A back-draft filling system and method using a shear-type anti-stuck efficiency-enhancing mechanism

Abstract

The present invention discloses a back-dragging filling system and method using a shear-type anti-stuck efficiency-enhancing mechanism. The system comprises: a casing provided with a return port; a drill rod inserted into the casing; an annulus formed between the drill rod and the casing, the annulus being connected to the return port; a filling mechanism for injecting filling sand fluid into the drill rod; a shear-type anti-stuck efficiency-enhancing mechanism comprising a mechanism body, a sleeve assembly, a telescopic wing assembly, a ball seat shear module, a steel ball, and a sand screen. When the filling mechanism injects filling sand fluid into the drill rod, the fluid pressure exerted on the steel ball pushes the sleeve body downward in the sleeve channel through the ball seat shear module to drive the extension of the telescopic wing assembly, and the sand screen opens along with the extension of the telescopic wing assembly. After the sand screen opens, it filters and isolates the particles in the filling sand fluid, thereby effectively solving the problem of easy jamming of the lifting pipe column and greatly improving the safety and reliability of the construction.

Description

Technical Field

[0001] The present invention relates to offshore oil and gas resource development technology, and in particular to a back-dragging filling system and method using a shearing-type anti-sticking and efficiency-enhancing mechanism. Background Art

[0002] In the process of developing offshore oil and gas resources and unconventional energy, it is often necessary to increase the reservoir contact area and increase the controllable production volume in the form of well groups. According to the oil and gas production design plan, a variety of different drilling and completion methods will be adopted. For example, for the main production wells, a systematic completion project will be adopted to carry out operations such as casing running, reservoir transformation, sand control, lifting, and flow assurance. However, for other supporting wells, a simple completion method will be adopted, such as only drilling and filling operations, to serve the purpose of auxiliary production.

[0003] The traditional method for implementing open hole filling completion at sea is to establish an annulus between the filling area and the tubing, and use tools such as screens and segmented packers to block and separate the filling sand to achieve overall or segmented filling. This construction technology and tools are relatively mature. However, in order to improve operational efficiency, shorten the operation cycle, and reduce offshore construction costs, open hole wells are also modified using open-circuit filling. Because this filling method does not establish a circulation and does not have a sand-retaining medium to block the filling particles, it faces two major problems. First, the filling modification effect is difficult to guarantee, and second, the sand-carrying fluid will carry some of the filling particles back through the annulus, which can easily cause the tubing to get stuck when it is lifted, seriously endangering the safety of well construction.

[0004] Currently, there is a lack of specialized tools to address the problem of pullback filling in offshore open-circuit drilling. The only way to optimize the filling process, such as filling volume, sand ratio, and filling particles, is to fail to fundamentally solve the technical difficulties faced by open-circuit pullback filling. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and to provide a back-dragging filling system and method using a shear-type anti-jamming and efficiency-enhancing mechanism.

[0006] To achieve the above object, the technical solution of the present invention is:

[0007] A back-draft filling system using a shear-type anti-jamming and efficiency-enhancing mechanism comprises:

[0008] a casing provided with a flowback port;

[0009] A drill pipe is inserted into the casing; an annulus is formed between the drill pipe and the casing, and the annulus is connected to the flowback port;

[0010] A filling mechanism, used for injecting a filling sand fluid into the drill pipe;

[0011] A shearing-type anti-stuck efficiency-enhancing mechanism is installed in the drill pipe and includes a mechanism body, a sleeve assembly, a telescopic wing assembly, a ball seat shear module, a steel ball, and a sand screen. The mechanism body is axially penetrated, with one end serving as an upper joint, the other end serving as a lower joint, and the middle portion serving as a sleeve channel; the sleeve assembly is arranged in the sleeve channel; the sleeve assembly includes a sleeve body, which is axially penetrated to serve as a central channel; the steel ball is placed on the ball seat shear module, and the ball seat shear module is installed in the central channel by means of a pin; the telescopic wing assembly is arranged on the axial surface of the mechanism body and is driven to extend and retract through the sleeve body; the sand screen is installed on the telescopic wing assembly;

[0012] When the filling mechanism injects filling sand fluid into the drill pipe, the fluid pressure exerted on the steel ball pushes the sleeve body to move downward in the sleeve channel through the ball seat shear module, thereby driving the extension of the telescopic wing assembly, and the sand retaining net opens following the extension of the telescopic wing assembly.

