Tubing shoe and short radius horizontal well multi-stage sliding sleeve jetting staged fracturing method

Abstract

The application provides a tubing shoe and a short-radius horizontal well multi-stage sliding sleeve jetting staged fracturing method, and relates to the field of oil and gas field development. The tubing shoe comprises a connecting cylinder assembly, a rotating shoe assembly, a base assembly, a transmission assembly, a locking assembly, a pin pulling assembly and a fishing tool. The rotating shoe assembly is rotationally connected to the lower end of the connecting cylinder assembly. The transmission assembly and the base assembly are fixed by clamping, which facilitates the recycling of the transmission assembly, the base assembly and components thereon. The recycled transmission assembly, the base assembly and components thereon can be assembled again in the reverse order, which is conducive to the reuse of the internal accessories of the tubing shoe. Since the transmission assembly, the base assembly and components thereon do not need to be drilled out, higher-strength parts can be used, the internal accessories of the tubing shoe have the effect of high strength, the structure of the tubing shoe is less likely to be damaged during operation, and the operation time of the tubing shoe is facilitated to be prolonged.

Description

Technical Field

[0001] This application relates to the field of oil and gas field development technology, and more specifically, to a method for multi-stage sliding sleeve jet fracturing of tubing shoes and short-radius horizontal wells. Background Technology

[0002] The structure of a multi-stage sliding sleeve jet fracturing string (which also serves as a completion string) for short-radius horizontal wells, from bottom to top, is: tubing shoe + small casing + first-stage jetting sliding sleeve + small casing + second-stage jetting sliding sleeve + small casing + nth-stage jetting sliding sleeve + small casing + release handle + tubing to the wellhead. During the casing running process, various factors such as formation stability and wellbore trajectory can cause wellbore narrowing, collapse, and high frictional resistance, which are unfavorable to the casing running into place. If the casing is not run to the predetermined depth, the resources of the target formation cannot be exploited. At the same time, if the casing running process is not smooth, it will increase the operation time and cost. The tubing shoe, also known as the guide shoe, is installed at the bottom of the casing string to guide the casing into the well, prevent the bottom of the casing from scraping or inserting into the well wall, and guide the casing smoothly to the bottom of the well.

[0003] In related technologies, tubing shoes use a transmission mechanism to drive a rotating sleeve to rotate. During the rotation of the rotating sleeve, the well wall is trimmed and the obstruction point is flushed, assisting the tubing string to pass through the obstruction point and reach the bottom of the well. However, if the tubing shoe needs to be drilled again for the next drilling operation, the internal accessories of the tubing shoe need to be removed by the drill bit. If the drill bit passes through the obstruction point repeatedly without encountering any obstruction, drilling can continue. Directly removing the internal accessories of the tubing shoe has two problems: first, it is wasteful and not easy to recycle; second, when designing the internal accessories of the tubing shoe, drilling removal needs to be considered, and high-strength components cannot be used because high-strength components are difficult to remove. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes an oil pipe shoe, wherein the internal accessories of the oil pipe shoe are fixed by a snap-fit ​​mechanism, the internal accessories of the shoe are recyclable, and the materials used to manufacture the internal accessories of the shoe can also be high-strength materials. The internal accessories of this oil pipe shoe have the advantages of high structural strength and easy recycling.

[0005] In a first aspect, embodiments of this application provide a tubing shoe, comprising: a connecting cylinder assembly, a rotating shoe assembly, a base assembly, a transmission assembly, a locking assembly, a pull pin assembly, and a retrieval tool.

[0006] The rotating shoe assembly is rotatably connected to the lower end of the connecting cylinder assembly. The base assembly is inserted into the connecting cylinder assembly. The upper end of the transmission assembly is located on the lower side of the base assembly. The outer wall of the transmission assembly is inserted into the rotating shoe assembly. The transmission assembly drives the rotating shoe assembly to rotate. The maximum outer diameter of the transmission assembly is smaller than the minimum inner diameter of the connecting cylinder assembly. The locking assembly is slidably inserted into the connecting cylinder assembly. The locking assembly can lock the rotating shoe assembly. The pull pin assembly is located in the base assembly. The pull pin assembly passes through the outer wall of the base assembly and inserts into the locking assembly. The pull pin assembly restricts the sliding of the base assembly by the locking assembly. The retrieval tool is screwed into the base assembly through a thread. The retrieval tool can drive the pull pin assembly to pull out the locking assembly.

[0007] According to some embodiments of this application, the connecting cylinder assembly includes a connecting cylinder, an isolation ring, and a first locking block. The isolation ring is disposed on the inner wall of the connecting cylinder, and the inner wall of the connecting cylinder is provided with first locking grooves at equal intervals near the upper side of the isolation ring. The first locking block is disposed on the inner wall of the connecting cylinder near the lower side of the isolation ring. The base assembly is slidably inserted into the first locking groove, and the lower side of the base assembly presses against the isolation ring. The first locking block is slidably inserted into the outer wall of the locking assembly.

[0008] According to some embodiments of this application, the rotating tube shoe assembly includes a rotating cylinder and a tube shoe toe. The tube shoe toe is disposed at the bottom end of the rotating cylinder. The inner wall of the upper end of the rotating cylinder is evenly provided with a second slot. The outer wall of the transmission assembly is inserted into the second slot. The lower end of the rotating cylinder is provided with a side flow hole. The top of the rotating cylinder is provided with a limit slot at equal intervals. The lower end of the locking assembly can be inserted into the limit slot, and the limit slot restricts the rotation of the locking assembly.

