A swivel and reverse circulation following pipe sampling system

Abstract

The application provides a conversion joint and a reverse circulation follow-up pipe sampling system, and belongs to the technical field of drilling, and comprises a double-wall drill pipe, an impactor, a reamer and a conversion joint, the impactor and the reamer are sleeved in the inside of the follow-up pipe; one end of the reamer extends out of the follow-up pipe; a residue discharge gap is formed between the outer peripheral wall of the impactor and the inner peripheral wall of the follow-up pipe; one end of the conversion joint is connected with one end of the double-wall drill pipe; the other end of the conversion joint is connected with the inner side end of the impactor; wherein, the residue discharge hole of the conversion joint is in communication with the middle passage of the double-wall drill pipe, and the residue discharge branch passage is in communication with the residue discharge gap; the air vent hole of the conversion joint is in communication with the air passage of the double-wall drill pipe, and the air vent branch passage is in communication with the middle air inlet passage of the impactor; the application can solve the problem that the reaming follow-up pipe drilling structure in the prior art cannot be directly applied to the RC reverse circulation follow-up pipe drilling process.

Description

Technical Field

[0001] This application belongs to the field of drilling technology, specifically relating to a conversion joint and a reverse circulation casing sampling system. Background Technology

[0002] The core of RC reverse circulation sampling technology is the double-wall drill pipe structure and the reverse circulation working principle. That is, the annular gap between the double-wall drill pipes is used to deliver compressed air downwards. After the compressed air is discharged through the drill bit, it carries rock cuttings into the inner tube of the double-wall drill pipe through the channel connecting the drill bit and the inner tube of the double-wall drill pipe, and finally discharges into the cyclone separator on the surface.

[0003] Therefore, it can be seen that the inner tube of the double-wall drill pipe discharges rock cuttings, and the annular gap of the double-wall drill pipe is used to introduce compressed air; while the existing normal reaming and casing drilling system (reaming bit, impactor, casing) has compressed air passing through the central hole and rock cuttings being discharged from the outside, so it cannot be directly applied to the RC reverse circulation casing drilling process. Utility Model Content

[0004] This application provides a conversion joint and a reverse circulation casing sampling system, which aims to solve the problem that existing reaming and casing drilling structures cannot be applied to RC reverse circulation casing drilling processes.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: A conversion adapter is provided, comprising: The connector body has one end for connecting to one end of the double-walled drill pipe and the other end for connecting to one end of the impactor; the impactor is fitted inside the casing, and the outer peripheral wall of the connector body has an annular component that contacts the inner peripheral wall of the casing, and the connector body can rotate relative to the casing. The connector body has a slag discharge hole that communicates with the middle channel of the double-walled drill rod, and a vent hole that communicates with the air passage of the double-walled drill rod; the slag discharge hole has a slag discharge branch channel that communicates with the position between the casing and the impactor, and the vent hole has a venting branch channel that communicates with the middle air inlet channel of the impactor.

[0006] In one possible implementation, the connector body is threadedly engaged with the double-walled drill pipe, and the connector body is threadedly engaged with the impactor; wherein the portion of the impactor that is threadedly engaged with the connector body has a tapered structure.

[0007] In one possible implementation, the vent and the vent branch channel form a set of venting structures, and the connector body is provided with several sets of venting structures along the circumferential direction.

[0008] In one possible implementation, there are several circumferentially arranged slag discharge branch channels, which are connected to the outer peripheral wall of the joint body; wherein, the slag discharge branch channels are offset from the vent holes.

[0009] In one possible implementation, the slag discharge hole is located at the center of the connector body, and the slag discharge hole is connected to one end of the connector body; The other end of the connector body is provided with a central hole, which is connected to the ventilation branch channel, but not connected to the slag discharge hole.

[0010] In one possible implementation, the outer diameter of the end of the connector body connected to the double-walled drill pipe is equal to the outer diameter of the double-walled drill pipe; the outer diameter of the end of the connector body connected to the impactor is equal to the outer diameter of the impactor.

