Downhole drill tool anti-caving tool, anti-caving drilling system, and anti-caving drilling method

Abstract

The application discloses a downhole drilling tool anti-collapse device, an anti-collapse drilling system and an anti-collapse drilling method. The anti-collapse device comprises a prevention tool body connected between an upper drilling string and a bottom drilling tool combination structure and provided with an axially-through first central hole; a one-way ball valve structure capable of being opened under the action of a pressure difference to make the first central hole in a through state or closed to make the first central hole in a closed state; and a pressure relief structure comprising a pressure relief short section body provided with a second central hole and a side wall one-way valve on the side wall of the pressure relief short section body, the side wall one-way valve being capable of being opened or closed under the action of a pressure difference between an outer annulus and the second central hole. The application can realize the identification and risk warning of the downhole drilling tool collapse risk through the change of the fluid velocity field in the wellbore without changing the operation process flow, and reduce the effective external extrusion pressure through the automatic adjustment of the internal and external pressure difference of the drilling tool.

Description

Technical Field

[0001] This invention relates to the field of drilling technology for oil and gas and geothermal resources, and in particular to a downhole drilling tool anti-crushing tool, an anti-crushing drilling system, and an anti-crushing drilling method. Background Technology

[0002] Downhole drill string crushing is one of the major challenges faced in oil and gas and geothermal resource drilling projects. As oil and gas exploration and development expands from shallow and medium-depth formations to deep and ultra-deep formations, and even into ultra-deep formations reaching tens of thousands of meters, formation pressures reach 100-200 MPa. The formation pressures in deep and ultra-deep formations exceed the safe resistance to external extrusion of conventional drill strings, making the risk of downhole drill string crushing during the drilling process even more prominent.

[0003] Currently, the approach used is based on pre-construction drill string risk prediction, which involves increasing the steel grade and wall thickness of the drill string to enhance its resistance to external extrusion and reduce the risk of downhole drill string failure. However, this method is costly in increasing the steel grade and wall thickness, and is limited by downhole space and drill string size, so the drill string's resistance to external extrusion cannot be increased indefinitely, and it cannot completely prevent drill string failure. Furthermore, there is currently a lack of downhole drill string failure early warning methods.

[0004] Therefore, based on years of experience and practice in related industries, the inventor proposes a downhole drilling tool anti-crushing tool, an anti-crushing drilling system, and an anti-crushing drilling method to overcome the defects of the prior art. Summary of the Invention

[0005] The purpose of this invention is to provide a downhole drilling tool anti-crushing tool, an anti-crushing drilling system, and an anti-crushing drilling method. Without altering the operational process, this invention identifies and warns of downhole drilling tool crushing risks by observing changes in the fluid velocity field within the wellbore. Furthermore, it automatically adjusts the pressure difference between the inside and outside of the drilling tool to reduce effective external crushing pressure. This achieves early warning and proactive prevention of downhole drilling tool crushing, ensuring the safety of the downhole drilling tool.

[0006] The objective of this invention is achieved by providing a downhole drilling tool anti-crushing tool, comprising:

[0007] The preventive tool body is connected between the upper drill string and the bottom drill string assembly structure, and the preventive tool body is provided with an axially penetrating first central hole;

[0008] A one-way ball valve structure is disposed in the first central hole. The one-way ball valve structure can be opened under the action of pressure difference to make the first central hole open, or the one-way ball valve structure can be closed under the action of pressure difference to make the first central hole closed.

[0009] A pressure relief structure, located below the one-way ball valve structure, includes a pressure relief sub-body connected in series with the prevention tool body. The pressure relief sub-body has an axially penetrating second central hole, which communicates with the first central hole. A sidewall one-way valve is provided on the side wall of the pressure relief sub-body. This sidewall one-way valve can open under the pressure difference between the outer annulus of the prevention tool body and the second central hole to allow fluid to flow inward from the outer annulus, or it can remain closed. The opening pressure of the sidewall one-way valve is less than the drill string yielding and bursting pressure.