[0009] According to some embodiments of this application, the base assembly includes a basin-shaped base, a limiting cylinder, a second locking block, and a sealing ring. The limiting cylinder is fixedly sleeved on the outer wall of the basin-shaped base. The second locking blocks are equally spaced on the outer wall of the limiting cylinder and are inserted into the first locking groove. The sealing ring is fixedly connected to the lower side of the limiting cylinder. The limiting cylinder presses the sealing ring against the isolation ring. The bottom of the basin-shaped base is inclined and has a jet hole facing the transmission assembly.

[0010] According to some embodiments of this application, the transmission assembly includes a mounting base, an impact impeller, a rotating shaft, a linkage cylinder, and a third locking block. The mounting base has a mounting chamber. The impact impeller is fixedly sleeved on the rotating shaft and located within the mounting chamber. The rotating shaft rotatably passes through the mounting base, and the jet orifice faces the impact impeller. The linkage cylinder is rotatably sleeved on the outer wall of the mounting base. The third locking block is fixedly connected to the outer wall of the linkage cylinder at equal intervals. The third locking block is inserted into the inner wall of the upper end of the rotating tube shoe assembly. The rotating shaft is drively connected to the linkage cylinder.

[0011] According to some embodiments of this application, a bevel gear ring is fixedly connected to the lower side of the linkage cylinder, and a bevel gear is fixedly sleeved at one end of the rotating shaft passing through the mounting base, with the bevel gear and the bevel gear ring meshing with each other.

[0012] According to some embodiments of this application, the locking assembly includes a locking cylinder and a limiting block. The outer wall of the locking cylinder has a third slot. The locking cylinder has guide limiting grooves evenly spaced along the circumferential direction. The upper side of the guide limiting groove near the inner wall of the locking cylinder is set as a slope surface. The pin pulling assembly passes through the basin-shaped base and is inserted into the guide limiting groove. The limiting block is inserted into the top of the rotating tube shoe assembly. The limiting block restricts the rotation of the rotating tube shoe assembly. The pin pulling assembly can push the locking cylinder to slide upward through the guide limiting groove.

[0013] According to some embodiments of this application, the pin-pulling assembly includes a double-ear seat, a double-rod swing frame, a slide rod, a pin, and a compression spring. The double-ear seat is fixedly connected to the lower side inside the basin-shaped base. The double-rod swing frame is rotatably connected to the upper end of the double-ear seat. The slide rod is disposed at the lower end inside the basin-shaped base and is located on both sides of the double-ear seat. The pin is slidably connected to the slide rod on both sides. The compression spring is sleeved on the slide rod and presses the pin against the inner wall of the basin-shaped base. The pin passes through the basin-shaped base and is inserted into the guide limiting groove. The retrieval tool can press down the upper rod of the double-rod swing frame, and the lower rod of the double-rod swing frame can move the pin to slide along the slide rod.

[0014] According to some embodiments of this application, the pin includes a pin body and a clamping plate. The clamping plate is fixedly connected to both sides of the pin body and slidably connected to the slide rod. The compression spring presses against the clamping plate, and the double-ear seat can block the clamping plate. A moving groove is provided in the pin body. The rod at the lower end of the double-rod swing frame is inserted into the moving groove. The rod at the lower end of the double-rod swing frame presses against the inner wall of the moving groove. The end of the pin body is set as an inclined surface. The inclined surface of the pin body cooperates with the inclined surface of the guide limiting groove to push the locking cylinder to slide upward.

[0015] Secondly, embodiments of this application provide a multi-stage sliding sleeve jet fracturing method for short-radius horizontal wells, which utilizes the tubing shoe to guide the small casing, specifically including the following steps:

[0016] S1: Running tubing string; After the short-radius horizontal well is completed, a multi-stage sliding sleeve jet fracturing construction tubing string is run in, which also serves as the completion tubing string. The tubing string, from bottom to top, consists of: tubing shoe, multi-stage interconnected small casing and jetting sliding sleeve, small casing, release sleeve, tubing to the wellhead. The depth of each stage of jetting sliding sleeve is selected in areas with good permeability that are conducive to fracturing and fracture generation.

[0017] S2: Fracturing preparation; installation of wellhead and surface manifold, positioning of fracturing operation vehicle, and pressure testing of surface manifold;

[0018] S3: Hydraulic perforation; the ball is dropped to open the lowest sandblasting sleeve, and a high-speed jet is used to perform hydraulic perforation on the open hole formation outside the small casing; the perforation fluid is injected from the tubing, sprayed through the sandblasting sleeve to the open hole formation outside the small casing, and returned along the annulus of the open hole section outside the casing to the annulus of the main wellbore, and returned to the surface through the wellhead casing gate; sufficient perforation makes the perforation hole more perfect, which is conducive to the subsequent fracturing to generate fractures at the perforation point;

[0019] S4: Jet fracturing; close the main well casing gate valve, inject fracturing fluid from the tubing, and spray it through the sand-jetting sleeve to the open hole formation outside the small casing. Due to the small nozzle diameter of the sand-jetting sleeve, according to Bernoulli's equation in fluid dynamics, under the action of high-pressure water jet, the maximum pressure in the open hole section outside the casing will be concentrated inside the hole, inducing reservoir fracturing. Subsequently, tubing sand fracturing, main well casing annulus, annulus communication between the casing and the open hole section annulus, fracturing fluid injection, displacement, and other processes are carried out.

[0020] S5: Repeat the above steps; throw the ball step by step to open the corresponding sandblasting sleeve and continue to the next section of construction until all sections of fracturing are completed.

