A fracturing pipe fitting

Abstract

A fracturing pipe fitting relates to the technical field of oilfield downhole tools, including an anchoring and packing integrated tool, the anchoring and packing integrated tool including a central pipe, an anchoring slip assembly, a sealing rubber tube assembly and a setting and unsealing assembly, the anchoring slip assembly and the sealing rubber tube assembly are respectively slidably sleeved on the outside of the central pipe and abut against each other, and a pressure transmission hole for pushing the anchoring slip assembly to move is provided on the central pipe; the setting and unsealing assembly includes an outer sleeve, fixed teeth, elastic teeth, an unlocking ring and a trigger ring, the unlocking ring moves downward during setting, so that the elastic teeth and the fixed teeth can be meshed, the unlocking ring is limited by an elastic limiting oblique pin, and the elastic limiting oblique pin is pressed into the central pipe by pushing the trigger ring during unsealing, so that the unlocking ring separates the elastic teeth from the fixed teeth. The present invention truly realizes timely anchoring when the packer is set and timely unanchoring when the packer is unsealed, so that the protection effect of the anchor on the packer is most ideal.

Description

Technical Field

[0001] The invention belongs to the technical field of oil field downhole tools, and in particular relates to a fracturing pipe fitting. Background Art

[0002] Fracturing is a common and important means of increasing production in the middle and late stages of oil development. During fracturing, the fracturing string (fracturing pipe fittings, including packers, switch sleeves, anchors, etc.) is lowered into the well through the oil pipe string.

[0003] Drag fracturing is a method of fracturing the fracturing string layer by layer from bottom to top. The steps of drag fracturing include: setting the upper and lower packers, opening the switch sleeve between the two packers, injecting fluid for fracturing, unsealing the upper and lower packers, lifting the fracturing string so that the switch sleeve reaches the upper oil layer, and repeating the above steps until the top layer is fracturing.

[0004] In the above-mentioned dragging of the fracturing string, one of the functions of the anchor is to fix the string to prevent the string from being pushed up and bending after being compressed; the second function is to protect the packer rubber sleeve from rupture and loss of sealing due to displacement of the tubing.

[0005] Most of the existing anchors and packers are two tools. After being set, the packer will be subjected to a large fracturing fluid pressure and a large top fluid pressure. Once the pressure is greater than the unsealing force, it is very likely to be unsealed accidentally. The existing anchor structure generally includes two types, one of which is without an anchor locking mechanism, the central pipe is anchored by pressure, and the pressure is removed to automatically unanchor; the other is with an anchor locking mechanism, and the unanchoring pin needs to be pulled off when unanchoring. Therefore, this type of anchor can only be anchored once and is not suitable for drag fracturing, which is an operation that does not lift the pipe string and directly conducts the next layer of fracturing. The current drag fracturing uses an anchor without an anchor locking mechanism. During the drag fracturing process, after the upper and lower packers are set and before the switch sleeve is opened, during the time when there is no pressure in the central pipe, the anchor is in an unanchored state, and the anchor cannot play the role of fixing the pipe string and protecting the packer. The packer will still be broken and unsealed due to the displacement of the oil pipe. Therefore, an anchoring device of the present invention which can be anchored in time when the packer is set and can be unanchored in time when the packer is unsealed becomes a target to be solved. Summary of the invention

[0006] In order to achieve the effect of timely anchoring of the anchor when the packer is set and timely unanchoring of the anchor when the packer is unsealed, the present invention provides a fracturing pipe fitting, which can ensure that the anchor protects the packer throughout the whole process.