[0013] Furthermore, the filling mechanism includes a filling sand storage chamber, a fluid storage chamber, a sand mixing skid, an injection pump and an injection pipeline. The sand mixing skid mixes the filling sand in the filling sand storage chamber and the liquid in the fluid storage chamber and then pumps the mixed mixture to the injection pipeline through the injection pump. The injection pipeline is connected to the drill pipe.

[0014] Furthermore, the filling mechanism further includes a derrick, and the derrick is used to vertically install the injection pipeline.

[0015] Furthermore, the main body of the mechanism is divided into three parts: upper, middle and lower parts. The diameter of the middle part is smaller than that of the upper and lower parts, and the middle part serves as the installation area of ​​the telescopic wing assembly.

[0016] Furthermore, the sleeve body is divided into three parts: an upper part, a middle part, and a lower part. The outer diameter of the upper part is smaller than the diameter of the sleeve channel and matches the outer diameter of the upper part. The outer diameter of the lower part is smaller than the diameter of the sleeve channel. A step is formed between the upper part and the middle part, and an inclined surface transitions between the middle part and the lower part. A slot is provided in the middle part of the sleeve body.

[0017] Furthermore, the sleeve assembly further comprises a spring pressure cap, a sleeve spring, and a sleeve spring seat; the spring pressure cap is disposed on the upper portion of the sleeve body, and the sleeve spring seat is disposed on the step; the sleeve spring is disposed in an area formed by the inner wall of the sleeve channel, the spring pressure cap, the sleeve spring seat, and the outer surface of the upper portion of the sleeve body; the sleeve assembly further comprises a sleeve positioning spring and a sleeve positioning spring clip; one end of the sleeve positioning spring abuts against the slot, and the other end abuts against the sleeve positioning spring clip;

[0018] A sleeve positioning hole corresponding to the sleeve positioning spring clip is provided in the inner wall of the sleeve channel.

[0019] Furthermore, a support rod mounting hole is provided on the inner wall of the sliding sleeve channel, and the support rod mounting hole is located below the sliding sleeve positioning hole;

[0020] The telescopic wing assembly includes a support rod and a wing rod; the support rod is installed in the support rod mounting hole, with a portion located outside the mechanism body and a portion located in the support rod mounting hole; the end of the support rod located outside the mechanism body is connected to the wing rod through a flexible joint, the end of the support rod located in the support rod mounting hole is a triangular portion, and the portion of the support rod located in the support rod mounting hole is sleeved with a support rod spring, one end of the support rod spring rests against the bottom of the support rod mounting hole, and the other end rests against the triangular portion.

[0021] Furthermore, a support rod bearing pulley is installed in the triangular portion.

[0022] Furthermore, a contact roller is installed at the end of the wing rod located below the support rod, and a wing rod bearing is installed at the end located above the support rod.

[0023] Accordingly, the present invention further provides an offshore towing and filling construction method, which is based on the above-mentioned system and is characterized in that the method comprises:

[0024] (1) Carry out directional drilling in the formation, adopt the open drilling method, and carry out drilling operations according to the designed trajectory. After the drilling operation is completed, turn to the backfill construction;

[0025] (2) During the backfilling construction, the filling sand and the fluid carrying the sand particles are prepared in advance on the platform or ship, and the sand ratio and filling displacement are designed according to the formation fracture pressure;

[0026] (3) Assemble the backhaul filling pipeline on the platform or ship, and connect the filling sand storage chamber, the fluid storage chamber and the sand mixing skid, the sand mixing skid and the injection pump, and the injection pump and the drill pipe;