[0021] S6: Blow out fluid from the tubing; at the same time, collect the return status of each stage of the ball from the ball receiver in the blowout line at the wellhead. If the return of each stage of the ball is normal and the fluid production is normal, proceed to the next step; if it is not normal, take measures such as backwashing the well or flushing sand inside the coiled tubing.

[0022] S7: Dismantle the wellhead, rotate the tubing forward, discard the lower tubing string from the drop point as the final completion tubing string, and pull out the upper tubing and drop point;

[0023] S8: Pumping begins operation.

[0024] The beneficial effects of this application are as follows: When retrieving the base assembly and transmission assembly, the retrieval tool is gradually screwed into the base assembly, the retrieval tool pushes the pin-pulling assembly, the pin-pulling assembly gradually exits the locking assembly, releasing the pin-pulling assembly from the locking assembly and the base assembly. Subsequently, the base assembly is pulled by the retrieval tool, and the transmission assembly gradually exits the connecting sleeve assembly and the rotating tubing shoe assembly along with the base assembly, and is retrieved to the wellhead with the retrieval tool. The transmission assembly and base assembly are fixed by a snap-fit, which facilitates the retrieval of the transmission assembly, base assembly and its components. The retrieved transmission assembly, base assembly and its components can be reassembled in reverse order, which is beneficial to the reuse of the internal accessories of the tubing shoe. Since the transmission assembly, base assembly and its components do not need to be drilled out, high-strength parts can be used, giving the internal accessories of the tubing shoe a high-strength effect, reducing structural damage to the tubing shoe during operation, and facilitating the improvement of the tubing shoe's operating time.

[0025] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a three-dimensional structural diagram of the oil pipe shoe during operation according to an embodiment of this application;

[0028] Figure 2 This is a three-dimensional structural diagram of the oil pipe shoe during recycling according to an embodiment of this application;

[0029] Figure 3 This is a three-dimensional structural diagram of the connection between the connecting cylinder assembly and the rotating tube shoe assembly according to an embodiment of this application;

[0030] Figure 4 This is a three-dimensional structural schematic diagram of the base assembly according to an embodiment of this application;

[0031] Figure 5 This is a three-dimensional structural schematic diagram of the transmission assembly according to an embodiment of this application;

[0032] Figure 6 This is a schematic diagram of the planar structure of the transmission assembly according to an embodiment of this application;

[0033] Figure 7This is a three-dimensional structural schematic diagram of the locking assembly according to an embodiment of this application;

[0034] Figure 8 According to the embodiments of this application Figure 4 An enlarged 3D structural diagram at point A in the middle;

[0035] Figure 9 This is a three-dimensional structural diagram of the pin component according to an embodiment of this application.

[0036] Icons: 100-Connecting cylinder assembly; 110-Connecting cylinder; 120-Isolation ring; 130-First slot; 140-First locking block; 200-Rotating tube shoe assembly; 210-Rotating cylinder; 220-Tube shoe toe; 230-Second slot; 240-Side flow hole; 250-Limiting slot; 300-Base assembly; 310-Bowl-shaped base; 320-Limiting cylinder; 330-Second locking block; 340-Jet hole; 350-Sealing ring; 400-Transmission assembly; 410-Mounting base; 420- Impact flow impeller; 430-shaft; 440-linkage cylinder; 450-third locking block; 460-bevel gear ring; 470-bevel gear; 500-locking assembly; 510-locking cylinder; 520-third slot; 530-guide limiting slot; 540-limiting block; 600-pin assembly; 610-double ear seat; 620-double rod swing frame; 630-slide rod; 640-pin part; 641-pin body; 642-pressure plate; 643-moving groove; 650-compression spring; 700-retrieval tool. Detailed Implementation

[0037] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0039] The following description, with reference to the accompanying drawings, describes an embodiment of the tubing shoe and a multi-stage sliding sleeve jet fracturing method for short-radius horizontal wells according to this application.

[0040] Please see Figures 1 to 9 This application provides a tubing shoe, including: a connecting cylinder assembly 100, a rotating tubing shoe assembly 200, a base assembly 300, a transmission assembly 400, a locking assembly 500, a pin-pulling assembly 600, and a retrieval tool 700.

[0041] In this embodiment, the rotating shoe assembly 200 is rotatably connected to the lower end of the connecting cylinder assembly 100. The base assembly 300 is inserted into the connecting cylinder assembly 100. The upper end of the transmission assembly 400 is disposed on the lower side of the base assembly 300, and the outer wall of the transmission assembly 400 is inserted into the rotating shoe assembly 200. The transmission assembly 400 drives the rotating shoe assembly 200 to rotate, and the maximum outer diameter of the transmission assembly 400 is smaller than the minimum inner diameter of the connecting cylinder assembly 100. The locking assembly 500 is slidably inserted into the connecting cylinder assembly 100, and the locking assembly 500 can lock the rotating shoe assembly 200. The pull pin assembly 600 is disposed in the base assembly 300, and the pull pin assembly 600 passes through the outer wall of the base assembly 300 and inserts into the locking assembly 500, thereby restricting the sliding of the base assembly 300. The retrieval tool 700 is screwed into the base assembly 300 via threads. The retrieval tool 700 can drive the pin-pulling assembly 600 to pull out the locking assembly 500. During the retrieval of the base assembly 300 and the transmission assembly 400, the retrieval tool 700 is gradually screwed into the base assembly 300. The retrieval tool 700 pushes the pin-pulling assembly 600, which gradually withdraws from the locking assembly 500, releasing the pin-pulling assembly 600 from the locking assembly 500 and the base assembly 300. Then, the retrieval tool 700 pulls the base assembly 300, and the transmission assembly 400, along with the base assembly 300, gradually withdraws from the connecting sleeve assembly 100 and the rotating tube shoe assembly 200, and is retracted to the wellhead with the retrieval tool 700. The base assembly 300 is fixed by a snap-fit, which facilitates the recycling of the transmission assembly 400, the base assembly 300 and its components. The recycled transmission assembly 400, the base assembly 300 and its components can be reassembled in reverse order, which is beneficial for the reuse of the internal accessories of the tubing shoe. Since the transmission assembly 400, the base assembly 300 and its components do not need to be drilled out, high-strength parts can be used, which gives the internal accessories of the tubing shoe a high strength effect, reduces the structural damage of the tubing shoe during operation, and facilitates the improvement of the operating time of the tubing shoe.