[0011] This application provides a conversion connector that, compared with the prior art, achieves precise switching between ventilation and slag discharge by setting independent slag discharge holes, vent holes, and corresponding branch channels inside the connector body. This allows the air passage of the double-walled drill pipe to connect with the central air intake channel of the impactor. Driven by compressed air, rock cuttings can enter the slag discharge hole through the slag discharge branch channel from the slag discharge gap between the impactor and the casing, and finally be discharged from the central channel of the double-walled drill pipe. The above-mentioned configuration of this application, on the one hand, connects the vent hole with the air passage of the double-walled drill pipe, and the vent branch channel with the central air intake channel of the impactor, satisfying the power requirement for compressed air to enter the central air intake channel of the impactor; on the other hand, the slag discharge hole connects with the central channel of the double-walled drill pipe, and the slag discharge branch channel connects with the slag discharge gap, realizing the reverse circulation slag discharge requirement of rock cuttings entering the slag discharge channel from the slag discharge gap between the casing and the impactor.

[0012] To achieve the above objectives, another technical solution adopted in this application is: A reverse circulation tube sampling system is provided, comprising: Double-walled drill pipe; As described above, one end of the adapter is connected to one end of the double-walled drill pipe; a casing is fitted onto the adapter. An impactor is connected to the other end of the adapter; the impactor is located inside the root tube, and there is a slag discharge gap between the outer peripheral wall of the impactor and the inner peripheral wall of the root tube; A reaming drill bit is connected to the other end of the impactor; the reaming drill bit extends into a root tube, and a slag discharge groove is provided on the outer peripheral wall of the reaming drill bit, the slag discharge groove communicating with the slag discharge gap; The slag discharge hole of the conversion joint is connected to the middle channel of the double-walled drill rod, and the slag discharge branch channel is connected to the slag discharge gap; the vent hole of the conversion joint is connected to the air passage of the double-walled drill rod, and the air passage branch channel is connected to the middle air inlet channel of the impactor.

[0013] In one possible implementation, the inner peripheral wall of the bottom end of the bottommost casing has a limiting step, and the outer peripheral wall of the reaming drill bit has a convex ring that contacts the limiting step.

[0014] In one possible implementation, the outer peripheral wall of the double-walled drill rod has a clamping surface, and the outer peripheral wall of the impactor also has a clamping surface, so that the clamping tool clamps the double-walled drill rod or clamps the impactor.

[0015] In one possible implementation, the diameter of the central channel of the double-walled drill pipe is equal to the diameter of the slag discharge hole of the conversion joint.

[0016] The beneficial effects of the reverse circulation tube sampling system provided in this application are the same as those of the conversion connector, and will not be repeated here. Attached Figure Description

[0017] Figure 1 A schematic diagram of a conversion connector provided in an embodiment of this application; Figure 2 A cross-sectional view of a reverse circulation tube sampling system provided in an embodiment of this application; Figure 3 for Figure 2 Enlarged diagram of section A in the middle; Figure 4 for Figure 2 Enlarged diagram of section B in the middle; Figure 5 A cross-sectional view of the slag discharge groove portion of a borehole drill bit in a reverse circulation pipe sampling system provided in an embodiment of this application; Figure 6 This is a cross-sectional view of the tube and connector body of a reverse circulation tube sampling system provided in an embodiment of this application.

[0018] Explanation of reference numerals in the attached drawings: 1. Connector body; 11. Slag discharge hole; 111. Slag discharge branch channel; 12. Ventilation hole; 121. Ventilation branch channel; 13. Center hole; 2. Double-walled drill rod; 21. Air passage; 22. Clamping surface; 3. Impactor; 31. Slag discharge gap; 4. Follow-up pipe; 41. Limiting step; 5. Annular component; 6. Reaming drill bit; 61. Convex ring; 62. Slag discharge groove. Detailed Implementation

[0019] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0020] Please refer to the following: Figures 1 to 6 This application describes a reverse circulation casing sampling system. The reverse circulation casing sampling system includes a connector body 1, one end of which is connected to one end of a double-walled drill rod 2, and the other end is connected to one end of an impactor 3. The impactor 3 is fitted inside the casing 4. The outer peripheral wall of the connector body 1 has an annular component 5 that contacts the inner peripheral wall of the casing 4. The connector body 1 is rotatable relative to the casing 4. The connector body 1 has a slag discharge hole 11 communicating with the central channel of the double-walled drill rod 2, and a vent hole 12 communicating with the air passage 21 of the double-walled drill rod 2. The slag discharge hole 11 has a slag discharge branch channel 111 communicating with the position between the casing 4 and the impactor 3, and the vent hole 12 has a venting branch channel 121 communicating with the central air inlet channel of the impactor 3.

