A coiled tubing depth calibration positioning tool for gas storage gas-tight pipe column

Abstract

The application provides a coiled tubing depth correction positioning tool for gas storage gas-tight pipe column, which can accurately correct the position of pipe column landing joint necking of the tool without pressure release, well killing and lifting the original well gas-tight pipe column, and ensure that the downhole tools such as safety valve and sliding sleeve of the well pipe column are not scratched when the depth correction positioning tool string is lifted. The tool comprises a coiled tubing and a depth correction positioning pipe connected with each other, the coiled tubing is connected with a ground pipe truck, the ground pipe truck is used to lower or lift the tool, inject pressure into the tool and monitor the load change of the tool; the depth correction positioning pipe comprises a three-jaw anchor shoe used to contact the landing short joint of the gas-tight pipe column and a necking part, and an outer cylinder used to accommodate the three-jaw anchor shoe, the outer cylinder is composed of a male joint slidingly sleeved on a center shaft and an outer wall of an upper joint, and a female joint connected with an outer wall at the bottom end of the male joint.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of oilfield downhole operation, and relates to a continuous tubing over-tubing perforation repair operation, in particular to a continuous tubing depth correction positioning tool for a gas storage gas-tight pipe column. BACKGROUND

[0002] For the permanent gas-tight pipe column of an oilfield gas storage, over-tubing perforation needs to be performed to increase the contact area between the oil pipe and the gas storage and adjust the storage capacity. Perforation is performed by drilling a series of holes in the oil pipe to form a channel between the oil pipe and the gas storage, so as to realize gas injection and extraction. If the gas storage well needs to be perforated and expanded, the operation must be performed without pulling out the original well pipe column, without pressure release and without well killing. The conventional depth correction tool cannot be used for operation and construction because the conventional depth correction tool is positioned by the gap of the oil pipe coupling, and there is no gap and step between the male and female couplings of each gas-tight pipe column in order to prevent corrosion of the gas-tight pipe column of the gas storage. Therefore, the over-tubing perforation of the gas-tight pipe column of the gas storage must be performed by using the continuous tubing under pressure. Furthermore, if the conventional depth correction tool is used for operation on the gas-tight pipe column of the gas storage, there is a high risk of scratching the safety valve and the sliding sleeve and other downhole tools of the gas-tight pipe column when the tool is pulled out. Based on this special requirement, a continuous tubing special pipe column depth correction tool needs to be developed to accurately position the gas-tight pipe column of the gas storage well by using the continuous tubing, and then a perforation tool string is lowered to perform perforation operation under pressure, so as to complete the storage capacity adjustment of the gas storage. SUMMARY

[0003] In order to overcome the deficiencies in the prior art, the application provides a continuous tubing depth correction positioning tool for a gas storage gas-tight pipe column, which can accurately correct the position of the pipe column seat joint necking down by using the depth correction positioning tool without pressure release, well killing and pulling out the original well gas-tight pipe column, and ensure that the safety valve and the sliding sleeve and other downhole tools of the pipe column in the well are not scratched when the depth correction positioning tool string is pulled out.

[0004] The technical scheme adopted by the application to solve the technical problems is:

[0005] The application discloses a continuous tubing depth calibration positioning tool for gas storage gas-tight pipe column, which comprises a continuous tubing and a depth calibration positioning pipe in communication, the continuous tubing is connected with a ground tubing truck, the ground tubing truck lowers or lifts the tool, injects pressure into the tool and monitors the load change of the tool; the depth calibration positioning pipe comprises a center shaft and an upper joint which are integrally arranged, the outer wall of the center shaft and the upper joint is slidably sleeved with a male joint, the bottom end of the outer wall of the male joint is connected with a female joint to form an outer cylinder; the outer wall of the center shaft is fixedly sleeved with a three-jaw anchor tile which is used to contact the short connection reduced diameter of the gas-tight pipe column, the female joint is sleeved outside the three-jaw anchor tile and is connected with a shearing pin which is used to be clamped with the three-jaw anchor tile; the extrusion cavity is formed between the outer cylinder and the center shaft and the three-jaw anchor tile, the extrusion cavity is in communication with the internal cavity of the center shaft, the shearing pin is located in the extrusion cavity, the force for cutting the shearing pin is transmitted from the internal cavity of the center shaft to the extrusion cavity, and the female joint can slide downward along the outer wall of the three-jaw anchor tile to store the three-jaw anchor tile into the outer cylinder after the shearing pin is cut.

