A detachable high-sealing double-wall drill pipe

Abstract

The present invention provides a detachable high-seal double-wall drill pipe, wherein an outer drill pipe upper joint and a lower joint are welded on the pipe body, and an inner connecting pipe is installed in the pipe body; an intermediate connecting pipe is threadedly connected with an inner pipe lower joint and an upper joint; a sealing sleeve is installed on the inner pipe upper joint, a combined sealing ring is installed between the sealing sleeves, and a sealing ring is installed on the inner diameter of the sealing sleeve; the sealing sleeve is connected to the shoulder through an elastic retaining ring B, the shoulder is installed in the shoulder hole on the inner wall of the outer drill pipe upper joint, the outer circle of the shoulder is connected to the outer drill pipe upper joint through the sealing ring B, and channels are evenly arranged on the shoulder axial direction; the present invention has the advantages that the structural stability and service life are improved and the risk of the sealing ring breaking and falling is reduced through the detachable sealing sleeve and the combined sealing ring, and the annulus between the inner connecting pipe and the outer drill pipe can withstand a high sealing pressure of more than 35MPa; the sealing sleeve is easy to disassemble and disassemble, and the easily damaged sealing sleeve and sealing ring can be replaced, thereby improving the service life of the entire double-wall drill pipe.

Description

Technical Field

[0001] The invention relates to the field of oil and gas exploration and development, and in particular to a detachable high-sealing double-wall drill pipe. Background Art

[0002] In oil, gas, geological and geothermal drilling operations, leaky formations are often encountered, which will cause drilling fluid leakage, resulting in huge economic losses and great difficulties in drilling operations. When the outer layer of the double-wall drill pipe is disconnected, the plug-in seal of the inner pipe is also separated. The conventionally used ordinary O-ring is easy to break and fall into the inner hole of the drill pipe, causing the blockage of the drilling fluid circulation channel or the blockage of the drill bit water hole. Summary of the invention

[0003] The purpose of the present invention is to provide a detachable high-sealing double-wall drill pipe to solve the deficiencies of the prior art.

[0004] The new technical solution of the present invention is: a detachable high-seal double-wall drill pipe, including an outer drill pipe and an inner connecting pipe, the outer drill pipe includes an outer drill pipe upper joint, a pipe body and an outer drill pipe lower joint, one end of the pipe body is welded with an outer drill pipe upper joint, the other end of the pipe body is welded with an outer drill pipe lower joint, and an inner connecting pipe is installed in the pipe body; the inner connecting pipe includes an inner tube upper joint, an inner tube lower joint, an intermediate connecting pipe, a shoulder, a sealing ring, an elastic retaining ring, a combined sealing ring and a sealing sleeve, one end of the intermediate connecting pipe is threadedly connected to the inner tube lower joint, and the other end of the intermediate connecting pipe is threadedly connected to one end of the inner tube upper joint; the other end of the inner tube upper joint A sealing sleeve A, a sealing sleeve B and a sealing sleeve C are installed. An elastic retaining ring groove is provided on the inner tube upper joint at one end of the sealing sleeve A, and an elastic retaining ring A is installed in the elastic retaining ring groove. The other end of the sealing sleeve A is connected with the sealing sleeve B through a combined sealing ring. The sealing sleeve B is connected with one end of the sealing sleeve C through a combined sealing ring, and a disassembly groove is provided on the sealing sleeve C. The inner diameters of the sealing sleeves C and B are installed with sealing ring A; the other end of the sealing sleeve C is connected with the shoulder through an elastic retaining ring B, and the shoulder is installed in the shoulder hole on the inner wall of the upper joint of the outer drill pipe. The outer circle of the shoulder is connected with the upper joint of the outer drill pipe through the sealing ring B, and the shoulder is evenly provided with channels in the axial direction.

[0005] The elastic circlip A is an elastic circlip for a shaft.

[0006] The elastic retaining ring B is an elastic retaining ring for a hole.

[0007] The sealing ring A is O-type.

[0008] There are two sealing rings A.

[0009] The sealing ring B is O-type.

[0010] There are two sealing rings B.

[0011] The sealing sleeve A, sealing sleeve B and sealing sleeve C are detachable.

[0012] There are 4 channels.

[0013] There are two combined sealing rings.

