraulic sealing tools and unsealing tools

Abstract

The present invention belongs to the technical field of wellhead sealing equipment, and specifically relates to a hydraulic seat sealing wellhead sealing tool, an auxiliary hydraulic seat sealing tool and an unsealing tool, aiming to solve the problem that the pressurized valve changing sealing tool in the prior art adopts a mechanical method to complete the sealing and unsealing, the sealing state is uncontrollable and there are safety risks. The hydraulic seat sealing wellhead plugging tool provided by the present application comprises a first tubular structure, a second tubular structure and a third tubular structure which are coaxially arranged in sequence; a hydraulic control element is arranged on the top of the second tubular structure to allow the liquid to be unidirectionally conducted from top to bottom, so that the piston in the third tubular structure moves upward to drive the seat sealing assembly sleeved on the outside of the piston to expand radially to complete the sealing, and the hydraulic seat sealing state is continuously maintained in the sealing tool cavity. After the sealing is completed, the well pressure can also produce an auxiliary sealing effect. After the operation is completed, the unsealing can also be achieved by hydraulic pressure. The present application can achieve tight sealing, stable seating and extraction, and the entire construction process is controllable, safe and reliable.

Description

Technical Field

[0001] The invention belongs to the technical field of wellhead plugging equipment, and in particular relates to a hydraulic seat-sealing wellhead plugging tool, an auxiliary hydraulic seat-sealing tool and a unsealing tool. Background Art

[0002] The valves at the wellheads of Christmas trees and gas trees are affected by factors such as fluid erosion, medium corrosion, and aging of valve seals, which can cause damage to the wellhead valves and bring safety hazards to oil and gas production. The conventional well-killing method of replacing valves has high operating costs, large overall workload, long construction period, and long production recovery time after replacement. Gas wells may even be unable to resume production after well killing.

[0003] In addition, the commonly used pressure-changing valve plugging tools need to be operated by wire to lower the plugging tool to the plugging position, and the sealing and releasing actions are completed mechanically. The sealing state is uncontrollable and there are safety risks. In addition, the site needs to be equipped with logging vehicles, cranes and other equipment, and the construction equipment and processes are complicated. Summary of the invention

[0004] In order to solve the above-mentioned problems in the prior art, that is, to solve the problem that the pressurized valve-changing plugging tool in the prior art uses a mechanical method to complete the sealing and unsealing, the sealing state is uncontrollable and there are safety risks, the first aspect of the present application provides a hydraulic seat wellhead plugging tool, including a first tubular structure, a second tubular structure and a third tubular structure coaxially arranged from top to bottom; the inner diameter of the bottom end of the first tubular structure matches the outer diameter of the top end of the second tubular structure, the outer diameter of the bottom end of the second tubular structure matches the inner diameter of the third tubular structure, and a hydraulic control element is fixedly arranged on the top end of the second tubular structure, the hydraulic control element is limited to the shoulder of the first tubular structure, and the hydraulic control element only allows the fluid to be unidirectionally conducted from top to bottom; the third tubular structure A first piston is provided inside the structure so as to slide up and down, and the first piston divides the inner cavity of the third tubular structure into an upper piston cavity and a lower piston cavity. A guide hole is provided in the center of the first piston, and the upper end of the guide hole is connected with the central hole of the second tubular structure, and the lower end is connected with the lower piston cavity. The second tubular structure is provided with an exhaust hole, and one end of the exhaust hole is connected with the outside, and the other end is connected with the inner cavity of the third tubular structure; a seat seal assembly and a seat seal assembly seat are provided on the outer sleeve of the third tubular structure, and the seat seal assembly seat is provided at the bottom of the seat seal assembly and connected to the first piston. When the first piston moves upward, it can drive the seat seal assembly seat to squeeze and compress the seat seal assembly so that the seat seal assembly expands radially.

[0005] In some preferred technical solutions, the third tubular structure includes a sealing section and a seat sealing section, the sealing section is fixedly arranged on the top of the seat sealing section, and the outer diameter of the sealing section is larger than that of the seat sealing section;

[0006] The seat seal assembly is sleeved on the outside of the seat seal section, and the seat seal assembly includes a slip, a cone, and a rubber cylinder arranged in sequence from top to bottom, and the outer diameter of the upper end of the cone matches the inner diameter of the slip.

