Downhole drilling tool anti-collapse tool, anti-collapse drilling system and anti-collapse drilling method

Abstract

The invention relates to an anti-collapse tool for a downhole drilling tool, an anti-collapse drilling system and an anti-collapse drilling method.The anti-collapse tool comprises a prevention tool body connected between an upper drill column and a bottom drilling tool combined structure and provided with an axially-through first center hole; the one-way ball valve structure can be opened under the action of pressure difference to enable the first center hole to be in a through state or closed to enable the first center hole to be in a closed state; the pressure relief structure comprises a pressure relief nipple body, a second center hole is formed in the pressure relief nipple body, a side wall one-way valve is arranged on the side wall of the pressure relief nipple body, and the side wall one-way valve can be opened or closed under the action of the pressure difference between the outer annulus and the second center hole. According to the method, under the condition that the operation technological process is not changed, recognition and risk early warning of the collapse risk of the underground drilling tool can be achieved through the change of the fluid velocity field in the shaft, and the effective external extrusion force is reduced by automatically adjusting the pressure difference between the interior and the exterior of the drilling tool.

Description

Technical Field

[0001] The invention relates to the technical field of oil, natural gas and geothermal resource drilling, and in particular to a downhole drilling tool anti-collapse tool, an anti-collapse drilling system and an anti-collapse drilling method. Background Art

[0002] Downhole drill tool crushing is one of the main problems faced in oil, gas and geothermal resource drilling projects. As oil and gas exploration and development expands from medium and shallow layers to deep and ultra-deep layers, and even into ultra-deep layers of 10,000 meters, the formation pressure reaches 100-200MPa. The formation pressure in deep and ultra-deep layers exceeds the safety anti-external crushing strength of conventional drill tools, and the risk of downhole drill tool crushing during the drilling process is more prominent.

[0003] At present, the method used is to improve the steel grade and wall thickness of drill tools based on the risk prediction of drill tools before construction, so as to improve the anti-external crushing ability of drill tools and reduce the risk of failure of underground drill tools due to crushing. However, this method has high cost for increasing the steel grade and wall thickness of drill tools, and is limited by the underground space and drill tool size. The anti-external crushing ability of drill tools cannot be infinitely improved, and the crushing of drill tools cannot be completely avoided. At the same time, there is currently a lack of early warning methods for underground drill tool crushing.

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

[0005] The purpose of the present invention is to provide a downhole drill tool anti-crushing tool, an anti-crushing drilling system and an anti-crushing drilling method, which can, without changing the operation process, on the one hand, realize the identification and risk warning of downhole drill tool crushing risk through the change of fluid velocity field in the wellbore, and on the other hand, reduce the effective external squeezing pressure by automatically adjusting the pressure difference between the inside and outside of the drill tool, so as to realize early warning and active prevention and control of downhole drill tool crushing and ensure the safety of downhole drill tools.

[0006] The object of the present invention is achieved by providing a downhole drilling tool anti-collapse tool, comprising:

[0007] A preventive tool body is connected between the upper drill string and the bottom drill assembly structure, and a first central hole is axially penetrated on the preventive tool body;

[0008] a one-way ball valve structure, arranged in the first center hole, the one-way ball valve structure can be opened under the action of pressure difference to make the first center hole in a through state, or the one-way ball valve structure can be closed under the action of pressure difference to make the first center hole in a truncated and closed state;

[0009] The pressure relief structure is arranged below the one-way ball valve structure, and comprises a pressure relief nipple body connected in series to the preventive tool body, wherein the pressure relief nipple body is provided with an axially through-going second center hole, and the second center hole is communicated with the first center hole; a side wall one-way valve is arranged on the side wall of the pressure relief nipple body, and the side wall one-way valve can be opened under the pressure difference between the outer annulus of the preventive tool body and the second center hole to allow the fluid to flow inward from the outer annulus or be in a closed state; the opening pressure of the side wall one-way valve is less than the yield and crushing pressure of the drill string.

[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 center hole is greater than the starting pressure of the side wall one-way valve, the side wall one-way valve opens to allow fluid to flow from the outer annulus into the second center hole; when the pressure difference between the outer annulus of the preventive tool body and the second center hole is less than or equal to the starting pressure of the side wall one-way valve, the side wall one-way valve is closed.

