An anti-circulation drilling top-injection side-discharge device

Abstract

The present invention discloses a reverse circulation drilling top-injection side-discharge device, which includes a main shaft, a bearing assembly and a flow splitting device; the upper and lower parts of the main shaft are respectively connected to a swivel and a dual-wall drill pipe; the bearing assembly is installed on the main shaft step; the flow splitting device is fixedly suspended below the bearing assembly; the drilling medium passing through the swivel enters the injection channel of the dual-wall drill pipe through the main channel A; the returned drilling medium sequentially enters the downstream sand discharge pipeline through the return channel of the dual-wall drill pipe, the main channel B, the lateral channel, the main chamber of the flow splitting device and the inner hole of the short sand discharge pipe joint. The bearing assembly and the flow splitting device adopt a split design. The drilling medium leaked after the seal in the flow splitting device is damaged will not contaminate the bearing group, and the bearing group does not need to be disassembled for replacing the seal of the flow splitting device, reducing the difficulty of seal replacement; the sealing ring of the flow splitting device adopts a composite structure of an internal lip-type rotary seal and an external packing seal, increasing the convenience of seal maintenance and the service life of the flow splitting device part.

Description

Technical Field

[0001] The present invention relates to a drilling tool, and more particularly to a reverse circulation drilling top injection side discharge device. Background Art

[0002] When drilling, the method of circulating the medium to carry cuttings or cores from the bottom of the well and returning them to the surface through the center of the drill pipe is called reverse circulation center sampling drilling. Usually, single-layer, double-layer or triple-layer drill pipes are used, but double-wall drill pipes are the most common. The circulating medium is pressed into the annulus between the two pipes and carries cuttings (cores) back to the surface from the center of the inner pipe. Therefore, this method is called double-pipe reverse circulation or double-wall drill pipe reverse circulation drilling. With the continuous innovation of reverse circulation drilling theory and drilling technology, the application of reverse circulation drilling technology in the fields of mineral exploration, water well drilling and oil drilling is becoming more and more extensive. During the double-wall drill pipe reverse circulation drilling process, an adapter needs to be connected between the swivel and the kelly. The main function of this adapter is to ensure the injection and return of the drilling medium. The common structure of this adapter is the side injection top discharge structure. This structure is not safe in oil drilling because if the fluid returned from the well is top discharged, it means that the returned fluid enters the hose and is discharged after passing through the swivel. The long-term erosion of the hose reduces the pressure-bearing capacity, which may cause the swivel to fail when injecting high-pressure fluid to solve complex working conditions; moreover, the conventional adapter rotates the bearing and the seal together. Seal leakage will cause bearing contamination, and replacing the seal requires disassembling the bearing, which is inconvenient for equipment maintenance. Summary of the Invention

[0003] The purpose of the present invention is to provide a reverse circulation drilling top injection side discharge device aiming at the problems existing in the prior art, realizing the connection between the swivel and the double-wall drill tool, realizing the injection and return of the drilling medium, protecting the hose, avoiding the contamination of the bearing group, and increasing the service life of the seal and the convenience of maintenance.

[0004] To achieve the above purpose, the present invention adopts the following design scheme:

[0005] A reverse circulation drilling top injection side discharge device includes a main shaft, a bearing assembly and a flow splitting device; wherein:

[0006] Joints for connecting the swivel and the double-wall drill tool are respectively provided at the upper and lower parts of the main shaft. The main shaft is a short shaft section, and a main channel A and a main channel B are axially machined inside. A lateral channel is radially machined. The main channel A is a through hole, and the main channel B is a blind hole axially machined from bottom to top inside the main shaft. There is a gap flow channel between the outside of the main channel B and the main channel A. This gap flow channel communicates with the injection channel of the double-wall drill tool. The inside of the main channel B communicates with the return channel and the lateral channel of the double-wall drill tool; a raised step is machined on the outer edge of the main shaft, and the step is located above the lateral channel;

[0007] The bearing assembly is installed on the spindle step and forms an axially limited rotational fit through the spindle step;

[0008] The flow splitting device is fixedly suspended below the bearing assembly and is in a rotationally sealed fit relative to the spindle; the flow splitting device includes a main chamber and a sand discharge pipe short section, and the inner holes of the main chamber and the sand discharge pipe short section, the main channel B, and the lateral channel are connected.

[0009] The above solution further includes:

[0010] The bearing assembly includes an outer cylinder, an upper end cover, a lower end cover, and a bearing set; the bearing set is installed between the outer cylinder and the spindle and rotates relative to each other; the upper end cover and the lower end cover are respectively installed on the upper and lower ends of the outer cylinder.

[0011] An upper end cover seal and a lower end cover seal are respectively installed between the upper end cover and the lower end cover and the spindle.

[0012] The bearing set is a set of angular contact ball bearings, and the set of angular contact ball bearings are installed face to face on the upper and lower end faces of the spindle step.