[0007] In some preferred technical schemes, the first tubular structure includes a first structural part, a second structural part and a third structural part connected in sequence, the outer surface of the first structural part is provided with a thread, the inner diameter of the first structural part is larger than the inner diameter of the second structural part and smaller than the inner diameter of the third structural part, the second structural part has a sealing cone surface, and the upper end of the sealing cone surface is smaller than the lower end.

[0008] In some preferred technical schemes, the hydraulic control element includes an elastic element, a seal and an elastic element mounting seat. The elastic element is fixed to the top of the second tubular structure through the elastic element mounting seat and is sleeved on the outside of the seal. The top of the seal is tightly matched with the sealing cone surface. The seal can move vertically downward under the action of an external force from top to bottom to compress the elastic element and move away from the sealing cone surface to form a hydraulic channel. After pressure relief, the seal moves vertically upward under the action of the elastic element and tightly matches the sealing cone surface to close the hydraulic pressure in the closed cavity.

[0009] A second aspect of the present application provides an auxiliary hydraulic sealing tool, which is used to seal the hydraulic sealing wellhead plugging tool described in any one of the above technical solutions, the sealing tool comprising a cylinder, a limiting sleeve, an auxiliary connecting rod and a blowout preventer box connected in sequence, a second piston being movably arranged in the cylinder, the second piston having an extension end extending outside the cylinder, the extension end being detachably connected to the upper end of the auxiliary connecting rod, and the lower end of the auxiliary connecting rod being detachably connected to the upper end of the first tubular structure; the limiting sleeve is arranged on the outside of the second piston and has a limiting portion extending inside the cylinder; the upper and lower ends of the cylinder are respectively provided with hydraulic holes and exhaust holes connected to the outside; the blowout preventer box is arranged on the outside of the auxiliary connecting rod, the bottom end of the blowout preventer box is open and fixed to the wellhead.

[0010] In some preferred technical schemes, one end of the auxiliary connecting rod is limited to the blowout preventer box, and the other end extends outside the blowout preventer box to be connected to the second piston. A first through hole is provided at the center of the auxiliary connecting rod, and a second through hole is provided transversely through the bottom of the connecting end of the auxiliary connecting rod and the second piston, and the second through hole is orthogonal to and connected to the first through hole.

[0011] In some preferred technical solutions, a pressure relief hole communicating with the outside is provided at the bottom of the blowout prevention box.

[0012] The third aspect of the present application provides an auxiliary hydraulic unsealing tool, which is used to unseal the hydraulic seat wellhead plugging tool described in any one of the above technical solutions, and the unsealing tool comprises a cylinder, a limit sleeve, an auxiliary connecting rod and a blowout prevention box connected in sequence, and a third piston is movably arranged in the cylinder;

[0013] The third piston includes a sliding sealing head, a piston cylinder and an unsealing rod, the sliding sealing head is provided with a through hole connected to the interior of the piston cylinder, the unsealing rod is movably installed in the interior of the piston rod, the bottom end of the piston cylinder extends outside the cylinder barrel and is detachably connected to the upper end of the auxiliary connecting rod, and the lower end of the auxiliary connecting rod is detachably connected to the upper end of the first tubular structure; a first through hole is provided at the center of the auxiliary connecting rod, and a second through hole is transversely penetrated at the bottom of the auxiliary connecting rod and the third piston connection end, and the second through hole is orthogonal to and connected to the first through hole; the unsealing rod has an extending end extending outside the piston cylinder, and the extending end matches the inner diameter of the first through hole;

[0014] The limiting sleeve is sleeved on the outside of the third piston and has a limiting portion extending inside the cylinder; the upper end and the lower end of the cylinder are respectively provided with a hydraulic hole and an exhaust hole connected to the outside; the blowout preventer box is sleeved on the outside of the auxiliary connecting rod, the upper end of the blowout preventer box is used to limit the auxiliary connecting rod, and the bottom end of the blowout preventer box is open and fixed to the wellhead.

[0015] In some preferred technical solutions, the bottom end of the unsealing rod is a pointed end.

[0016] In some preferred technical solutions, a pressure relief hole communicating with the outside is provided at the bottom of the blowout prevention box.