[0010] In a preferred embodiment of the present invention, when the pressure difference between the outer annulus of the preventive tool body and the second central hole is greater than the starting pressure of the side wall check valve, the side wall check valve opens to allow fluid to flow from the outer annulus into the second central hole; when the pressure difference between the outer annulus of the preventive tool body and the second central hole is less than or equal to the starting pressure of the side wall check valve, the side wall check valve is closed.

[0011] In a preferred embodiment of the present invention, the sidewall one-way valve includes a valve seat hole provided on the sidewall of the pressure relief stub body. The valve seat hole includes a first seat hole near the second central hole, and a second seat hole is provided in communication with the first seat hole. The diameter of the first seat hole is larger than the diameter of the second seat hole, and a first step is formed between the first seat hole and the second seat hole. A valve core is slidably disposed in the valve seat hole. The valve core includes a first core seat and a second core seat. The first core seat can slide along the first seat hole, and the second core seat can slide along the second seat hole. A second step is formed between the first core seat and the second core seat, and the second step can abut against the first step to close the sidewall one-way valve.

[0012] In a preferred embodiment of the present invention, the one-way ball valve structure includes a ball valve seat structure, wherein a ball opening and closing element capable of moving up and down is provided within the ball valve seat structure.

[0013] In a preferred embodiment of the present invention, the ball valve seat structure includes a ball valve sealing groove and an annular spring base that are spaced apart vertically on the side wall of the first central hole. The annular spring base has an axially penetrating third central hole. An upwardly extending spring structure is connected to the annular spring base. The top end of the spring structure abuts against the ball opening and closing member. The ball valve sealing groove has an axially penetrating fourth central hole. The ball opening and closing member can move up and down to abut against and close the fourth central hole or move away from the fourth central hole.

[0014] In a preferred embodiment of the present invention, the bottom end of the preventive tool body is provided with a lower connector for connecting to the bottom drill assembly structure.

[0015] In a preferred embodiment of the present invention, the top of the preventive tool body is provided with an upper connector for connecting to the upper drill string.

[0016] The object of the present invention can also be achieved as follows: a drilling system for preventing crushing of drilling tools includes an upper drill string, a bottom drill string assembly structure, and a surface signal receiving device. The top of the upper drill string is connected to a surface drilling rig that provides power for drilling, and the bottom of the upper drill string is connected to the aforementioned downhole drill string anti-crushing tool and the bottom drill string assembly structure. The surface signal receiving device is used to receive and identify drilling fluid pulse signals to identify the status of downhole valves and provide early warning of drill string crushing risk.

[0017] In a preferred embodiment of the present invention, the bottom end of the downhole drilling tool anti-crushing tool is connected to the bottom drilling tool assembly structure via a lower connector thread, and the top end of the downhole drilling tool anti-crushing tool is connected to the upper drill string via an upper connector thread.

[0018] The objective of this invention can also be achieved as follows: a method for preventing well collapse, comprising,

[0019] Assemble the aforementioned anti-crushing drilling system by lowering the bottom drill string assembly, downhole anti-crushing tools, and upper drill string into the wellbore; during drilling, drilling fluid is injected through the upper drill string, the surface drilling rig is turned on to provide power for drilling, and the surface signal receiving device receives and identifies the drilling fluid pulse signal.

[0020] When the pressure difference between the outer annulus of the tool body and the second central hole is less than the opening pressure of the side wall check valve, the side wall check valve is closed. At this time, under the pressure of the injected drilling fluid, the check ball valve structure opens, the drilling fluid flow channel is open, and the drilling fluid flows downward normally for drilling.

[0021] When the pressure difference between the outer annulus and the second central hole of the prevention tool body is greater than the opening pressure of the side wall check valve, the side wall check valve opens and the fluid flows in from the outer annulus. Under the action of the fluid pressure flowing into the second central hole, the check ball valve structure is in the closed state, cutting off and closing the drilling fluid flow channel.

[0022] Closing the drilling fluid flow channel alters the drilling fluid velocity field. The ground signal receiving device installed at the wellhead receives and identifies drilling fluid pulse signals, providing an early warning of the risk of drill string crushing. After receiving the drill string crushing risk warning, the staff analyzes the situation and determines the necessary actions.

