A self-lubricating orifice dynamic sealing device for air reverse circulation

Abstract

The present invention discloses a self-lubricating orifice dynamic sealing device for air reverse circulation, which relates to the field of orifice sealing technology in geological drilling. It includes a gripper, a double-wall drill pipe, bolts, and an orifice dynamic sealing assembly. The orifice dynamic sealing assembly is fixedly installed on the gripper through bolts. The double-wall drill pipe penetrates through the orifice dynamic sealing assembly, and the double-wall drill pipe is rotationally matched with the orifice dynamic sealing assembly. The orifice dynamic sealing assembly is used to support and lubricate the double-wall drill pipe. The orifice dynamic sealing assembly includes a shaft core, a bearing outer sleeve, tapered roller bearings, and a sealing sleeve. By directly fixing the orifice dynamic sealing assembly on the gripper, it can be connected and used with different reverse circulation drilling rigs. The sealing sleeve contacts the outer wall of the double-wall drill pipe to play a role in dynamic sealing. Lubricating oil is injected through a lubricating injection pipe to ensure sealing and reduce friction, while also ensuring heat dissipation at high-frequency friction points. The conical rubber seal seals the orifice.

Description

Technical Field

[0001] The present invention relates to the technical field of orifice sealing in the field of geological drilling, and specifically to a self-lubricating orifice dynamic sealing device for air reverse circulation. Background Art

[0002] The air reverse circulation continuous sampling and coring drilling technology can achieve continuous sampling, with a sampling efficiency higher than that of core drilling by retrieving the drill string, low labor intensity, and can effectively avoid complex situations such as borehole wall leakage, and is applicable to drilling in lost circulation formations and arid and water-deficient areas. Therefore, it has been widely used worldwide. During the air reverse circulation drilling process, compressed gas is used as the circulating medium to carry the cuttings generated by the bottom hole bit and return to the surface through the central channel of the double-wall drill pipe. However, in the actual drilling process, a small amount of rock powder will return to the orifice from the annular gap between the drill pipe and the borehole, generating cuttings and dust at the orifice, which will seriously pollute the drill site environment, pose a threat to the health of on-site construction personnel, and at the same time is not conducive to the formation of reverse circulation, becoming a major weak point affecting the drilling efficiency.

[0003] During the geological survey process, it is necessary to judge the formation conditions based on the rock powder and rock samples returned to the surface through the central channel of the air reverse circulation, and take rock samples for analysis and testing. However, during the reverse circulation drilling process, without an orifice sealing device, a large amount of cuttings and rock powder return from the outer wall of the drill pipe and the borehole and are discharged through the orifice, and the rock powder collected in the central channel of the borehole cannot be completely obtained, and there is a possibility of losing representative samples, which cannot accurately and truly reflect the formation conditions and cannot meet the requirements of geological surveys.

[0004] Currently, the domestic air reverse circulation orifice sealing and blowout prevention devices usually use rubber seals and flexible protective covers sleeved on the drill pipe to prevent the discharge of annulus cuttings. In this method, the rubber seal is fixed and cannot rotate with the drill pipe. After working for a certain period of time, the rubber seal wears severely, and it cannot achieve a good sealing effect after the gap increases. The orifice rotary blowout preventer used in oil drilling has a complex structure, a large overall height and mass, is not easy to handle and transport, and is inconvenient to connect with the existing air reverse circulation equipment, and cannot meet the usage requirements of air reverse circulation drilling. Summary of the Invention