[0017] Beneficial effects of the present invention:

[0018] The present invention is lowered into the well by the thrust of the hydraulic piston rod and seals the well by the hydraulic action. The hydraulic pressure is continuously maintained in the cavity of the sealing tool to ensure the sealing state. After the sealing is completed, the well pressure can also produce an auxiliary sealing effect. After the operation is completed, the pressure-maintaining device is opened by the hydraulic pushing of the sealing rod to relieve the pressure and seal, thereby ensuring that the wellhead sealing tool can achieve the purpose of sealing tightly, holding the well and being taken out, so that the entire construction process is controllable and the construction is safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0020] Figure 1 It is a schematic diagram of the overall structure of a hydraulic seat wellhead plugging tool according to an embodiment of the present invention;

[0021] Figure 2It is a schematic diagram of the overall structure of an auxiliary hydraulic sealing tool according to an embodiment of the present invention;

[0022] Figure 3 It is a schematic diagram of the overall structure of an auxiliary hydraulic unsealing tool according to an embodiment of the present invention;

[0023] List of reference numerals:

[0024] 1-first tubular structure; 2-seal; 3-elastic element; 4-elastic element mounting seat; 5-second tubular structure, 5-1-exhaust hole; 6-adjusting ring; 7-third tubular structure; 8-first piston, 8-1-pressure transmission hole; 9-slip; 10-cone; 11-rubber cylinder; 12-seat seal assembly seat; 13-stabilizing nail; 21-cylinder head; 22-cylinder barrel, 22-1 hydraulic hole, 22-2-exhaust hole; 23-piston head; 24-piston rod; 25-limiting sleeve ; 26-auxiliary connecting rod, 26-1-hydraulic hole, 26-2-pressure relief hole; 27-blowout preventer box, 27-1 pressure relief hole, 27-2-blowout preventer box bolt hole; 31-cylinder head, 32-cylinder barrel, 32-1-hydraulic hole, 32-2-drain hole, 33-sliding sealing head, 34-piston cylinder, 35-limiting sleeve, 36-auxiliary connecting rod, 36-1-hydraulic hole, 36-2-pressure relief hole; 37-blowout preventer box, 37-2-blowout preventer box bolt hole, 38-unsealing rod. DETAILED DESCRIPTION

[0025] In order to make the embodiments, technical solutions and advantages of the present invention more obvious, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are part of the embodiments of the present invention, rather than all the embodiments. It should be understood by those skilled in the art that these implementation modes are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0026] The first aspect of the present invention provides a hydraulic seat wellhead plugging tool, comprising a first tubular structure, a second tubular structure and a third tubular structure coaxially arranged in sequence from top to bottom; the inner diameter of the bottom end of the first tubular structure matches the outer diameter of the top end of the second tubular structure, the outer diameter of the bottom end of the second tubular structure matches the inner diameter of the third tubular structure, a hydraulic control element is fixedly arranged on the top end of the second tubular structure, the hydraulic control element is limited to the shoulder of the first tubular structure, and the hydraulic control element only allows the fluid to pass unidirectionally from top to bottom; a first piston is slidably arranged inside the third tubular structure, and the first piston moves the third tubular structure The inner cavity of the structure is divided into an upper piston cavity and a lower piston cavity, a guide hole is arranged at the center of the first piston, the upper end of the guide hole is communicated with the central hole of the second tubular structure, and the lower end is communicated with the lower piston cavity, the second tubular structure is provided with an exhaust hole, one end of the exhaust hole is communicated with the outside, and the other end is communicated with the inner cavity of the third tubular structure; a seat seal assembly and a seat seal assembly seat are arranged on the outer sleeve of the third tubular structure, the seat seal assembly seat is arranged at the bottom of the seat seal assembly and is connected to the first piston, and when the first piston moves upward, it can drive the seat seal assembly seat to squeeze and compress the seat seal assembly, so that the seat seal assembly expands radially.

[0027] The second aspect of the present invention provides an auxiliary hydraulic sealing tool, which is used to seal the above-mentioned hydraulic sealing wellhead plugging tool, the sealing tool comprises a cylinder, a limiting sleeve, an auxiliary connecting rod and a blowout preventer box connected in sequence, a second piston is movably arranged in the cylinder, the second piston has an extension end extending outside the cylinder, the extension end is detachably connected to the upper end of the auxiliary connecting rod, and the lower end of the auxiliary connecting rod is detachably connected to the upper end of the first tubular structure; the limiting sleeve is arranged on the outside of the second piston and has a limiting portion extending inside the cylinder; the upper and lower ends of the cylinder are respectively provided with hydraulic holes and exhaust holes connected to the outside; the blowout preventer box is arranged on the outside of the auxiliary connecting rod, and the bottom end of the blowout preventer box is open and fixed to the wellhead.