[0011] In a preferred embodiment of the present invention, the side wall one-way valve includes a valve seat hole arranged on the side wall of the pressure relief nipple body, the valve seat hole includes a first seat hole close to the second center hole, the first seat hole is connected to the second seat hole, the aperture size of the first seat hole is larger than the aperture size of the second seat hole, and a first step portion is formed between the first seat hole and the second seat hole; a valve core is slidably arranged 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, the second core seat can slide along the second seat hole, a second step portion is formed between the first core seat and the second core seat, and the second step portion can abut against the first step portion to close the side wall one-way valve.

[0012] In a preferred embodiment of the present invention, the one-way ball valve structure includes a ball valve seat structure, and a ball opening and closing member that can move up and down is arranged in 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 connected to the side wall of the first center hole at upper and lower intervals, the annular spring base is provided with a third center hole axially passing through, the annular spring base is connected with a spring structure extending upward, the top end of the spring structure is abutted against the ball opening and closing member, the ball valve sealing groove is provided with a fourth center hole axially passing through, the ball opening and closing member can move up and down to abut and close the fourth center hole or leave the fourth center hole.

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

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

[0016] The purpose of the present invention can also be achieved in this way. A crush prevention drilling system includes an upper drill string, a bottom drill tool combination structure and a ground signal receiving device. The top end of the upper drill string is connected to a ground drilling rig that provides power for drilling, and the bottom end of the upper drill string is connected to the aforementioned downhole drill tool crush prevention tool and the bottom drill tool combination structure. The ground signal receiving device is used to receive and identify drilling fluid pulse signals to identify the downhole valve status and warn of the risk of drill tool crush.

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

[0018] The object of the present invention can also be achieved by providing an anti-collapse drilling method, comprising:

[0019] Assemble the aforementioned anti-squeeze drilling system, lower the bottom drilling tool assembly structure, the downhole drilling tool anti-squeeze tool, and the upper drill string into the wellbore; during the drilling process, inject drilling fluid through the upper drill string, start the ground drilling rig equipment to provide power for drilling, and the ground signal receiving device receives and identifies the drilling fluid pulse signal;

[0020] When the pressure difference between the outer annulus of the prevention tool body and the second center hole is less than the opening pressure of the side wall one-way valve, the side wall one-way valve is in a closed state. At this time, under the pressure of the injected drilling fluid, the one-way ball valve structure is opened, the drilling fluid flow channel is in a through state, and the drilling fluid flows downward normally for drilling;

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

[0022] The closure of the drilling fluid circulation channel changes the drilling fluid velocity field. The ground signal receiving device installed at the wellhead receives and identifies the drilling fluid pulse signal, and warns of the risk of drill tool crushing. After receiving the drill tool crushing risk warning, the staff analyzes the operations that need to be performed based on it.

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

[0024] The present invention can, without changing the operation process flow, change the medium flow direction through the pressure relief structure to automatically adjust the pressure difference between the inside and outside of the drill tool, reduce the effective external squeezing pressure of the drill tool, and prevent the tool from being crushed by active prevention and control; by combining the pressure relief structure with the one-way ball valve structure, the one-way ball valve structure realizes the state switching of the drilling fluid flow channel, and can flexibly control the flow direction of the drilling fluid in the pipe string, effectively preventing the blowout and well surge caused by excessive pressure in the drill tool, and changes the drilling fluid velocity field, sends a drilling fluid pulse signal to the ground, realizes the identification of the downhole valve state and the early warning of the risk of drilling tool crushing; effectively identifies the working state of the downhole tool through the monitoring of the flow field, and realizes the early warning of the risk of drilling tool crushing; ensures the safety of downhole drilling tools through early warning and active prevention and control. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0026] in:

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

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

[0029] In the figure:

[0030] 100. Downhole drilling tool anti-crushing tool;

[0031] 1. Upper joint;

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

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

[0034] 4. Pressure relief structure; 40. Second center hole; 41. Pressure relief nipple body; 411. Valve seat hole; 412. Valve core; 42. Side wall one-way valve; 5. Lower joint; 6. External annulus; 7. Wellbore;

[0035] 200. Prevent the drilling system from being crushed;

[0036] 201. Bottom drilling tool assembly structure; 202. Upper drill string; 203. Ground signal receiving device; 204. Ground drilling equipment. DETAILED DESCRIPTION

[0037] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described with reference to the accompanying drawings.