[0013] The described flow splitting device includes an upper cover plate, a lower cover plate, an intermediate cylinder, and a connecting cylinder; the upper cover plate and the lower cover plate are annular circular plates, and the intermediate cylinder is a cylindrical structure; the upper cover plate is located above the lateral channel of the spindle; the lower cover plate is located below the lateral channel of the spindle; the intermediate cylinder is installed between the upper cover plate and the lower cover plate; a main chamber is formed between the upper cover plate, the lower cover plate, the intermediate cylinder, and the spindle; the upper cover plate is fixedly connected to the connecting cylinder, and the connecting cylinder is fixedly connected to the bearing assembly.

[0014] An upper cover plate sealing ring is installed between the inner hole of the upper cover plate and the spindle, and a lower cover plate sealing ring is installed between the inner hole of the lower cover plate and the spindle.

[0015] The sand discharge pipe short section is installed on the intermediate cylinder, and the inner hole of the sand discharge pipe short section is tangent to the inner hole of the intermediate cylinder.

[0016] Both the upper cover plate sealing ring and the lower cover plate sealing ring are composed of two forms of sealing rings, namely, a lip-shaped rotary seal close to the main chamber and a packing seal on the outside.

[0017] The advantages of the present invention are: (1) The bearing assembly and the flow splitting device adopt a split design. The drilling medium leaked after the seal in the flow splitting device is damaged will not contaminate the bearing set, and the replacement of the seal in the flow splitting device does not require the disassembly of the bearing set, reducing the difficulty of seal replacement; (2) The sealing ring of the flow splitting device adopts a composite structure of an internal lip-shaped rotary seal and an external packing seal, increasing the convenience of seal maintenance and the service life of the flow splitting device part. Brief Description of the Drawings

[0018] Figure 1 It is a schematic diagram of the external structure of an anti-circulation drilling top injection side discharge device of the present invention.

[0019] Figure 2 Yes Figure 1 Schematic diagram along the A-A section.

[0020] Figure 3 Yes Figure 2 Schematic diagram of the B-B section.

[0021] In the figure: 10. Main shaft, 11. Main channel A, 12. Lateral channel, 13. Main channel B, 20. Bearing assembly, 21. Upper end cover seal, 22. Upper end cover, 23. Bearing set, 24. Outer cylinder, 25. Lower end cover, 26. Lower end cover seal, 30. Diverting device, 31. Upper cover sealing ring, 32. Upper cover, 33. Intermediate cylinder, 34. Lower cover, 35. Lower cover sealing ring, 36. Sand discharge pipe short section, 37. Main chamber, 38. Connecting cylinder, 39. Inner hole of the sand discharge pipe short section, 40. Double-wall drill tool, 41. Inner pipe, 42. Outer pipe, 43. Return channel, 44. Injection channel. Detailed implementation mode

[0022] The following combines the attached Figure 1 、attached Figure 2 and attached Figure 3 to further describe the present invention:

[0023] Embodiment 1, a reverse circulation drilling top injection and side discharge device, includes a main shaft 10, a bearing assembly 20 and a diverting device 30; wherein:

[0024] The upper and lower parts of the main shaft 10 are respectively provided with joints for connecting the water faucet and the double-wall drill tool 40. The main shaft 10 is an axial short section, and the main channel A 11 and the main channel B 13 are axially machined inside, and the lateral channel 12 is radially machined; the main channel A 11 is a through hole, the main channel B 13 is a blind hole axially machined from bottom to top inside the main shaft 10, and there is a clearance flow channel between the outside of the main channel B 13 and the main channel A 11, and this clearance flow channel is communicated with the injection channel 44 of the double-wall drill tool. The inside of the main channel B 13 is communicated with the return channel 43 of the double-wall drill tool and the lateral channel 12; a raised step is machined on the outer edge of the main shaft 10, and the step is located above the lateral channel 12;

[0025] The bearing assembly 20 is installed on the step of the main shaft 10 and forms an axially limited rotary fit through the step of the main shaft 10;

[0026] The diverting device 30 is fixedly suspended below the bearing assembly 20 and is rotationally sealed and fitted relative to the main shaft; the diverting device 30 includes a main chamber 37 and a sand discharge pipe short section 36, and the main chamber 37 is communicated with the inner hole 39 of the sand discharge pipe short section, the main channel B 13 and the lateral channel 12.

[0027] Embodiment 2, further including based on Embodiment 1:

[0028] The bearing assembly 20 includes an outer cylinder 24, an upper end cover 22, a lower end cover 25, and a bearing set 23; the bearing set 23 is installed between the outer cylinder 24 and the main shaft 10, and the two rotate relative to each other; the upper end cover 22 and the lower end cover 25 are respectively installed on the upper and lower ends of the outer cylinder 24.