[0028] A third aspect of the present invention provides an auxiliary hydraulic unsealing tool, which is used to unseale the above-mentioned hydraulic seat wellhead plugging tool, and the unsealing tool comprises a cylinder barrel, a limit sleeve, an auxiliary connecting rod and a blowout prevention box connected in sequence, and a third piston is movably arranged in the cylinder barrel;

[0029] The third piston includes a sliding sealing head, a piston cylinder and an unsealing rod, the sliding sealing head is provided with a through hole connected to the interior of the piston cylinder, the unsealing rod is movably installed in the interior of the piston rod, the bottom end of the piston cylinder extends outside the cylinder barrel and is detachably connected to the upper end of the auxiliary connecting rod, and the lower end of the auxiliary connecting rod is detachably connected to the upper end of the first tubular structure; a first through hole is provided at the center of the auxiliary connecting rod, and a second through hole is transversely penetrated at the bottom of the auxiliary connecting rod and the third piston connection end, and the second through hole is orthogonal to and connected to the first through hole; the unsealing rod has an extending end extending outside the piston cylinder, and the extending end matches the inner diameter of the first through hole;

[0030] The limiting sleeve is sleeved on the outside of the third piston and has a limiting portion extending inside the cylinder; the upper end and the lower end of the cylinder are respectively provided with a hydraulic hole and an exhaust hole connected to the outside; the blowout preventer box is sleeved on the outside of the auxiliary connecting rod, the upper end of the blowout preventer box is used to limit the auxiliary connecting rod, and the bottom end of the blowout preventer box is open and fixed to the wellhead.

[0031] In order to more clearly illustrate the hydraulic seat wellhead sealing tool of the present invention, a preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0032] As a preferred embodiment of the present invention, the hydraulic seat wellhead plugging tool of the present invention is as follows Figure 1 As shown, it includes a first tubular structure 1, a second tubular structure 5 and a third tubular structure which are coaxially arranged from top to bottom; wherein the inner diameter of the bottom end of the first tubular structure 1 matches the outer diameter of the top end of the second tubular structure 5, the outer diameter of the bottom end of the second tubular structure 5 matches the inner diameter of the third tubular structure, and a hydraulic control element is fixedly arranged on the top end of the second tubular structure 5, the hydraulic control element is limited to the shoulder of the first tubular structure 1, and the hydraulic control element only allows the fluid to be unidirectionally conducted from top to bottom;

[0033] Furthermore, the first tubular structure 1 includes a first structural part, a second structural part and a third structural part which are connected in sequence, wherein a thread is arranged on the outer surface of the first structural part, the inner diameter of the first structural part is larger than the inner diameter of the second structural part and smaller than the inner diameter of the third structural part, and the second structural part has a sealing cone surface, and the upper end of the sealing cone surface is smaller than the lower end.

[0034] In some preferred embodiments, the hydraulic control element includes an elastic element 3, a seal 2 and an elastic element mounting seat 4. The elastic element 3 is fixed to the top of the second tubular structure 5 through the elastic element mounting seat 4 and is sleeved on the outside of the seal 2. The top of the seal 2 is tightly matched with the sealing cone surface. The seal 2 can move vertically downward under the external force from top to bottom to compress the elastic element 3 and move away from the sealing cone surface of the first tubular structure 1 to form a hydraulic channel, that is, a fluid channel. After pressure relief, the seal 2 moves vertically upward under the action of the elastic element 3 and tightly matches the sealing cone surface to close the hydraulic pressure in the cavity.

[0035] A first piston 8 is slidably arranged inside the third tubular structure, and the first piston 8 includes a piston section and a connecting section, wherein the piston section divides the inner cavity of the third tubular structure into an upper piston cavity and a lower piston cavity, and the piston section has an extension portion extending inside the second tubular structure 5, the outer diameter of the extension portion matches the inner diameter of the second tubular structure 5, and a guide hole is arranged at the center of the piston section, the upper end of the guide hole is connected to the center hole of the second tubular structure, and the lower end is connected to the lower piston cavity, that is, the guide hole passes through the extension portion and is connected to the bottom end of the piston section so that the inner cavity of the second tubular structure 5 is connected to the lower piston cavity.