[0005] The object of the present invention is to provide a self-lubricating orifice dynamic sealing device for air reverse circulation. By directly fixing the orifice dynamic sealing assembly on the chuck, it is convenient to unscrew and disassemble, and can be connected and used with different reverse circulation drilling rigs. The overall structure is simple, with a small mass and convenient disassembly; the sealing sleeve contacts the outer wall of the double-wall drill pipe and rotates with the drill pipe to play a role of dynamic sealing; lubricating oil is injected through the lubricating filling pipe to ensure sealing and reduce friction while ensuring heat dissipation at the high-frequency friction part. The conical rubber seal seals the orifice, effectively avoiding dust pollution at the orifice and improving the service life of the dynamic seal, thus solving the problems in the background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A self-lubricating orifice dynamic sealing device for air reverse circulation, comprising a chuck, a double-wall drill pipe, bolts and an orifice dynamic sealing assembly. The orifice dynamic sealing assembly is fixedly installed on the chuck through bolts. The double-wall drill pipe penetrates through the orifice dynamic sealing assembly, and the double-wall drill pipe is rotationally matched with the orifice dynamic sealing assembly. The orifice dynamic sealing assembly is used to support and lubricate the double-wall drill pipe. The orifice dynamic sealing assembly includes a shaft core, a bearing outer sleeve, tapered roller bearings and a sealing sleeve. The shaft core is located inside the bearing outer sleeve. Tapered roller bearings are arranged between the bearing outer sleeve and the shaft core. The inner ring of the tapered roller bearing is fixedly installed on the outer side of the shaft core, and the outer ring of the tapered roller bearing is fixedly installed on the inner wall of the bearing outer sleeve. A sealing sleeve is rotationally installed inside one side of the shaft core located outside the bearing outer sleeve. An upper gland is rotationally installed by threading at one end of the shaft core close to the sealing sleeve. The upper gland is used to fix the connection between the sealing sleeve and the shaft core. The double-wall drill pipe penetrates through the sealing sleeve, and the sealing sleeve is used to support the double-wall drill pipe.

[0008] Further, the inner ring of the shaft core near the sealing sleeve side is subjected to reaming treatment. A washer is arranged between the sealing sleeve and the reamed table surface inside the shaft core. An upper bearing gland is arranged between the shaft core and the bearing outer sleeve. A skeleton seal is embedded inside the inner ring of the upper bearing gland. The shaft core, the bearing outer sleeve and the upper bearing gland are fixedly connected through a first transition connection body.

[0009] Further, the side of the bearing outer sleeve away from the sealing sleeve is connected to the orifice sealing body through a first transition connection body. A lower bearing gland is arranged between the bearing outer sleeve and the orifice sealing body. A bearing spacer sleeve is embedded inside the inner ring of the lower bearing gland. A bearing locknut is arranged at one end of the shaft core away from the sealing sleeve. The bearing outer sleeve, the lower bearing gland and the bearing locknut are fixedly connected through a second transition connection body.

[0010] Further, a lubricating filling pipe is provided on the outer bearing sleeve. The lubricating filling pipe communicates with the interior of the outer ring of the tapered roller bearing through the outer ring of the tapered roller bearing, and a one-way valve is installed on the lubricating filling pipe.

[0011] Further, the outer end of the orifice seal body away from the seal sleeve is tapered, and the orifice seal body is rotationally matched with the double-wall drill pipe.

[0012] Further, an annular groove is provided in the seal sleeve. The inner diameter of the seal sleeve is slightly smaller than the outer diameter of the double-wall drill pipe. The relationship between the outer diameter D of the double-wall drill pipe and the inner diameter d of the seal sleeve is D = 1.05d.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0014] The self-lubricating orifice dynamic seal device for air reverse circulation provided by the present invention directly fixes the orifice dynamic seal assembly on the chuck, which is convenient for screwing and unscrewing, and can be connected and used with different reverse circulation drilling rigs. The overall structure is simple, with a small mass and is convenient for disassembly; the seal sleeve contacts the outer wall of the double-wall drill pipe and rotates together with the drill pipe to play a role in dynamic sealing; lubricating oil is filled through the lubricating filling pipe to ensure sealing and reduce friction, and at the same time, it can ensure heat dissipation at the high-frequency friction part. The tapered rubber seal seals the orifice, effectively avoiding dust pollution at the orifice and improving the service life of the dynamic seal. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic installation diagram of the orifice seal assembly of the present invention;

[0016] Figure 2 is a schematic cross-sectional view of the orifice seal assembly of the present invention.