[0042] Please see Figures 2 to 3The connecting cylinder assembly 100 includes a connecting cylinder 110, an isolation ring 120, and a first locking block 140. The isolation ring 120 is disposed on the inner wall of the connecting cylinder 110. First locking grooves 130 are equally spaced on the inner wall of the connecting cylinder 110 near the upper side of the isolation ring 120. The first locking block 140 is disposed on the inner wall of the connecting cylinder 110 near the lower side of the isolation ring 120. The base assembly 300 is slidably inserted into the first locking groove 130, and the lower side of the base assembly 300 presses against the isolation ring 120. The first locking block 140 is slidably inserted into the outer wall of the locking assembly 500. The base assembly 300 and the locking assembly 500 are locked in a snap-fit ​​manner through the first locking groove 130 and the first locking block 140, respectively. The rotational freedom of the base assembly 300 and the locking assembly 500 is restricted. The base assembly 300 presses against the isolation ring 120, forming a seal between the base assembly 300 and the isolation ring 120.

[0043] Please see Figures 2 to 3 The rotating shoe assembly 200 includes a rotating cylinder 210 and a shoe head 220. The shoe head 220 is located at the bottom of the rotating cylinder 210. Second slots 230 are evenly distributed on the inner wall of the upper end of the rotating cylinder 210. The outer wall of the transmission assembly 400 is inserted into the second slots 230. A side flow hole 240 is provided at the lower end of the rotating cylinder 210. Limiting slots 250 are evenly spaced on the top of the rotating cylinder 210. The lower end of the locking assembly 500 can be inserted into the limiting slots 250, which restrict the rotation of the locking assembly 500. The transmission assembly 400 is fixed by a snap-fit ​​connection through the second slots 230, thus restricting the rotational freedom between the transmission assembly 400 and the rotating cylinder 210.

[0044] Please see Figures 1 to 3 The base assembly 300 includes a basin-shaped base 310, a limiting cylinder 320, a second locking block 330, and a sealing ring 350. The limiting cylinder 320 is fixedly sleeved on the outer wall of the basin-shaped base 310. The second locking blocks 330 are evenly spaced on the outer wall of the limiting cylinder 320 and are inserted into the first locking groove 130. The sealing ring 350 is fixedly connected to the lower side of the limiting cylinder 320 and the limiting cylinder 320 presses the sealing ring 350 against the isolation ring 120. The bottom of the basin-shaped base 310 is inclined and has a jet hole 340 facing the transmission assembly 400. The basin-shaped base 310 presses the sealing ring 350 against the isolation ring 120 to form a seal at that location. When the tubing shoe is in operation, the drilling fluid pressure on the upper side of the basin-shaped base 310 is high. Under the action of pressure, the basin-shaped base 310 is further pressed against the sealing ring 350, so as to maintain the seal between the basin-shaped base 310 and the isolation ring 120 when the tubing shoe is in operation.

[0045] Please see Figures 1 to 6The transmission assembly 400 includes a mounting base 410, an impact impeller 420, a rotating shaft 430, a linkage cylinder 440, and a third locking block 450. The mounting base 410 has a mounting chamber. The impact impeller 420 is fixedly sleeved on the rotating shaft 430, and the impact impeller 420 is located within the mounting chamber. The rotating shaft 430 rotatably passes through the mounting base 410, with the jet hole 340 facing the impact impeller 420. The linkage cylinder 440 rotatably sleeves on the outer wall of the mounting base 410. The third locking block 450 is fixedly connected at equal intervals to the outer wall of the linkage cylinder 440 and inserted into the inner wall of the upper end of the rotating tube shoe assembly 200. The rotating shaft 430 is drively connected to the linkage cylinder 440. A bevel gear ring 460 is fixedly connected to the lower side of the linkage cylinder 440. A bevel gear 470 is fixedly sleeved on one end of the rotating shaft 430 passing through the mounting base 410, and the bevel gear 470 and the bevel gear ring 460 mesh with each other. When the tubing shoe is in operation, drilling fluid rushes towards the impeller 420 through the jet hole 340. The impeller 420 rotates accordingly, and the shaft 430 rotates with the impeller 420, which in turn drives the bevel gear 470 to rotate. Through the bevel gear meshing principle, the bevel gear 470 drives the bevel gear ring 460 to rotate. The bevel gear ring 460 drives the linkage cylinder 440 to rotate around the mounting base 410. The linkage cylinder 440 is inserted into the second slot 230 through the third locking block 450, which restricts the rotational freedom between the linkage cylinder 440 and the rotating cylinder 210. The rotating cylinder 210 rotates with the linkage cylinder 440. The drilling fluid flowing into the rotating cylinder 210 is ejected through the side flow hole 240 to form a back thrust, which is beneficial to the rotation of the rotating cylinder 210. As the rotating cylinder 210 rotates, it trims the well wall and circulates and flushes the obstruction point, assisting the tubing string to pass through the obstruction position and descend to the bottom of the well.