[0036] The second tubular structure 5 is provided with an exhaust hole, one end of which is connected to the outside, and the other end is connected to the inner cavity of the third tubular structure; in some preferred embodiments, the exhaust hole is an L-shaped structure with an opening direction toward the lower right corner, that is, one end of the exhaust hole is connected to the upper piston cavity, and the other end is connected to the outside, so that when the first piston 8 moves upward, the air in the upper piston cavity can be discharged to the outside of the sealing tool.

[0037] The third tubular structure outer sleeve is provided with a seat seal assembly and a seat seal assembly seat. The seat seal assembly seat is arranged at the bottom of the seat seal assembly and is connected to the first piston. When the first piston moves upward, it can drive the seat seal assembly seat to squeeze and compress the seat seal assembly to make the seat seal assembly expand radially.

[0038] The third tubular structure 7 includes a sealing section and a seat sealing section. The sealing section is fixedly arranged at the top of the seat sealing section, and the outer diameter of the sealing section is larger than that of the seat sealing section. The seat sealing assembly is sleeved outside the seat sealing section, and the seat sealing assembly includes a slip 9, a cone 10, and a rubber cylinder 11 arranged in sequence from top to bottom. The outer diameter of the upper end of the cone 10 matches the inner diameter of the slip 9. Preferably, refer to Figure 1 The seat seal assembly is arranged at the bottom of the third tubular structure 7, and is sleeved on the outside of the connecting section of the first piston 8, and the seat seal assembly is limited between the seat seal assembly seats 12. When the first piston 8 moves upward, it can drive the seat seal assembly seat 12 to move upward and then compress the rubber cylinder 11. The rubber cylinder 112 drives the cone 10 to move upward and then makes the slip 9 expand radially, so that the seat seal assembly is closely matched with the inner diameter of the pipe wall to complete the seat seal.

[0039] Specifically, the sealing tool of the present invention is mainly composed of a first tubular structure 1, a seal 2, an elastic element 3, an elastic element mounting seat 4, a second tubular structure 5, an adjustment ring 6, a third tubular structure 7, a first piston 8, a cava 9, a cone 10, a rubber cylinder 11, a rubber cylinder seat 12 and a stabilizing pin 13. The first tubular structure 1 is threadedly connected to the upper end of the second tubular structure 5, the upper end of the seal 2 is pressed against the inner side of the first tubular structure 1, the two ends of the elastic element 3 are respectively sleeved on the seal 2 and the elastic element mounting seat 4, the elastic element mounting seat 4 is installed between the first tubular structure 1 and the second tubular structure 5, the upper end of the third tubular structure 7 is threadedly connected to the lower end of the second tubular structure 5, the adjusting ring 6 is threadedly installed on the outer side of the second tubular structure 5, the first piston 8 is installed on the inner sides of the second tubular structure 5 and the third tubular structure 7, the slip 9 is installed on the third tubular structure 7 and sleeved on the outer side of the first piston 8, the cone 10 and the rubber cylinder 11 are installed on the outer side of the first piston 8, the seat seal assembly seat 12 is threadedly installed on the outer side of the first piston 8, and the stabilizing pin 13 is threadedly installed on the seat seal assembly seat 12.

[0040] After the plugging tool of the present application opens the seal 2 by hydraulic action, the hydraulic pressure passes through the pressure transmission hole 8-1 of the first piston 8 and pushes the first piston 8 upward, and is emptied through the exhaust hole 5-1 on the second tubular structure 5. During the upward movement of the power piston 8, the seat seal assembly seat 12 is driven upward to squeeze the rubber cylinder 11, and at the same time, the cone 10 is driven upward to open the slip 9, so that the rubber cylinder 11 is sealed with the pipe wall, and the slip 9 is anchored on the pipe wall to complete the sealing. After the hydraulic oil injection is stopped, under the action of the elastic element 3, the seal 2 forms a seal with the second step 1-1 inside the first tubular structure 1, locks the inner cavity pressure of the plugging tool, forms a continuous sealing force, and ensures the sealing performance of the plugging tool. At the same time, after the sealing, the pressure in the well can act on the rubber cylinder 11 and transmit the cone 10, enhancing the sealing effect and sealing performance of the plugging tool. When unsealing, the pressure in the cavity of the plugging tool is released by pushing the seal 2 to complete the unsealing.