[0006] Based on the above scheme, the continuous tubing is connected with the depth calibration positioning pipe and is lowered into the gas-tight pipe column, the position of the short connection is determined by monitoring the load change of the ground tubing truck according to the characteristics that the gas-tight pipe column is arranged with a short connection reduced diameter, the position of the short connection is calibrated by referring to the data table of the well completion casing, the depth of the continuous tubing perforation is further corrected, the accurate depth calibration of the continuous tubing perforation well section is realized; meanwhile, the shearing pin is used as a cutting mechanism, the female joint can slide along the three-jaw anchor tile after being cut, the three-jaw anchor tile is stored, the downhole tool of the pipe column is not damaged when the tool is lifted, and the reliability and safety of the operation are ensured.

[0007] Further, the hole in communication with the extrusion cavity is formed in the center shaft, and the internal cavity of the center shaft is provided with a flow-cutting variable-diameter port below the hole, and the flow-cutting variable-diameter port is used to clamp the sealing steel ball which is put in by the continuous tubing.

[0008] Based on the above scheme, when the tool needs to be lifted, the sealing steel ball is put into the internal cavity of the center shaft through the continuous tubing, the sealing steel ball is blocked at the flow-cutting variable-diameter port, the downward force of the outer cylinder on the shearing pin is cut off by the injection pressure from the ground tubing truck through the hole into the extrusion cavity, and the downward movement of the outer cylinder is ensured.

[0009] Further, the three-jaw anchor tile comprises an end head and three downward extending anchor claws which are connected to the end head at equal intervals; the outer wall of the end head is provided with a convex edge which is used to clamp the shearing pin, the bottom of the lower claw end of the anchor claw is provided with an inclined surface a, the outer side of the lower claw end of the anchor claw is a trapezoidal boss which is sequentially connected by an inclined surface b, a plane and an inclined surface c, and the trapezoidal boss is used to contact the reduced diameter when the tool is lowered to the position of the short connection reduced diameter of the gas-tight pipe column.

[0010] Based on the above scheme, the anchor claw is arranged to enable the tool to be accurately positioned and contacted to the reduced diameter, and the design of the trapezoidal boss can increase the contact area, so that the tool can be more easily contacted with the reduced diameter when it is lowered to the reduced diameter; the three-jaw anchor shoe adopts an integrated design, the overall structure is compact and firm, and can bear larger load and pressure.

[0011] Further, the two inner bottom angles of the trapezoidal boss are 30° and 60° respectively.

[0012] Based on the above scheme, the area of the trapezoidal boss and the reduced diameter contact surface can be ensured to be just right, avoiding too small contact area leading to unobvious load change, and avoiding too large contact area leading to contact with the reduced diameter being stuck.

[0013] Further, it further includes an adjusting mechanism for adjusting the angle, outer diameter and elasticity of the three-jaw anchor shoe, the adjusting mechanism includes a taper sleeve, a compression spring and a hexagonal pad which are sequentially connected from top to bottom and are sleeved on the outer wall of the central shaft, the taper sleeve is threadedly connected with the outer wall of the central shaft, and the upper end of the taper sleeve has an inclined surface d which cooperates with and abuts against the inclined surface a at the bottom of the lower jaw end of the anchor claw.