[0046] Please see Figures 1 to 7 In related technologies, the base assembly, transmission assembly, and accessories inside the tubing shoe can be recycled. However, when the next drilling operation is required, after the base assembly, transmission assembly, and accessories can be recycled, the tubing shoe head needs to be removed by the drill bit. Since the connecting sleeve assembly and the rotating tubing shoe assembly are rotatably connected, it is not easy for the drill bit to remove the tubing shoe head. Therefore, it is necessary to lock the connecting sleeve assembly and the rotating tubing shoe assembly. On the basis that the base assembly, transmission assembly, and accessories can be recycled, how to achieve the locking between the connecting sleeve assembly and the rotating tubing shoe assembly, and how to release the locking between the two when the connecting sleeve assembly and the rotating tubing shoe assembly are reused, are the technical problems that need to be solved.

[0047] Specifically, the locking assembly 500 includes a locking cylinder 510 and a limiting block 540. The outer wall of the locking cylinder 510 is provided with a third slot 520. The locking cylinder 510 is provided with guide limiting grooves 530 at equal intervals along the circumferential direction. The upper side of the guide limiting groove 530 near the inner wall of the locking cylinder 510 is set as a slope. The pin-pulling assembly 600 passes through the basin-shaped base 310 and is inserted into the guide limiting groove 530. The limiting block 540 is inserted into the top of the rotating tube shoe assembly 200. The limiting block 540 restricts the rotation of the rotating tube shoe assembly 200. The pin-pulling assembly 600 can push the locking cylinder 510 to slide upward through the guide limiting groove 530.

[0048] Please see Figures 1 to 8 The pin-pulling assembly 600 includes a double-ear seat 610, a double-rod swing frame 620, a slide rod 630, a pin 640, and a compression spring 650. The double-ear seat 610 is fixedly connected to the lower side inside the basin-shaped base 310. The double-rod swing frame 620 is rotatably connected to the upper end of the double-ear seat 610. The slide rod 630 is located at the lower end inside the basin-shaped base 310 and is located on both sides of the double-ear seat 610. The pin 640 is slidably connected to the slide rod 630 on both sides. The compression spring 650 is sleeved on the slide rod 630 and presses the pin 640 against the inner wall of the basin-shaped base 310. The pin 640 passes through the basin-shaped base 310 and is inserted into the guide limiting groove 530. The retrieval tool 700 can press down the upper rod of the double-rod swing frame 620, and the lower rod of the double-rod swing frame 620 can move the pin 640 to slide along the slide rod 630.

[0049] Please see Figures 1 to 9The pin 640 includes a pin body 641 and a clamping plate 642. The clamping plate 642 is fixedly connected to both sides of the pin body 641. The clamping plate 642 is slidably connected to the slide rod 630. The compression spring 650 is pressed against the clamping plate 642. The double ear seat 610 can block the clamping plate 642. The pin body 641 has a toggle groove 643. The lower end of the double rod swing frame 620 is inserted into the toggle groove 643. The lower end of the double rod swing frame 620 presses against the inner wall of the toggle groove 643. The end of the pin body 641 is set as an inclined surface. The inclined surface of the pin body 641 cooperates with the inclined surface of the guide limiting groove 530 to push the locking cylinder 510 to slide upward.During the retrieval of the base assembly 300 and the transmission assembly 400, the retrieval tool 700 is gradually screwed into the basin-shaped base 310. The retrieval tool 700 gradually presses against the upper rod of the double-bar swing frame 620. The retrieval tool 700 pushes the upper rod of the double-bar swing frame 620 to rotate around the double-ear seat 610, causing the lower rod of the double-bar swing frame 620 to swing accordingly. The lower rod of the double-bar swing frame 620 pushes the pin 641 through the inner wall of the pressing and actuating groove 643 to gradually pull it out of the guide limiting groove 530 of the locking cylinder 510. The pressing plate 642 on the pin 641 gradually presses against the compression spring 650, increasing the elasticity of the compression spring 650. After the locking cylinder 510 is completely pulled out, it falls under gravity, and the limiting block 540 inserts into the limiting slot 250 on the rotating cylinder 210. The limiting block 540 locks the rotating cylinder 210 in place. The rotational freedom between the locking cylinder 510 and the connecting cylinder 110 is restricted by the first locking block 140 and the third locking slot 520. This mutual locking of the connecting cylinder 110, the locking cylinder 510, and the rotating cylinder 210 ensures that during the next drilling operation, the mutual locking of these components reduces... When drilling the toe of the tube, the rotating cylinder 210 rotates as drilling proceeds, facilitating the removal of the toe. Using the base assembly 300 and transmission assembly 400, external force is applied to press down on the upper rod of the double-bar swing frame 620, causing the pin 641 to retract. Subsequently, the transmission assembly 400 and base assembly 300 are sequentially inserted into the connecting cylinder 110 and rotating cylinder 210. The third locking block 450 on the linkage cylinder 440 is inserted into the second locking groove 230, and the second locking block 330 on the limiting cylinder 320 is inserted into the first locking groove 130, forming a snap-fit ​​positioning. The external force pressing down on the upper rod of the double-bar swing frame 620 is released, and the pin is pushed under the elastic force of the compression spring 650. The pin 641 slides along the slide bar 630, and the pin 641 gradually inserts into the guide limiting groove 530. The inclined surface of the pin 641 cooperates with the inclined surface of the guide limiting groove 530 to push the locking cylinder 510 to slide upward, so that the limiting block 540 leaves the limiting slot 250, thereby releasing the locking of the connecting cylinder assembly and the rotating tube shoe assembly. By pulling the pin assembly, the locking and unlocking of the connecting cylinder assembly and the rotating tube shoe assembly are realized simultaneously. Furthermore, the locking cylinder 510 is restricted by the isolation ring 120, so that the base assembly 300 and the transmission assembly 400 are snapped and fixed in the connecting cylinder 110 and the rotating cylinder 210, which facilitates the recycling and reuse of the base assembly 300 and the transmission assembly 400.