[0041] The second aspect of the present application provides an auxiliary hydraulic sealing tool, which is used to seal the hydraulic sealing wellhead plugging tool described in the above embodiment, referring to Figure 2The sealing tool of the present application includes a cylinder 22, a limiting sleeve 25, an auxiliary connecting rod 26 and a blowout preventer box 27 connected in sequence. Furthermore, a cylinder head 21 is also provided on the top of the cylinder 22, and the cylinder head 21 is connected to the cylinder 22 by threads. A second piston is movably provided in the cylinder 22, and the second piston has an extension end extending outside the cylinder 22, and the extension end is detachably connected to the upper end of the auxiliary connecting rod 26, and the lower end of the auxiliary connecting rod 26 is detachably connected to the upper end of the first tubular structure 1; the limiting sleeve 25 is sleeved on the outside of the second piston and has a limiting portion extending inside the cylinder 22. Further, the limiting sleeve 25 is connected to the cylinder 22 by threads; the upper and lower ends of the cylinder 22 are respectively provided with a hydraulic hole 21-1 and an exhaust hole 22-2 connected to the outside; the blowout preventer box 27 is sleeved on the outside of the auxiliary connecting rod 26, and the bottom end of the blowout preventer box 27 is open and fixed to the wellhead. Preferably, the second piston includes a piston head 23 and a piston rod 24 , wherein the piston head 23 and the piston rod 24 are threadedly connected and installed in the cylinder 22 , the piston rod 24 has an extended end, and the piston rod 24 is threadedly connected to the auxiliary connecting rod 26 .

[0042] One end of the auxiliary connecting rod 26 is limited to the blowout box 27, and the other end extends outside the blowout box 27 to connect with the second piston 24. A first through hole is provided at the center of the auxiliary connecting rod 26, and a second through hole is provided transversely through the bottom of the connecting end of the auxiliary connecting rod 26 and the second piston 24, and the second through hole is orthogonal to and connected with the first through hole. In some preferred embodiments, a pressure relief hole 27-1 communicating with the outside is provided at the bottom of the blowout box 27. Preferably, the second through hole is divided into two through holes by the first through hole, referring to the attached drawings, which are respectively a hydraulic hole 26-1 and a pressure relief hole 26-2.

[0043] The plugging tool is connected to the auxiliary connecting rod 26 by threading, and the blowout preventer box 27 is installed on the wellhead flange by bolts through the bolt holes 27-2 of the blowout preventer box. The auxiliary connecting rod 26 is connected to the piston rod 24 by threading, and the piston rod 24 is connected to the piston head 23 by threading. When it is sent in, hydraulic pressure is injected through the hydraulic hole 22-1 on the cylinder barrel 22 to push the piston head 23 downward along the inner side of the cylinder barrel 22. When it is downward, it is emptied through the exhaust hole 22-2 on the cylinder barrel 22, and the piston rod 24, the auxiliary connecting rod 26 and the plugging tool are driven to descend to the sealing position in turn. When sealing, hydraulic pressure is injected through the hydraulic hole 26-1 on the auxiliary connecting rod 26 to complete the sealing of the plugging tool. After sealing, the pressure can be released through the pressure release hole 26-2 on the auxiliary connecting rod 26 and the pressure release hole 27-1 of the blowout preventer box 27, and the sealing performance of the plugging tool is tested.

[0044] The third aspect of the present application provides an auxiliary hydraulic unsealing tool, which is used to unseal the hydraulic seat wellhead plugging tool of the above embodiment, referring to Figure 3The unsealing tool of the present application comprises a cylinder barrel 32, a limiting sleeve 35, an auxiliary connecting rod 36 and a blowout prevention box 37 connected in sequence. Preferably, the top of the cylinder barrel 32 is sealed. Preferably, a cylinder head 31 is threadedly connected to the top of the cylinder barrel 32, and a third piston is movably arranged in the cylinder barrel 32. The third piston comprises a sliding sealing head 33, a piston cylinder 34 and an unsealing rod 38. The sliding sealing head 33 is threadedly connected to the piston cylinder 34 and installed in the cylinder barrel 32. The sliding sealing head 33 is provided with a through hole communicating with the inside of the piston cylinder 34. The unsealing rod 38 is movably installed in the piston cylinder 34. The bottom end of the auxiliary connecting rod 36 extends outside the cylinder 32 and is detachably connected to the upper end of the auxiliary connecting rod 36. Preferably, the piston cylinder 34 and the auxiliary connecting rod 36 are threadedly connected, and the lower end of the auxiliary connecting rod 36 is detachably connected to the upper end of the first tubular structure 1. A first through hole is provided at the center of the auxiliary connecting rod 36, and a second through hole is transversely provided at the bottom of the auxiliary connecting rod 36 and the third piston connection end, and the second through hole is orthogonal to and connected to the first through hole. The unsealing rod 38 has an extended end extending outside the piston cylinder 34, and the extended end matches the inner diameter of the first through hole. In some preferred embodiments, the bottom end of the unsealing rod 38 is a pointed end. This arrangement enables the unsealing rod to push open the pressure-maintaining device of the plugging tool, release the pressure, and complete the unsealing.

