Maintenance operation tool and method for cavity construction of salt-cavern gas storage

Abstract

The invention discloses a maintenance operation tool and method for salt cavern gas storage cavity construction, and the maintenance operation tool comprises an upper connecting mechanism, an anchoring mechanism, a screw rod mechanism and a cutting knife mechanism; the anchoring mechanism is arranged on the outer side of the upper connecting mechanism; the upper connecting mechanism is in threaded connection with one end of the screw rod mechanism; and the other end of the screw rod mechanism is in threaded connection with the cutting knife mechanism. According to the maintenance operation tool for salt cavern gas storage cavity construction, the defects of a traditional pipe cutting tool are effectively overcome, the pipe cutting effect is guaranteed, meanwhile, the phenomenon of tripping or loosening of a pipe column caused by pipe cutting torque is prevented, and the safety of salt cavern gas storage cavity construction operation is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of salt cavern underground storage construction, and in particular relates to a salt cavern gas storage cavity building and maintenance operation tool and method. Background Art

[0002] In the process of cavern making, the salt cavern gas storage is required to dissolve the cavity in a controlled manner, and the pipe string needs to be adjusted periodically during the process. The existing pipe string adjustment methods mainly include lifting and lowering the pipe string by a workover rig and cutting the pipe for adjustment. However, when nitrogen dissolution is used for cavity dissolution, the outer pipe of the cavity is generally made of gas-tight casing. If the method of lifting and lowering the pipe string by a workover rig is still used, it is easy to cause the seal failure during the buckle-up process of the upper pipe string. Therefore, in this case, the method of cutting the pipe to adjust the pipe string is generally adopted. However, during the process of cutting the pipe, due to the effect of the cutter torque, it is very likely that the outer pipe of the cavity will be disengaged or loosened at a certain depth or a certain section of the pipe string, resulting in the failure of the gas sealing performance of the outer pipe of the cavity, which seriously affects the underground safety during the cavity making process.

[0003] A Chinese patent application (application number CN202222116513.1) discloses a salt mine brine well casing cutting device, including a pipe inserting device, a cutting mechanism and a pressing mechanism. The center of the pipe inserting device is provided with a cutting mechanism for inserting into the salt mine brine well casing for pipe cutting, and the upper end of the cutting mechanism is provided with a pressing mechanism for pressing down and positioning the cutting assembly. The pipe cutting device proposed in the patent is only applicable to cemented casing, not to freely suspended casing strings, and has certain limitations. Summary of the invention

[0004] In view of the above problems, the present invention discloses a salt cavern gas storage cavity making and maintenance operation tool, comprising: an upper connection mechanism, an anchoring mechanism, a screw mechanism and a cutting knife mechanism;

[0005] The anchoring mechanism is arranged outside the upper connecting mechanism;

[0006] The upper connection mechanism is connected to one end of the screw mechanism via a threaded connection;

[0007] The other end of the screw mechanism is connected to the cutter mechanism through threads.

[0008] Furthermore, the upper connection mechanism comprises: an upper connection head, a top head and an anti-drop baffle;

[0009] The upper joint is tubular, and a first cylindrical space, a second cylindrical space and a third cylindrical space are sequentially arranged inside, and a plurality of grooves are arranged on the circumference of the outer wall, and each groove is connected to the interior of the upper joint;

[0010] The anti-drop baffle is composed of a round tube and a round disc, and the vertical cross section is T-shaped; a top telescopic spring is arranged in the round tube, and a plurality of holes are arranged on the round disc;

[0011] The anti-drop baffle is connected to the upper joint via a third positioning pin;

[0012] The ram is composed of a hemisphere and a cylinder. The hemisphere abuts against one end of the second cylindrical space, and the diameter of the hemisphere is larger than the diameter of the second cylindrical space. The cylinder is arranged in the round tube of the anti-drop baffle and abuts against the ram telescopic spring.

[0013] Furthermore, the diameter of the first cylindrical space is smaller than the diameter of the second cylindrical space, and the diameter of the second cylindrical space is smaller than the diameter of the third cylindrical space;

[0014] The third cylindrical space is close to the screw mechanism.