[0014] Based on the above scheme, the adjusting mechanism provides the functions of adjusting the angle, outer diameter and elasticity of the three-jaw anchor shoe, by screwing the taper sleeve to adjust the tightness of the contact between the taper sleeve and the three-jaw anchor shoe, the angle and outer diameter of the three-jaw anchor shoe relative to the central shaft can be changed, and then the elasticity of the three-jaw anchor shoe is adjusted, meeting the requirements of the ground tubing load signal, improving the sensitivity of the tool to the short connection, and making the vehicle data acquisition more obvious; at the same time, the design of the compression spring enables the three-jaw anchor shoe to have a certain elasticity, which can adapt to the slight deformation and change inside the pipe string, and improve the stability of positioning.

[0015] Further, the adjusting mechanism further includes a positioning nut and a locking nut which are threadedly connected with the outer wall of the central shaft, the positioning nut is arranged below the hexagonal pad and abuts against the hexagonal pad to fix the position of the hexagonal pad, and the locking nut is arranged below the positioning nut and abuts against the positioning nut to lock the position of the positioning nut; the positioning nut is provided with a locking screw arranged in the radial direction, and the locking nut is provided with a fastening screw arranged in the radial direction.

[0016] Based on the above scheme, the positioning nut can fix the position of the hexagonal pad, ensuring the stable connection of the adjusting mechanism with the central shaft, and the locking nut locks the positioning nut at the required position to prevent it from loosening and shifting during use, thereby improving the stability and reliability of the adjusting mechanism.

[0017] Further, the inner wall of the end of the three-jaw anchor shoe is fixedly connected with the outer wall of the central shaft through a clamping nut.

[0018] Further, a plurality of O-shaped sealing rings are arranged between the male joint, the central shaft and the upper joint.

[0019] Further, the depth calibration positioning method of the tool comprises the following steps:

[0020] The depth calibration positioning pipe is connected with the coiled tubing through the upper joint, the coiled tubing and the depth calibration positioning pipe are lowered in the gas storage gas-tight string through the ground tubing truck, the tool load pressure is monitored by the ground tubing truck during the lowering process, when the three-jaw anchor tile contacts the gas-tight string landing short joint reducer, the load pressure monitored by the ground tubing truck changes, the position of the landing short joint is determined, at this time, a mark is made on the coiled tubing at the wellhead, and the ground tubing truck is used to pressurize into the extrusion cavity until the shear pin is cut off, then the female joint slides downward together with the male joint to store the three-jaw anchor tile into the outer cylinder, after the three-jaw anchor tile is stored, the coiled tubing and the depth calibration positioning pipe are pulled up, and the depth calibration positioning pipe is detached from the coiled tubing, the perforating gun is connected to the coiled tubing at the marked position and is lowered into the gas storage gas-tight string, the mark on the coiled tubing is used as a reference line to control the depth of the perforating gun, and the perforating gun is lowered to the preset depth to perform the perforating operation.

[0021] The beneficial effects of the present application include:

[0022] To solve the problem of depth calibration positioning of the coiled tubing in the gas storage gas-tight string, the present application provides a depth calibration positioning tool specially used for the gas-tight string to calibrate the position of the landing joint of the gas-tight string, the landing short joint position is calibrated by referring to the completion casing data table, then the coiled tubing is lowered to calibrate the perforating depth of the coiled tubing, and at the same time, the safety valve and the sliding sleeve of the downhole tool in the well string are ensured not to be scratched when the depth calibration tool string is pulled up. The depth calibration positioning tool specially used for the coiled tubing can complete the accurate depth calibration of the perforating well section, the perforating operation and the supplemental layer process without pressure relief, well killing and pulling up the original gas-tight string of the well, realizes the purpose of adjusting the capacity of the gas storage, fills the technical gap of the domestic gas-tight string depth calibration positioning tool, has short well occupation period, high construction efficiency, avoids the well control risk, is convenient for dynamic adjustment of the capacity of the gas storage, provides favorable technical support for the capacity increase of the gas storage, improves the scale gas storage capacity and the natural gas supply guarantee capacity, has remarkable economic benefits and certain social benefits. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a schematic diagram of the overall structure of the present application;

[0024] Figure 2 is a schematic diagram of the center shaft structure;

[0025] Figure 3 is a schematic diagram of the overall structure of the three-jaw anchor tile;

[0026] Figure 4is a sectional view of a three-fluke anchor shoe structure;

[0027] Figure 5 is a top view of a three-fluke anchor shoe structure.

