One-way pup joint with valve element capable of being taken out and using method of one-way pup joint

Abstract

The invention discloses a one-way pup joint with a removable valve core and a use method thereof, and belongs to the field of drilling tools. The one-way valve comprises a shell and a one-way valve arranged in the shell. One end of the one-way valve abuts against the limiting step, the other end of the one-way valve is provided with a connecting pipe, and the end of the connecting pipe is provided with a fishing spearhead. A clamping component which can be radially contracted and expanded is arranged in the connecting pipe, and the clamping component is driven to be radially contracted through axial movement of the connecting pipe; the clamping component is unfolded and embedded into the limiting ring groove in the initial state and is matched with the limiting step to axially fix the one-way valve. During separation, the fishing spearhead is connected through the fishing device, the connecting pipe is pulled to drive the clamping component to contract, and the one-way valve is taken out. The using method includes the steps that after drilling is completed, the fishing device is put down to be connected with the fishing spearhead and lifted upwards to drive the connecting pipe to move, the clamping component is driven to contract to relieve limiting, and the one-way valve moves upwards to be separated. Through a separation mechanism of the one-way valve, the tripping-in success rate and safety of the screen pipe are improved.

Description

Technical Field

[0001] This invention belongs to the field of drilling tool technology, specifically relating to a valve core removable one-way short section and its usage method. Background Technology

[0002] When drilling in high-gas formations in coal mines, the high-pressure methane gas present in these formations can rapidly lose its balance when the borehole penetrates the strata, easily gushing out in large quantities from the drill pipe as a high-pressure jet. This high-pressure gas surge not only poses a serious safety threat to workers but can also trigger underground explosions or fires, significantly impacting safe production in coal mines. Therefore, one-way valves must be installed during drilling to prevent backflow of methane and ensure safe drilling operations. As a crucial safety device, the one-way valve allows drilling fluid or gas to flow in one direction while preventing reverse flow, effectively controlling the backflow of methane from the drill pipe. However, existing one-way valves have revealed significant limitations in practical applications, particularly the valve core within them, which hinders subsequent operations.

[0003] Currently available one-way subs all share a common problem: they prevent the screen pipe from being lowered during drilling. After drilling, if subsequent operations such as gas extraction are required, screen pipes are typically lowered to maintain borehole stability and extraction efficiency. However, because the one-way valve core is fixed inside the sub and cannot be removed or separated, the screen pipe cannot be lowered directly through the drill string. In practice, the drill rod must be withdrawn from the borehole first, and then the screen pipe must be attempted to be lowered in the open hole. This method has many drawbacks. First, the instability and complexity of the open hole wall are major problems. High-gas formations often have soft and easily collapsing rock strata. After the drill rod is withdrawn, the borehole wall lacks support and is prone to collapse or deformation, causing the screen pipe to be obstructed during lowering. Second, in the open hole state, residual gas or other impurities may remain, further interfering with the smooth lowering of the screen pipe. In addition, due to the influence of formation pressure and hydrodynamics, the path of the screen pipe is difficult to control, often resulting in jamming, bending, or deviation. These factors combined significantly reduce the success rate of screen pipe installation, sometimes requiring multiple attempts or re-drilling, severely impacting drilling quality and subsequent gas extraction efficiency. Furthermore, this method of removing the drill pipe before installing the screen pipe increases operation time and costs, prolongs underground downtime, and consequently affects the overall production schedule of the coal mine. More importantly, in high-gas environments, open-hole operation increases the risk of gas leaks, potentially triggering secondary safety accidents.

[0004] These shortcomings of existing technologies stem from inherent problems in the design of one-way valves, namely, the inability to separate or remove the valve core, resulting in permanent blockage of the internal passage and making it unsuitable for the operation of running screens while drilling. To address these issues, the industry urgently needs a new type of one-way short joint that can achieve convenient valve core separation while fulfilling gas control functions, thereby providing a smooth passage for screen installation. Summary of the Invention