[0015] Furthermore, the anchoring mechanism comprises: a positioning member and an anchoring mechanism telescopic spring;

[0016] The positioning member includes a positioning block and a sliding guide column;

[0017] The positioning block is composed of a quadrangular column and a rectangular parallelepiped, one end of the sliding guide column is connected to the rectangular parallelepiped, and the other end is provided with an annular protrusion; a convex point is provided on one side of the positioning block;

[0018] A plurality of the positioning members are sealingly and slidably connected to the upper joint, and the positioning members are arranged on the sides of the grooves on the outer wall of the upper joint;

[0019] One end of the telescopic spring of the anchoring mechanism is fixedly connected to the positioning piece, and the other end is fixedly connected to the bottom of the groove of the outer wall of the upper joint.

[0020] Furthermore, the screw mechanism comprises: a screw upper joint, an anti-drop pull rod, a screw stator, a screw rotor and a screw lower joint;

[0021] The screw upper joint is a cylinder with a through hole in the middle and a channel outside the through hole, which is connected to the screw stator through a second positioning pin;

[0022] The anti-drop pull rod is arranged in the through hole of the upper joint of the screw, and one end is connected to one end of the screw rotor through a thread;

[0023] The screw stator and the screw rotor are tubular;

[0024] One end of the screw stator is connected to the upper joint through a thread;

[0025] The screw rotor is arranged inside the screw stator;

[0026] One end of the screw lower joint is connected to the screw rotor.

[0027] Furthermore, the screw mechanism further comprises: an annular limiting member;

[0028] The annular limiting piece is connected to the other end of the anti-drop pull rod, and the diameter of the annular limiting piece is larger than the diameter of the through hole of the joint on the screw rod.

[0029] Furthermore, the cutting knife mechanism comprises: a housing, a transmission shaft, a liquid containing chamber, a push block, a cutting knife and a cutting knife base;

[0030] The shell is tubular, with a thread provided on the outer wall at one end, and is connected to the screw stator through the thread;

[0031] The transmission shaft has a cross-shaped vertical section, one end of which is provided with a thread, and an annular boss is provided on the outer wall;

[0032] One end of the transmission shaft is connected to the other end of the lower joint of the screw rod, and the other end passes through the transmission shaft fixing ring and the push block to be connected to the cutter base;

[0033] The bottom surface of the annular boss of the transmission shaft abuts against the transmission shaft fixing ring; a plurality of holes are arranged on the transmission shaft fixing ring, and the transmission shaft fixing ring is connected to the housing through a first positioning pin;

[0034] The push block is in the form of a hollow cylinder, and the outer wall is slidably connected to the inner wall of the shell;

[0035] A liquid containing chamber is formed between the pushing block and the transmission shaft fixing ring;

[0036] The vertical cross section of the cutter base is in a concave shape;

[0037] A plurality of said cutting knives are circumferentially arranged between the housing and the cutting knife base;

[0038] The tail of the cutting knife is in the form of a bevel and abuts against the pushing block.

[0039] Furthermore, the cutting knife mechanism further comprises: a transverse spring and a longitudinal spring;

[0040] The transverse spring is arranged between the cutting knife and the cutting knife base;

[0041] The longitudinal spring is sleeved on the outside of the transmission shaft, and one end of the longitudinal spring is in contact with the push block, and the other end is in contact with the cutter base.

[0042] Furthermore, the cutting knife mechanism further comprises: a pressure relief hole;

[0043] A plurality of pressure relief holes are arranged on the outer shell of the cutting knife mechanism and are communicated with the liquid containing chamber.

[0044] The present invention also discloses an operation method using the above-mentioned salt cavern gas storage cavity building and maintenance operation tool, comprising the following steps:

[0045] Connect the upper joint to the drill pipe or tubing through the joint, and push the anchor mechanism outward under the pressure of the liquid to center and fix the upper joint on the inner wall of the pipe string;

[0046] The liquid continues to move downward, pushing the top head downward, and the liquid flows downward through the hole in the anti-drop baffle plate;

[0047] The liquid flows through the upper joint of the screw and flows into the screw rotor. Under the action of the liquid, the screw rotor rotates, driving the lower joint of the screw and the transmission shaft to rotate, and the transmission shaft drives the cutter to rotate;

[0048] The liquid continues to flow downward and enters the liquid containing chamber. Under the thrust of the liquid, the push block moves downward, and by contacting the slope surface of the cutter, the cutter moves horizontally, thereby realizing the opening of the cutter and completing the pipe cutting operation.

[0049] When the pipe cutting operation is completed, the wellhead is depressurized, the fluid in the salt cavern gas storage cavity building maintenance operation tool stops flowing, and the cutter is retracted under the action of the transverse spring.