[0045] The limiting sleeve 35 is sleeved on the outside of the third piston and has a limiting portion extending inside the cylinder 32. The limiting sleeve 35 is connected to the cylinder 32 by threads. The upper and lower ends of the cylinder 32 are respectively provided with a hydraulic hole and an exhaust hole connected to the outside. The blowout preventer box 37 is sleeved on the outside of the auxiliary connecting rod 36. The upper end of the blowout preventer box 37 is used to limit the auxiliary connecting rod 36. The bottom end of the blowout preventer box 37 is open and fixed to the wellhead. Preferably, the bottom end of the blowout preventer box 37 is provided with a pressure relief hole 37-1 connected to the outside.

[0046] Specifically, when the auxiliary hydraulic unsealing tool of the present application is unsealed, hydraulic pressure is injected through the hydraulic hole 32-1 on the cylinder barrel 32. Since the sliding sealing head is provided with a through hole, hydraulic pressure can enter the piston cylinder to push the unsealing rod 38 downward along the piston cylinder 34, so that the bottom of the unsealing rod 38 pushes open the pressure maintaining device of the sealing tool to release the pressure and complete the unsealing. When the tool is started, even if the unsealing rod moves upward, hydraulic pressure can be injected through the drain hole 32-2 on the cylinder barrel 32 to push the sliding sealing head 33 upward along the cylinder barrel 32, and in turn drive the piston cylinder 34 and the auxiliary connecting rod 36 upward to complete the unsealing action. After the tool reaches the blowout preventer box 37, the wellhead valve is closed, and the pressure is released through the pressure relief hole 36-2 on the auxiliary connecting rod 36 and the pressure relief hole 37-1 of the blowout preventer box 37 to ensure construction safety.

[0047] The present application is based on the inventive concept of hydraulic action, and designs a hydraulic wellhead sealing tool, an auxiliary hydraulic sealing tool, and an auxiliary hydraulic unsealing tool. It is understandable that the blowout preventer box and the auxiliary connecting rod in the auxiliary hydraulic sealing tool and the auxiliary hydraulic unsealing tool of the present application can be used interchangeably. Specifically, after the auxiliary hydraulic sealing tool drives the hydraulic wellhead sealing tool to complete the sealing, the auxiliary connecting rod and the piston rod are disassembled, and then the bottom end of the piston cylinder of the auxiliary hydraulic unsealing tool is connected to the top end of the auxiliary connecting rod, so that the auxiliary hydraulic sealing tool can be replaced with the auxiliary hydraulic unsealing tool.

[0048] The technical solutions in the above embodiments of the present application have at least the following technical effects and advantages:

[0049] The present invention is lowered into the well by the thrust of the hydraulic piston rod and seals the well by the hydraulic action. The hydraulic pressure is continuously maintained in the cavity of the sealing tool to ensure the sealing state. After the sealing is completed, the well pressure can also produce an auxiliary sealing effect. After the operation is completed, the pressure-maintaining device is opened by the hydraulic pushing of the sealing rod to relieve the pressure and seal, thereby ensuring that the wellhead sealing tool can achieve the purpose of sealing tightly, holding the well and being taken out, so that the entire construction process is controllable and the construction is safe and reliable.

[0050] It should be noted that in the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0051] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] The term "comprise" or any other similar term is intended to cover a non-exclusive inclusion, such that a process, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, article, or apparatus / device.