[0027] (4) Place the steel ball into the tubing through the drill pipe, and use the fluid in the injection pump to push the steel ball to the ball seat shear module, continue to pressurize, increase the fluid pressure to P, and the pressure P will generate a downward thrust F on the steel ball, and the sleeve body will move downward; when the sleeve positioning spring enters the sleeve positioning hole, the sleeve positioning spring changes from compression to tension, pushing the sleeve positioning spring into the sleeve positioning hole, playing a role in limiting axial displacement, completing the sleeve positioning, and at this time, no further pressure is applied; in this process, the support rod spring and the sleeve spring are gradually compressed, and the support rod moves radially outward under the push of the support rod bearing pulley, gradually supporting the wing rod; the wing rod revolves around the wing rod bearing as a fulcrum, and gradually forms an angle with the mechanism body; when the sleeve positioning spring enters the sleeve positioning hole, the angle reaches the maximum value, the contact roller contacts the well wall, and the wing rod will change the sand screen from a compressed state to a stretched state. After the sand screen is opened, the mesh diameter is smaller than the filling sand diameter, allowing the fluid to pass but blocking the filling sand;

[0028] (5) When the sleeve is positioned, the maximum compression force F2 of the sleeve spring is reached. The hydraulic pressure above the steel ball is continuously increased by the injection pump, so that the force F acting on the steel ball is greater than F1. F1 is the shearing force between the ball seat and the sleeve shear pin. At this time, the ball seat shear module is sheared, and the shear module slides to the bottom of the well together with the steel ball.

[0029] (6) After the filling sand and fluid in the filling sand storage chamber and the fluid storage chamber are mixed, the injection pump provides pumping power and is pumped into the drill pipe through the injection pipeline. The fluid carrying sand flows to the bottom of the pipe string and enters the wellbore, gradually filling the well. The fluid passes through the sand interception net and then returns through the annulus between the casing and the drill pipe, and flows out at the return port. During the filling process, the derrick provides the lifting and pulling force, and lifts the drill pipe and the entire pipe string at the designed rate, realizing filling while pulling back;

[0030] (7) After filling is completed, the tubing is pulled out with force. When the pull-back force F4 is greater than the shear pin shear force F3 of the upper joint of the mechanism, F3 is the shear force of the tubing shear pin, and the tubing shear pin breaks. The tubing below the shear pin remains in the well, and the upper tubing continues to be pulled out until the operation is completed.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The back-pulling filling system using the shear-type anti-stuck lifting mechanism of the present invention can filter and isolate particles in the filling sand fluid, thereby effectively solving the problem of easy sticking of the lifting pipe column and greatly improving the safety and reliability of the construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of the composition of a back-draft filling system using a shear-type anti-sticking and efficiency-enhancing mechanism provided in an embodiment of the present invention;

[0034] Figure 2 This is a structural diagram of the shear-type anti-jamming and efficiency-enhancing mechanism in a closed state;

[0035] Figure 3 This is a structural diagram of the shear-type anti-jamming and efficiency-enhancing mechanism in an open state;

[0036] Figure 4 It is a partial enlarged structural diagram of the sliding sleeve assembly and the telescopic wing assembly;

[0037] Figure 5 This is a top view of the shear-type anti-jamming and efficiency-enhancing mechanism;

[0038] In the figure: 1. steel ball; 2. wing rod bearing; 3. wing rod; 4. well wall; 5. support rod; 6. support rod spring; 7. support rod bearing pulley; 8. lower joint; 9. support rod spring seat; 10. flexible joint; 11. sleeve spring seat; 12. sleeve spring; 13. spring pressure cap; 14. ball seat shear module; 15. upper joint; 16. mechanism body; 17. contact roller; 18. sleeve body; 19. sleeve positioning hole; 20. sleeve positioning spring; 21. sleeve positioning spring; 22. sand barrier; 23. derrick; 24. injection pipeline; 25. injection pump; 26. sand mixing skid; 27. sand filling reservoir chamber; 28. fluid storage chamber; 29. ​​formation; 30. shear type anti-sticking and efficiency-enhancing mechanism; 31. casing; 32. drill pipe; 33. return port; 34. shear pin. DETAILED DESCRIPTION