[0028] In the figure: 1 - locking nut, 2 - fastening screw, 3 - positioning nut, 4 - locking screw, 5 - hexagonal pad, 6 - compression spring, 7 - cone sleeve, 8 - three-fluke anchor shoe, 9 - female joint, 10 - clamping nut, 11 - shearing pin, 12 - male joint, 13 - O-shaped sealing ring, 14 - central shaft, 15 - upper joint, 16 - extrusion cavity, 17 - hole, 18 - cut-off variable-diameter port;

[0029] 8-1 - end, 8-2 - anchor fluke, 8-3 - convex edge, 8-4 - inclined surface a, 8-5 - trapezoidal boss. DETAILED DESCRIPTION

[0030] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0031] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "inclined", "flat", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as limiting the devices or components referred to in a particular orientation, constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "a", "b", "c" are only used to distinguish components, and cannot be understood as indicating or implying relative importance.

[0032] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0033] Embodiment 1

[0034] A continuous tubing depth correction positioning tool for a gas storage gas-tight string, the depth correction positioning pipe being in communication with the continuous tubing, the continuous tubing being in communication with a surface tubing truck, the surface tubing truck lowering or raising the tool, injecting pressure into the tool, and monitoring changes in the load of the tool;

[0035] As shown in Figure 1 The depth correction positioning pipe comprises a central shaft 14 and an upper joint 15 which are integrally arranged, the outer wall of the central shaft 14 and the upper joint 15 slidingly sleeving a male joint 12, the bottom end of the male joint 12 being connected with a female joint 9 to form an outer cylinder; a plurality of O-shaped sealing rings 13 are arranged between the male joint 12 and the central shaft 14 and the upper joint 15.

[0036] The outer wall of the central shaft 14 is fixed to the three-jaw anchor tile 8 at the short connection and reduced diameter of the gas-tight string by the sleeve nut 10. The female joint 9 is sleeved on the outside of the three-jaw anchor tile 8, and the shear pin 11 is connected to the three-jaw anchor tile 8. An extrusion cavity 16 is formed between the outer cylinder, the central shaft 14 and the three-jaw anchor tile 8. A hole 17 is formed in the central shaft 14 and communicates with the extrusion cavity 16. A flow-blocking variable-diameter port 18 is arranged in the inner cavity of the central shaft 14 below the hole 17. The flow-blocking variable-diameter port 18 is used to clamp the sealing steel ball dropped by the coiled tubing. The shear pin 11 is located in the extrusion cavity 16. The force for cutting the shear pin 11 is transmitted from the hole 17 of the central shaft 14 to the extrusion cavity 16. After the shear pin 11 is cut, the female joint 9 can slide downward along the outer wall of the three-jaw anchor tile 8 to store the three-jaw anchor tile 8 in the outer cylinder.

[0037] Reference Figures 3-5 The three-jaw anchor tile 8 includes an integral end head 8-1 and three downwardly extending anchor claws 8-2 connected to the end head 8-1 at equal intervals. The outer wall of the end head 8-1 is provided with a protruding edge 8-3 for clamping the shear pin 11. The lower claw end of the anchor claw 8-2 has an inclined surface a8-4. The outer side of the lower claw end of the anchor claw 8-2 is a trapezoidal boss 8-5 formed by an inclined surface b, a flat surface and an inclined surface c connected in sequence. The trapezoidal boss 8-5 is used to contact the reduced diameter when the tool is lowered to the reduced diameter of the gas-tight string. Preferably, the two inner bottom angles of the trapezoidal boss 8-5 are 30° and 60° respectively, preventing the contact area of the trapezoidal boss 8-5 with the reduced diameter from being too large or too small.