[0021] The adapter provided in this application, compared with the prior art, achieves precise switching between ventilation and slag discharge by setting independent slag discharge holes 11, ventilation holes 12, and corresponding branch channels inside the adapter body 1. This allows the air passage 21 of the double-wall drill rod 2 to connect with the central air intake channel of the impactor 3. Driven by compressed air, rock cuttings pass through the slag discharge groove 62 on the reaming drill bit 6, and can enter the slag discharge hole 11 through the slag discharge branch channel 111 from the slag discharge gap 31 between the impactor 3 and the casing 4, and finally exit from the double-wall drill rod. The middle channel of 2 is discharged; the above-mentioned configuration of this application, on the one hand, the vent 12 is connected to the air passage 21 of the double wall drill rod 2, and the air branch passage 121 is connected to the middle air intake passage of the impactor 3, which meets the power requirement of compressed air entering the middle air intake passage of the impactor 3; on the other hand, the slag discharge hole 11 is connected to the middle channel of the double wall drill rod 2, and the slag discharge branch passage 111 is connected to the slag discharge gap 31, which realizes the reverse circulation slag discharge requirement of rock cuttings entering the slag discharge channel from the slag discharge gap 31 between the root pipe 4 and the impactor 3.

[0022] By setting an annular component 5 on the joint body 1, it is possible to ensure that the relative rotation between the joint body 1 and the casing 4 does not affect the drilling operation; it can also play a radial limiting role to reduce the occurrence of radial offset. In summary, this application can solve the problem that the existing hole-reaming casing 4 drilling structure cannot be directly applied to the RC reverse circulation casing 4 drilling process.

[0023] In some embodiments, such as Figures 1 to 6As shown, the connector body 1 is threadedly engaged with the double-walled drill rod 2, and the connector body 1 is threadedly engaged with the impactor 3; wherein, the part of the impactor 3 that is threadedly engaged with the connector body 1 has a conical structure.

[0024] The connector body 1 is threadedly engaged with the double-walled drill rod 2, which facilitates the assembly and disassembly of the connector body 1 and the double-walled drill rod 2. The threaded connection part on the impactor 3 is set with a tapered structure, and the connector body 1 is provided with a tapered threaded hole. The tapered structure has an automatic centering function, which can ensure the coaxiality of the impactor 3 and the connector body 1.

[0025] In some embodiments, such as Figures 1 to 6 As shown, the vent hole 12 and the vent branch channel 121 are a set of venting structures, and several sets of venting structures are provided in the circumferential direction inside the connector body 1; there are several slag discharge branch channels 111 arranged in the circumferential direction, and the slag discharge branch channels 111 are connected to the outer peripheral wall of the connector body 1; wherein, the slag discharge branch channels 111 and the vent hole 12 are staggered.

[0026] By setting up multiple ventilation structures, the air supply flow and pressure stability can be improved, ensuring that the impactor 3 obtains sufficient and continuous power to meet drilling requirements; the circumferentially evenly distributed ventilation structure can make the force of airflow acting on the impactor 3 more uniform.

[0027] By setting up several slag discharge branch channels 111, the total flow cross-sectional area of ​​slag discharge can be increased, the efficiency of rock cuttings discharge can be improved, and the amount of rock cuttings accumulating between the root pipe 4 and the impactor 3 can be reduced. The slag discharge branch channels 111 and the ventilation holes 12 are staggered to avoid the situation where the slag discharge branch channels and the ventilation holes 12 are interconnected, thereby avoiding the situation where the slag discharge branch channels and the ventilation holes 12 interfere with each other. With the above-mentioned settings of this application, the ventilation function and the slag discharge function do not interfere with each other, and the smooth operation of ventilation and slag discharge can be guaranteed.

[0028] In some embodiments, such as Figures 1 to 6 As shown, the slag discharge hole 11 is located at the center of the connector body 1, and the slag discharge hole 11 is connected to one end of the connector body 1; wherein, the other end of the connector body 1 is provided with a central hole 13, which is connected to the ventilation branch channel 121, and the central hole 13 is not connected to the slag discharge hole 11.