[0039] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0040] Example:

[0041] See Figure 1 As shown, it is a schematic diagram of the composition of the back-pull filling system using the shear-type anti-sticking and efficiency-enhancing mechanism provided in this embodiment, which mainly includes a casing 31, a drill rod 32, a filling mechanism and a shear-type anti-sticking and efficiency-enhancing mechanism 30.

[0042] Among them, the drill rod 32 is inserted into the casing 31, and an annulus is formed between the drill rod 32 and the casing 31. The end of the casing above the mud line is enclosed, but a return port 33 is provided at the enclosed position to facilitate the discharge of pure fluid; the filling mechanism is connected to the drill rod 32, so that filling sand fluid can be injected into the drill rod 32.

[0043] The shear-type anti-stuck efficiency-enhancing mechanism is installed in the drill pipe, including a mechanism body 16, a sleeve assembly, a telescopic wing assembly, a ball seat shear module 14, a steel ball 1 and a sand-blocking net 22; the mechanism body 16 is axially penetrated, one end serves as an upper joint 15 for connecting to the upper pipe column, the other end serves as a lower joint 8, and the middle part serves as a sleeve channel; the sleeve assembly is arranged in the sleeve channel, including a sleeve body 18, and the sleeve body 18 is axially penetrated to serve as a central channel; the steel ball is placed on the ball seat shear module 14, and the ball seat shear module 14 is installed in the central channel by means of a pin; the telescopic wing assembly is arranged on the axial surface of the mechanism body 16 and is driven to extend and retract through the sleeve body 16; the sand-blocking net 22 is installed on the telescopic wing assembly.

[0044] When the filling mechanism injects filling sand fluid into the drill pipe, the steel ball 1 is subjected to pressure and transmitted to the ball seat shear module 14, and the ball seat shear module 14 pushes the sliding sleeve body 18 to move downward in the sliding sleeve channel, thereby driving the extension of the telescopic wing assembly, and the sand screen 22 opens along with the extension of the telescopic wing assembly. Figure 1 As shown, when the sand retaining net 22 is opened, it can stick to the well wall 4. Since the mesh diameter of the sand retaining net 22 is smaller than the diameter of the filling sand, it can allow the passage of fluid and block the migration of filling particles. Therefore, a layer of sand barrier can be formed in the annulus to filter and isolate the particles in the filling sand fluid, thereby effectively solving the problem of easy jamming of the lifting pipe string and greatly improving the safety and reliability of the construction.

[0045] In one embodiment, the filling mechanism includes a filling sand storage chamber 27, a fluid storage chamber 28, a sand mixing skid 26, an injection pump 25, and an injection pipeline 24. The sand mixing skid 26 is used to mix the filling sand in the filling sand storage chamber 27 with the liquid in the fluid storage chamber 28, and then pump the mixture to the injection pipeline 24 via the injection pump 25. The injection pipeline 24 is connected to the drill pipe 32. Furthermore, to provide operating space and power for the injection pipeline 24 and the drill pipe 32, the filling mechanism also includes a derrick 23 for suspending the injection pipeline 24.

[0046] In a specific embodiment, if Figure 2-5 As shown, the mechanism body 16 is divided into three sections: upper, middle, and lower. The diameter of the middle section is smaller than that of the upper and lower sections, and the middle section serves as the mounting area for the telescopic wing assembly. In other words, the mechanism body 16 adopts a reduced diameter design, resulting in no noticeable protrusions on the outer cylindrical surface of the mechanism, thus preventing any adverse effects on the string running process.