[0050] Compared with the prior art, the embodiments of the present invention have at least the following advantages:

[0051] 1) The salt cavern gas storage cavity making maintenance operation tool of the present invention effectively avoids the disadvantages of traditional pipe cutting tools, prevents the pipe string from being disengaged or loosened due to the pipe cutting torque while ensuring the pipe cutting effect, and greatly improves the safety of the salt cavern gas storage cavity making operation;

[0052] 2) The salt cavern gas storage cavity building and maintenance operation tool of the present invention has a compact structure, is easy to operate, and can greatly improve the efficiency of pipe cutting operations;

[0053] 3) By introducing fluid into the maintenance tool for the salt cavern gas storage cavity making, the cutter is controlled to extend outward to perform the pipe cutting operation. After the operation is completed, the fluid is discharged and the cutter is retracted. The control method is simple, the tool can operate stably for a long time, and the number of maintenance times is reduced.

[0054] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0056] Figure 1 A schematic structural diagram of a cavity-making and maintenance work tool for a salt cavern gas storage according to an embodiment of the present invention is shown;

[0057] Figure 2 A schematic structural diagram of a positioning member according to an embodiment of the present invention is shown.

[0058] : 1. upper joint; 2. positioning member; 3. top head; 4. anti-drop baffle; 5. screw upper joint; 6. anti-drop pull rod; 7. screw stator; 8. screw rotor; 9. screw lower joint; 10. transmission shaft; 11. liquid containing chamber; 12. pushing block; 13. cutting knife; 14. transverse spring; 15. longitudinal spring; 16. cutting knife base; 17. pressure relief hole; 18. first positioning pin; 19. second positioning pin; 20. annular limit member; 21. third positioning pin; 22. top head telescopic spring; 23. anchoring mechanism telescopic spring. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] In order to overcome the shortcomings of the above-mentioned traditional pipe cutting tools, the present invention proposes a salt cavern gas storage cavity making and maintenance operation tool and method, which can effectively avoid the disadvantages of the above-mentioned two methods, while ensuring the pipe cutting effect and preventing the pipe column from being disengaged or loosened due to the pipe cutting torque.

[0061] Figure 1 The schematic diagram of the structure of the maintenance tool for the salt cavern gas storage according to the embodiment of the present invention is shown. Figure 1 As shown, a salt cavern gas storage cavity making and maintenance operation tool proposed by the present invention comprises: an upper connection mechanism, an anchoring mechanism, a screw mechanism and a cutting knife mechanism;

[0062] The anchoring mechanism is arranged outside the upper connecting mechanism;

[0063] The bottom end of the upper connection mechanism is connected to the top end of the screw mechanism via threads;

[0064] The bottom end of the screw mechanism is connected with the top end of the cutter mechanism through threads.

[0065] The upper connection mechanism is used to connect with the drill pipe or the oil pipe and the screw mechanism;

[0066] The anchoring mechanism is used to center the maintenance operation tool of the salt cavern gas storage on the inner wall of the pipe string and fix it on the inner wall of the pipe string;

[0067] The screw mechanism is used to provide power for the rotation of the cutter mechanism;

[0068] The cutting knife mechanism is used for cutting the casing.

[0069] The salt cavern gas storage cavity making maintenance operation tool of the present invention can effectively avoid the disadvantages of traditional pipe cutting tools, prevent the disengagement or loosening of the pipe column caused by the pipe cutting torque while ensuring the pipe cutting effect, and greatly improve the safety of the salt cavern gas storage cavity making operation.

[0070] In some embodiments, the upper connection mechanism includes: an upper connection 1, a top head 3 and an anti-drop baffle 4;

[0071] The top outer wall of the upper joint 1 is provided with threads, and the top is connected to the drill pipe or oil pipe through a joint;

[0072] The upper joint 1 is tubular, and a first cylindrical space, a second cylindrical space and a third cylindrical space are sequentially arranged inside from top to bottom. A plurality of grooves are arranged on the circumference of the outer wall, and each groove is connected to the interior of the upper joint 1; cylindrical grooves are arranged above and below each groove;

[0073] The anti-drop baffle 4 is composed of a round tube and a round disc, and the vertical cross section is T-shaped;

[0074] A top telescopic spring 22 is arranged in the circular tube, and a plurality of holes are arranged on the circular disc;

[0075] The anti-drop baffle plate 4 is arranged inside the third cylindrical space and connected to the upper joint 1 via the third positioning latch 21;

[0076] The plug 3 is composed of a hemisphere and a cylinder. The hemisphere abuts against one end of the side wall of the second cylindrical space, and the diameter of the hemisphere is larger than the diameter of the second cylindrical space. The cylinder is arranged in the round tube of the anti-drop baffle 4 and abuts against the plug telescopic spring 22.