[0017] In the figure: 1, shaft core; 2, outer bearing sleeve; 3, lower bearing gland; 4, upper bearing gland; 5, tapered roller bearing; 6, bearing spacer; 7, bearing locknut; 8, seal sleeve; 9, upper end gland; 10, first transition connector; 11, orifice seal body; 12, washer; 13, skeleton seal; 14, lubricating filling pipe; 15, second transition connector; 21, chuck; 22, double-wall drill pipe; 23, bolt; 24, orifice dynamic seal assembly. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] AsFigure 1 and Figure 2 As shown in Figure 2 , a self-lubricating orifice dynamic seal device for air reverse circulation includes a chuck 21, a double-wall drill pipe 22, bolts 23 and an orifice dynamic seal assembly 24. The orifice dynamic seal assembly 24 is fixedly installed on the chuck 21 through the bolts 23. The double-wall drill pipe 22 penetrates through the orifice dynamic seal assembly 24, and the double-wall drill pipe 22 is rotationally matched with the orifice dynamic seal assembly 24. The chuck 21 and the orifice dynamic seal assembly 24 are used to clamp and limit the double-wall drill pipe 22, which can ensure the stability of the double-wall drill pipe 22 during the rotation operation. The orifice dynamic seal assembly 24 is used to support and lubricate the double-wall drill pipe 22. The orifice dynamic seal assembly 24 includes a shaft core 1, a bearing outer sleeve 2, tapered roller bearings 5 and a seal sleeve 8. The shaft core 1 is located inside the bearing outer sleeve 2, and tapered roller bearings 5 are arranged between the bearing outer sleeve 2 and the shaft core 1. The inner ring of the tapered roller bearing 5 is fixedly installed on the outer side of the shaft core 1, and the outer ring of the tapered roller bearing 5 is fixedly installed on the inner wall of the bearing outer sleeve 2. A seal sleeve 8 is rotationally installed inside one side of the shaft core 1 located outside the bearing outer sleeve 2. A top gland 9 is rotationally installed on the shaft core 1 near one end of the seal sleeve 8 by threads. The top gland 9 is used to fix the connection between the seal sleeve 8 and the shaft core 1. The double-wall drill pipe 22 penetrates through the seal sleeve 8, and the seal sleeve 8 is used to support the double-wall drill pipe 22. There is only axial relative movement between the double-wall drill pipe 22 and the seal sleeve 8.

[0020] The inner ring of the shaft core 1 near one side of the seal sleeve 8 is reamed. A washer 12 is arranged between the seal sleeve 8 and the reamed table surface inside the shaft core 1. After the top gland 9 is rotationally matched with the shaft core 1 by threads, the washer 12 undergoes a slight deformation, which can prevent the seal sleeve 8 from rotating inside the shaft core 1 and lock the connection between the top gland 9 and the shaft core 1 at the same time. A top bearing gland 4 is arranged between the shaft core 1 and the bearing outer sleeve 2. A skeleton seal 13 is embedded inside the inner ring of the top bearing gland 4. The shaft core 1, the bearing outer sleeve 2 and the top bearing gland 4 are fixedly connected through a first transition connector 10, so that the shaft core 1 and the bearing outer sleeve 2 form an integral body. The top bearing gland 4 and the skeleton seal 13 can play a shock-absorbing role.

[0021] One side of the bearing outer sleeve 2 away from the sealing sleeve 8 is connected to the orifice sealing body 11 through a first transition connector 10. A lower bearing gland 3 is arranged between the bearing outer sleeve 2 and the orifice sealing body 11. A bearing spacer sleeve 6 is embedded in the inner ring of the lower bearing gland 3, which can support and maintain the relative position between the shaft core 1 and the bearing outer sleeve 2. One end of the shaft core 1 away from the sealing sleeve 8 is provided with a bearing locknut 7, which can reduce the direct friction between the shaft core 1 and the bearing outer sleeve 2. The bearing outer sleeve 2, the lower bearing gland 3 and the bearing locknut 7 are fixedly connected through a second transition connector 15, so that the bearing outer sleeve 2 and the bearing locknut 7 form an integral body, and the lower bearing gland 3 and the bearing spacer sleeve 6 can play a shock-absorbing role.

[0022] An annular groove is arranged in the sealing sleeve 8. The inner diameter of the sealing sleeve 8 is slightly smaller than the outer diameter of the double-wall drill pipe 22. The relationship between the outer diameter D of the double-wall drill pipe 22 and the inner diameter d of the sealing sleeve 8 is D = 1.05d. Under the action of gravity, the double-wall drill pipe 22 is embedded in the sealing sleeve 8. Through the slight deformation of the annular protrusion in the sealing sleeve 8, the connection tightness between the double-wall drill pipe 22 and the sealing sleeve 8 can be increased, and the relative rotation between the sealing sleeve 8 and the double-wall drill pipe 22 can be reduced, reducing the friction and heat generation between the sealing sleeve 8 and the double-wall drill pipe 22.

[0023] A lubricating filling pipe 14 is arranged on the bearing outer sleeve 2. The lubricating filling pipe 14 is communicated with the inside of the tapered roller bearing 5 through the outer ring of the tapered roller bearing 5. Lubricating oil is filled into the tapered roller bearing 5 through the lubricating filling pipe 14, which can play the role of bearing lubrication and temperature reduction for the tapered roller bearing 5. A check valve is installed on the lubricating filling pipe 14 to prevent external impurities from entering the tapered roller bearing 5.