[0038] The specific embodiments of the present invention described herein are only used to explain the purpose of the present invention and cannot be understood as limiting the present invention in any way. Under the guidance of the present invention, technicians can conceive of any possible variations based on the present invention, which should be considered to belong to the scope of the present invention. It should be noted that when an element is referred to as "arranged on" another element, it can be directly on the other element or there can also be a central element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a central element at the same time. The terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be the internal communication of two elements, it can be directly connected, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation method.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

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

[0041] A prevention tool body 3 is connected between the upper drill string and the bottom drill assembly structure, and a first central hole 30 is axially penetrated on the prevention tool body 3;

[0042] The one-way ball valve structure 2 is arranged in the first central hole 30. The 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 the 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 is arranged below the one-way ball valve structure 2, and includes a pressure relief nipple body 41 connected in series to the prevention tool body 3. An axially penetrating second center hole 40 is arranged on the pressure relief nipple body 41, and the second center hole 40 is connected to the first center hole 30. The second center hole 40 is connected to the first center hole 30 to form a drilling fluid flow channel of the tool; a side wall one-way valve 42 is arranged on the side wall of the pressure relief nipple body 41, and the side wall one-way valve 42 can be opened under the pressure difference between the outer annulus 6 of the prevention tool body 3 (the annulus between the prevention tool body 3 and the wellbore 7) and the second center hole 40 to allow the fluid to flow inward from the outer annulus 6 or be in a closed state; the opening pressure P1 of the side wall one-way valve 42 is less than the yield pressure P of the drill string.

[0044] When the pressure difference between the outer annulus 6 of the prevention tool body 3 and the second center hole 40 is less than the opening pressure of the side wall one-way valve 42, the side wall one-way valve 42 is in a closed state, the outer annulus 6 of the prevention tool body 3 and the second center hole 40 have no connecting channel, and there is no medium exchange inside and outside the drill bit. At this time, under the pressure of the injected drilling fluid, the one-way ball valve structure 2 opens, the drilling fluid circulation channel is in a through state, and the drilling fluid flows downward normally for drilling.

[0045] When the pressure difference between the outer annulus 6 of the prevention tool body 3 and the second center hole 40 is greater than the opening pressure of the side wall one-way valve 42, the side wall one-way valve 42 opens, the outer annulus 6 of the prevention tool body 3 is connected to the second center hole 40, the fluid flows inward from the outer annulus 6, and the pressure difference between the inside and outside of the drill bit gradually decreases, effectively reducing the external extrusion pressure, reducing or eliminating the risk of drilling tool crushing. Under the action of the fluid pressure flowing into the second center hole 40, the hydraulic pressure below the one-way ball valve structure 2 increases, and the one-way ball valve structure 2 is closed under the action of the pressure difference, cutting off and closing the drilling fluid circulation channel. The closing of the drilling fluid circulation channel effectively prevents blowouts and well surges that may be caused by excessive pressure in the drilling tool. The closing of the drilling fluid circulation channel changes the velocity field of the drilling fluid, sends a drilling fluid pulse signal to the ground, and realizes the identification of the downhole valve status and the early warning of the risk of drilling tool crushing.

[0046] The downhole drill tool anti-collapse tool 100 provided by the present invention can, without changing the operating process flow, change the medium flow direction through the pressure relief structure 4 to automatically adjust the pressure difference between the inside and outside of the drill tool, reduce the effective external squeezing pressure, and prevent the tool from being crushed through active prevention and control; by combining the pressure relief structure 4 with the one-way ball valve structure 2, the one-way ball valve structure 2 realizes the state switching of the drilling fluid flow channel, and can flexibly control the flow direction of the drilling fluid in the pipe string, effectively preventing blowouts and well surges that may be caused by excessive pressure in the drill tool, and changes the drilling fluid velocity field, sending a drilling fluid pulse signal to the ground, realizing the identification of the downhole valve state and the early warning of the risk of drilling tool crushing.

[0047] Further, if Figure 1As shown, when the pressure difference between the outer annulus 6 of the prevention tool body 3 and the second center hole 40 is greater than the starting pressure of the side wall one-way valve 42, the side wall one-way valve 42 opens to allow fluid to flow from the outer annulus into the second center hole; when the pressure difference between the outer annulus 6 of the prevention tool body 3 and the second center hole 40 is less than or equal to the starting pressure of the side wall one-way valve 42, the side wall one-way valve 42 is closed.