[0047] In a specific embodiment, the above-mentioned sliding sleeve body 18 is divided into three parts: upper, middle and lower parts. The outer diameter of the upper part is smaller than the diameter of the sliding sleeve channel, the outer diameter of the upper part matches the diameter of the sliding sleeve channel, and the outer diameter of the lower part is smaller than the diameter of the sliding sleeve channel. A step is formed between the upper and middle parts, and an inclined surface transitions between the middle and lower parts; a slot is provided at the middle position of the sliding sleeve body 18. The above-mentioned sleeve assembly also includes a spring pressure cap 13, a sleeve spring 12 and a sleeve spring seat 11; the spring pressure cap 13 is arranged on the inner wall of the sleeve channel and located at the upper part of the sleeve body 18, and the sleeve spring seat 11 is arranged on the step between the upper and middle parts of the sleeve body 18; the sleeve spring 12 is arranged in the area formed by the inner wall of the sleeve channel, the spring pressure cap 13, the sleeve spring seat 11 and the upper outer surface of the sleeve body 18; the sleeve assembly also includes a sleeve positioning spring 20 and a sleeve positioning spring clip 21; one end of the sleeve positioning spring 20 abuts against the slot hole, and the other end abuts against the sleeve positioning spring clip 21; a sleeve positioning hole 19 corresponding to the sleeve positioning spring clip is provided in the inner wall of the sleeve channel, and a support rod mounting hole is provided on the inner wall of the sleeve channel, and the support rod mounting hole is located below the sleeve positioning hole 19.

[0048] In one embodiment, the telescopic wing assembly includes a support rod 5 and a wing rod 3. The support rod 3 is mounted in a support rod mounting hole, with a portion located outside the mechanism body 1 and a portion located inside the support rod mounting hole. The end of the support rod 3 located outside the mechanism body is connected to the wing rod 3 via a flexible joint 10. The end of the support rod 5 located in the support rod mounting hole is a triangular portion that contacts the inclined surface between the middle and lower portions of the sliding sleeve body 18. The portion of the support rod 3 located in the support rod mounting hole is sleeved with a support rod spring 13. One end of the support rod spring 13 abuts against a support rod spring 9 at the bottom of the support rod mounting hole, and the other end abuts against the triangular portion, in which a support rod bearing pulley 7 is mounted. The end of the wing rod 3 located below the support rod 5 is mounted with a contact roller 17, and the end located above the support rod is mounted with a wing rod bearing 2, which is fixedly mounted to the mechanism body 16.

[0049] Based on the above-mentioned backhaul filling system using the shear-type anti-sticking and efficiency-enhancing mechanism, this embodiment also provides an offshore backhaul filling construction method, in which the drill pipe carries a bottom hole power head screw motor, and the drill tool assembly is: drill bit + screw motor + short blind pipe + shear-type anti-sticking and efficiency-enhancing mechanism + shear pin short section + drill pipe. The method mainly includes the following steps

[0050] (1) Carry out directional drilling in the formation, adopt the open drilling method, and carry out drilling operations according to the designed trajectory. After the drilling operation is completed, turn to the backfill construction;

[0051] (2) During the backfilling construction, the filling sand and the fluid carrying the sand particles are prepared in advance on the platform or ship. The filling sand and the fluid can be specially designed according to the characteristics of the formation. For example, the filling sand can be multi-layer coated sand or ultra-light sand, and the fluid can be environmentally friendly mud or reservoir protection mud. The sand ratio and filling displacement are designed according to the formation fracture pressure.

[0052] (3) After the back-towing filling pipeline is assembled on the platform or ship, the filling sand storage chamber 27, the fluid storage chamber 28 and the sand mixing skid 26, the sand mixing skid 26 and the injection pump 25, and the injection pump 25 and the drill pipe 32 are connected to each other. The drill pipe 32 and the anti-sticking and efficiency-enhancing mechanism 30 have been connected during the drilling stage, so there is no need to reconnect them.