[0038] The tool also includes an adjusting mechanism for adjusting the angle, outer diameter and elasticity of the three-jaw anchor tile 8. The adjusting mechanism includes a taper sleeve 7, a compression spring 6, a hexagonal pad 5, a positioning nut 3 and a locking nut 1, which are sequentially connected from top to bottom and are sleeved on the outer wall of the central shaft 14. The taper sleeve 7 is threadedly connected to the outer wall of the central shaft 14. The upper end of the taper sleeve 7 has an inclined surface d for abutting with the inclined surface a8-4 of the lower claw end of the anchor claw 8-2. The positioning nut 3 is arranged below the hexagonal pad 5 and abuts with the hexagonal pad 5 to fix the position of the hexagonal pad 5. The locking nut 1 is arranged below the positioning nut 3 and abuts with the positioning nut 3 to lock the position of the positioning nut 3. The locking nut 1 is provided with a radially arranged locking screw 2, and the positioning nut 3 is provided with a radially arranged locking screw 4.

[0039] The depth calibration positioning method of the tool includes the following steps:

[0040] After the angle, outer diameter and elasticity of the three-jaw anchor shoe 8 of the depth calibration positioning pipe are adjusted by the adjusting mechanism, the depth calibration positioning pipe is connected with the coiled tubing through the upper joint 15, and the coiled tubing is connected with the ground tubing truck, the coiled tubing and the depth calibration positioning pipe are lowered in the gas storage gas-tight pipe column through the ground tubing, the tool load pressure is monitored by the ground tubing truck during the lowering process, when the three-jaw anchor shoe 8 contacts the short connection reduced diameter of the gas-tight pipe column, the load pressure monitored by the ground tubing truck changes, the position of the short connection is determined, at this time, a mark is made on the coiled tubing at the wellhead, and the ground tubing truck is used to pressurize the extrusion cavity 16, until the shear pin 11 is cut off, the female joint 9 slides downward together with the male joint 12 to store the three-jaw anchor shoe 8 in the outer cylinder, after the three-jaw anchor shoe 8 is stored, the coiled tubing and the depth calibration positioning pipe are pulled up, and the depth calibration positioning pipe is separated from the coiled tubing, the perforating gun is connected to the coiled tubing with the mark and is lowered into the gas storage gas-tight pipe column, the mark on the coiled tubing is used as a reference line to control the depth of the perforating gun, and the perforating gun is perforated after being lowered to the preset depth.

[0041] In summary, the working principle of the present application is that the coiled tubing is connected with the depth calibration positioning pipe and lowered into the well, the load monitored by the ground tubing truck changes when the three-jaw anchor shoe 8 contacts the reduced diameter of the short connection, so that the position of the short connection is determined, the outer cylinder is provided to prevent the downhole tool from being damaged when the tool is lowered into the pipe column, the elasticity of the three-jaw anchor shoe is adjusted to meet the load signal requirement of the ground tubing truck, the sensitivity of the tool in passing the short connection is improved, and the data acquisition of the truck is more obvious, the short connection position is calibrated by referring to the completion casing data table, the coiled tubing perforation depth is further corrected, and the precise depth calibration of the coiled tubing perforation well section is realized.

[0042] The research on the special coiled tubing depth calibration positioning tool for the gas storage gas-tight pipe has been completed, the technical problem of precise depth calibration positioning of the 4-inch gas-tight pipe column of the oilfield gas storage has been solved, and the next step can be applied to the precise positioning problem of the 3.0-inch and 5.0-inch gas-tight pipe columns of the gas storage, so as to facilitate the reservoir reconstruction, gas layer expansion and other process requirements of the gas storage well.