[0048] Further, if Figure 1 As shown, the side wall one-way valve 42 includes a valve seat hole 411 arranged on the side wall of the pressure relief short joint body 41, the valve seat hole 411 includes a first seat hole close to the second center hole, the second seat hole is connected to the first seat hole, the aperture size of the first seat hole is larger than the aperture size of the second seat hole, and a first step portion is formed between the first seat hole and the second seat hole; a valve core 412 is slidably arranged 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, the second core seat can slide along the second seat hole, and a second step portion is formed between the first core seat and the second core seat, and the second step portion can be pressed against the first step portion to close the side wall one-way valve 42.

[0049] Further, if Figure 1 As shown, the one-way ball valve structure 2 includes a ball valve seat structure, in which a ball opening and closing member 22 capable of moving up and down is arranged.

[0050] Further, if Figure 1 As shown, the ball valve seat structure includes a ball valve sealing groove 21 and an annular spring base 24 connected to the side wall of the first center hole 30 at upper and lower intervals. The annular spring base 24 is provided with an axially through third center hole 240, and the annular spring base 24 is connected with an upwardly extending spring structure 23. The top end of the spring structure 23 is abutted against a ball opening and closing member 22. The ball valve sealing groove 21 is provided with an axially through fourth center hole 210, and the ball opening and closing member 22 can move up and down to abut and close the fourth center hole 210 or leave the fourth center hole 210.

[0051] In the embodiment of the present invention, the ball valve sealing slot 21 is an annular limiting structure fixed in the first center hole 30, the ball opening and closing member 22 is a movable ball located below the ball valve sealing slot 21, and the spring structure 23 connected to the lower part thereof realizes upward or downward movement through the stretching and contraction of the spring structure 23 under the action of the upper and lower pressure difference of the ball opening and closing member 22 (when the side wall one-way valve 42 is opened, the pressure in the wellbore increases, and the spring structure 23 stretches under the action of the pressure; when the side wall one-way valve 42 is closed, the pressure in the wellbore is small, and the spring structure 23 expands and contracts under the action of the downstream of the drilling fluid), and the bottom end of the spring structure 23 is fixed by an annular spring base 24. When the ball opening and closing member 22 is at the ball valve sealing slot 21 under the action of the pressure difference and the spring structure 23, the one-way ball valve structure 2 is closed, and when the ball opening and closing member 22 is below the ball valve sealing slot 21 under the action of the pressure difference and the spring structure 23, the one-way ball valve structure 2 is opened.

[0052] Further, if Figure 1 As shown, the bottom end of the prevention tool body 3 is provided with a lower joint 5 for connecting to the bottom drilling tool assembly structure 201 .

[0053] Further, if Figure 1 As shown, the top end of the prevention tool body 3 is provided with an upper joint 1 for connecting to an upper drill string 202 .

[0054] like Figure 2 As shown, the present invention also provides an anti-collapse drilling system 200, including an upper drill string 202, a bottom drill tool assembly structure 201 and a ground signal receiving device 203 (existing technology), the top of the upper drill string 202 is connected to a ground drilling rig 204 (existing technology) that provides power for drilling, the bottom end of the upper drill string 202 is connected to a downhole drill tool anti-collapse tool 100 and a bottom drill tool assembly structure 201, and the ground signal receiving device 203 is used to receive and identify drilling fluid pulse signals to identify the downhole valve status and warn of the risk of drill tool collapsing.

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

[0056] A method for preventing collapse of a well, comprising:

[0057] like Figure 2 As shown, an anti-collapse drilling system 200 is assembled, and a bottom drill assembly structure 201, a downhole drill anti-collapse tool 100, and an upper drill string 202 are lowered into the wellbore 7; during the drilling process, drilling fluid is injected through the upper drill string 202, and the ground drilling rig equipment 204 is turned on to provide power for drilling, and the ground signal receiving device 203 receives and identifies the drilling fluid pulse signal.

[0058] When the pressure difference between the outer annulus 6 of the prevention tool body 3 and the second center hole 40 is less than the opening pressure P1 of the side wall one-way valve 42, the opening pressure of the side wall one-way valve 42 is not reached, the risk of drilling tool crushing is small, the side wall one-way valve 42 is in a closed state, the outer annulus 6 of the prevention tool body 3 and the second center hole 40 have no connection channel, there is no medium exchange inside and outside the drilling tool, and the drilling fluid inside the drilling tool cannot flow through the side wall one-way valve 42, preventing leakage. At this time, under the pressure of the injected drilling fluid, the ball opening and closing member 22 compresses the spring structure 23 to move downward, the ball opening and closing member 22 and the ball valve sealing groove 21 are separated, the one-way ball valve structure 2 is opened, the drilling fluid circulation channel is in a through state, and the drilling fluid flows in from the gap between the ball valve sealing groove 21 and the ball opening and closing member 22, and the drilling fluid flows downward normally for drilling.