[0023] As described above, the downhole drilling tool anti-crushing tool, anti-crushing drilling system, and anti-crushing drilling method of the present invention have the following beneficial effects:

[0024] This invention can automatically adjust the internal and external pressure difference of the drill string by changing the flow direction of the medium through a pressure relief structure without changing the operation process, thereby reducing the effective external extrusion pressure on the drill string and preventing tool crushing through active prevention and control. By combining the pressure relief structure and the one-way ball valve structure, the one-way ball valve structure realizes the state switching of the drilling fluid flow channel, which can flexibly control the drilling fluid flow direction within the tubing string, effectively preventing blowouts and well kicks that may be caused by excessive pressure inside the drill string. It also changes the drilling fluid velocity field and sends drilling fluid pulse signals to the surface, realizing the identification of downhole valve status and drill string crushing risk warning. By monitoring the flow field, it can effectively identify the working status of downhole tools and realize drill string crushing risk warning. The safety of downhole drilling tools is ensured through both early warning and active prevention and control. Attached Figure Description

[0025] The accompanying drawings are intended only to illustrate and explain the present invention and do not limit the scope of the invention.

[0026] in:

[0027] Figure 1 : This is a schematic diagram of the downhole drilling tool anti-crushing tool of the present invention.

[0028] Figure 2 : This is a schematic diagram of the anti-crushing drilling system of the present invention.

[0029] In the picture:

[0030] 100. Tools to prevent downhole drilling tools from being crushed;

[0031] 1. Connector;

[0032] 2. One-way ball valve structure; 21. Ball valve sealing groove; 210. Fourth center hole; 22. Ball opening and closing element; 23. Spring structure; 24. Annular spring base; 240. Third center hole;

[0033] 3. Prevention tool body; 30. First center hole;

[0034] 4. Pressure relief structure; 40. Second center hole; 41. Pressure relief sub body; 411. Valve seat hole; 412. Valve core; 42. Side wall check valve; 5. Lower connector; 6. Outer annulus; 7. Well shaft;

[0035] 200. Anti-crushing drilling system;

[0036] 201. Bottom drill string assembly structure; 202. Upper drill string; 203. Ground signal receiving device; 204. Ground drilling rig equipment. Detailed Implementation

[0037] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0038] The specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art can conceive of any possible modifications based on the invention, all of which should be considered within the scope of the invention. It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there may be an intervening element. The terms "mounted," "connected," and "linked" should be interpreted broadly; for example, they can refer to mechanical or electrical connections, or internal communication between two elements, and can be direct or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0040] like Figure 1 As shown, the present invention provides a downhole drilling tool anti-crushing tool 100, comprising:

[0041] The preventive tool body 3 is connected between the upper drill string and the bottom drill string assembly structure, and the preventive tool body 3 is provided with an axially penetrating first central hole 30;

[0042] One-way ball valve structure 2 is disposed in the first central hole 30. One-way ball valve structure 2 can be opened under the action of pressure difference to make the first central hole 30 in a through state, or one-way ball valve structure 2 can be closed under the action of pressure difference to make the first central hole 30 in a cut-off closed state.

[0043] The pressure relief structure 4, located below the one-way ball valve structure 2, includes a pressure relief sub-body 41 connected in series with the prevention tool body 3. The pressure relief sub-body 41 has an axially penetrating second central hole 40, which communicates with the first central hole 30, forming a drilling fluid flow channel for the tool. A side wall one-way valve 42 is provided on the side wall of the pressure relief sub-body 41. The side wall one-way valve 42 can be opened under the pressure difference between the outer annulus 6 (the annulus between the prevention tool body 3 and the wellbore 7) and the second central hole 40 to allow fluid to flow in from the outer annulus 6 or to be closed. The opening pressure P1 of the side wall one-way valve 42 is less than the drill string yielding and crushing pressure P.