[0077] Upper joint 1, used to connect with drill pipe or oil pipe through joint;

[0078] The top head 3 is used to control the opening or closing of the internal passage of the upper joint 1;

[0079] The anti-drop baffle plate 4 is used to provide support for the top head 3 and provide a channel for the fluid to flow.

[0080] Exemplarily, the anti-drop baffle plate 4 is circumferentially provided with four holes for rapid downward flow of fluid.

[0081] Although four holes are used as an example for illustrative description, the present invention is not limited thereto, and different numbers of holes can be provided in the anti-drop baffle plate 4 according to actual conditions, such as 2, 3, 5, etc. Those skilled in the art can comprehensively consider the purpose of the fluid flow of the present invention and the actual application conditions, as long as the principle of the present invention can be realized.

[0082] When there is no fluid flow inside the salt cavern gas storage cavity building and maintenance work tool, the plug 3 moves upward due to the action of the plug telescopic spring 22 to achieve sealing with the upper part of the salt cavern gas storage cavity building and maintenance work tool. When there is fluid flowing downward inside the salt cavern gas storage cavity building and maintenance work tool, the plug telescopic spring 22 contracts, the plug 3 moves downward, and the channel opens.

[0083] In some embodiments, the diameter of the first cylindrical space is smaller than the diameter of the second cylindrical space, and the diameter of the second cylindrical space is smaller than the diameter of the third cylindrical space;

[0084] The third cylindrical space is close to the screw mechanism.

[0085] In some embodiments, the anchoring mechanism includes: a positioning member 2 and an anchoring mechanism telescopic spring 23;

[0086] like Figure 2 As shown, the positioning member 2 includes a positioning block and a sliding guide column;

[0087] The positioning block is composed of a quadrangular column and a rectangular parallelepiped, one end of the sliding guide column is connected to the rectangular parallelepiped, and the other end is provided with an annular protrusion; a convex point is provided on one side of the positioning block;

[0088] The side of the positioning member 2 is provided with a convex point, which can effectively increase the friction of the contact surface. The end of the sliding guide post is provided with an annular protrusion, which is used to limit the sliding stroke of the positioning member 2 and prevent the positioning member 2 from falling off;

[0089] A plurality of positioning members 2 are circumferentially arranged outside the upper joint 1 and are sealed and slidably connected to the upper joint 1. The positioning members 2 are arranged on the side of the groove of the outer wall of the upper joint 1. The positioning members 2 completely cover the groove. The sliding guide column of the positioning member 2 is arranged in the cylindrical groove and is restricted in movement by the annular protrusion.

[0090] One end of the anchoring mechanism telescopic spring 23 is fixedly connected to the positioning member 2 , and the other end is fixedly connected to the bottom of the groove on the outer wall of the upper joint 1 .

[0091] When the upper joint 1 is filled with liquid, the positioning member 2 is pushed outward by the liquid to achieve centering and fixation with the casing string. After the liquid is depressurized, the positioning member 2 is retracted under the tensile force of the telescopic spring 23 of the anchoring mechanism, and the salt cavern gas storage cavity making maintenance operation tool is in a freely movable state.

[0092] Exemplarily, four positioning members 2 are provided and evenly distributed circumferentially on the outer side of the upper joint 1 .

[0093] Although four positioning members 2 are used as an example for illustrative description above, the present invention is not limited thereto, and different numbers of positioning members 2 can be provided in the anchoring mechanism according to actual conditions, such as 2, 3, 6, etc. Those skilled in the art can comprehensively consider the centering and fixing purposes of the present invention and actual application conditions, as long as the principle of the present invention can be realized.

[0094] Positioning member 2, used to center the maintenance operation tool for the salt cavern gas storage in the pipe string and fix it in the pipe string;

[0095] The anchoring mechanism telescopic spring 23 is used to provide a tensile force to retract the positioning member 2.