[0005] In view of this, the purpose of this invention is to solve the operational problem of the inability to separate the valve core in existing one-way short sections, which prevents the screen pipe from being lowered during drilling, and to provide a one-way short section with a removable valve core and its usage method. By pulling the retrieval spearhead, the connecting pipe is moved axially, thereby driving the locking component to retract radially. After the locking component retracts to its limit position, the one-way valve moves upward as a whole and separates from the housing.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A removable one-way valve section includes a housing and a one-way valve disposed within the housing, wherein the one-way valve is detachably connected to the housing; a limiting step and a limiting annular groove are respectively provided at both ends of the one-way valve within the housing, one end of the one-way valve abuts against the limiting step, and the other end is provided with a connecting pipe; a spearhead is connected to the end of the connecting pipe away from the one-way valve; a locking member is provided inside the connecting pipe that can retract and expand radially along the housing, the locking member is connected to the connecting pipe, and the radial retraction of the locking member is driven by the axial movement of the connecting pipe; The connecting pipe has an opening on its side wall, and the engaging member has an engaging spring inside. Under the elastic force of the engaging spring, the engaging member initially unfolds from the opening and is embedded in the limiting ring groove, cooperating with the limiting step to axially fix the one-way valve. When the one-way valve is detached from the housing, the retrieval device connects to the retrieval spearhead, pulls the connecting pipe to move, thereby causing the locking component to retract and contact the axial limit, thus removing the one-way valve.

[0007] Furthermore, the engaging component includes a caliper frame, a caliper, a rocker arm, and a caliper pin. The connecting tube is fitted onto the caliper frame and slides axially with the caliper frame. One end of the caliper frame is fixedly connected to the one-way valve, and the other end extends into the connecting tube. One end of the caliper is hinged to the caliper frame via a pin, and the other end is hinged to the rocker arm. The rocker arm is hinged to the caliper frame via a caliper pin. The caliper frame is provided with a sliding groove arranged axially. The caliper pin is slidably disposed in the sliding groove and passes through the caliper and is fixedly connected to the connecting pipe. The connecting pipe drives the caliper pin to move axially within the sliding groove, thereby driving the rocker arm to rotate and causing the caliper to retract radially.

[0008] Furthermore, the engaging spring is located inside the connecting tube and is fitted onto the caliper frame. One end of the engaging spring is provided with a spring baffle that abuts against it, and the spring baffle is fixed to the caliper frame by a baffle bolt. The other end of the engaging spring abuts against the caliper pin, so that the engaging component is in the unfolded state.

[0009] Furthermore, the spring stop is located at the end of the caliper bracket.

[0010] Furthermore, the engaging component includes two symmetrically arranged calipers and swing arms, with the two swing arms sharing the caliper pin.

[0011] Furthermore, the two calipers are hinged to the same pin, forming a V-shaped structure.

[0012] Furthermore, the end of the connecting pipe away from the one-way valve is provided with a spear-catching seat. One end of the spear-catching seat is connected to the connecting pipe through a traction pin, and the other end is connected to the spear-catching head through a connecting pin, so that the spear-catching head drives the connecting pipe to move axially through the spear-catching seat and the traction pin.

[0013] Furthermore, the spear holder is equipped with a spearhead spring and a spearhead positioning pin; one end of the spearhead extends into the spear holder and is clearance-fitted with the spear holder; one end of the spearhead spring abuts against the inner hole end face of the spear holder, and the other end abuts against the end of the spearhead through the spearhead positioning pin, so that the spearhead has flexible movement space within the gap range with the spear holder.

[0014] Furthermore, the spear holder is provided with a strip groove along the axial direction, and the traction pin is slidably disposed in the strip groove, so that the spear holder has axial movement space in the connecting pipe.

[0015] Furthermore, the one-way valve includes a valve core, a valve core spring, and a valve core seat. The valve core is elastically connected to the valve core seat through the valve core spring. The end of the engaging member connected to the one-way valve is provided with a conical surface. Under the action of the valve core spring, the valve core abuts against the conical surface, thereby realizing the one-way sealing function of the one-way valve within the housing.

[0016] A method for using the valve core removable one-way short section as described above: After drilling is completed, the retrieval device is lowered and connected to the retrieval spearhead. The retrieval spearhead is then lifted, causing the locking component to retract. After the locking component disengages from the limiting ring groove, the one-way valve moves upward, thereby separating the one-way valve from the housing.

[0017] Furthermore, after the one-way valve separates from the housing, the retrieval device lifts the one-way valve out of the drill string, providing a channel for the subsequent lowering of the screen pipe.

[0018] Furthermore, after the engaging component retracts to its limit position, it releases its engagement with the limiting annular groove, and the one-way valve begins to move upward as a whole.