[0044] When the pressure difference between the outer annulus 6 of the preventive tool body 3 and the second central hole 40 is less than the opening pressure of the side wall check valve 42, the side wall check valve 42 is closed. There is no connection channel between the outer annulus 6 of the preventive tool body 3 and the second central hole 40, and there is no exchange of media inside and outside the drill string. At this time, under the pressure of the injected drilling fluid, the one-way ball valve structure 2 is opened, the drilling fluid flow channel is open, and the drilling fluid flows downward normally for drilling.

[0045] When the pressure difference between the outer annulus 6 and the second central hole 40 of the preventive tool body 3 exceeds the opening pressure of the sidewall check valve 42, the sidewall check valve 42 opens, connecting the outer annulus 6 and the second central hole 40. Fluid flows inward from the outer annulus 6, gradually reducing the pressure difference between the inside and outside of the drill string, effectively reducing external pressure and lowering or eliminating the risk of drill string crushing. Under the pressure of the fluid flowing into the second central hole 40, the hydraulic pressure below the one-way ball valve structure 2 increases, and the one-way ball valve structure 2 closes under the pressure difference, cutting off the drilling fluid flow channel. The closure of the drilling fluid flow channel effectively prevents blowouts and well kicks that may be caused by excessive pressure inside the drill string. The closure of the drilling fluid flow channel changes the drilling fluid velocity field, sending a drilling fluid pulse signal to the surface, realizing the identification of downhole valve status and early warning of drill string crushing risk.

[0046] The downhole drilling tool anti-crushing tool 100 provided by this invention can automatically adjust the internal and external pressure difference of the drilling tool by changing the flow direction of the medium through the pressure relief structure 4 without changing the operation process, thereby reducing the effective external crushing pressure and preventing tool crushing through active control. By combining the pressure relief structure 4 and the one-way ball valve structure 2, the one-way ball valve structure 2 realizes the state switching of the drilling fluid flow channel, which can flexibly control the flow direction of the drilling fluid in the tubing string, effectively preventing well blowouts and well kicks that may be caused by excessive pressure inside the drilling tool, and changing the drilling fluid velocity field to send drilling fluid pulse signals to the surface, thereby realizing the identification of the downhole valve status and early warning of drilling tool crushing risk.

[0047] Furthermore, such as Figure 1As shown, when the pressure difference between the outer annulus 6 and the second central hole 40 of the preventive tool body 3 is greater than the starting pressure of the side wall check valve 42, the side wall check valve 42 opens to allow fluid to flow from the outer annulus into the second central hole; when the pressure difference between the outer annulus 6 and the second central hole 40 of the preventive tool body 3 is less than or equal to the starting pressure of the side wall check valve 42, the side wall check valve 42 is closed.

[0048] Furthermore, such as Figure 1 As shown, the sidewall one-way valve 42 includes a valve seat hole 411 provided on the sidewall of the pressure relief short body 41. The valve seat hole 411 includes a first seat hole near the second center hole, and a second seat hole is provided in communication with the first seat hole. The diameter of the first seat hole is larger than the diameter of the second seat hole. A first step is formed between the first seat hole and the second seat hole. A valve core 412 is slidably provided in the valve seat hole 411. The valve core 412 includes a first core seat and a second core seat. The first core seat can slide along the first seat hole, and the second core seat can slide along the second seat hole. A second step is formed between the first core seat and the second core seat. The second step can abut against the first step to close the sidewall one-way valve 42.

[0049] Furthermore, such as Figure 1 As shown, the one-way ball valve structure 2 includes a ball valve seat structure, and a ball opening and closing element 22 that can move up and down is provided inside the ball valve seat structure.

[0050] Furthermore, such as Figure 1 As shown, the ball valve seat structure includes a ball valve sealing groove 21 and an annular spring base 24 that are spaced apart on the side wall of the first central hole 30. The annular spring base 24 is provided with an axially penetrating third central hole 240. An upwardly extending spring structure 23 is connected to the annular spring base 24. The top end of the spring structure 23 abuts against and connects to the ball opening and closing member 22. The ball valve sealing groove 21 is provided with an axially penetrating fourth central hole 210. The ball opening and closing member 22 can move up and down to abut against and close the fourth central hole 210 or leave the fourth central hole 210.