[0029] The slag discharge hole 11 is located at the center of the connector body 1, corresponding to the middle channel of the double-walled drill pipe 2, ensuring the straightness of the slag discharge channel and reducing the resistance of rock cuttings during flow. The center hole 13 at the other end of the connector body 1 is connected to the ventilation branch channel 121, and the center hole 13 is isolated from the slag discharge hole 11, ensuring that the ventilation process and the slag discharge process are independent of each other. After the connector body 1 is connected to the impactor 3, the center hole 13 on the connector body 1 is connected to the middle air intake channel of the impactor 3, allowing the compressed gas in the ventilation channel 21 of the double-walled drill pipe 2 to enter the middle air intake channel of the impactor 3, ensuring the normal operation of the impactor 3.

[0030] In some embodiments, such as Figures 1 to 6 As shown, the outer diameter of the end of the connector body 1 connected to the double-wall drill rod 2 is equal to the outer diameter of the double-wall drill rod 2; the outer diameter of the end of the connector body 1 connected to the impactor 3 is equal to the outer diameter of the impactor 3; by making the outer diameters of the two ends of the connector body 1 equal to the outer diameters of the double-wall drill rod 2 and the impactor 3 respectively, a smooth transition of the outer circumference can be achieved.

[0031] Based on the same technical concept, this application also provides a reverse circulation casing 4 sampling system, including a double-walled drill rod 2, an impactor 3, a reaming drill bit 6, and a conversion joint. The impactor 3 and the reaming drill bit 6 are sleeved inside the casing 4. One end of the impactor 3 is connected to the conversion joint, and the reaming drill bit 6 is connected to the other end of the impactor 3, with one end of the reaming drill bit 6 extending out of the casing 4. A slag discharge gap 31 is provided between the outer peripheral wall of the impactor 3 and the inner peripheral wall of the casing 4. One end of the conversion joint is connected to the double-walled drill rod 2. One end of rod 2 is connected; the other end of the adapter is connected to the inner end of impactor 3; the outer peripheral wall of the reaming drill bit 6 has a slag discharge groove 62, which is connected to the slag discharge gap 31; wherein, the slag discharge hole 11 of the adapter is connected to the middle channel of the double-wall drill rod 2, and the slag discharge branch channel 111 is connected to the slag discharge gap 31; the vent hole 12 of the adapter is connected to the air passage 21 of the double-wall drill rod 2, and the air passage 121 is connected to the middle air inlet channel of impactor 3.

[0032] It should be noted that the compressed air passes sequentially through the air passage 21 of the double-wall drill pipe 2, the air vent 12 of the conversion joint, the air branch passage 121, and the air intake passage in the middle of the impactor 3, ensuring the normal operation of the impactor 3. The compressed gas is finally discharged from the reaming drill bit 6. The discharged compressed gas, carrying rock cuttings, enters the space between the outer peripheral wall of the impactor 3 and the inner peripheral wall of the casing 4 from the slag discharge groove of the reaming drill bit 6. After passing through the slag discharge branch passage 111, the slag discharge hole 11 of the conversion joint, and the middle passage of the double-wall drill pipe 2, it is finally discharged into the cyclone separator on the surface. With the above settings, the casing 4 advances synchronously during drilling, which can effectively prevent the hole wall from collapsing and is suitable for drilling and sampling in loose strata and quicksand layers.

[0033] In some embodiments, such as Figures 1 to 6 As shown, the inner peripheral wall of the bottom end of the bottom tube 4 has a limiting step 41, and the outer peripheral wall of the reaming drill bit 6 has a convex ring 61 that contacts the limiting step 41; the convex ring 61 has an avoidance groove that communicates with the slag discharge groove 62 of the reaming drill bit 6.

[0034] During drilling, when the reaming bit 6 breaks the rock downwards, the convex ring 61 can contact the limiting step 41, and the downward force of the reaming bit 6 can be transmitted to the limiting step 41, driving the casing 4 to move downwards synchronously; the cooperation between the convex ring 61 and the limiting step 41 can limit the radial displacement of the reaming bit 6, reduce the radial offset of the reaming bit 6, and improve the stability during drilling.

[0035] In some embodiments, such as Figures 1 to 6 As shown, the outer peripheral wall of the double-wall drill rod 2 has a clamping surface 22, and the outer peripheral wall of the impactor 3 also has a clamping surface 22, so that the clamping tool can clamp the double-wall drill rod 2 or clamp the impactor 3.