[0050] This application also provides a multi-stage sliding sleeve jet fracturing method for short-radius horizontal wells, which utilizes tubing shoes to guide small casing, specifically including the following steps:

[0051] S1: Running tubing string; After the short-radius horizontal well is completed, a multi-stage sliding sleeve jet fracturing construction tubing string is run in, which also serves as the completion tubing string. The tubing string from bottom to top consists of: tubing shoe, multi-stage interconnected small casing and sandblasting sliding sleeve, small casing, release handle, tubing to the wellhead. The depth of each stage of sandblasting sliding sleeve is selected in areas with good permeability that are conducive to fracturing and fracture generation.

[0052] S2: Fracturing preparation; installation of wellhead and surface manifold, positioning of fracturing operation vehicle, and pressure testing of surface manifold;

[0053] S3: Hydraulic perforation; the ball is dropped to open the lowest sandblasting sleeve, and a high-speed jet is used to perform hydraulic perforation on the open hole formation outside the small casing; the perforation fluid is injected from the tubing, sprayed through the sandblasting sleeve to the open hole formation outside the small casing, and returned along the annulus of the open hole section outside the casing to the annulus of the main wellbore, and returned to the surface through the wellhead casing gate; sufficient perforation makes the perforation hole more perfect, which is conducive to the subsequent fracturing to generate fractures at the perforation point;

[0054] S4: Jet fracturing; close the main well casing gate valve, inject fracturing fluid from the tubing, and spray it through the sand-jetting sleeve to the open hole formation outside the small casing. Due to the small nozzle diameter of the sand-jetting sleeve, according to Bernoulli's equation in fluid dynamics, under the action of high-pressure water jet, the maximum pressure in the open hole section outside the casing will be concentrated inside the hole, inducing reservoir fracturing. Subsequently, tubing sand fracturing, main well casing annulus, annulus communication between the casing and the open hole section annulus, fracturing fluid injection, displacement, and other processes are carried out.

[0055] S5: Repeat the above steps; throw the ball step by step to open the corresponding sandblasting sleeve and continue to the next section of construction until all sections of fracturing are completed;

[0056] S6: Blow out fluid from the tubing; at the same time, collect the return status of each stage of the ball from the ball receiver in the blowout line at the wellhead. If the return of each stage of the ball is normal and the fluid production is normal, proceed to the next step; if it is not normal, take measures such as backwashing the well or flushing sand inside the coiled tubing.

[0057] S7: Dismantle the wellhead, rotate the tubing forward, discard the lower tubing string from the drop point as the final completion tubing string, and pull out the upper tubing and drop point;

[0058] S8: Pumping begins operation.

[0059] This method is designed for ultra-short radius horizontal wells that do not require cementing. Multiple stages of blasting sleeves are connected within an 88.9mm completion string, with each sleeve positioned in a location with good permeability, conducive to fracturing and fracture initiation. The blasting sleeves are opened stage by staged ball-dropping, and high-speed jets are used to hydraulically perforate the open-hole formation. The perforating fluid returns along the annulus outside the small casing to the main wellbore annulus, and then exits to the surface through the wellhead casing gate valve, resulting in an extremely well-perforated hole, which facilitates subsequent fracturing and fracture initiation at the perforation point. Due to the small nozzle diameter of the blasting sleeves, according to Bernoulli's equation in fluid dynamics, the maximum pressure in the open-hole section outside the small casing will concentrate inside the perforation under the action of the high-pressure water jet, inducing formation fracturing, followed by fracturing and displacement processes. By progressively dropping balls to apply pressure, opening the sandblasting sleeve, and repeating the above steps, the combined effect of these three aspects can achieve segmented fracturing of ultra-short radius horizontal wells without cementing outside the casing. This significantly increases the production capacity of oil and gas wells, solves the problem of effective segmented fracturing to increase production in low-permeability and low-yield formations, and allows more untapped remaining reserves to be utilized. It provides technical support for tapping potential and increasing production in the mid-to-late stages of oil and gas fields. The entire construction process is safe, efficient, simple, and easy to implement.