[0029] An upper end cover seal 21 and a lower end cover seal 26 are respectively installed between the upper end cover 22 and the lower end cover 25 and the main shaft 10.

[0030] The bearing set 23 is composed of two angular contact ball bearings, and the two angular contact ball bearings are installed face to face on the upper and lower end faces of the step of the main shaft 10.

[0031] The shunt device 30 includes an upper cover plate 32, a lower cover plate 34, an intermediate cylinder 33, and a connecting cylinder 38; the upper cover plate 32 and the lower cover plate 34 are annular circular plates, and the intermediate cylinder 33 is a cylindrical structure; the upper cover plate 32 is located above the lateral channel 12 of the main shaft 10; the lower cover plate 34 is located below the lateral channel 12 of the main shaft; the intermediate cylinder 33 is installed between the upper cover plate 32 and the lower cover plate 34; a main chamber 37 is formed between the upper cover plate 32, the lower cover plate 34, the intermediate cylinder 33, and the main shaft 10; the upper cover plate 32 is fixedly connected to the connecting cylinder 38, and the connecting cylinder 38 is fixedly connected to the bearing assembly 20.

[0032] An upper cover plate seal ring 31 is installed between the inner hole of the upper cover plate and the main shaft, and a lower cover plate seal ring 35 is installed between the inner hole of the lower cover plate and the main shaft.

[0033] The short sand discharge pipe section 36 is installed on the intermediate cylinder 33, and the inner hole 39 of the short sand discharge pipe section is tangent to the inner hole of the intermediate cylinder 33.

[0034] Both the upper cover plate seal ring 31 and the lower cover plate seal ring 35 are composed of two forms of seal rings, namely a lip-shaped rotary seal close to the main chamber 37 and a packing seal on the outside.

[0035] Typical Embodiment 3. An anti-circulation drilling top-injection side-discharge device includes a main shaft 10, a bearing assembly 20, and a flow-dividing device 30. The upper and lower parts of the main shaft 10 are respectively connected to a swivel (not shown in the figure) and a double-wall drill string 40. The double-wall drill string 40 includes an inner pipe 41 and an outer pipe 42. A drilling medium return channel 43 is formed inside the inner pipe 42, and a drilling medium injection channel 44 is formed between the inner pipe and the outer pipe. The main shaft 10 is an axially short section, with a main channel A11 and a main channel B13 axially machined inside, and a lateral channel 12 radially machined. The main channel A11 is a through hole, and the drilling medium passing through the swivel enters the injection channel 44 of the double-wall drill string through the main channel A11. The main channel B13 is a blind hole axially machined from bottom to top inside the main shaft 10, and is respectively communicated with the return channel 43 of the double-wall drill string and the lateral channel 12. A raised step is machined on the outer edge of the main shaft 10, and the step is located above the lateral channel 12; the bearing assembly 20 is installed on the step of the main shaft 10. The flow-dividing device 30 is fixedly suspended below the bearing assembly 20, and the two rotate relative to the main shaft 10; the flow-dividing device 30 includes a main chamber 37 and a sand discharge pipe short section 36, and the inner hole 39 of the main chamber 37 is communicated with the inner hole of the sand discharge pipe short section. The drilling medium sequentially enters the downstream sand discharge pipeline through the return channel 43 of the double-wall drill string, the main channel B13, the lateral channel 12, the main chamber 37 of the flow-dividing device, and the inner hole 39 of the sand discharge pipe short section.

[0036] The bearing assembly 20 includes an outer cylinder 24, an upper end cover 22, a lower end cover 25, a bearing set 23, an upper end cover seal 21, and a lower end cover seal 26; a bearing set 23 is installed between the outer cylinder 24 and the main shaft 10, and the two rotate relative to each other; the upper and lower ends of the outer cylinder 24 are respectively installed with the upper end cover 22 and the lower end cover 25, and the upper end cover seal 21 and the lower end cover seal 26 are respectively installed between the upper end cover 22 and the lower end cover 25 and the main shaft 10. The bearing set 23 is two angular contact ball bearings, and the two angular contact ball bearings are installed face to face on the upper and lower end faces of the step of the main shaft 10.