[0053] (4) First, the steel ball 1 is placed into the interior of the pipe string through the drill pipe 32, and the fluid is used by the injection pump 25 to push the ball to the ball seat 14, and the pressure is continued to increase to P. P acts on the steel ball 1 and generates a downward thrust F. The pin will break when subjected to the pressure of F1, and the sleeve body 18 moves downward. During the downward pressure process of the sleeve body 18, when the sleeve positioning spring 21 enters the sleeve positioning hole 19, the sleeve spring 12 is subjected to the maximum compression force of F2, where F1>F2; when the sleeve positioning spring 21 moves to align with the sleeve positioning hole 19, the sleeve positioning spring 20 changes from compression to tension, pushing the sleeve positioning spring 21 into the sleeve positioning hole 19, playing a role in limiting axial displacement and completing positioning. At this time, the pressure is no longer continued; in this process, the support rod spring 6 and the sleeve spring 12 are gradually compressed, and the support rod 5 moves radially outward under the push of the support rod bearing pulley 7, gradually supporting the wing rod 3. Wing rod 3, with wing rod bearing 2 as its fulcrum, gradually forms an angle with mechanism body 16. When sleeve positioning spring 21 enters sleeve positioning hole 19, the angle reaches its maximum value, contact roller 17 contacts well wall 4, and wing rod 3 shifts sand screen 22 from a compressed state to a stretched state. When the sand screen is expanded, its mesh diameter is smaller than the sand filling diameter, allowing fluid to pass but blocking the sand filling.

[0054] (5) When the positioning of the sleeve is completed, the maximum compression force F2 of the sleeve spring is reached, and the hydraulic pressure above the steel ball is continuously increased by the injection pump, so that the force F acting on the steel ball is greater than F1, where F1 is the shearing force between the ball seat and the sleeve shear pin. At this time, the ball seat shearing module 14 is sheared, and the shearing module 14 slides to the bottom of the well together with the steel ball 1, which will not have any impact on the subsequent filling construction; at this time, since the sleeve positioning spring card 21 is in the sleeve positioning hole 19, the sleeve body 18 will not continue to move downward, and the sand screen always remains in an open state and in contact with the well wall 4;

[0055] (6) After the filling sand and fluid in the filling sand storage chamber 27 and the fluid storage chamber 28 are mixed by the sand mixing pry 26, the injection pump 25 provides pumping power and is pumped into the drill pipe 32 through the injection pipeline 24. After the fluid carrying sand flows to the bottom of the pipe string, it enters the wellbore and gradually fills the well. The fluid passes through the sand interception net 22 and then returns through the annulus between the casing 31 and the drill pipe 32, and flows out at the return port 33. During the filling process, the derrick 23 provides the lifting and pulling force, and lifts the drill pipe 32 and the entire pipe string at the designed rate, realizing the filling while pulling back;

[0056] (7) After filling is completed, the tubing is pulled out with force. When the pull-back force F4 is greater than the shear force F3 of the shear pin 34 of the upper joint of the mechanism, F3 is the shear force of the tubing shear pin 34. The tubing shear pin 34 breaks, and the tubing below the shear pin 34 remains in the well. The upper tubing continues to be pulled out until the operation is completed.