[0007] The technical solution provided by the present invention is: a fracturing pipe fitting, including a fracturing oil pipe, an anchor, a packer, a switch sleeve and a plug, wherein the switch sleeve is located between two packers; the anchor and the packer are an integrated structure, which is called an anchoring and packing integrated tool, and the anchoring and packing integrated tool includes an upper joint, a central pipe, an anchoring slip assembly, a sealing rubber cylinder assembly, a sealing and unsealing assembly and a lower joint, wherein the upper and lower ends of the central pipe are respectively connected to the upper joint and the lower joint, and the anchoring slip assembly and the sealing rubber cylinder assembly are respectively slidably sleeved on the outer side of the central pipe ... The sealing tube components are abutted against each other, and a pressure transmission hole 1 is opened on the central tube for pushing the anchoring slip assembly to move. The hydraulic pressure in the central tube enters the upper part of the anchoring slip assembly through the pressure transmission hole 1, and the hydraulic pressure pushes the anchoring slip assembly downward, thereby realizing anchoring and sealing at the same time, and the unsealing does not fail when the anchoring does not fail; the sealing and unsealing assembly comprises an outer sleeve, fixed teeth, elastic teeth and an unlocking ring, the outer sleeve is fixedly connected to the anchoring slip assembly, and moves downward or upward with the anchoring slip assembly, the fixed teeth are fixedly connected to the outer sleeve, the elastic teeth are fixedly connected to the central tube, and the elastic teeth can be in the center The tube bounces radially, and an unlocking ring sleeve is also fixedly connected to the center tube. The unlocking ring slides in the unlocking ring sleeve. A spring 1 is arranged between the unlocking ring and the unlocking ring sleeve. A pressure transmission hole 2 is provided on the center tube for pushing the unlocking ring to slide downward and compressing the spring 1. The hydraulic pressure in the center tube enters the top of the unlocking ring through the pressure transmission hole 2. The hydraulic pressure pushes the unlocking ring to move downward. An elastic limiting oblique pin is arranged on the center tube for preventing the unlocking ring from sliding in the direction of the elastic teeth. The elastic limiting oblique pin bounces radially in the center tube. In the initial state, the elastic limiting oblique pin is located in the unlocking ring and is pressed into the center tube by the unlocking ring. When After the unlocking ring as a whole passes through the elastic limiting oblique pin, the elastic limiting oblique pin pops out from the center tube to limit the unlocking ring. A trigger ring is also slidably provided on the elastic center tube. When the trigger ring slides along the center tube, the elastic limiting oblique pin is pushed into the center tube. A pressure transmission hole three for pushing the trigger ring to slide is provided on the center tube above the trigger ring. The lower end of the trigger ring can be tightly abutted against the unlocking ring, thereby releasing the limiting effect of the elastic limiting oblique pin on the unlocking ring. A ball seat is provided on the center tube between the pressure transmission hole three and the pressure transmission hole two. After the ball is thrown, the liquid can only pass through the pressure transmission hole three, and the pressure transmission hole two and the pressure transmission hole one at this time will not pass the liquid.

[0008] A further technical solution is: guide blocks for installing elastic teeth are arranged at circumferential intervals on the outer side of the central tube, the guide blocks are located on both sides of the elastic teeth, the guide blocks play a guiding and limiting role for the elastic teeth, and spring sheets are arranged between the elastic teeth and the central tube. Under the action of the spring sheets, the elastic teeth have a tendency to move away from the central tube.

[0009] A further technical solution is that the middle annular portion of the trigger ring is provided with an opening for accommodating the guide block to avoid mechanical interference.

[0010] A further technical solution is that a piston is provided as a sliding seal between the outer sleeve at the lower part of the pressure transmission hole and the central tube, and the piston acts to push the anchoring slip assembly.

[0011] A further technical solution is: a piston 2 is provided as a sliding seal between the outer sleeve at the upper part of the pressure transmission hole 3 and the central tube, and the piston 2 plays a role in further sealing the outer sleeve and the upper joint to avoid leakage at this place when the central tube is pressurized.