[0051] In an embodiment of the present invention, the ball valve sealing groove 21 is an annular limiting structure fixed within the first central hole 30. The ball opening and closing component 22 is a movable ball located below the ball valve sealing groove 21, with a spring structure 23 connected to its lower part. Under the action of the pressure difference between the upper and lower parts of the ball opening and closing component 22, the spring structure 23 moves upward or downward through stretching and contraction (when the side wall one-way valve 42 is open, the pressure inside the wellbore increases, and the spring structure 23 stretches under the pressure; when the side wall one-way valve 42 is closed, the pressure inside the wellbore is smaller, and the spring structure 23 expands and contracts under the action of the downstream drilling fluid). The bottom end of the spring structure 23 is fixed by an annular spring base 24. When the ball opening and closing component 22 is at the ball valve sealing groove 21 under the action of the pressure difference and the spring structure 23, the one-way ball valve structure 2 is closed; when the ball opening and closing component 22 is below the ball valve sealing groove 21 under the action of the pressure difference and the spring structure 23, the one-way ball valve structure 2 is open.

[0052] Furthermore, such as Figure 1 As shown, the bottom end of the prevention tool body 3 is provided with a lower connector 5 for connecting the bottom drill assembly structure 201.

[0053] Furthermore, such as Figure 1 As shown, the top of the prevention tool body 3 is provided with an upper connector 1 for connecting the upper drill string 202.

[0054] like Figure 2 As shown, the present invention also provides a drilling system 200 to prevent drilling from being crushed, including an upper drill string 202, a bottom drill string assembly structure 201, and a surface signal receiving device 203 (prior art). The top end of the upper drill string 202 is connected to a surface drilling rig 204 (prior art) that provides power for drilling, and the bottom end of the upper drill string 202 is connected to a downhole drilling anti-crushing tool 100 and the bottom drill string assembly structure 201. The surface signal receiving device 203 is used to receive and identify drilling fluid pulse signals to identify the status of downhole valves and warn of drill string crushing risks.

[0055] Furthermore, the bottom end of the downhole drilling tool anti-crushing tool 100 is threadedly connected to the bottom drilling tool assembly structure 201 via the lower connector 5, and the top end of the downhole drilling tool anti-crushing tool 100 is threadedly connected to the upper drill string 202 via the upper connector 1.

[0056] A method for preventing well collapse includes:

[0057] like Figure 2 As shown, the anti-crushing drilling system 200 is assembled by lowering the bottom drill string assembly structure 201, the downhole drill string anti-crushing tool 100, and the upper drill string 202 into the wellbore 7. During drilling, drilling fluid is injected through the upper drill string 202, and the surface drilling rig equipment 204 is turned on to provide power for drilling. The surface signal receiving device 203 receives and identifies the drilling fluid pulse signal.

[0058] When the pressure difference between the outer annulus 6 and the second central hole 40 of the preventive tool body 3 is less than the opening pressure P1 of the side wall check valve 42, the opening pressure of the side wall check valve 42 is not reached, the risk of drill string crushing is small, and the side wall check valve 42 is in the closed state. There is no connection between the outer annulus 6 and the second central hole 40 of the preventive tool body 3, and there is no exchange of media inside and outside the drill string. The drilling fluid inside the drill string cannot flow through the side wall check valve 42, preventing leakage. At this time, under the pressure of the injected drilling fluid, the ball opening / closing element 22 compresses the spring structure 23 and moves downward. The ball opening / closing element 22 and the ball valve sealing groove 21 separate, the one-way ball valve structure 2 opens, and the drilling fluid flow channel is open. The drilling fluid flows in through the gap between the ball valve sealing groove 21 and the ball opening / closing element 22, and the drilling fluid flows downward normally for drilling.