[0096] In some embodiments, the screw mechanism includes: a screw upper joint 5, an anti-drop pull rod 6, a screw stator 7, a screw rotor 8 and a screw lower joint 9;

[0097] The screw upper joint 5 is a cylinder with a through hole in the middle and a channel outside the through hole, which is connected to the screw stator 7 through a second positioning pin 19;

[0098] The liquid flows downward from the hole on the screw upper joint 5 and flows into between the screw rotor 8 and the screw stator 7;

[0099] The anti-drop pull rod 6 is arranged in the through hole of the screw upper joint 5, and one end is connected to one end of the screw rotor 8 by a thread;

[0100] The screw stator 7 and the screw rotor 8 are tubular;

[0101] One end of the screw stator 7 is connected to the upper joint 1 through a thread;

[0102] The screw rotor 8 is arranged inside the screw stator 7;

[0103] The top end of the screw lower joint 9 is connected to the bottom end of the screw rotor 8 , and the bottom end of the screw lower joint 9 is connected to the top end of the rotating shaft 10 .

[0104] Exemplarily, the screw lower joint 9 may be configured as a universal joint to achieve torque transmission of the screw rotor 8 .

[0105] The screw upper joint 5 is used to fix the position of the screw rotor 8 to prevent it from sliding down;

[0106] An anti-drop tie rod 6, used for connecting the screw rotor 8;

[0107] The screw stator 7 is used to provide a specific rotating flow channel to improve the utilization of the energy of the pumped liquid and increase the torque;

[0108] The screw rotor 8 is used to convert the kinetic energy of the pumped liquid into rotational mechanical energy;

[0109] The screw lower joint 9 is used for the non-centering rotation of the screw drill 8. The screw lower joint 9 plays the role of a universal joint to achieve torque transmission of the screw rotor 8.

[0110] Exemplarily, the screw upper joint 5 is fixedly connected to the upper joint 1 via two second positioning pins 19 .

[0111] Although two second positioning pins 19 are used as an example for illustrative description, the present invention is not limited thereto, and different numbers of second positioning pins 19 can be provided in the screw mechanism according to actual conditions, such as 3, 4, 6, etc. Those skilled in the art can comprehensively consider the fixed purpose of the present invention and the actual application conditions, as long as the principle of the present invention can be realized.

[0112] By setting the screw rotor 8, when the high-pressure fluid flows into the screw rotor 8, under the action of the fluid, the screw rotor 8 is driven to rotate, and the transmission shaft 10 is driven to rotate, so as to provide sufficient power for the cutter 13 to rotate and cut the pipe. The salt cavern gas storage cavity making and maintenance operation tool of the present invention has a compact structure and is easy to operate, and can greatly improve the efficiency of the pipe cutting operation. The power source is highly stable, and the cutter 13 can be quickly started to perform the pipe cutting operation according to the actual operation situation.

[0113] In some embodiments, a salt cavern gas storage cavity making and maintenance operation tool, the screw mechanism further includes: an annular stopper 20;

[0114] The annular stopper 20 is connected to the other end of the anti-drop pull rod 6 , and the diameter of the annular stopper 20 is larger than the diameter of the through hole of the screw upper joint 5 .

[0115] In some embodiments, the cutting knife mechanism includes: a housing, a transmission shaft 10, a liquid containing chamber 11, a push block 12, a cutting knife 13 and a cutting knife base 16;

[0116] The housing is tubular, with a thread provided on the outer wall at one end, and connected to the screw stator 7 through a thread;

[0117] The transmission shaft 10 has a cross-shaped vertical section, one end of which is provided with a thread, and an annular boss is provided on the outer wall;

[0118] One end of the transmission shaft 10 is connected to the other end of the screw lower joint 9, and the other end passes through the transmission shaft fixing ring and the push block 12 to be connected to the cutter base 16;

[0119] The bottom surface of the annular boss of the transmission shaft 10 abuts against the transmission shaft fixing ring; a plurality of holes are arranged on the transmission shaft fixing ring, and the transmission shaft fixing ring is connected to the housing through a first positioning pin 18;

[0120] Exemplarily, the transmission shaft fixing ring is fixedly connected to the housing via four first positioning pins 18 , and the four first positioning pins 18 are evenly arranged circumferentially to improve the connection stability of the transmission shaft fixing ring 4 .