[0019] The beneficial effects of this invention are as follows: The removable one-way short section with a valve core and its usage method of this invention effectively control gas surges during drilling. Furthermore, after drilling is completed, the valve core design of the one-way short section offers significant advantages in easy retrieval and automatic separation from the main body. This feature opens a clear internal channel for the subsequent smooth installation of the screen pipe, thus solving the operational problem of traditional one-way valves being unable to be used for screen pipe installation during drilling. Specifically, this design, through the separation mechanism of the one-way valve, avoids the drawback of requiring the drill string to be removed for open-hole screen pipe installation in existing technologies, significantly improving the success rate of screen pipe installation. In high-gas formations, open-hole operations often fail due to factors such as borehole wall collapse, residual gas, and path deviation. This invention allows for the direct separation of the one-way valve inside the drill string before screen pipe installation, maintaining the integrity and stability of the borehole and reducing the risk of secondary accidents.

[0020] Furthermore, the optimized structure of this short section streamlines the fixing and disengagement process of the one-way valve. The double fixing mechanism, achieved through the interlocking component embedded in the limiting ring groove and the limiting step abutting against each other, ensures reliable sealing during drilling and prevents gas backflow. During disengagement, a coordinated mechanism involving the lifting of the retrieval spearhead, movement of the connecting pipe, axial movement of the caliper pin, rotation of the rocker arm, and retraction of the caliper, makes operation simple and efficient. It can be completed simply by lowering the retrieval device, without the need for complex tools or multiple attempts. This not only shortens operation time and reduces labor costs but also improves overall construction efficiency, contributing to the continuity of coal mine production.

[0021] In addition, the spearhead of the present invention adopts a flexible design. Through the spearhead spring and the spearhead positioning pin, the spearhead has flexible movement space within the gap range of the spearhead seat. This design improves the adaptability of the retrieval operation, can better cope with vibration or displacement in complex downhole environments, reduce the risk of jamming, and improve the success rate of retrieval and operational safety.

[0022] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0023] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the structure of the removable one-way short section of the valve core of the present invention.

[0024] Reference numerals: 1-Spearhead; 2-Connecting pin; 3-Spearhead seat; 4-Traction pin; 5-Spring baffle; 6-Clamping spring; 7-Caliper; 8-Caliper bracket; 9-Valve core spring; 10-Valve core seat; 11-Housing; 12-Valve core; 13-Connecting pipe; 14-Rocker arm; 15-Caliper pin; 16-Baffle bolt; 17-Spearhead spring; 18-Spearhead positioning pin. Detailed Implementation

[0025] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0026] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0027] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0028] Example 1 like Figure 1As shown, a valve core removable one-way short section includes a housing 11 and a one-way valve disposed within the housing 11. The one-way valve is detachably connected to the housing 11. Limiting steps and limiting annular grooves are respectively provided at both ends of the one-way valve within the housing 11. One end of the one-way valve abuts against the limiting step, and the other end is connected to a connecting pipe 13. A spearhead 1 is connected to the end of the connecting pipe 13 away from the one-way valve. A locking member that can retract and expand radially along the housing 11 is provided within the connecting pipe 13. The locking member is connected to the connecting pipe 13, and the radial retraction of the locking member is driven by the axial movement of the connecting pipe 13. An opening is provided on the side wall of the connecting pipe 13, and a locking spring 6 is provided inside the locking member. Under the elastic force of the locking spring 6, the locking member initially unfolds from the opening and is embedded in the limiting ring groove, cooperating with the limiting step to axially fix the one-way valve. When the one-way valve is detached from the housing 11, the retrieval device connects to the retrieval spearhead 1, pulls the connecting pipe 13 to move, thereby causing the locking component to retract and contact the axial limit, thus removing the one-way valve.

[0029] The engaging components include a caliper frame 8, a caliper 7, a rocker arm 14, and a caliper pin 15. A connecting pipe 13 is fitted onto the caliper frame 8 and slides axially with it. One end of the caliper frame 8 is fixedly connected to a one-way valve, and the other end extends into the connecting pipe 13. One end of the caliper 7 is hinged to the caliper frame 8 via a pin, and the other end is hinged to the rocker arm 14. The rocker arm 14 is hinged to the caliper frame 8 via the caliper pin 15. The caliper frame 8 is provided with an axially arranged groove. The caliper pin 15 slides within the groove and passes through the caliper 7, which is fixedly connected to the connecting pipe 13. The connecting pipe 13 drives the caliper pin 15 to move axially within the groove, thereby driving the rocker arm 14 to rotate and causing the caliper 7 to retract radially.

[0030] The engaging spring 6 is located inside the connecting tube 13 and is fitted onto the caliper frame 8. One end of the engaging spring 6 is provided with a spring baffle 5 that abuts against it. The spring baffle 5 is fixed to the end of the caliper frame 8 by a baffle bolt 16. The other end of the engaging spring 6 abuts against the caliper pin 15, so that the engaging component is in the unfolded state.