[0057] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made based on the essence of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A back-draft filling system using a shear-type anti-jamming and efficiency-enhancing mechanism, characterized in that: include: a casing provided with a flowback port; A drill pipe is inserted into the casing; an annulus is formed between the drill pipe and the casing, and the annulus is connected to the flowback port; A filling mechanism, used for injecting a filling sand fluid into the drill pipe; A shearing-type anti-stuck efficiency-enhancing mechanism is installed in the drill pipe and includes a mechanism body, a sleeve assembly, a telescopic wing assembly, a ball seat shear module, a steel ball, and a sand screen. The mechanism body is axially penetrated, with one end serving as an upper joint, the other end serving as a lower joint, and the middle portion serving as a sleeve channel; the sleeve assembly is arranged in the sleeve channel; the sleeve assembly includes a sleeve body, which is axially penetrated to serve as a central channel; the steel ball is placed on the ball seat shear module, and the ball seat shear module is installed in the central channel by means of a pin; the telescopic wing assembly is arranged on the axial surface of the mechanism body and is driven to extend and retract through the sleeve body; the sand screen is installed on the telescopic wing assembly; When the filling mechanism injects filling sand fluid into the drill pipe, the fluid pressure exerted on the steel ball pushes the sliding sleeve body downward in the sliding sleeve channel through the ball seat shear module, thereby driving the extension of the telescopic wing assembly, and the sand retaining net opens along with the extension of the telescopic wing assembly; When the sleeve moves down a certain distance, it is axially positioned by the positioning device. After positioning, the liquid pressure above the steel ball continues to increase to cut off the shear pin between the ball seat and the sleeve. At this time, the ball seat shear module is cut off, and the ball seat shear module slides to the bottom of the well together with the steel ball. The filling sand fluid flows to the bottom of the pipe string and enters the wellbore; when the sand retaining net is opened, it can stick to the well wall. Since the mesh diameter of the sand retaining net is smaller than the diameter of the filling sand, it can allow the passage of fluid and at the same time block the migration of filling particles. A layer of sand barrier can be formed in the annulus to filter and isolate the particles in the filling sand fluid, so as to solve the problem of easy jamming of the pipe string when it is lifted.

2. The back-pull filling system with shear-type anti-sticking and efficiency-enhancing mechanism according to claim 1 is characterized in that: The filling mechanism includes a filling sand storage chamber, a fluid storage chamber, a sand mixing skid, an injection pump and an injection pipeline. The sand mixing skid mixes the filling sand in the filling sand storage chamber and the liquid in the fluid storage chamber and then pumps the mixed mixture to the injection pipeline through the injection pump. The injection pipeline is connected to the drill pipe.

3. The back-pull filling system with shear-type anti-sticking and efficiency-enhancing mechanism according to claim 2 is characterized in that: The filling mechanism further comprises a derrick, and the derrick is used to vertically install the injection pipeline.

4. The back-dragging filling system using a shear-type anti-sticking and efficiency-enhancing mechanism according to claim 1 or 3, characterized in that: The mechanism body is divided into three parts: upper, middle and lower parts. The diameter of the middle part is smaller than that of the upper and lower parts. The middle part serves as the installation area of ​​the telescopic wing assembly.

5. The back-dragging filling system using a shear-type anti-jamming and efficiency-enhancing mechanism according to claim 1 or 3, characterized in that: The sleeve body is divided into three parts: upper, middle and lower parts. The outer diameter of the upper part is smaller than the diameter of the sleeve channel, and the outer diameter of the upper part matches the diameter of the sleeve channel. The outer diameter of the lower part is smaller than the diameter of the sleeve channel. A step is formed between the upper and middle parts, and an inclined surface transitions between the middle and lower parts. A slot is provided at the middle position of the sleeve body.

6. The back-pull filling system using a shear-type anti-sticking and efficiency-enhancing mechanism as claimed in claim 5, characterized in that: The sleeve assembly further includes a spring pressure cap, a sleeve spring, and a sleeve spring seat; the spring pressure cap is disposed on the upper portion of the sleeve body, and the sleeve spring seat is disposed on the step; the sleeve spring is disposed in an area formed by the inner wall of the sleeve channel, the spring pressure cap, the sleeve spring seat, and the upper outer surface of the sleeve body; the sleeve assembly further includes a sleeve positioning spring and a sleeve positioning spring clip; one end of the sleeve positioning spring abuts against the slot, and the other end abuts against the sleeve positioning spring clip; A sleeve positioning hole corresponding to the sleeve positioning spring clip is provided in the inner wall of the sleeve channel.