[0059] When the pressure difference between the outer annulus 6 and the second central hole 40 of the preventive tool body 3 exceeds the opening pressure P1 of the sidewall one-way valve 42, the drill string is at risk of being crushed. Upon reaching the preset opening pressure of the sidewall one-way valve 42, the valve opens, connecting the outer annulus 6 and the second central hole 40 to form a medium exchange channel between the second central hole 40 (inner annulus) and the outer annulus 6. Fluid flows inward from the outer annulus 6, gradually reducing the pressure difference between the inside and outside of the drill string, effectively reducing external pressure and lowering or eliminating the risk of drill string crushing. Under the pressure of the fluid flowing into the second central hole 40, the hydraulic pressure below the one-way ball valve structure 2 increases, the spring structure 23 stretches and moves upward, pushing the ball opening / closing element 22 upward until it reaches the ball valve sealing groove 21. At this time, there is no gap between the ball opening / closing element 22 and the ball valve sealing groove 21, and the one-way ball valve structure 2 is in the closed state, cutting off the drilling fluid flow channel. The closure of the drilling fluid flow channel effectively prevents blowouts and well surges that may be caused by excessive pressure inside the drill string. The one-way ball valve structure 2 can flexibly control the flow direction of drilling fluid in the tubing string and effectively prevent well blowouts and well surges during pressure relief.

[0060] Closing the drilling fluid flow channel alters the drilling fluid velocity field. The surface signal receiver 203 installed at the wellhead receives and identifies drilling fluid pulse signals, enabling the identification of downhole valve status and providing early warning of drill string crush risk. Upon receiving the drill string crush risk warning, operators can analyze the necessary actions, such as increasing the drilling fluid density to balance the internal and external pressure difference, thereby reducing or eliminating the drill string crush risk.

[0061] As described above, the downhole drilling tool anti-crushing tool, anti-crushing drilling system, and anti-crushing drilling method of the present invention have the following beneficial effects:

[0062] This invention can automatically adjust the internal and external pressure difference of the drill string by changing the flow direction of the medium through a pressure relief structure without changing the operation process, thereby reducing the effective external extrusion pressure on the drill string and preventing tool crushing through active prevention and control. By combining the pressure relief structure and the one-way ball valve structure, the one-way ball valve structure realizes the state switching of the drilling fluid flow channel, which can flexibly control the drilling fluid flow direction within the tubing string, effectively preventing blowouts and well kicks that may be caused by excessive pressure inside the drill string. It also changes the drilling fluid velocity field and sends drilling fluid pulse signals to the surface, realizing the identification of downhole valve status and drill string crushing risk warning. By monitoring the flow field, it can effectively identify the working status of downhole tools and realize drill string crushing risk warning. The safety of downhole drilling tools is ensured through both early warning and active prevention and control.

[0063] The above description is merely an illustrative embodiment of the present invention and is not intended to limit the scope of the invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A tool for preventing the crushing of downhole drilling tools, characterized in that, include, The preventive tool body is connected between the upper drill string and the bottom drill string assembly structure, and the preventive tool body is provided with an axially penetrating first central hole; A one-way ball valve structure is disposed in the first central hole. The one-way ball valve structure can be opened under the action of pressure difference to make the first central hole open, or the one-way ball valve structure can be closed under the action of pressure difference to make the first central hole closed. A pressure relief structure, located below the one-way ball valve structure, includes a pressure relief sub-body connected in series with the prevention tool body. The pressure relief sub-body has an axially penetrating second central hole, which communicates with the first central hole. A sidewall one-way valve is provided on the side wall of the pressure relief sub-body. This sidewall one-way valve can open under the pressure difference between the outer annulus of the prevention tool body and the second central hole to allow fluid to flow inward from the outer annulus, or it can remain closed. The opening pressure of the sidewall one-way valve is less than the drill string yielding and bursting pressure.

2. The downhole drilling tool anti-crushing tool as described in claim 1, characterized in that, When the pressure difference between the outer annulus of the preventive tool body and the second central hole is greater than the starting pressure of the side wall check valve, the side wall check valve opens to allow fluid to flow from the outer annulus into the second central hole; when the pressure difference between the outer annulus of the preventive tool body and the second central hole is less than or equal to the starting pressure of the side wall check valve, the side wall check valve is closed.