[0031] The engaging component includes two symmetrically arranged calipers 7 and rocker arms 14, with the two rocker arms 14 sharing a caliper pin 15. The two calipers 7 are hinged to the same pin, forming a V-shaped structure.

[0032] A spear-catching seat 3 is provided at the end of the connecting pipe 13 away from the one-way valve. One end of the spear-catching seat 3 is connected to the connecting pipe 13 through a traction pin 4, and the other end is connected to the spear-catching head 1 through a connecting pin 2, so that the spear-catching head 1 drives the connecting pipe 13 to move axially through the spear-catching seat 3 and the traction pin 4.

[0033] The spear holder 3 is equipped with a spearhead spring 17 and a spearhead positioning pin 18. One end of the spearhead 1 extends into the spear holder 3 and is clearance-fitted with the spear holder 3. One end of the spearhead spring 17 abuts against the inner end face of the spear holder 3, and the other end abuts against the end of the spearhead 1 through the spearhead positioning pin 18, so that the spearhead 1 has flexible movement space within the gap range with the spear holder 3.

[0034] The spear holder 3 has a strip groove along the axial direction, and the traction pin 4 is slidably disposed in the strip groove, so that the spear holder 3 has axial movement space in the connecting pipe 13.

[0035] The one-way valve includes a valve core 12, a valve core spring 9, and a valve core seat 10. The valve core 12 is elastically connected to the valve core seat 10 through the valve core spring 9. The end of the locking member connected to the one-way valve is provided with a conical surface. Under the action of the valve core spring 9, the valve core 12 abuts against the conical surface, thereby realizing the one-way sealing function of the one-way valve in the housing 11.

[0036] During drilling operations in high-gas formations in coal mines, a one-way short section is installed inside the drill string. The valve core 12, under the action of the valve core spring 9, abuts against the conical surface to achieve a one-way seal, preventing high-pressure gas from flowing back out from inside the drill pipe. After drilling is completed, a retrieval device is lowered and connected to the retrieval spearhead 1. The retrieval spearhead 1 is lifted, and the connecting pipe 13 is moved axially through the retrieval spearhead seat 3 and the traction pin 4. The connecting pipe 13 drives the caliper pin 15 to move axially in the slide groove, driving the rocker arm 14 to rotate, causing the caliper 7 to retract radially. The locking component disengages from the limiting ring groove, and the one-way valve moves upward, achieving separation of the one-way valve from the housing 11. After the one-way valve separates from the housing 11, the retrieval device lifts the one-way valve out of the drill string, providing a channel for the subsequent lowering of the screen pipe. After the locking component retracts to its limit position, it releases the engagement with the limiting ring groove, and the one-way valve begins to move upward as a whole. The entire process requires no additional tools and is automatically separated only by the retrieval device, facilitating stable operation in complex underground environments.

[0037] Example 2 This embodiment describes the usage method of the removable one-way valve core in Embodiment 1. The usage method specifically includes the following steps: When starting the one-way short section during drilling operations in high-gas formations in coal mines, the one-way short section is first installed inside the drill string. One end of the one-way valve abuts against the limiting step. Under the action of the locking spring 6, the locking component unfolds from the opening of the connecting pipe 13 and is embedded in the limiting ring groove to achieve axial fixation. Under the action of the valve core spring 9, the valve core 12 abuts against the conical surface to form a one-way seal and prevent gas backflow.

[0038] After drilling is completed, the retrieval device is lowered and connected to the retrieval spearhead 1. The retrieval spearhead 1 is then lifted, and the retrieval spearhead 1 drives the retrieval spear seat 3 to move axially via the connecting pin 2. The retrieval spear seat 3 drives the connecting pipe 13 to move axially via the traction pin 4. The connecting pipe 13 drives the caliper pin 15 to move axially within the sliding groove of the caliper frame 8, driving the rocker arm 14 to rotate and causing the caliper 7 to retract radially. After the locking component retracts to its limit position, it releases its engagement with the limiting ring groove, and the one-way valve begins to move upward as a whole, realizing the separation of the one-way valve from the housing 11.