[0060] The working principle of this tubing shoe and multi-stage sliding sleeve jet fracturing method for short-radius horizontal wells is as follows: During the retrieval of the base assembly 300 and the transmission assembly 400, the retrieval tool 700 is gradually screwed into the basin-shaped base 310. The retrieval tool 700 gradually presses against the upper rod of the double-rod swing frame 620, and pushes the upper rod of the double-rod swing frame 620 to rotate around the double-ear seat 610. The lower rod of the double-rod swing frame 620 swings accordingly. The lower rod of the double-rod swing frame 620 pushes the pin 641 through the inner wall of the pressing and actuating groove 643 to gradually pull out the guide limiting groove 530 of the locking cylinder 510. Subsequently, the retrieval tool 700 pulls the base assembly 300, and the transmission assembly 400 moves with the base assembly 300. The connecting sleeve assembly 100 and the rotating tubing shoe assembly 200 are gradually withdrawn and retrieved to the wellhead along with the retrieval tool 700. The transmission assembly 400 and the base assembly 300 are fixed by snap-fit, which facilitates the recovery of the transmission assembly 400, the base assembly 300 and their components. The recovered transmission assembly 400, the base assembly 300 and their components can be reassembled in reverse order, which is beneficial for the reuse of the internal accessories of the tubing shoe. Since the transmission assembly 400, the base assembly 300 and their components do not need to be drilled out, high-strength parts can be used, which gives the internal accessories of the tubing shoe a high strength effect, reduces the structural damage of the tubing shoe during operation, and facilitates the improvement of the operating time of the tubing shoe.As the pin 641 is gradually pulled out of the guide limiting groove 530 of the locking cylinder 510, the pressing plate 642 on the pin 641 gradually presses the compression spring 650, increasing the elastic force of the compression spring 650. After the pin 641 is completely pulled out of the locking cylinder 510, the locking cylinder 510 falls under the action of gravity, and the limiting block 540 inserts into the limiting slot 250 on the rotating cylinder 210, locking the rotating cylinder 210. The rotational freedom between the locking cylinder 510 and the connecting cylinder 110 is restricted by the first locking block 140 and the third locking groove 520. The rotational freedom between the locking cylinder 510 and the rotating cylinder 210 is restricted by the limiting block 540 and the limiting slot 250, thus locking the connecting cylinder 110, locking cylinder 510, and rotating cylinder 210 together. During the next drilling operation, the mutual locking between the connecting cylinder 110, locking cylinder 510, and rotating cylinder 210 reduces the occurrence of the rotating cylinder 210 rotating during drilling and removing the pipe shoe head, facilitating the removal of the pipe shoe head. The base assembly 300 and transmission assembly 400 are then used to press the upper end of the double-bar swing frame 620 with external force. The rod body and pin 641 are retracted. Then, the transmission assembly 400 and base assembly 300 are sequentially inserted into the connecting cylinder 110 and rotating cylinder 210. The third locking block 450 on the linkage cylinder 440 is inserted into the second locking groove 230, and the second locking block 330 on the limiting cylinder 320 is inserted into the first locking groove 130 to form a snap-fit ​​positioning. The external force pressing on the upper end of the double-rod swing frame 620 is released. Under the elastic force of the compression spring 650, the pin 641 is pushed to slide along the slide rod 630, and the pin 641 gradually inserts into the guide limiting groove 530. The inclined surface of 1 cooperates with the inclined surface of the guide limiting groove 530 to push the locking cylinder 510 to slide upward, so that the limiting block 540 leaves the limiting slot 250, releasing the locking of the connecting cylinder assembly and the rotating tube shoe assembly. The locking and unlocking of the connecting cylinder assembly and the rotating tube shoe assembly are realized simultaneously by the pin pulling assembly. Furthermore, the locking cylinder 510 is restricted by the isolation ring 120, so that the base assembly 300 and the transmission assembly 400 are snapped and fixed in the connecting cylinder 110 and the rotating cylinder 210, which facilitates the recycling and reuse of the base assembly 300 and the transmission assembly 400.

[0061] The above are merely embodiments of this application and are not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

Claims

1. A pipe shoe, characterized in that, include: Connecting cylinder assembly; A rotating tube shoe assembly, wherein the rotating tube shoe assembly is rotatably connected to the lower end of the connecting cylinder assembly; A base assembly, which is inserted into the connecting cylinder assembly; A transmission assembly, the upper end of which is disposed on the lower side of the base assembly, the outer wall of which is inserted into the rotating tube shoe assembly, the transmission assembly driving the rotating tube shoe assembly to rotate, and the maximum outer diameter of which is smaller than the minimum inner diameter of the connecting cylinder assembly; A locking assembly is slidably inserted into the connecting cylinder assembly, and the locking assembly is capable of locking the rotating tube shoe assembly; A pin pull assembly is disposed within the base assembly, the pin pull assembly passes through the outer wall of the base assembly and is inserted into the locking assembly, the pin pull assembly restricting the sliding of the base assembly by the locking assembly; A retrieval tool is screwed into the base assembly via threads, and the retrieval tool can drive the pull pin assembly to pull out the locking assembly.

2. The tubing shoe according to claim 1, characterized in that, The connecting cylinder assembly includes a connecting cylinder, an isolation ring, and a first locking block. The isolation ring is disposed on the inner wall of the connecting cylinder. The inner wall of the connecting cylinder is provided with first locking grooves at equal intervals near the upper side of the isolation ring. The first locking block is disposed on the inner wall of the connecting cylinder near the lower side of the isolation ring. The base assembly is slidably inserted into the first locking groove. The lower side of the base assembly presses against the isolation ring. The first locking block is slidably inserted into the outer wall of the locking assembly.

3. The tubing shoe according to claim 1, characterized in that, The rotating tube shoe assembly includes a rotating cylinder and a tube shoe toe. The tube shoe toe is located at the bottom of the rotating cylinder. The inner wall of the upper end of the rotating cylinder is evenly provided with second slots. The outer wall of the transmission assembly is inserted into the second slots. The lower end of the rotating cylinder is provided with a side flow hole. The top of the rotating cylinder is provided with limit slots at equal intervals. The lower end of the locking assembly can be inserted into the limit slots, and the limit slots restrict the rotation of the locking assembly.

4. The tubing shoe according to claim 2, characterized in that, The base assembly includes a basin-shaped base, a limiting cylinder, a second locking block, and a sealing ring. The limiting cylinder is fixedly sleeved on the outer wall of the basin-shaped base. The second locking blocks are equally spaced on the outer wall of the limiting cylinder and are inserted into the first locking groove. The sealing ring is fixedly connected to the lower side of the limiting cylinder. The limiting cylinder presses the sealing ring against the isolation ring. The bottom of the basin-shaped base is inclined and has a jet hole facing the transmission assembly.