[0012] A further technical solution is: a second spring is arranged between the fixed teeth and the unlocking ring sleeve, and the second spring plays a role in accelerating the unblocking and improving the probability of successful unblocking.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] 1. The anchoring slip assembly of the present invention is in close contact with the sealing rubber cylinder assembly. As long as the anchoring slip assembly is not invalid, the sealing rubber cylinder assembly will not fail to seal due to unsealing. In addition, the anchoring slip assembly and the sealing rubber cylinder assembly are integrated, which can truly anchor in time when the packer is set and unanchor in time when the packer is unsealed. Moreover, unsealing and unanchoring are achieved in the same step, which simplifies the operation.

[0015] 2. The anchoring slip assembly and the sealing rubber cartridge assembly of the present invention can be anchored, unanchored, set, and unsealed multiple times, which is beneficial to reducing the number of times the tubing is raised and lowered during drag fracturing, and is beneficial to improving operating efficiency and reducing costs.

[0016] 3. The spring 2 of the present invention is conducive to achieving rapid unsealing and unanchoring, while ensuring successful unsealing and unanchoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0018] Figure 2 It is a cross-sectional view of the integrated structure of the anchor and the packer in the present invention.

[0019] Figure 3 yes Figure 2 A partial enlarged view of point I in the middle.

[0020] Figure 4 yes Figure 3 A partial enlarged view of point II in the middle.

[0021] In the figure: 1. oil pipe; 2. anchoring and sealing integrated tool; 3. switch sleeve; 4. plug; 201. upper joint; 202. pressure transmission hole 1; 203. outer sleeve; 204. piston 1; 205. anchoring slip assembly; 206. sealing rubber cylinder assembly; 207. lower joint; 208. piston 2; 209. trigger ring; 210. ball seat; 211. fixed teeth; 212. elastic teeth; 213. unlocking ring; 214. unlocking ring sleeve; 215. center tube; 216. spring 1; 217. elastic limit inclined pin; 218. spring 2; 219. pressure transmission hole 2; 220. guide block; 221. opening; 222. pressure transmission hole 3. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0023] The structure of the fracturing pipe fitting (fracturing pipe string) in the prior art includes an oil pipe 1, an anchor, a packer, a switch sleeve 3 and a plug 4. The switch sleeve 3 is located between two packers.

[0024] The innovation of the present invention lies in that the anchor and the packer are an integrated structure, which is called an anchoring and packing integrated tool 2.

[0025] like Figure 2As shown, the anchoring and isolation integrated tool 2 includes an upper joint 201, a central tube 215, an anchoring slip assembly 205, a sealing rubber tube assembly 206, a sealing and unsealing assembly and a lower joint 207. The upper and lower ends of the central tube 215 are respectively connected to the upper joint 201 and the lower joint 207. The anchoring slip assembly 205 and the sealing rubber tube assembly 206 are respectively slidably sleeved on the outer side of the central tube 215, the sealing rubber tube assembly 206 abuts against the lower joint 207, the anchoring slip assembly 205 abuts against the upper end of the sealing rubber tube assembly 206, and the anchoring slip assembly 205 The upper part is fixedly connected with an outer sleeve 203, and an annular space is left between the outer sleeve 203 and the center tube 215. A piston 204 is provided in the annular space for sliding sealing. A pressure transmission hole 202 for pushing the anchoring slip assembly 205 to move is provided on the center tube 215 above the piston 204. The hydraulic pressure in the center tube 215 enters the upper part of the piston 204 through the pressure transmission hole 202, and the hydraulic pressure pushes the piston 204 downward, and then pushes the anchoring slip assembly 205 downward, and at the same time realizes the anchoring of the anchoring slip assembly 205 and the setting of the sealing rubber cartridge assembly 206. It can be seen from the above structure that the setting of the sealing rubber cartridge assembly 206 does not fail when the anchoring does not fail.

[0026] The anchoring slip assembly 205 includes a cone and a slip. The cone and the slip cooperate with each other through a conical surface. When the cone extends into the slip, the slip is pressed out and anchored on the casing wall.

[0027] The sealing rubber cylinder assembly 206 comprises a rubber cylinder and a rubber cylinder spacer ring. The rubber cylinder and the rubber cylinder spacer ring are spaced apart, and the spacer ring supports the rubber cylinder.