[0121] Although the above description is made by taking four first positioning pins 18 as an example, the present invention is not limited thereto, and different numbers of first positioning pins 18 may be provided in the cutter mechanism according to actual conditions, such as 2, 3, 6, etc. Those skilled in the art may comprehensively consider the fixed purpose of the present invention and the actual application conditions, as long as the principle of the present invention can be realized.

[0122] The push block 12 is a hollow cylinder, and its outer wall is slidably connected to the inner wall of the housing; the inner wall of the push block 12 is sealed and slidably connected to the outer wall of the transmission shaft 10;

[0123] A liquid containing chamber 11 is formed between the pushing block 12 and the transmission shaft fixing ring;

[0124] The cutter base 16 has a concave cross-section, and is provided with a plurality of groove sliding channels inside, and the cutter 13 is arranged on the groove sliding channels, so as to facilitate the extension and retraction of the cutter 13;

[0125] The plurality of cutting knives 13 are circumferentially arranged between the housing and the cutting knife base 16;

[0126] The tail of the cutting knife 13 is beveled and abuts against the pushing block 12 .

[0127] The outer shell is used for support and provides interior space;

[0128] The transmission shaft 10 is used to drive the cutting knife 13 to rotate;

[0129] The liquid containing chamber 11 is used to contain liquid and provide downward power for the pushing block 12;

[0130] The push block 12 is used to push the cutting knife 13 to move outward laterally so that the cutting knife 13 is fully extended;

[0131] A cutting knife 13, used for cutting the casing;

[0132] The cutter base 16 is used to fix the cutter 13 and drive the cutter 13 to rotate.

[0133] Exemplarily, the cutting knife mechanism is provided with four cutting knives 13 , which are evenly arranged on the cutting knife base 16 in the circumferential direction.

[0134] Although four cutting knives 13 are used as an example for illustrative description, the present invention is not limited thereto, and different numbers of cutting knives 13 can be provided in the cutting mechanism according to actual conditions, such as 2, 3, 5, 6, etc. Those skilled in the art can comprehensively consider the principle of the present invention and actual application conditions, as long as rapid pipe cutting can be achieved.

[0135] The push block 12 is centrally connected to the transmission shaft 10. Under the action of the fluid, the push block 12 moves downward, pushing the cutter 13 to move horizontally, and the cutter 13 opens. The control method of the cutter 13 is simple, the tool can operate stably for a long time, and the number of maintenance times is reduced.

[0136] In some embodiments, the cutting knife mechanism further includes: a transverse spring 14 and a longitudinal spring 15;

[0137] The plurality of transverse springs 14 are disposed between the cutting knife 13 and the cutting knife base 16;

[0138] The longitudinal spring 15 is sleeved on the outside of the transmission shaft 10 , and one end of the longitudinal spring 15 abuts against the push block 12 , and the other end abuts against the cutter base 16 .

[0139] The transverse spring 14 is used to provide elastic force for the cutting knife 13, and when the pushing block 12 moves upward, the cutting knife 13 is pushed to retract inward;

[0140] The longitudinal spring 15 is used to provide elastic force for the push block 12 , and pushes the push block 12 to move upward when the liquid containing chamber 11 is depressurized.

[0141] The transverse spring 14 can provide sufficient elastic force for the contraction of the cutter 13, ensuring that the cutter 13 is smoothly retracted into the shell after the pipe cutting operation is completed, effectively preventing the cutter 13 from scratching the pipe wall. The longitudinal spring 15 can provide sufficient elastic force for the push block 12 to move upward, ensuring that the push block 12 moves up to the initial position after the liquid inside the salt cavern gas storage cavity maintenance operation tool is depressurized.

[0142] In some embodiments, the cutting knife mechanism further includes: a pressure relief hole 17;

[0143] The plurality of pressure relief holes 17 are disposed on the outer shell of the cutter mechanism and are communicated with the liquid containing chamber 11 .

[0144] The pressure relief hole 17 is used to relieve the pressure of the liquid in the liquid containing chamber 11 .

[0145] Exemplarily, two pressure relief holes 17 are provided on the cutting knife mechanism.

[0146] The liquid in the liquid containing chamber 11 can be quickly discharged through the pressure relief hole 17, thereby releasing the downward thrust of the liquid on the push block 12, ensuring that the push block 12 moves up to the initial position under the elastic force of the longitudinal spring 15, and ensuring that the cutter 13 is quickly retracted.