3. The downhole drilling tool anti-crushing tool as described in claim 2, characterized in that, The sidewall one-way valve includes a valve seat hole on the sidewall of the pressure relief stub body. The valve seat hole includes a first seat hole near the second central hole, and a second seat hole is connected to the first seat hole. The diameter of the first seat hole is larger than the diameter of the second seat hole, and a first step is formed between the first seat hole and the second seat hole. A valve core is slidably disposed in the valve seat hole. The valve core includes a first core seat and a second core seat. The first core seat can slide along the first seat hole, and the second core seat can slide along the second seat hole. A second step is formed between the first core seat and the second core seat, and the second step can abut against the first step to close the sidewall one-way valve.

4. The downhole drilling tool anti-crushing tool as described in claim 2, characterized in that, The one-way ball valve structure includes a ball valve seat structure, and a ball opening and closing element that can move up and down is provided inside the ball valve seat structure.

5. The downhole drilling tool anti-crushing tool as described in claim 4, characterized in that, The ball valve seat structure includes a ball valve sealing groove and an annular spring base that are spaced apart on the side wall of the first central hole. The annular spring base has an axially penetrating third central hole. An upwardly extending spring structure is connected to the annular spring base. The top end of the spring structure abuts against the ball opening and closing component. The ball valve sealing groove has an axially penetrating fourth central hole. The ball opening and closing component can move up and down to abut against and close the fourth central hole or move away from the fourth central hole.

6. The downhole drilling tool anti-crushing tool as described in claim 1, characterized in that, The bottom end of the prevention tool body is provided with a lower connector for connecting to the bottom drill assembly structure.

7. The downhole drilling tool anti-crushing tool as described in claim 1, characterized in that, The top of the preventive tool body is provided with an upper connector for connecting to the upper drill string.

8. A drilling system for preventing crushing, characterized in that, The device includes an upper drill string, a bottom drill string assembly structure, and a surface signal receiving device. The top end of the upper drill string is connected to a surface drilling rig that provides power for drilling. The bottom end of the upper drill string is connected to the downhole drill string anti-crushing tool and the bottom drill string assembly structure as described in any one of claims 1 to 7. The surface signal receiving device is used to receive and identify drilling fluid pulse signals to identify the status of downhole valves and provide early warning of drill string crushing risks.

9. The anti-crushing drilling system as described in claim 8, characterized in that, The bottom end of the downhole drilling tool anti-crushing tool is connected to the bottom drilling tool assembly structure via a lower connector thread, and the top end of the downhole drilling tool anti-crushing tool is connected to the upper drill string via an upper connector thread.

10. A method for preventing well collapse, characterized in that, include, Assemble the anti-crushing drilling system as described in claim 8 or 9, and lower the bottom drill string assembly structure, the downhole drill string anti-crushing tool, and the upper drill string into the wellbore; during the drilling process, drilling fluid is injected through the upper drill string, the surface drilling rig is turned on to provide power for drilling, and the surface signal receiving device receives and identifies the drilling fluid pulse signal; When the pressure difference between the outer annulus of the tool body and the second central hole is less than the opening pressure of the side wall check valve, the side wall check valve is closed. At this time, under the pressure of the injected drilling fluid, the check ball valve structure opens, the drilling fluid flow channel is open, and the drilling fluid flows downward normally for drilling. When the pressure difference between the outer annulus and the second central hole of the prevention tool body is greater than the opening pressure of the side wall check valve, the side wall check valve opens and the fluid flows in from the outer annulus. Under the action of the fluid pressure flowing into the second central hole, the check ball valve structure is in the closed state, cutting off and closing the drilling fluid flow channel. Closing the drilling fluid flow channel alters the drilling fluid velocity field. The ground signal receiving device installed at the wellhead receives and identifies drilling fluid pulse signals, providing an early warning of the risk of drill string crushing. After receiving the drill string crushing risk warning, the staff analyzes the situation and determines the necessary actions.

Images