[0059] When the pressure difference between the outer annulus 6 of the prevention tool body 3 and the second center hole 40 is greater than the opening pressure P1 of the side wall one-way valve 42, the drilling tool is at risk of being crushed. When the preset opening pressure of the side wall one-way valve 42 is reached, the side wall one-way valve 42 is opened, and the outer annulus 6 of the prevention tool body 3 is connected with the second center hole 40 to form a medium exchange channel between the second center hole 40 (inner annulus) and the outer annulus 6. The fluid flows inward from the outer annulus 6, and the pressure difference between the inside and outside of the drilling tool gradually decreases, effectively reducing the external extrusion pressure, and reducing or eliminating the risk of crushing the drilling tool. Under the action of the fluid pressure flowing into the second center hole 40, the hydraulic pressure below the one-way ball valve structure 2 increases, the spring structure 23 stretches and moves upward, and pushes the ball opening and closing member 22 to move upward until the ball valve sealing groove 21. At this time, there is no gap between the ball opening and closing member 22 and the ball valve sealing groove 21, and the one-way ball valve structure 2 is in a closed state, cutting off and closing the drilling fluid circulation channel. The closing of the drilling fluid circulation channel effectively prevents the blowout and well surge that may be caused by excessive pressure in the drilling tool. The one-way ball valve structure 2 can flexibly control the flow direction of drilling fluid in the pipe string and effectively prevent the occurrence of blowouts and well spurts when the pressure is released.

[0060] The closing of the drilling fluid circulation channel changes the velocity field of the drilling fluid. The ground signal receiving device 203 installed at the wellhead receives and identifies the drilling fluid pulse signal, thereby identifying the downhole valve status and warning the risk of drilling tool crushing. After receiving the warning of drilling tool crushing risk, the staff can analyze the operations to be performed based on it, such as increasing the density of the drilling fluid to balance the internal and external pressure difference, thereby reducing or eliminating the risk of drilling tool crushing.

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

[0062] The present invention can, without changing the operation process flow, change the medium flow direction through the pressure relief structure to automatically adjust the pressure difference between the inside and outside of the drill tool, reduce the effective external squeezing pressure of the drill tool, and prevent the tool from being crushed by active prevention and control; by combining the pressure relief structure with the one-way ball valve structure, the one-way ball valve structure realizes the state switching of the drilling fluid flow channel, and can flexibly control the flow direction of the drilling fluid in the pipe string, effectively preventing the blowout and well surge caused by excessive pressure in the drill tool, and changes the drilling fluid velocity field, sends a drilling fluid pulse signal to the ground, realizes the identification of the downhole valve state and the early warning of the risk of drilling tool crushing; effectively identifies the working state of the downhole tool through the monitoring of the flow field, and realizes the early warning of the risk of drilling tool crushing; ensures the safety of downhole drilling tools through early warning and active prevention and control.

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

Claims

1. A downhole drilling tool anti-collapse tool, characterized in that: include, A preventive tool body is connected between the upper drill string and the bottom drill assembly structure, and a first central hole is axially penetrated on the preventive tool body; a one-way ball valve structure, arranged in the first center hole, the one-way ball valve structure can be opened under the action of pressure difference to make the first center hole in a through state, or the one-way ball valve structure can be closed under the action of pressure difference to make the first center hole in a truncated and closed state; The pressure relief structure is arranged below the one-way ball valve structure, and comprises a pressure relief nipple body connected in series to the preventive tool body, wherein the pressure relief nipple body is provided with an axially through-going second center hole, and the second center hole is communicated with the first center hole; a side wall one-way valve is arranged on the side wall of the pressure relief nipple body, and the side wall one-way valve can be opened under the pressure difference between the outer annulus of the preventive tool body and the second center hole to allow the fluid to flow inward from the outer annulus or be in a closed state; the opening pressure of the side wall one-way valve is less than the yield and crushing pressure of the drill string.