[0053] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. An auxiliary hydraulic unsealing tool, characterized in that: The unsealing tool is used to unseal the hydraulic seat wellhead plugging tool; The hydraulic seat wellhead plugging tool comprises a first tubular structure, a second tubular structure and a third tubular structure coaxially arranged in sequence from top to bottom; the inner diameter of the bottom end of the first tubular structure matches the outer diameter of the top end of the second tubular structure, the outer diameter of the bottom end of the second tubular structure matches the inner diameter of the third tubular structure, a hydraulic control element is fixedly arranged on the top end of the second tubular structure, the hydraulic control element is limited to the shoulder of the first tubular structure, and the hydraulic control element only allows the fluid to pass unidirectionally from top to bottom; a first piston is slidably arranged inside the third tubular structure, and the first piston divides the inner cavity of the third tubular structure into an upper piston and a lower piston. The plug cavity and the lower piston cavity, the center of the first piston is provided with a guide hole, the upper end of the guide hole is connected with the central hole of the second tubular structure, and the lower end is connected with the lower piston cavity, the second tubular structure is provided with an exhaust hole, one end of the exhaust hole is connected with the outside, and the other end is connected with the inner cavity of the third tubular structure; the outer sleeve of the third tubular structure is provided with a seat seal assembly and a seat seal assembly seat, the seat seal assembly seat is arranged at the bottom of the seat seal assembly and connected to the first piston, and when the first piston moves upward, it can drive the seat seal assembly seat to squeeze and compress the seat seal assembly, so that the seat seal assembly expands radially to complete the seat seal; The unsealing tool comprises a cylinder, a limiting sleeve, an auxiliary connecting rod and a blowout prevention box connected in sequence, and a third piston is movably arranged in the cylinder; The third piston includes a sliding sealing head, a piston cylinder and an unsealing rod, the sliding sealing head is provided with a through hole connected to the interior of the piston cylinder, the unsealing rod is movably installed in the interior of the piston cylinder, the bottom end of the piston cylinder extends outside the cylinder barrel and is detachably connected to the upper end of the auxiliary connecting rod, and the lower end of the auxiliary connecting rod is detachably connected to the upper end of the first tubular structure; a first through hole is provided at the center of the auxiliary connecting rod, and a second through hole is transversely penetrated at the bottom of the auxiliary connecting rod and the third piston connection end, and the second through hole is orthogonal to and connected to the first through hole; the unsealing rod has an extending end extending outside the piston cylinder, and the extending end matches the inner diameter of the first through hole; The limiting sleeve is sleeved on the outside of the third piston and has a limiting portion extending inside the cylinder; the upper end and the lower end of the cylinder are respectively provided with a hydraulic hole and an exhaust hole connected to the outside; the blowout preventer box is sleeved on the outside of the auxiliary connecting rod, the upper end of the blowout preventer box is used to limit the auxiliary connecting rod, and the bottom end of the blowout preventer box is open and fixed to the wellhead.

2. The auxiliary hydraulic unsealing tool according to claim 1, characterized in that: The third tubular structure includes a sealing section and a seat sealing section, the sealing section is fixedly arranged on the top of the seat sealing section, and the outer diameter of the sealing section is larger than that of the seat sealing section, and the seat sealing assembly is sleeved on the outside of the seat sealing section; the seat sealing assembly includes a slip, a cone, and a rubber cylinder arranged in sequence from top to bottom, and the outer diameter of the upper end of the cone matches the inner diameter of the slip.

3. The auxiliary hydraulic unsealing tool according to claim 1, characterized in that: The first tubular structure includes a first structural part, a second structural part and a third structural part which are connected in sequence. A thread is arranged on the outer surface of the first structural part. The inner diameter of the first structural part is larger than the inner diameter of the second structural part and smaller than the inner diameter of the third structural part. The second structural part has a sealing cone surface, and the upper end of the sealing cone surface is smaller than the lower end.

4. The auxiliary hydraulic unsealing tool according to claim 3, characterized in that: The hydraulic control element includes an elastic element, a sealing element and an elastic element mounting seat. The elastic element is fixed to the top of the second tubular structure through the elastic element mounting seat and is sleeved on the outside of the sealing element. The top of the sealing element is tightly matched with the sealing cone surface. Under the action of an external force from top to bottom, the sealing element can move vertically downward to compress the elastic element and move away from the sealing cone surface to form a hydraulic channel. After pressure relief, the sealing element moves vertically upward under the action of the elastic element and is tightly matched with the sealing cone surface to close the hydraulic pressure in the cavity.

5. The auxiliary hydraulic unsealing tool according to claim 1, characterized in that: The bottom end of the unsealing rod is a pointed end.

6. The auxiliary hydraulic unsealing tool according to claim 5, characterized in that: The bottom end of the blowout prevention box is provided with a pressure relief hole communicated with the outside.

Images