[0043] There is no special gas-tight string depth calibration positioning tool in China at present. The coiled tubing special depth calibration tool can accurately calibrate the position of the string landing joint necking without decompression, well killing, and lifting the original well gas-tight string. Meanwhile, the depth pulse signal of the coiled tubing truck is read by the storage gamma tester, and the measured gamma curve is compared with the original formation gamma curve to further calibrate the coiled tubing perforation depth. At the same time, the design of pressure plays a role in recycling the anchor claw of the outer cylinder to prevent scratching the sliding sleeve and safety valve when lifting the tool string. The special coiled tubing depth calibration tool is the first case in China, which has a broad application prospect for precise perforation of oilfield gas storage gas-tight string under pressure, string shooting, etc., and fills the domestic construction gap.

[0044] Application Example 1

[0045] Construction purpose: double 035-20 well tubing perforation under pressure

[0046] String structure: 2.0" coiled tubing + outer connector + hydraulic safety joint + 94mm coiled tubing depth calibration positioning tool; φ76mm perforating gun.

[0047] Construction process: double 035-20 well is a key well of gas storage, which is a directional well with wellhead pressure of 20MPa. If perforation is needed to expand the capacity of the reservoir, the original well string must not be lifted. The wellhead pressure of this well is 20MPa, and the formation pressure is 24.6MPa. This time, coiled tubing perforation operation is selected; coiled tubing is used to pass through the well to the upper landing nipple (2662.71m); coiled tubing is used to wash the well to the artificial well bottom (2890m), and the liquid level is maintained to the wellhead; the perforation notification single perforates the well section 2811.7-2832.1m, 17.4m / 3 layers for perforation operation; gas lift liquid discharge and induced blowout production.

[0048] In order to accurately position the perforation depth, the "double depth calibration" method is used in this construction, that is, the self-made coiled tubing depth calibration positioning tool is used for depth calibration, and the coiled tubing storage gamma tester is used for depth calibration at the same time. Through the comparison and analysis of the high-speed acquisition load / depth curve and the measured curve of the gamma tester ground test, the perforation construction is accurately positioned to within 0.5 meters of the target layer.

[0049] Obviously, the above embodiments are only examples for clarity, and are not limited to the implementation. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and impossible to exhaust all the embodiments. The obvious changes and variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A coiled tubing depth correction positioning tool for gas reservoir integrity string, characterized in that, The application relates to a continuous oil pipe and a depth calibration positioning pipe, the continuous oil pipe is connected with a ground pipe truck, the ground pipe truck is used for lowering or lifting a tool, injecting pressure into the tool and monitoring tool load change; the depth calibration positioning pipe comprises a center shaft (14) and an upper joint (15) which are integrally arranged, the center shaft (14) and the upper joint (15) are slidably sleeved with a male joint (12) on the outer wall, the bottom end of the male joint (12) is connected with a female joint (9) to form an outer cylinder, the outer wall of the center shaft (14) is fixedly sleeved with a three-claw anchor tile (8) used for contacting a gas-tight pipe column, the female joint (9) is sleeved on the outer part of the three-claw anchor tile (8), and a shearing pin (11) used for clamping the three-claw anchor tile (8) is connected on the wall of the female joint (9); an extrusion cavity (16) is formed between the outer cylinder and the center shaft (14) and the three-claw anchor tile (8), the extrusion cavity (16) is communicated with the inner cavity of the center shaft (14), the shearing pin (11) is located in the extrusion cavity (16), force for cutting the shearing pin (11) is transmitted from the inner cavity of the center shaft (14) to the extrusion cavity (16), and the female joint (9) can slide downwards along the outer wall of the three-claw anchor tile (8) to store the three-claw anchor tile (8) into the outer cylinder after the shearing pin (11) is cut; A hole (17) is formed in the shaft of the center shaft (14) and is communicated with the extrusion cavity (16), and a cut-off variable-diameter port (18) is arranged below the hole (17) in the inner cavity of the center shaft (14), and the cut-off variable-diameter port (18) is used for clamping a sealing steel ball which is put in by the continuous oil pipe; The three-claw anchor tile (8) comprises an end head (8-1) and three downwardly extending anchor claws (8-2) which are connected to the end head (8-1) at equal intervals, a convex edge (8-3) used for clamping the shearing pin (11) is arranged on the outer wall of the end head (8-1), the lower claw end of the anchor claw (8-2) is provided with an inclined surface a (8-4), the outer side of the lower claw end of the anchor claw (8-2) is a trapezoidal boss (8-5) which is sequentially connected by an inclined surface b, a plane and an inclined surface c, and the trapezoidal boss (8-5) is used for contacting a reduced diameter part when the tool is lowered to the reduced diameter part of the gas-tight pipe column; The angles of two inner bottom corners of the trapezoidal boss (8-5) are 30 DEG and 60 DEG respectively; The application further discloses an adjusting mechanism used for adjusting the angle, the outer diameter and the elasticity of the three-claw anchor tile (8), the adjusting mechanism comprises a taper sleeve (7), a compression spring (6) and a hexagonal pad (5) which are sequentially connected from top to bottom and are sleeved on the outer wall of the center shaft (14), the taper sleeve (7) is threadedly connected with the outer wall of the center shaft (14), and the upper end of the taper sleeve (7) is provided with an inclined surface d which is used for abutting against the inclined surface a (8-4) of the lower claw end of the anchor claw (8-2).