7. The back-pull filling system using a shear-type anti-sticking and efficiency-enhancing mechanism according to claim 6, characterized in that: A support rod mounting hole is provided on the inner wall of the sliding sleeve channel, and the support rod mounting hole is located below the sliding sleeve positioning hole; The telescopic wing assembly includes a support rod and a wing rod; the support rod is installed in the support rod mounting hole, with a portion located outside the mechanism body and a portion located in the support rod mounting hole; the end of the support rod located outside the mechanism body is connected to the wing rod through a flexible joint, the end of the support rod located in the support rod mounting hole is a triangular portion, and the portion of the support rod located in the support rod mounting hole is sleeved with a support rod spring, one end of the support rod spring rests against the bottom of the support rod mounting hole, and the other end rests against the triangular portion.

8. The back-pull filling system using a shear-type anti-sticking and efficiency-enhancing mechanism according to claim 7, characterized in that: A support rod bearing pulley is installed in the triangular portion.

9. The back-pull filling system using a shear-type anti-sticking and efficiency-enhancing mechanism according to claim 8, characterized in that: The end of the wing rod located below the support rod is equipped with a contact roller, and the end of the wing rod located above the support rod is equipped with a wing rod bearing.

10. A method for offshore towing and filling construction, the method being based on the system according to claim 9, characterized in that: The method comprises: (1) Carry out directional drilling in the formation, adopt the open-circuit drilling method, and carry out drilling operations according to the designed trajectory. After the drilling operation is completed, turn to the backfill construction; (2) During the backfilling construction, the filling sand and the fluid carrying the sand particles are prepared in advance on the platform or ship, and the sand ratio and filling volume are designed according to the formation fracture pressure; (3) Assemble the backhaul filling pipeline on the platform or ship, and connect the filling sand storage chamber, the fluid storage chamber and the sand mixing skid, the sand mixing skid and the injection pump, and the injection pump and the drill pipe; (4) Place the steel ball into the tubing through the drill pipe, and use the fluid of the injection pump to push the steel ball to the ball seat shear module, and continue to pressurize to increase the fluid pressure to P. The pressure P acts on the steel ball to generate a downward thrust F, and the sleeve body moves downward; when the sleeve positioning spring enters the sleeve positioning hole, the sleeve positioning spring changes from compression to tension, pushing the sleeve positioning spring into the sleeve positioning hole, playing a role in limiting axial displacement, completing the sleeve positioning, and at this time, no further pressure is applied; in this process, the support rod spring and the sleeve spring are gradually compressed, and the support rod moves radially outward under the push of the support rod bearing pulley, gradually supporting the wing rod; the wing rod revolves around the wing rod bearing as a fulcrum, and gradually forms an angle with the main body of the mechanism; when the sleeve positioning spring enters the sleeve positioning hole, the angle reaches the maximum value, the contact roller contacts the well wall, and the wing rod will change the sand screen from a compressed state to a stretched state. After the sand screen is opened, the mesh diameter is smaller than the filling sand diameter, allowing fluid to pass but blocking the filling sand; (5) When the positioning of the sleeve is completed, the maximum compression force F2 of the sleeve spring is reached. The hydraulic pressure above the steel ball is continuously increased by the injection pump, so that the force F acting on the steel ball is greater than F1. F1 is the shearing force between the ball seat and the sleeve shear pin. At this time, the ball seat shear module is sheared off, and the shear module slides to the bottom of the well together with the steel ball. (6) After the filling sand and fluid in the filling sand storage chamber and the fluid storage chamber are mixed, the injection pump provides pumping power and is pumped into the drill pipe through the injection pipeline. The fluid carrying sand flows to the bottom of the pipe string and enters the wellbore, gradually filling the well. The fluid passes through the sand interception net and then returns through the annulus between the casing and the drill pipe, and flows out at the return port. During the filling process, the derrick provides the lifting and pulling force, and lifts the drill pipe and the entire pipe string at the designed rate, realizing filling while pulling back; (7) After filling is completed, the tubing is pulled out with force. When the pull-back force F4 is greater than the shear pin shear force F3 of the upper joint of the mechanism, F3 is the shear force of the tubing shear pin, and the tubing shear pin breaks. The tubing below the shear pin remains in the well, and the upper tubing continues to be pulled out until the operation is completed.

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