[0014] The beneficial effects of the present invention are as follows: the present invention improves the structural stability and service life through the detachable sealing sleeve and the combined sealing ring, reduces the risk of the sealing ring breaking and falling, and the annulus between the inner connecting pipe and the outer drill pipe can withstand a high sealing pressure of more than 35MPa; the sealing sleeve is easy to disassemble and disassemble, and the easily damaged sealing sleeve and sealing ring can be replaced, thereby improving the service life of the entire double-wall drill pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the present invention.

[0016] Figure 2 It is a schematic diagram of the structure of the joint on the inner tube.

[0017] Figure 3 for Figure 2 Schematic diagram of AA.

[0018] Among them: 1 is the upper joint of the outer drill pipe, 2 is the pipe body, 3 is the lower joint of the outer drill pipe, 4 is the lower joint of the inner tube, 5 is the intermediate connecting pipe, 6 is the upper joint of the inner tube, 7 is the shoulder, 701 is the channel, 8 is the sealing ring B, 9 is the elastic retaining ring B, 10 is the sealing sleeve A, 11 is the sealing sleeve B, 12 is the sealing sleeve C, 13 is the sealing ring A, 14 is the combined sealing ring, 15 is the elastic retaining ring A, and 16 is the disassembly groove. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings.

[0020] A detachable high-seal double-wall drill pipe, comprising an outer drill pipe and an inner connecting pipe, wherein the outer drill pipe comprises an outer drill pipe upper joint 1, a pipe body 2 and an outer drill pipe lower joint 3, one end of the pipe body 2 is welded with the outer drill pipe upper joint 1, the other end of the pipe body 2 is welded with the outer drill pipe lower joint 3, and the inner connecting pipe is installed in the pipe body 2; the inner connecting pipe comprises an inner tube upper joint 6, an inner tube lower joint 4, an intermediate connecting pipe 5, a shoulder 7, a sealing ring, an elastic retaining ring, a combined sealing ring 14 and a sealing sleeve, one end of the intermediate connecting pipe 5 is threadedly connected to the inner tube lower joint 4, and the other end of the intermediate connecting pipe 5 is threadedly connected to one end of the inner tube upper joint 6; the other end of the inner tube upper joint 6 is installed with a sealing sleeve A10, a sealing sleeve B11 and a sealing sleeve Sleeve C12, an elastic retaining ring groove is provided on the inner tube upper joint 6 at one end of the sealing sleeve A10, and an elastic retaining ring A15 is installed in the elastic retaining ring groove, the other end of the sealing sleeve A10 is connected with the sealing sleeve B11 through a combined sealing ring 14, the sealing sleeve B11 is connected with one end of the sealing sleeve C12 through the combined sealing ring 14, and a disassembly groove 16 is provided on the sealing sleeve C12, and a sealing ring A13 is installed on the inner diameter of the sealing sleeve C12 and the sealing sleeve B11; the other end of the sealing sleeve C12 is connected with the shoulder 7 through an elastic retaining ring B9, the shoulder 7 is installed in the shoulder hole on the inner wall of the outer drill pipe upper joint 1, the outer circle of the shoulder 7 is connected with the outer drill pipe upper joint 1 through a sealing ring B8, and the shoulder 7 is evenly provided with a channel 701 in the axial direction.

[0021] The elastic retaining ring A15 is an elastic retaining ring for shaft.

[0022] The elastic retaining ring B9 is an elastic retaining ring for a hole.

[0023] The sealing ring A13 is O-type.

[0024] There are two sealing rings A13.

[0025] The sealing ring B8 is O-type.

[0026] There are two sealing rings B8.

[0027] The sealing sleeve A10, the sealing sleeve B11 and the sealing sleeve C12 are detachable.

[0028] There are four channels 701.

[0029] There are two combined sealing rings 14.

[0030] A detachable high-seal double-wall drill pipe is composed of an outer drill pipe and an inner connecting pipe, wherein the inner connecting pipe is assembled by threading an intermediate connecting pipe 5, an inner pipe upper joint 6, and an inner pipe lower joint 4, and a detachable sealing sleeve is assembled on the inner pipe upper joint 6. The outer surface of the detachable sealing sleeve is processed with two sealing grooves and one disassembly groove 16, and a combined sealing ring 14 is installed in the two sealing grooves; an O-type sealing ring A13 is installed on the contact surface between the detachable sealing sleeve and the inner pipe upper joint 6.