5. The tubing shoe according to claim 4, characterized in that, The transmission assembly includes a mounting base, an impact impeller, a rotating shaft, a linkage cylinder, and a third locking block. The mounting base has a mounting chamber. The impact impeller is fixedly sleeved on the rotating shaft and located within the mounting chamber. The rotating shaft rotatably passes through the mounting base, and the jet orifice faces the impact impeller. The linkage cylinder is rotatably sleeved on the outer wall of the mounting base. The third locking block is fixedly connected to the outer wall of the linkage cylinder at equal intervals and inserted into the inner wall of the upper end of the rotating tube shoe assembly. The rotating shaft is drivenly connected to the linkage cylinder.

6. The tubing shoe according to claim 5, characterized in that, A bevel gear ring is fixedly connected to the lower side of the linkage cylinder, and a bevel gear is fixedly sleeved at one end of the rotating shaft passing through the mounting base. The bevel gear and the bevel gear ring mesh with each other.

7. The tubing shoe according to claim 4, characterized in that, The locking assembly includes a locking cylinder and a limiting block. The outer wall of the locking cylinder has a third slot. The locking cylinder has guide limiting grooves evenly spaced along the circumference. The upper side of the guide limiting groove near the inner wall of the locking cylinder is set as a slope. The pin pulling assembly passes through the basin-shaped base and is inserted into the guide limiting groove. The limiting block is inserted into the top of the rotating tube shoe assembly. The limiting block restricts the rotation of the rotating tube shoe assembly. The pin pulling assembly can push the locking cylinder to slide upward through the guide limiting groove.

8. The tubing shoe according to claim 7, characterized in that, The pin-pulling assembly includes a double-ear seat, a double-rod swing frame, a slide rod, a pin, and a compression spring. The double-ear seat is fixedly connected to the lower side inside the basin-shaped base. The double-rod swing frame is rotatably connected to the upper end of the double-ear seat. The slide rod is located at the lower end inside the basin-shaped base and is situated on both sides of the double-ear seat. The pin is slidably connected to the slide rod on both sides. The compression spring is sleeved on the slide rod and presses the pin against the inner wall of the basin-shaped base. The pin passes through the basin-shaped base and is inserted into the guide limiting groove. The retrieval tool can press down the upper rod of the double-rod swing frame, and the lower rod of the double-rod swing frame can move the pin to slide along the slide rod.

9. The tubing shoe according to claim 8, characterized in that, The pin includes a pin body and a clamping plate. The clamping plate is fixedly connected to both sides of the pin body and slidably connected to the slide rod. The compression spring presses against the clamping plate. The double-ear seat can block the clamping plate. A moving groove is provided in the pin body. The lower end of the double-bar swing frame is inserted into the moving groove. The lower end of the double-bar swing frame presses against the inner wall of the moving groove. The end of the pin body is set as an inclined surface. The inclined surface of the pin body cooperates with the inclined surface of the guide limiting groove to push the locking cylinder to slide upward.

10. A multi-stage sliding sleeve jet fracturing method for short-radius horizontal wells, utilizing the tubing shoe as described in any one of claims 1-9 to guide the small casing, characterized in that... Includes the following steps: S1: Running tubing string; After the short-radius horizontal well is completed, a multi-stage sliding sleeve jet fracturing construction tubing string is run in, which also serves as the completion tubing string. The tubing string, from bottom to top, consists of: tubing shoe, multi-stage interconnected small casing and jetting sliding sleeve, small casing, release sleeve, tubing to the wellhead. The depth of each stage of jetting sliding sleeve is selected in areas with good permeability that are conducive to fracturing and fracture generation. S2: Fracturing preparation; installation of wellhead and surface manifold, positioning of fracturing operation vehicle, and pressure testing of surface manifold; S3: Hydraulic perforation; the ball is dropped to open the lowest sandblasting sleeve, and a high-speed jet is used to perform hydraulic perforation on the open hole formation outside the small casing; the perforation fluid is injected from the tubing, sprayed through the sandblasting sleeve to the open hole formation outside the small casing, and returned along the annulus of the open hole section outside the casing to the annulus of the main wellbore, and returned to the surface through the wellhead casing gate; sufficient perforation makes the perforation hole more perfect, which is conducive to the subsequent fracturing to generate fractures at the perforation point; S4: Jet fracturing; close the main well casing gate valve, inject fracturing fluid from the tubing, and spray it through the sand-jetting sleeve to the open hole formation outside the small casing. Due to the small nozzle diameter of the sand-jetting sleeve, according to Bernoulli's equation in fluid dynamics, under the action of high-pressure water jet, the maximum pressure in the open hole section outside the casing will be concentrated inside the hole, inducing reservoir fracturing. Subsequently, tubing sand fracturing, main well casing annulus, annulus communication between the casing and the open hole section annulus, fracturing fluid injection, displacement, and other processes are carried out. S5: Repeat the above steps; throw the ball step by step to open the corresponding sandblasting sleeve and continue to the next section of construction until all sections of fracturing are completed. S6: Blow out fluid from the tubing; at the same time, collect the return status of each stage of the ball from the wellhead blowout line ball receiver. If the return of each stage of the ball is normal and the fluid production is normal, proceed to the next step. If it is not normal, measures such as backwashing the well or flushing sand inside the coiled tubing should be taken. S7: Dismantle the wellhead, rotate the tubing forward, discard the lower tubing string from the drop point as the final completion tubing string, and pull out the upper tubing and drop point; S8: Pumping begins operation.

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