[0036] The clamping surface 22 on the double-wall drill pipe 2 has the same effect as the clamping surface 22 on the impactor 3. Taking the clamping surface 22 on the double-wall drill pipe 2 as an example, the following explanation is provided: The outer peripheral wall of the adapter is also provided with a clamping surface 22. When disassembling the adapter, the operator can clamp the two disassembly tools on the clamping surfaces 22 of the adapter and the double-wall drill pipe 2 respectively, and then rotate the two disassembly tools in opposite directions to loosen the adapter, which is convenient for subsequent disassembly of the adapter. After the adapter is installed on the double-wall drill pipe 2, the adapter can be tightened by rotating the two disassembly tools in opposite directions to ensure the connection between the adapter and the double-wall drill pipe 2.

[0037] In some embodiments, such as Figures 1 to 6 As shown, the diameter of the central channel of the double-walled drill rod 2 is equal to the diameter of the slag discharge hole 11 of the conversion joint; through the above setting, a smooth transition between the slag discharge hole 11 and the central channel of the double-walled drill rod 2 can be achieved, reducing the sudden change in resistance during the rock cuttings flow process and ensuring the stability of the slag discharge flow rate.

[0038] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A conversion connector, characterized in that, include: The connector body has one end for connecting to one end of the double-walled drill pipe and the other end for connecting to one end of the impactor; the impactor is fitted inside the casing, and the outer peripheral wall of the connector body has an annular component that contacts the inner peripheral wall of the casing, and the connector body can rotate relative to the casing. The connector body has a slag discharge hole that communicates with the middle channel of the double-walled drill rod, and a vent hole that communicates with the air passage of the double-walled drill rod; the slag discharge hole has a slag discharge branch channel that communicates with the position between the casing and the impactor, and the vent hole has a venting branch channel that communicates with the middle air inlet channel of the impactor.

2. The adapter as described in claim 1, characterized in that, The connector body is threadedly engaged with the double-walled drill pipe, and the connector body is threadedly engaged with the impactor; wherein, the part of the impactor that is threadedly engaged with the connector body has a tapered structure.

3. A conversion connector as described in claim 1, characterized in that, The vent and the vent branch channel form a set of venting structures, and the connector body is provided with several sets of venting structures along the circumferential direction.

4. A conversion connector as described in claim 3, characterized in that, The slag discharge branch channels are arranged in a circumferential manner, and the slag discharge branch channels are connected to the outer peripheral wall of the joint body; wherein, the slag discharge branch channels are staggered with the vent holes.

5. A conversion connector as described in claim 1, characterized in that, The slag discharge hole is located at the center of the connector body and is connected to one end of the connector body; The other end of the connector body is provided with a central hole, which is connected to the ventilation branch channel, but not connected to the slag discharge hole.

6. A conversion connector as described in claim 1, characterized in that, The outer diameter of the end of the connector body that connects to the double-walled drill pipe is equal to the outer diameter of the double-walled drill pipe; the outer diameter of the end of the connector body that connects to the impactor is equal to the outer diameter of the impactor.

7. A reverse circulation tube sampling system, characterized in that, include: Double-walled drill pipe; The adapter as described in any one of claims 1-6 is connected at one end to one end of the double-walled drill pipe; a casing is fitted onto the adapter. An impactor is connected to the other end of the conversion joint; the impactor is located inside the root tube, and there is a slag discharge gap between the outer peripheral wall of the impactor and the inner peripheral wall of the root tube; A reaming drill bit is connected to the other end of the impactor; The reaming drill bit extends into a root tube, and a slag discharge groove is provided on the outer peripheral wall of the reaming drill bit, which is connected to the slag discharge gap; The slag discharge hole of the conversion joint is connected to the middle channel of the double-walled drill rod, and the slag discharge branch channel is connected to the slag discharge gap; the vent hole of the conversion joint is connected to the air passage of the double-walled drill rod, and the air passage branch channel is connected to the middle air inlet channel of the impactor.

8. The reverse circulation tube sampling system as described in claim 7, characterized in that, The inner peripheral wall of the bottom end of the bottom tube has a limiting step, and the outer peripheral wall of the reaming drill bit has a convex ring that contacts the limiting step.

9. The reverse circulation tube sampling system as described in claim 7, characterized in that, The outer peripheral wall of the double-walled drill rod has a clamping surface, and the outer peripheral wall of the impactor also has a clamping surface, so that the clamping tool can clamp the double-walled drill rod or the impactor.

10. The reverse circulation tube sampling system as described in claim 7, characterized in that, The diameter of the central channel of the double-walled drill pipe is equal to the diameter of the slag discharge hole of the conversion joint.

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