2. The downhole drilling tool anti-collapse tool according to claim 1, characterized in that: When the pressure difference between the outer annulus of the preventive tool body and the second center hole is greater than the starting pressure of the side wall one-way valve, the side wall one-way valve opens to allow fluid to flow from the outer annulus into the second center hole; when the pressure difference between the outer annulus of the preventive tool body and the second center hole is less than or equal to the starting pressure of the side wall one-way valve, the side wall one-way valve is in a closed state.

3. The downhole drilling tool anti-collapse tool according to claim 2, characterized in that: The side wall one-way valve includes a valve seat hole arranged on the side wall of the pressure relief nipple body, the valve seat hole includes a first seat hole close to the second center hole, a second seat hole is connected to the first seat hole, the aperture size of the first seat hole is larger than the aperture size of the second seat hole, and a first step portion is formed between the first seat hole and the second seat hole; a valve core is slidably arranged 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, the second core seat can slide along the second seat hole, a second step portion is formed between the first core seat and the second core seat, and the second step portion can abut against the first step portion to close the side wall one-way valve.

4. The downhole drilling tool anti-collapse tool according to claim 2, characterized in that: The one-way ball valve structure comprises a ball valve seat structure, in which a ball opening and closing member capable of moving up and down is arranged.

5. The downhole drilling tool anti-collapse tool according to claim 4, characterized in that: The ball valve seat structure includes a ball valve sealing groove and an annular spring base connected to the side wall of the first center hole at upper and lower intervals. The annular spring base is provided with an axially penetrating third center hole. The annular spring base is connected with an upwardly extending spring structure. The top end of the spring structure is abutted against the ball opening and closing member. The ball valve sealing groove is provided with an axially penetrating fourth center hole. The ball opening and closing member can move up and down to abut and close the fourth center hole or leave the fourth center hole.

6. The downhole drilling tool anti-collapse tool according to claim 1, characterized in that: The bottom end of the preventive tool body is arranged to be connected to a lower joint of a bottom drilling tool assembly structure.

7. The downhole drilling tool anti-collapse tool according to claim 1, characterized in that: The top end of the preventive tool body is provided with an upper joint for connecting to an upper drill string.

8. An anti-collapse drilling system, characterized in that: The invention comprises an upper drill string, a bottom drill tool assembly structure and a ground signal receiving device, wherein the top end of the upper drill string is connected to a ground drilling rig that provides power for drilling, and the bottom end of the upper drill string is connected to a downhole drill tool anti-collapse tool and a bottom drill tool assembly structure as described in any one of claims 1 to 7, and the ground signal receiving device is used to receive and identify drilling fluid pulse signals to identify the downhole valve status and warn of the risk of drill tool collapse.

9. The anti-collapse drilling system according to claim 8, characterized in that: The bottom end of the downhole drilling tool anti-collapse tool is threadedly connected to the bottom drilling tool assembly structure through a lower joint, and the top end of the downhole drilling tool anti-collapse tool is threadedly connected to the upper drill string through an upper joint.

10. A method for preventing collapse of a well, characterized in that: include, Assemble the anti-collapse drilling system as described in claim 8 or 9, lower the bottom drilling tool assembly structure, the downhole drilling tool anti-collapse tool, and the upper drill string into the wellbore; during the drilling process, inject drilling fluid through the upper drill string, start the ground drilling rig equipment to provide power for drilling, and the ground signal receiving device receives and identifies the drilling fluid pulse signal; When the pressure difference between the outer annulus of the prevention tool body and the second center hole is less than the opening pressure of the side wall one-way valve, the side wall one-way valve is in a closed state. At this time, under the pressure of the injected drilling fluid, the one-way ball valve structure is opened, the drilling fluid flow channel is in a through state, and the drilling fluid flows downward normally for drilling; When the pressure difference between the outer annulus of the prevention tool body and the second center hole is greater than the opening pressure of the side wall one-way valve, the side wall one-way valve opens, and the fluid flows inward from the outer annulus. Under the pressure of the fluid flowing into the second center hole, the one-way ball valve structure is in a closed state, cutting off and closing the drilling fluid flow channel; The closure of the drilling fluid circulation channel changes the drilling fluid velocity field. The ground signal receiving device installed at the wellhead receives and identifies the drilling fluid pulse signal, and warns of the risk of drill tool crushing. After receiving the drill tool crushing risk warning, the staff analyzes the operations that need to be performed based on it.

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