[0147] Based on the above-mentioned salt cavern gas storage cavity building and maintenance operation tool, the present application also discloses a salt cavern gas storage cavity building and maintenance operation method, including the following steps:

[0148] The top of the upper joint 1 is connected to the drill pipe or oil pipe through a joint, and an upper anchoring mechanism is installed on the outer side of the lower part. Under the pressure of the liquid, the anchoring mechanism is pushed outward to center and fix the upper joint 1 on the inner wall of the pipe string;

[0149] The liquid continues to move downward, acting on the top head 3, pushing the top head 3 to move downward, the top head telescopic spring 22 is forced to contract, and the liquid flows downward through the hole in the anti-drop baffle 4;

[0150] The liquid flows through the screw upper joint 5 and flows into the screw rotor 8. Under the action of the liquid, the screw rotor 8 rotates, thereby driving the screw lower joint 9 and the transmission shaft 10 to rotate, and the transmission shaft 10 drives the cutter 13 to rotate;

[0151] The liquid continues to flow downward and enters the liquid containing chamber 11, acting on the top of the push block 12. Under the thrust of the liquid, the push block 12 moves downward, contacts the slope surface of the cutter 13, and pushes the cutter 13 to move horizontally, thereby opening the cutter 13 and completing the pipe cutting operation.

[0152] When the pipe cutting operation is completed, the wellhead is depressurized, the fluid in the salt cavern gas storage cavity building maintenance operation tool stops flowing, and the cutter 13 moves in the opposite direction under the action of the transverse spring 14. The cutter 13 is retracted, and at the same time, under the action of the longitudinal spring 15, the push block 12 moves upward.

[0153] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0154] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0155] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0156] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0157] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In the present invention, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine different embodiments or examples described in the present invention and features of different embodiments or examples without contradiction.

[0158] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A salt cavern gas storage cavity building and maintenance operation tool, characterized in that: include: Upper connection mechanism, anchoring mechanism, screw mechanism and cutting knife mechanism; The anchoring mechanism is arranged outside the upper connecting mechanism; The upper connection mechanism is connected to one end of the screw mechanism via a threaded connection; The other end of the screw mechanism is connected to the cutter mechanism through threads.

2. The salt cavern gas storage cavity building and maintenance tool according to claim 1 is characterized in that: The upper connection mechanism comprises: an upper connection head (1), a top head (3) and an anti-drop baffle (4); The upper joint (1) is tubular, and has a first cylindrical space, a second cylindrical space and a third cylindrical space arranged in sequence therein; a plurality of grooves are arranged in the circumferential direction of the outer wall, and each groove is connected to the interior of the upper joint (1); The anti-drop baffle (4) is composed of a circular tube and a circular disk, and has a T-shaped vertical cross section; a top telescopic spring (22) is arranged in the circular tube, and a plurality of holes are arranged on the circular disk; The anti-drop baffle (4) is connected to the upper joint (1) via a third positioning pin (21); The ram (3) is composed of a hemisphere and a cylinder. The hemisphere abuts against one end of the second cylindrical space, and the diameter of the hemisphere is greater than the diameter of the second cylindrical space. The cylinder is arranged in the round tube of the anti-drop baffle (4) and abuts against the ram telescopic spring (22).

3. The salt cavern gas storage cavity building and maintenance work tool according to claim 2 is characterized in that: The diameter of the first cylindrical space is smaller than the diameter of the second cylindrical space, and the diameter of the second cylindrical space is smaller than the diameter of the third cylindrical space; The third cylindrical space is close to the screw mechanism.

4. The salt cavern gas storage cavity building and maintenance tool according to claim 3 is characterized in that: The anchoring mechanism comprises: a positioning member (2) and an anchoring mechanism telescopic spring (23); The positioning member (2) comprises a positioning block and a sliding guide column; The positioning block is composed of a quadrangular column and a rectangular parallelepiped, one end of the sliding guide column is connected to the rectangular parallelepiped, and the other end is provided with an annular protrusion; a convex point is provided on one side of the positioning block; The plurality of positioning members (2) are sealingly and slidably connected to the upper joint (1), and the positioning members (2) are arranged on the side of the groove on the outer wall of the upper joint (1); One end of the anchoring mechanism telescopic spring (23) is fixedly connected to the positioning member (2), and the other end is fixedly connected to the bottom of the groove on the outer wall of the upper joint (1).