[0028] It should be noted that the structural forms of the anchoring cava assembly 205 and the sealing rubber tube assembly 206 are not limited to the above-mentioned structures. As long as the rubber tube structure can realize extrusion expansion sealing, it belongs to the sealing rubber tube assembly 206 described in the present invention, and as long as the cava structure can realize extrusion anchoring, it belongs to the anchoring cava assembly 205 described in the present invention.

[0029] like Figure 2 , 3As shown, the setting and unsealing assembly includes an outer sleeve 203, a fixed tooth 211, an elastic tooth 212 and an unlocking ring 213. The outer sleeve 203 moves along with the anchoring slip assembly 205, the fixed tooth 211 is fixedly connected to the outer sleeve 203 and moves along with the movement of the outer sleeve 203, and the elastic tooth 212 is fixedly connected to the center pipe 215 and can bounce in the radial direction of the center pipe 215. The center tube 215 is also fixedly connected with an unlocking ring sleeve 214, and the unlocking ring 213 slides in the unlocking ring sleeve 214. A spring 1 216 is arranged between the unlocking ring 213 and the unlocking ring sleeve 214. The center tube 215 is provided with a pressure transmission hole 219 for pushing the unlocking ring 213 to slide downward and compressing the spring 1 216. The hydraulic pressure in the center tube 215 enters the top of the unlocking ring 213 through the pressure transmission hole 219, and the hydraulic pressure pushes the unlocking ring 213 to move downward. The center tube 215 is provided with an elastic limiting oblique pin 217, which bounces in the radial direction of the center tube 215. In the initial state, the elastic limiting oblique pin 217 is located in the unlocking ring 213 and is pressed into the center tube 215 by the unlocking ring 213. At this time, the elastic limiting oblique pin 217 cannot limit the sliding of the unlocking ring 213. When the unlocking ring 21 After the whole passes through the elastic limiting oblique pin 217, the elastic limiting oblique pin 217 pops out from the center tube 215 to limit the unlocking ring 213. A trigger ring 209 is also slidably arranged on the elastic center tube 215. When the trigger ring 209 slides along the center tube 215, the elastic limiting oblique pin 217 is pushed into the center tube 215. A pressure transmission hole 3 222 for pushing the trigger ring 209 to slide is provided on the center tube 215 above the trigger ring 209. The lower end of the trigger ring 209 can be tightly abutted against the unlocking ring 213, thereby releasing the limiting effect of the elastic limiting oblique pin 217 on the unlocking ring 213. A ball seat 210 is arranged on the center tube 215 between the pressure transmission hole 3 222 and the pressure transmission hole 219. When a ball is thrown and pressed, the hydraulic pressure is only transmitted through the pressure transmission hole 3 222, and the pressure transmission hole 219 and the pressure transmission hole 1 202 do not transmit pressure at this time.

[0030] As can be seen from the above structure, the anchoring slip assembly 205 and the sealing rubber cylinder assembly 206 in the present application are unsealed and unanchored at the same time, which can truly anchor in time when the packer is set and unanchor in time when the packer is unsealed. Moreover, unsealing and unanchoring are achieved in the same step, which simplifies the operation.

[0031] It can also be seen from the above structure that the anchoring slip assembly 205 and the sealing rubber cylinder assembly 206 can be anchored, unanchored, set and unsealed multiple times, which is beneficial to reducing the number of times the pipe string is raised and lowered during drag fracturing, and is beneficial to improving operating efficiency and reducing costs.

[0032] like Figure 2As shown, the structure of the elastic limiting oblique pin 217 includes an oblique pin and a small spring, and both ends of the small spring are pressed between the oblique pin and the center tube 215, so that the oblique pin can slide relative to the center tube 215.

