Tubing head capable of being replaced under pressure

Abstract

A tubing head capable of being replaced under pressure relates to the technical field of oil extraction well mouths. A plurality of bearing blocks are arranged on the lower end face of the ring groove of the four-way joint, the bearing blocks are circumferentially and uniformly arranged, a rubber capsule adheres to the four-way joint in the ring groove, a step ring formed by a step shaft is machined on the lower side of the outer circle of the tubing hanger, and the upper end faces of the bearing blocks are located on the lower side of the step ring. The oil pipe hanger has the advantages that the upper portion of the oil pipe hanger is in threaded sealing connection with the screwed plug, compressed air is introduced into the rubber capsule, the rubber capsule expands, the rubber capsule pushes the bearing block to block the lower side of the step ring, the rubber capsule seals the annular space of the oil pipe hanger and the four-way joint, and the functions of temporarily supporting the oil pipe hanger and sealing are achieved; at the moment, the bearing pin and the positioning pin are detached, the reducing sleeve and the sealing seat can be detached for replacement, well stopping is not needed, the sealing seat can be replaced under pressure without well stopping, operation time is short, and productivity can be improved.

Description

Technical Field

[0001] This utility model relates to the field of oil wellhead technology, and in particular to an oil tubing head that can be replaced under pressure. Background Technology

[0002] In existing fracturing wellhead equipment, the tubing head four-way junctions are generally vertically intersecting. The fracturing fluid flowback fluid (containing sand particles) enters from the annulus of the tubing and casing and exits through the horizontal interfaces on both sides of the tubing four-way junction. After the fracturing flowback fluid flows in and out of the central main duct, the fluid will cause high-speed scouring of the sealing seat at the bottom of the tubing hanger, leading to seal failure. At this time, the sealing seat needs to be replaced. When replacing the sealing seat, the tubing and casing need to be depressurized, resulting in a long well shutdown time and a large amount of manpower and resources. Utility Model Content

[0003] To address the current problem of needing to shut down the well when replacing the tubing head seal, this invention provides a tubing head that can be replaced under pressure.

[0004] The technical solution provided by this utility model is: a replaceable oil pipe head under pressure, including a four-way connector, an oil pipe hanger installed inside the four-way connector, an adapter sleeve fitted on the outside of the oil pipe hanger, the adapter sleeve and the oil pipe hanger being axially positioned and connected by a load-bearing pin, a positioning pin being radially threaded to the upper part of the four-way connector, the positioning pin axially limiting the adapter sleeve, a sealing seat fitted on the lower side of the adapter sleeve of the oil pipe hanger, the sealing seat being connected to the oil pipe hanger through a sealing ring clearance fit, a conical hole being machined in the inner hole of the four-way connector, the sealing seat sitting on the conical hole, and the sealing seat and the four-way connector being hard sealed by the conical annular surface;

[0005] The inner hole of the four-way has an annular groove on the lower side of the conical hole. Several load-bearing blocks are arranged on the lower end face of the annular groove of the four-way. The load-bearing blocks are evenly arranged around the circumference. A rubber capsule is bonded to the four-way in the annular groove. The rubber capsule is bonded to the load-bearing blocks. A stepped ring formed by a stepped shaft is machined on the lower side of the outer circle of the oil pipe hanger. The upper end face of the load-bearing block is located on the lower side of the stepped ring.

[0006] The four-way valve has a through hole at the annular groove position, and the outer side of the rubber capsule is vulcanized and fixed to the air pipe. The air pipe extends out to the outside of the four-way valve through the through hole, and the outer end of the air pipe is threaded.

[0007] When the rubber bladder expands, it pushes the load-bearing block to block the underside of the step ring, and the rubber bladder seals the annulus of the tubing hanger and the four-way valve.

[0008] The beneficial effects of this utility model are as follows: When it is necessary to replace the sealing seat, the upper threaded sealing connection plug of the tubing hanger is used to introduce compressed air into the rubber bladder. The rubber bladder expands and pushes the load-bearing block to block the lower side of the step ring. The rubber bladder seals the annular space of the tubing hanger and the four-way connector, providing temporary support and sealing for the tubing hanger. At this time, the load-bearing pin and the positioning pin can be removed, and the adapter sleeve and the sealing seat can be removed and replaced without stopping the well. The sealing seat can be replaced under pressure without stopping the well, which shortens the operation time and helps to improve production capacity. Attached Figure Description

[0009] Appendix Figure 1 This is a schematic diagram of the structure of this utility model;

[0010] Appendix Figure 2 It is attached Figure 1 Enlarged view of point B;

[0011] Appendix Figure 3 It is attached Figure 1 AA cross-section view;

[0012] Appendix Figure 4 This is a working drawing of this utility model;

[0013] Appendix Figure 5 This is a schematic diagram of the four-way structure in this utility model.