[0024] One end of the orifice sealing body 11 away from the sealing sleeve 8 is tapered on the outside, which can divert the rock powder during the rising process of the rock powder. The orifice sealing body 11 is rotationally matched with the double-wall drill pipe 22, which can reduce the rock powder between the double-wall drill pipe 22 and the hole wall from being blown out of the orifice, playing the role of orifice sealing, and is conducive to the formation of reverse circulation.

[0025] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.

[0026] Although 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. A self-lubricating orifice dynamic sealing device for air reverse circulation, comprising a holder (21), a double-wall drill pipe (22), bolts (23) and an orifice dynamic sealing assembly (24), characterized in that: A hole orifice dynamic seal assembly (24) is fixedly installed on the gripper (21) through bolts (23). A double-wall drill pipe (22) is penetrated through the hole orifice dynamic seal assembly (24). The double-wall drill pipe (22) is rotationally matched with the hole orifice dynamic seal assembly (24). The hole orifice dynamic seal assembly (24) is used for supporting and lubricating the double-wall drill pipe (22). The hole orifice dynamic seal assembly (24) includes a shaft core (1), a bearing outer sleeve (2), tapered roller bearings (5), and a seal sleeve (8). The shaft core (1) is located inside the bearing outer sleeve (2). Tapered roller bearings (5) are arranged between the bearing outer sleeve (2) and the shaft core (1). The inner ring of the tapered roller bearing (5) is fixedly installed on the outer side of the shaft core (1), and the outer ring of the tapered roller bearing (5) is fixedly installed on the inner wall of the bearing outer sleeve (2). A seal sleeve (8) is rotationally installed inside one side of the shaft core (1) located outside the bearing outer sleeve (2). An upper gland (9) is rotationally installed by threading at one end of the shaft core (1) close to the seal sleeve (8). The upper gland (9) is used for fixing the connection between the seal sleeve (8) and the shaft core (1). The double-wall drill pipe (22) is penetrated through the seal sleeve (8). The seal sleeve (8) is used for supporting the double-wall drill pipe (22). The inner ring of the shaft core (1) close to one side of the seal sleeve (8) is reamed. A washer (12) is arranged between the seal sleeve (8) and the reamed table surface inside the shaft core (1). An upper bearing gland (4) is arranged between the shaft core (1) and the bearing outer sleeve (2). A skeleton seal (13) is embedded inside the inner ring of the upper bearing gland (4). The shaft core (1), the bearing outer sleeve (2), and the upper bearing gland (4) are fixedly connected through a first transition connector (10). One side of the bearing outer sleeve (2) away from the seal sleeve (8) is connected to a hole orifice seal body (11) through a first transition connector (10). A lower bearing gland (3) is arranged between the bearing outer sleeve (2) and the hole orifice seal body (11). A bearing spacer sleeve (6) is embedded inside the inner ring of the lower bearing gland (3). A bearing locknut (7) is arranged at one end of the shaft core (1) away from the seal sleeve (8). The bearing outer sleeve (2), the lower bearing gland (3), and the bearing locknut (7) are fixedly connected through a second transition connector (15).

2. The self-lubricating orifice dynamic sealing device for air reverse circulation according to claim 1, characterized in that: A lubricating filling pipe (14) is arranged on the bearing outer sleeve (2). The lubricating filling pipe (14) is communicated with the inside of the tapered roller bearing (5) through the outer ring of the tapered roller bearing (5). A one-way valve is installed on the lubricating filling pipe (14).

3. The self-lubricating orifice dynamic sealing device for air reverse circulation according to claim 2, characterized in that: The outer side of one end of the hole orifice seal body (11) away from the seal sleeve (8) is conical. The hole orifice seal body (11) is rotationally matched with the double-wall drill pipe (22).

4. The self-lubricating orifice dynamic seal device for air reverse circulation according to claim 3, characterized in that: An annular groove is arranged inside the seal sleeve (8). The inner diameter of the seal sleeve (8) is slightly smaller than the outer diameter of the double-wall drill pipe (22). The relationship between the outer diameter D of the double-wall drill pipe (22) and the inner diameter d of the seal sleeve (8) is D = 1.05d.

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