[0033] The outer side of the central tube 215 is provided with guide blocks 220 for installing the elastic teeth 212 at intervals in the annular direction. The guide blocks 220 are located on both sides of the elastic teeth 212. The guide blocks 220 guide and limit the elastic teeth 212. A spring sheet is provided between the elastic teeth 212 and the central tube 215. Under the action of the spring sheet, the elastic teeth 212 have a tendency to move away from the central tube 215. The middle part of the trigger ring 209 is provided with an opening 221 in the annular direction for accommodating the guide blocks 220. The existence of the opening 221 allows the trigger ring 209 to slide within a certain range.

[0034] A piston 1 204 is provided as a sliding seal between the outer sleeve 203 and the central tube 215 at the lower part of the pressure transmission hole 1 202, and the piston 1 204 plays the role of pushing the anchoring slip assembly 205. A piston 208 is provided as a sliding seal between the outer sleeve 203 and the central tube 215 at the upper part of the pressure transmission hole 3 222, and the piston 208 plays the role of further sealing the outer sleeve 203 and the upper joint 201 to prevent leakage at this place when the central tube 215 is pressurized.

[0035] A second spring 218 is provided between the fixed teeth 211 and the unlocking ring sleeve 214. The second spring 218 accelerates the unlocking and increases the probability of successful unlocking.

[0036] The anchoring and setting process of this application is: the pipe fittings are as follows: Figure 1 After the connection is completed, the oil pipe 1 is pressurized, and the pressure is transmitted from the pressure transmission hole 1 202, the pressure transmission hole 219, and the pressure transmission hole 3 222 respectively. The hydraulic pressure transmitted from the pressure transmission hole 1 202 pushes the piston 1 204 downward, and the piston 1 204 pushes the anchoring slip assembly 205 downward, anchoring the anchoring slip assembly 205 and squeezing the sealing rubber tube assembly 206 to seal. At this time, the spring 218 is compressed and stores elastic potential energy. The hydraulic pressure transmitted from the pressure transmission hole 219 pushes the unlocking ring 213 downward. After the unlocking ring 213 moves downward, the elastic teeth 212 pop outward relative to the center tube 215 and mesh with the fixed teeth 211, thereby playing a locking role, so that the anchoring slip assembly 205 and the sealing rubber tube assembly 206 cannot be unanchored and unsealed.

[0037] During the downward movement of the unlocking ring 213, the elastic force of the spring 1 216 is overcome, so that the spring 1 216 stores elastic potential energy. After the unlocking ring 213 passes through the elastic limiting bevel pin 217 as a whole, the elastic limiting bevel pin 217 pops out of the center tube 215. The elastic limiting bevel pin 217 limits the unlocking ring 213, so that the unlocking ring 213 cannot slide upward, thereby failing to release the engagement between the elastic teeth 212 and the fixed teeth 211.

[0038] The hydraulic pressure transmitted from the second pressure transmission hole 219 and the third pressure transmission hole 222 makes the forces at both ends of the trigger ring 209 consistent, and at this time the trigger ring 209 does not slide.

[0039] The unanchoring and unsealing process of the present application is: a soluble ball is put into the oil pipe 1, and the soluble ball falls on the ball seat 210 between the pressure transmission hole 219 and the pressure transmission hole 3 222, and pressure is injected into the oil pipe 1. Only the pressure transmission hole 3 222 enters the liquid, and the liquid pushes the trigger ring 209 to move downward, and the trigger ring 209 contacts the elastic limiting inclined pin 217 through the inclined surface, and the elastic limiting inclined pin 217 is pressed into the center tube 215, and the trigger ring 209 is tightly against the upper end of the unlocking ring 213 when it moves downward. When the pressure injected into the oil pipe 1 is removed, the elastic potential energy stored in the spring 1 216 pushes the unlocking ring 213 and the trigger ring 209 to tightly abut and slide upward, so that the unlocking ring 213 returns to the original position through the elastic limiting inclined pin 217, and the unlocking ring 213 pushes the elastic teeth 212 in the direction close to the center tube 215, forcing the elastic teeth 212 to separate from the fixed teeth 211.