[0014] In the diagram, 1-four-way connector, 101-conical hole, 102-annular groove, 103-through hole, 2-oil pipe hanger, 201-step ring, 3-sealing seat, 4-adapter sleeve, 5-positioning pin, 6-load-bearing pin, 7-load-bearing block, 8-rubber capsule, 9-air pipe, 10-plug. Detailed Implementation

[0015] like Figures 1-5 As shown, a replaceable oil pipe head under pressure includes a four-way connector 1, an oil pipe hanger 2 installed inside the four-way connector 1, an adapter sleeve 4 sleeved on the outside of the oil pipe hanger 2, the adapter sleeve 4 and the oil pipe hanger 2 are axially positioned and connected by a load-bearing pin 6, a positioning pin 5 is radially threaded to the upper part of the four-way connector 1, the positioning pin 5 axially limits the adapter sleeve 4, a sealing seat 3 is sleeved on the lower side of the adapter sleeve 4 of the oil pipe hanger 2, the sealing seat 3 is connected to the oil pipe hanger 2 through a sealing ring clearance fit, a conical hole 101 is machined in the inner hole of the four-way connector 1, the sealing seat 3 sits on the conical hole 101, and the sealing seat 3 and the four-way connector 1 are hard sealed by the conical annular surface;

[0016] The inner hole of the four-way 1 has an annular groove 102 on the lower side of the conical hole 101. Several load-bearing blocks 7 are arranged on the lower end face of the annular groove 102 of the four-way 1. The load-bearing blocks 7 are evenly arranged around the circumference. A rubber capsule 8 is bonded to the four-way 1 in the annular groove 102. The rubber capsule 8 is bonded to the load-bearing blocks 7 together. A stepped ring 201 formed by a stepped shaft is machined on the lower side of the outer circle of the oil pipe hanger 2. The upper end face of the load-bearing block 7 is located on the lower side of the stepped ring 201.

[0017] The four-way connector 1 has a through hole 103 at the position of the annular groove 102, which is open to both the inside and outside. The rubber capsule 8 is vulcanized and fixed to the air pipe 9. The air pipe 9 extends to the outside of the four-way connector 1 through the through hole 103. The outer end of the air pipe 9 is threaded for connecting to the air source.

[0018] When the rubber capsule 8 expands, it pushes the load-bearing block 7 to block the underside of the step ring 201, and the rubber capsule 8 seals the annular space between the oil pipe hanger 2 and the four-way 1.

[0019] When the sealing seat 3 needs to be replaced, the threaded sealing plug 10 on the upper part of the tubing hanger 2 introduces compressed air into the rubber capsule 8. The rubber capsule 8 expands and pushes the load-bearing block 7 to block the lower side of the step ring 201. The rubber capsule 8 seals the annular space between the tubing hanger 2 and the four-way connector 1, providing temporary support for the tubing hanger 2 and a sealing function. At this time, the load-bearing pin 6 and the positioning pin 5 can be removed, and the adapter sleeve 4 and the sealing seat 3 can be removed and replaced without stopping the well. The replacement of the sealing seat 3 under pressure does not require stopping the well, and the operation time is short, which is conducive to improving production capacity.

Claims

1. A pressure-containing replaceable tubing head comprising a four-way (1), characterised in that: The cross (1) is provided with a tubing hanger (2) inside, and the tubing hanger (2) is sleeved with an adapter sleeve (4) outside, the adapter sleeve (4) and the tubing hanger (2) are connected by a bearing pin (6) in axial direction, the cross (1) is provided with a positioning pin (5) in radial direction on the upper part, the positioning pin (5) limits the axial position of the adapter sleeve (4), the tubing hanger (2) is sleeved with a sealing seat (3) below the adapter sleeve (4), the sealing seat (3) is connected with the tubing hanger (2) by gap fit of a sealing ring, the inner hole of the cross (1) is processed with a conical hole (101), the sealing seat (3) is seated on the conical hole (101), and the sealing seat (3) is hard sealed with the cross (1) through a conical ring surface; The inner hole of the cross (1) is provided with a ring groove (102) below the conical hole (101), the cross (1) is provided with a plurality of bearing blocks (7) on the lower end surface of the ring groove (102), the bearing blocks (7) are arranged uniformly in the circumferential direction, the cross (1) is bonded with a rubber capsule (8) in the ring groove (102), the rubber capsule (8) is bonded with the bearing blocks (7), and the tubing hanger (2) is processed with a stepped ring (201) formed by a stepped shaft on the lower side of the outer circle, and the upper end surface of the bearing block (7) is located below the stepped ring (201). The cross (1) is provided with a through hole (103) penetrating through the inside and outside at the position of the ring groove (102), the rubber capsule (8) is fixedly connected with an air pipe (9) outside through vulcanization, the air pipe (9) extends to the outside of the cross (1) through the through hole (103), and the air pipe (9) is processed with threads on the outside port.

2. A pressure-containing replaceable tubing head according to claim 1, characterized in that: When the rubber capsule (8) expands, the rubber capsule (8) pushes the bearing blocks (7) to block below the stepped ring (201), and the rubber capsule (8) seals the annular space of the tubing hanger (2) and the cross (1).

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