5. The salt cavern gas storage cavity building and maintenance tool according to claim 4 is characterized in that: The screw mechanism comprises: a screw upper joint (5), an anti-drop pull rod (6), a screw stator (7), a screw rotor (8) and a screw lower joint (9); The screw upper joint (5) is a cylinder with a through hole in the middle and a channel outside the through hole, and is connected to the screw stator (7) via a second positioning pin (19); The anti-drop pull rod (6) is arranged in the through hole of the screw upper joint (5), and one end is connected to one end of the screw rotor (8) through a thread; The screw stator (7) and the screw rotor (8) are tubular; One end of the screw stator (7) is connected to the upper joint (1) via a thread; The screw rotor (8) is arranged inside the screw stator (7); One end of the screw lower joint (9) is connected to the screw rotor (8).

6. The salt cavern gas storage cavity building and maintenance tool according to claim 5 is characterized in that: The screw mechanism further comprises: an annular limiting member (20); The annular limiting member (20) is connected to the other end of the anti-drop pull rod (6), and the diameter of the annular limiting member (20) is greater than the diameter of the through hole of the screw upper joint (5).

7. The salt cavern gas storage cavity building and maintenance tool according to claim 6 is characterized in that: The cutting knife mechanism comprises: a housing, a transmission shaft (10), a liquid containing chamber (11), a pushing block (12), a cutting knife (13) and a cutting knife base (16); The outer shell is tubular, with a thread provided on the outer wall at one end, and is connected to the screw stator (7) through the thread; The transmission shaft (10) has a cross-shaped vertical cross section, one end of which is provided with a thread, and an annular boss is provided on the outer wall; One end of the transmission shaft (10) is connected to the other end of the screw lower joint (9), and the other end passes through the transmission shaft fixing ring and the pushing block (12) and is connected to the cutter base (16); The bottom surface of the annular boss of the transmission shaft (10) abuts against the transmission shaft fixing ring; a plurality of holes are arranged on the transmission shaft fixing ring, and the transmission shaft fixing ring is connected to the housing via a first positioning pin (18); The pushing block (12) is in the form of a hollow cylinder, and its outer wall is slidably connected to the inner wall of the shell; A liquid containing chamber (11) is formed between the pushing block (12) and the transmission shaft fixing ring; The cutter base (16) has a concave shape in vertical cross section; A plurality of cutting knives (13) are circumferentially arranged between the housing and the cutting knife base (16); The tail of the cutting knife (13) is beveled and abuts against the pushing block (12).

8. The salt cavern gas storage cavity building and maintenance tool according to claim 7 is characterized in that: The cutting knife mechanism further comprises: a transverse spring (14) and a longitudinal spring (15); The transverse spring (14) is arranged between the cutting knife (13) and the cutting knife base (16); The longitudinal spring (15) is sleeved on the outside of the transmission shaft (10), and one end of the longitudinal spring is in contact with the push block (12), and the other end of the longitudinal spring is in contact with the cutter base (16).

9. The salt cavern gas storage cavity building and maintenance tool according to claim 8, characterized in that: The cutting knife mechanism further comprises: a pressure relief hole (17); The plurality of pressure relief holes (17) are arranged on the outer shell of the cutting knife mechanism and are communicated with the liquid containing chamber (11).

10. An operation method using the salt cavern gas storage cavity building and maintenance operation tool according to any one of claims 1 to 9, characterized in that: The following steps are involved: The upper joint (1) is connected to the drill pipe or the oil pipe through a joint, and under the pressure of the liquid, the anchoring mechanism is pushed outward to center and fix the upper joint (1) on the inner wall of the pipe string; The liquid continues to move downward, pushing the top head (3) downward, and the liquid flows downward through the hole in the anti-drop baffle plate (4); The liquid flows through the screw upper joint (5) and flows into the screw rotor (8). Under the action of the liquid, the screw rotor (8) rotates, driving the screw lower joint (9) and the transmission shaft (10) to rotate, and the transmission shaft (10) drives the cutter (13) to rotate; The liquid continues to flow downward and enters the liquid containing chamber (11). Under the thrust of the liquid, the push block (12) moves downward and contacts the slope surface of the cutter (13), causing the cutter (13) to move laterally, thereby opening the cutter (13) and completing the pipe cutting operation. When the pipe cutting operation is completed, the wellhead is depressurized, the fluid in the salt cavern gas storage cavity building maintenance operation tool stops flowing, and the cutter (13) is retracted under the action of the transverse spring (14).

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