[0040] When unanchoring and unsealing, the elastic potential energy stored in the second spring 218 allows the outer sleeve 203 to return quickly, so that the anchoring slip assembly 205 and the sealing rubber cylinder assembly 206 can be unanchored and unsealed quickly, and the success rate of unanchoring and unsealing is also guaranteed.

Claims

1. A fracturing pipe fitting, comprising a fracturing oil pipe (1), an anchor, a packer, a switch sleeve (3) and a plug (4), wherein the switch sleeve (3) is located between two packers, and is characterized in that: The anchor and the packer are an integrated structure, which is called an anchoring and packing integrated tool (2). The anchoring and packing integrated tool (2) comprises an upper joint (201), a central tube (215), an anchoring slip assembly (205), a sealing rubber tube assembly (206), a setting and unsealing assembly and a lower joint (207). The upper and lower ends of the central tube (215) are respectively connected to the upper joint (201) and the lower joint (207). The anchoring slip assembly (205) and the sealing rubber tube assembly (206) are respectively slidably mounted on the central tube (215). The outer side of the anchoring slip assembly (205) is abutted against the sealing rubber tube assembly (206), and a pressure transmission hole (202) for pushing the anchoring slip assembly (205) to move is opened on the central tube (215); the setting and unsealing assembly comprises an outer sleeve (203), fixed teeth (211), elastic teeth (212) and an unlocking ring (213); the outer sleeve (203) is fixedly connected to the anchoring slip assembly (205), the fixed teeth (211) is fixedly connected to the outer sleeve (203), the elastic teeth (212) is fixedly connected to the central tube (215), and the outer sleeve (203) is fixedly connected to the anchoring slip assembly (205). ) is fixedly connected and the elastic teeth (212) can bounce in the radial direction of the center tube (215), the center tube (215) is also fixedly connected to an unlocking ring sleeve (214), the unlocking ring (213) slides in the unlocking ring sleeve (214), a spring (216) is arranged between the unlocking ring (213) and the unlocking ring sleeve (214), the center tube (215) is provided with a pressure transmission hole (219) for pushing the unlocking ring (213) to slide and compress the spring (216), and the center tube (215) is provided with an elastic limiting oblique pin (217), The elastic limiting oblique pin (217) is elastically elastic in the radial direction of the center tube (215), and a trigger ring (209) is also slidably arranged on the center tube (215). When the trigger ring (209) slides along the center tube (215), the elastic limiting oblique pin (217) is pushed into the center tube (215). A pressure transmission hole (222) for pushing the trigger ring (209) to slide is provided on the center tube (215) above the trigger ring (209), and a ball seat (210) is provided on the center tube (215) between the pressure transmission hole (222) and the pressure transmission hole (219).

2. A fracturing pipe fitting according to claim 1, characterized in that: Guide blocks (220) for mounting the elastic teeth (212) are arranged at intervals in the annular direction on the outer side of the central tube (215); the guide blocks (220) are located on both sides of the elastic teeth (212); a spring sheet is arranged between the elastic teeth (212) and the central tube (215); under the action of the spring sheet, the elastic teeth (212) have a tendency to move away from the central tube (215).

3. A fracturing pipe fitting according to claim 2, characterized in that: The trigger ring (209) has an opening (221) in the middle annular direction for accommodating the guide block (220).

4. The fracturing pipe fitting according to claim 1, characterized in that: A piston 1 (204) is provided in a sliding seal between the outer sleeve (203) at the lower part of the pressure transmission hole 1 (202) and the central tube (215).

5. The fracturing pipe fitting according to claim 1, characterized in that: A piston 2 (208) is provided in a sliding seal between the outer sleeve (203) at the upper part of the pressure transmission hole 3 (222) and the center tube (215).

6. The fracturing pipe fitting according to claim 1, characterized in that: A second spring (218) is provided between the fixed teeth (211) and the unlocking ring sleeve (214).

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