2. The coiled tubing depth calibration positioning tool for gas storage gas seal string according to claim 1, characterized in that, The adjusting mechanism further comprises a positioning nut (3) and a locking nut (1) threaded on the outer wall of the central shaft (14), the positioning nut (3) is arranged below the hexagonal pad (5) and abuts against the hexagonal pad (5) to fix the position of the hexagonal pad (5), the locking nut (1) is arranged below the positioning nut (3) and abuts against the positioning nut (3) to lock the position of the positioning nut (3), the positioning nut (3) is provided with a locking screw (4) arranged in a radial direction, and the locking nut (1) is provided with a fastening screw (2) arranged in a radial direction.

3. The coiled tubing depth calibration positioning tool for gas storage gas seal string according to claim 1, characterized in that, The inner wall of the end (8-1) of the three-jaw anchor shoe (8) is fixedly connected with the outer wall of the central shaft (14) through a clamping nut (10).

4. The coiled tubing depth calibration positioning tool for gas storage gas seal string according to claim 1, characterized in that, The male connector (12) is provided with a plurality of O-shaped sealing rings (13) between the central shaft (14) and the upper connector (15).

5. The coiled tubing depth calibration positioning tool for gas storage gas seal string according to any one of claims 1-4, characterized in that, The depth calibration positioning method of the tool comprises the following steps: The depth calibration positioning pipe is connected with the coiled tubing through the upper connector (15) thereof, the coiled tubing is connected with the surface tubing truck, the coiled tubing and the depth calibration positioning pipe are lowered in the gas storage gas-tight string through the surface tubing, the tool load pressure is monitored by the surface tubing truck during the lowering process, when the three-jaw anchor shoe (8) contacts the landing short circuit reduced diameter of the gas-tight string, the load pressure monitored by the surface tubing truck changes, the position of the landing short circuit is determined, a mark is made on the coiled tubing at the wellhead at this time, and the extrusion cavity (16) is pressed by the surface tubing truck until the female connector (9) slides downward together with the male connector (12) to store the three-jaw anchor shoe (8) in the outer cylinder after the shear pin (11) is cut off, the coiled tubing and the depth calibration positioning pipe are pulled out upward after the three-jaw anchor shoe (8) is stored, and the depth calibration positioning pipe is separated from the coiled tubing, the perforating gun is connected to the coiled tubing with the mark and is lowered into the gas storage gas-tight string, the mark on the coiled tubing is used as a reference line to control the depth of the perforating gun, and the perforating gun is perforated after being lowered to the preset depth.

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