[0031] The outer drill pipe upper joint 1 and the outer drill pipe lower joint 3 use double-shoulder special threaded joints with large inner holes, and the inner diameter is 20% larger than the inner diameter of the traditional drill pipe joint; the inner surface of the outer drill pipe upper joint 1 is processed with a shoulder hole of a certain axial depth, and the inner tube upper joint 6 is hung in the shoulder hole on the inner surface of the outer drill pipe upper joint 1 through the shoulder 7. The inner tube upper joint 6 and the outer drill pipe upper joint 1 are axially fixed through the elastic retaining ring B9, and the shoulder 7 is axially processed with a channel 701. One end of the inner tube upper joint 6 is processed with a shaft elastic retaining ring groove, and the axial fixation of the sealing sleeve and the inner tube upper joint 6 is achieved by installing the shaft elastic retaining ring A15 in the groove. The end of the inner tube lower joint 4 has a centering structure design, and sufficient drilling fluid flow channels are reserved.

[0032] The annular gap between the inner connecting pipe and the outer drill pipe is the first transmission channel for drilling fluid (or gas); the inner hole of the inner connecting pipe is the second transmission channel for drilling fluid. Each double-wall drill pipe is connected by the thread of the outer drill pipe to form a drill pipe column to transmit torque, drilling pressure and withstand the pressure of drilling fluid. The inner connecting pipes are mostly connected by plug-in, and a high-pressure sealing structure is processed at the plug-in part to withstand the pressure of drilling fluid and gas.

Claims

1. A detachable high-seal double-wall drill pipe, comprising an outer drill pipe and an inner connecting pipe, wherein the outer drill pipe comprises an outer drill pipe upper joint (1), a pipe body (2) and an outer drill pipe lower joint (3), characterized in that: An outer drill pipe upper joint (1) is welded to one end of the pipe body (2), and an outer drill pipe lower joint (3) is welded to the other end of the pipe body (2). An inner connecting pipe is installed in the pipe body (2); the inner connecting pipe comprises an inner pipe upper joint (6), an inner pipe lower joint (4), an intermediate connecting pipe (5), a shoulder (7), a sealing ring, an elastic retaining ring, a combined sealing ring (14) and a sealing sleeve; one end of the intermediate connecting pipe (5) is threadedly connected to the inner pipe lower joint (4), and the end of the inner pipe lower joint (4) has a centering structure; the other end of the intermediate connecting pipe (5) is threadedly connected to one end of the inner pipe upper joint (6); the other end of the inner pipe upper joint (6) is installed with a sealing sleeve A (10), a sealing sleeve B (11) and a sealing sleeve C (12); an elastic retaining ring groove is provided on the inner pipe upper joint (6) at one end of the sealing sleeve A (10), and the elastic retaining ring groove has a sealing ring. An elastic retaining ring A (15) is installed. The other end of the sealing sleeve A (10) is connected to the sealing sleeve B (11) through a combined sealing ring (14). The sealing sleeve B (11) is connected to one end of the sealing sleeve C (12) through the combined sealing ring (14). The sealing sleeve C (12) is provided with a disassembly groove (16). The inner diameters of the sealing sleeves C (12) and B (11) are provided with sealing rings A (13). The other end of the sealing sleeve C (12) is connected to the shoulder (7) through an elastic retaining ring B (9). The shoulder (7) is installed in the shoulder hole on the inner wall of the outer drill pipe upper joint (1). The outer circle of the shoulder (7) is connected to the outer drill pipe upper joint (1) through a sealing ring B (8). The shoulder (7) is evenly provided with channels (701) in the axial direction. The sealing sleeves A (10), B (11) and C (12) are detachable.

2. The detachable high-seal double-wall drill pipe according to claim 1, characterized in that: The elastic retaining ring A (15) is an elastic retaining ring for a shaft.

3. The detachable high-seal double-wall drill pipe according to claim 1, characterized in that: The elastic retaining ring B (9) is an elastic retaining ring for a hole.

4. The detachable high-seal double-wall drill pipe according to claim 1, characterized in that: The sealing ring A (13) is O-type.

5. A detachable high-seal double-wall drill pipe according to claim 1 or 4, characterized in that: There are two sealing rings A (13).

6. The detachable high-seal double-wall drill pipe according to claim 1, characterized in that: The sealing ring B (8) is O-type.

7. A detachable high-seal double-wall drill pipe according to claim 1 or 6, characterized in that: There are two sealing rings B (8).

8. The detachable high-seal double-wall drill pipe according to claim 1, characterized in that: There are four channels (701).

9. The detachable high-seal double-wall drill pipe according to claim 1, characterized in that: There are two combined sealing rings (14).

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