[0039] After separation, the retrieval device lifts the one-way valve out of the drill string, providing a channel for the subsequent lowering of the screen pipe; the retrieval spearhead 1 has flexible movement space within the gap of the retrieval spearhead seat 3, and a stable connection is ensured by the spearhead spring 17 and the spearhead positioning pin 18 to avoid jamming.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A removable one-way valve section, comprising a housing and a one-way valve disposed within the housing, characterized in that, The one-way valve is detachably connected to the housing; the housing has a limiting step and a limiting annular groove at both ends of the one-way valve, one end of the one-way valve abuts against the limiting step, and the other end is provided with a connecting pipe; the end of the connecting pipe away from the one-way valve is connected to a spearhead; the connecting pipe has a locking member that can retract and expand radially along the housing, the locking member is connected to the connecting pipe, and the radial retraction of the locking member is driven by the axial movement of the connecting pipe; The connecting pipe has an opening on its side wall, and the engaging member has an engaging spring inside. Under the elastic force of the engaging spring, the engaging member initially unfolds from the opening and is embedded in the limiting ring groove, cooperating with the limiting step to axially fix the one-way valve. When the one-way valve is detached from the housing, the retrieval device connects to the retrieval spearhead, pulls the connecting pipe to move, thereby causing the locking component to retract and contact the axial limit, thus removing the one-way valve.

2. The valve core removable one-way short section according to claim 1, characterized in that, The engaging component includes a caliper frame, calipers, a rocker arm, and caliper pins. The connecting tube is fitted onto the caliper frame and slides axially with the caliper frame. One end of the caliper frame is fixedly connected to the one-way valve, and the other end extends into the connecting tube. One end of the caliper is hinged to the caliper frame via a pin, and the other end is hinged to the rocker arm. The rocker arm is hinged to the caliper frame via a caliper pin. The caliper frame is provided with a sliding groove arranged axially. The caliper pin is slidably disposed in the sliding groove and passes through the caliper and is fixedly connected to the connecting pipe. The connecting pipe drives the caliper pin to move axially within the sliding groove, thereby driving the rocker arm to rotate and causing the caliper to retract radially.

3. The valve core removable one-way short section according to claim 2, characterized in that, The engaging spring is located inside the connecting tube and is fitted onto the caliper frame. One end of the engaging spring is provided with a spring baffle that abuts against it, and the spring baffle is fixed to the caliper frame by a baffle bolt. The other end of the engaging spring abuts against the caliper pin, so that the engaging component is in the unfolded state.

4. The valve core removable one-way short section according to claim 3, characterized in that, The spring stop is located at the end of the caliper bracket.

5. The valve core removable one-way short section according to claim 2, characterized in that, The engaging component includes two symmetrically arranged calipers and swing arms, with the two swing arms sharing the caliper pin.

6. The valve core removable one-way short section according to claim 5, characterized in that, The two calipers are hinged to the same pin, forming a V-shaped structure.

7. The valve core removable one-way short section according to claim 1, characterized in that, The end of the connecting pipe away from the one-way valve is provided with a spear holder. One end of the spear holder is connected to the connecting pipe through a traction pin, and the other end is connected to the spearhead through a connecting pin, so that the spearhead drives the connecting pipe to move axially through the spear holder and the traction pin.

8. The valve core removable one-way short section according to claim 7, characterized in that, The spear holder is equipped with a spearhead spring and a spearhead positioning pin; one end of the spearhead extends into the spear holder and is clearance-fitted with the spear holder; one end of the spearhead spring abuts against the inner hole end face of the spear holder, and the other end abuts against the end of the spearhead through the spearhead positioning pin, so that the spearhead has flexible movement space within the gap range with the spear holder.

9. The valve core removable one-way short section according to claim 8, characterized in that, The spear holder is provided with a strip groove along the axial direction, and the traction pin is slidably disposed in the strip groove, so that the spear holder has axial movement space in the connecting pipe.

10. The valve core removable one-way short section according to claim 1, characterized in that, The one-way valve includes a valve core, a valve core spring, and a valve core seat. The valve core is elastically connected to the valve core seat through the valve core spring. The end of the engaging member connected to the one-way valve is provided with a conical surface. Under the action of the valve core spring, the valve core abuts against the conical surface, thereby realizing the one-way sealing function of the one-way valve in the housing.

11. A method of using a valve core removable one-way short section as described in any one of claims 1 to 10, characterized in that, After drilling is completed, the retrieval device is lowered and connected to the retrieval spearhead. The retrieval spearhead is then lifted, causing the locking component to retract. After the locking component disengages from the limiting ring groove, the one-way valve moves upward, thus separating the one-way valve from the housing.

12. The method of use according to claim 11, characterized in that, After the check valve separates from the housing, the retrieval device lifts the check valve out of the drill string, providing a channel for the subsequent lowering of the screen pipe.

13. The method of use according to claim 11, characterized in that, After the locking component retracts to its limit position, it releases its engagement with the limiting annular groove, and the one-way valve begins to move upward as a whole.

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