[0037] The flow splitting device 30 includes an upper cover plate 32, a lower cover plate 34, an intermediate cylinder 33 and a connecting cylinder 38; the upper cover plate 32 and the lower cover plate 34 are annular circular plates, and the intermediate cylinder 33 is a cylindrical structure; the upper cover plate 32 is located above the main shaft side channel 12, and an upper cover plate sealing ring 31 is installed between the inner hole of the upper cover plate and the main shaft; the lower cover plate 34 is located below the main shaft side channel 12, and a lower cover plate sealing ring 35 is installed between the inner hole of the lower cover plate and the main shaft; the intermediate cylinder 33 is installed between the upper cover plate 32 and the lower cover plate 34; a main chamber 37 is formed between the upper cover plate 32, the lower cover plate 34, the intermediate cylinder 33 and the main shaft 10; the upper cover plate 32 is fixedly connected to the connecting cylinder 38, and the connecting cylinder 38 is fixedly connected to the bearing assembly 20. The short joint 36 of the sand discharge pipe is installed on the intermediate cylinder 33, and the inner hole 39 of the short joint of the sand discharge pipe is tangent to the inner hole of the intermediate cylinder 33. Both the upper cover plate sealing ring 31 and the lower cover plate sealing ring 35 are composed of two forms of sealing rings, namely, a lip-shaped rotary seal close to the main chamber 37 and a packing seal on the outside. When the lip-shaped rotary seal fails, the packing gland is tightened so that the packing seal becomes effective.

[0038] The outer cylinder 24 of the bearing assembly 20 is connected to the non-rotating body of the swivel through an anti-rotation device, so as to prevent the outer cylinder 24 from rotating, and further prevent the flow splitting device 30 and the sand discharge pipeline from rotating.

[0039] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An anti-circulation drilling top-injection side-discharge device, characterized in that it includes a main shaft (10), a bearing assembly (20) and a flow splitting device (30); wherein: joints for connecting a swivel and a double-wall drill pipe (40) are respectively provided at the upper and lower parts of the main shaft (10). The main shaft (10) is a short shaft section, and a main channel A (11) and a main channel B (13) are axially machined inside, and a lateral channel (12) is radially machined; the main channel A (11) is a through hole, and the main channel B (13) is a blind hole axially machined from bottom to top inside the main shaft (10). There is a clearance flow channel between the outside of the main channel B (13) and the main channel A (11), and this clearance flow channel communicates with the injection channel (44) of the double-wall drill pipe. The inside of the main channel B (13) communicates with the return channel (43) and the lateral channel (12) of the double-wall drill pipe; a raised step is machined on the outer edge of the main shaft (10), and the step is located above the lateral channel (12); the bearing assembly (20) is installed on the step of the main shaft (10) and forms an axially limited rotary fit through the step of the main shaft (10); the flow splitting device (30) is fixedly suspended below the bearing assembly (20) and is rotationally sealed and fitted relative to the main shaft; the flow splitting device (30) includes a main chamber (37) and a sand discharge pipe short section (36), and the main chamber (37), the inner hole (39) of the sand discharge pipe short section, the main channel B (13) and the lateral channel (12) communicate; an upper cover seal ring (31) is installed between the inner hole of the first upper cover and the main shaft, and a lower cover seal ring (35) is installed between the inner hole of the first lower cover and the main shaft; the sand discharge pipe short section (36) is installed on the intermediate cylinder (33), and the inner hole (39) of the sand discharge pipe short section is tangent to the inner hole of the intermediate cylinder (33); the flow splitting device (30) includes a second upper cover (32), a second lower cover (34), an intermediate cylinder (33) and a connecting cylinder (38); the second upper cover (32) and the second lower cover (34) are annular circular plates, and the intermediate cylinder (33) is a cylindrical structure; the second upper cover (32) is located above the lateral channel (12) of the main shaft (10); the second lower cover (34) is located below the lateral channel (12) of the main shaft; the intermediate cylinder (33) is installed between the second upper cover (32) and the second lower cover (34); a main chamber (37) is formed between the second upper cover (32), the second lower cover (34), the intermediate cylinder (33) and the main shaft (10); the second upper cover (32) is fixedly connected to the connecting cylinder (38), and the connecting cylinder (38) is fixedly connected to the bearing assembly (20).

2. An anti-circulation drilling top-injection side-discharge device according to claim 1, characterized in that: the bearing assembly (20) includes an outer cylinder (24), an upper end cover (22), a lower end cover (25) and a bearing group (23); the bearing group (23) is installed between the outer cylinder (24) and the main shaft (10), and the two rotate relative to each other; the upper end cover (22) and the lower end cover (25) are respectively installed on the upper and lower ends of the outer cylinder (24).

3. An anti-circulation drilling top-injection side-discharge device according to claim 2, characterized in that: An upper end cap seal (21) and a lower end cap seal (26) are respectively installed between the upper end cap (22) and the lower end cap (25) and the main shaft (10).

4. An anti-circulation drilling top-injection side-discharge device according to claim 3, characterized in that: The bearing group (23) is composed of two angular contact ball bearings, and the two angular contact ball bearings are mounted face to face on the upper and lower end faces of the step of the main shaft (10).

5. An anti-circulation drilling top-injection side-discharge device according to claim 4, characterized in that: Both the upper cover plate seal ring (31) and the lower cover plate seal ring (35) are composed of two forms of seal rings, namely, a lip-type rotary seal near the main chamber (37) and a packing seal on the outside.

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