Self-pressure-relief intermediate joint for oil pipe transmission perforation

Abstract

The invention relates to the technical field of oil and gas well perforation, in particular to a self-pressure-relief middle connector for oil pipe transmission perforation. The self-pressure-relief middle connector device for oil pipe transmission perforation comprises a self-pressure-relief middle connector, an axial through hole is formed in the middle of the self-pressure-relief middle connector, a plurality of axial pressure relief holes are evenly formed in the two end faces of the self-pressure-relief middle connector respectively, and radial through holes are formed in the tail ends of the pressure relief holes and communicated with threaded tool withdrawal grooves in the outer wall to form L-shaped pressure relief channels. The two ends of the self-pressure-relief middle connector are connected with the upper-stage perforating gun and the lower-stage perforating gun respectively, detonating cords are arranged in the perforating guns, booster tubes are arranged at the tail ends of the detonating cords, righting tubes are arranged outside the detonating cords, and the two detonating cords penetrate into the self-pressure-relief middle connector to enable the two booster tubes to be in butt joint. According to the self-pressure-relief intermediate joint, the original double-male and male-female type joint is designed into a whole, the material cost is saved, the operation steps and the construction difficulty are reduced, the L-shaped pressure relief channel is formed in the self-pressure-relief intermediate joint, pressure relief is carried out in the dismounting process, internal pressure and gas are prevented from escaping to cause personnel injury, and the safety of the device is improved.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas well perforation, and in particular to a self-depressurizing intermediate joint for oil pipe transmission perforation. Background Art

[0002] Tubing-transported perforation is a perforation completion method developed in the 1970s. As time goes by, the technology has gradually developed and improved. Its principle is to connect all the perforators of the oil and gas layers to be perforated in a well in series and then connect them to the tail end of the tubing, forming a hard-connected pipe string and lowering it into the well. By measuring the radial curve or magnetic positioning curve in the tubing, calibrating the depth and aligning the perforation layer, and using a variety of detonation methods to detonate the perforators, all the oil layers to be perforated can be perforated at one time. In the prior art, the tubing-transported perforation through the interlayer uses detonating cords for energy transfer, resulting in pressure in the empty barrel through the detonating cord. The gun connection method of the double male plus male and female connectors used on site often causes the pressure in the gun string to escape when the intermediate joint is disassembled, injuring the on-site personnel and causing serious construction accidents. In addition, the construction cost of this joint is high, the efficiency is low, the operation is complex and the construction is difficult. Therefore, in view of the above shortcomings, a self-decompression intermediate joint for tubing-transported perforation is proposed. Summary of the invention

[0003] 1. Technical issues to be resolved In view of the deficiencies in the prior art, the present invention provides a self-depressurizing intermediate joint for oil pipe transmission perforating, which solves the problems of internal pressure of the gun string escaping and injuring people when the intermediate joint is disassembled using a double male plus male and female joint, and the high construction cost, low efficiency and great construction difficulty of installing and disassembling the intermediate joint.

[0004] (II) Technical solution In order to solve the above problems, the present invention provides a self-pressure relief intermediate joint for oil pipe transmission perforation, comprising: an upper-stage perforating gun with bullet, a self-pressure relief intermediate joint and a lower-stage perforating gun without bullet; One end of the self-pressure relief intermediate joint is threadedly connected to the upper-level ejection hole gun, and the other end is threadedly connected to the lower-level ejection hole gun; the inner sides of the threads at both ends of the self-pressure relief intermediate joint are provided with threaded back grooves; the two end surfaces of the self-pressure relief intermediate joint are respectively and evenly provided with a number of radial pressure relief holes, the bottom end depth of the pressure relief hole is flush with the threaded back groove, and a through hole radially connected to the threaded back groove is provided at the bottom end of each pressure relief hole, and the through hole and the pressure relief hole form an L-shaped pressure relief structure; when the two ends of the self-pressure relief intermediate joint are connected and fixed to the upper-level ejection hole gun or the lower-level ejection hole gun, the through hole on the threaded back groove at the bottom end of the pressure relief hole is closed; The middle of the self-decompression intermediate joint is provided with an axial through hole, through which the detonating cord passes. Preferably, the detonating cord is divided into two sections, and a detonating tube is respectively provided at the joint of the two sections of the detonating cord.

[0005] Preferably, a righting tube is provided outside the detonating cord.

[0006] Preferably, one end of the straightening tube is connected to the upper stage with a bullet-carrying perforating gun or the upper stage without a bullet-carrying perforating gun by a thread. Preferably, the straightening tube is provided with a plurality of axial through holes, and rubber top screws are provided in the through holes.

[0007] Preferably, both ends of the through hole in the self-pressure relief intermediate joint are of bell-mouth structure.

[0008] Preferably, the outer diameter of the straightening tube is provided with a milling flattening structure.

[0009] Preferably, the self-pressure relief intermediate joint is provided with a clamping plate groove.

[0010] (III) Beneficial effects The self-pressure relief intermediate joint for oil pipe transmission perforating provided by the present invention integrates the original double male and male female joint design into one, which saves material costs, reduces the operating steps during use and reduces the difficulty of perforating construction. A pressure relief hole is provided on the self-pressure relief intermediate joint and a through hole connected to the threaded tool withdrawal groove is provided on the pressure relief hole to form an L-shaped pressure relief hole, so that the internal pressure of the gun string can be fully released during the disassembly process, thereby preventing the internal pressure and gas from escaping and causing personal injury, thereby improving the safety of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of a self-depressurizing intermediate joint for oil pipe transmission perforation according to the present invention; Figure 2 This is a structural diagram of a self-pressure relief intermediate joint for oil pipe transmission perforation of the present invention; Figure 3 This is a structural diagram of the self-depressurizing intermediate joint straightening pipe for oil pipe transmission perforation of the present invention.

[0012] Among them, 1. The upper stage is equipped with a bullet-ejecting perforating gun; 2. The straightening tube; 3. The detonating cord; 4. The rubber top screw; 5. The detonating tube; 6. The self-pressure-relieving intermediate joint; 7. The lower stage is not equipped with a bullet-ejecting perforating gun. Implementation

[0013] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 are within the scope of protection of the present invention.

[0014] In the description of the present invention, it is necessary to understand that the orientations or positional relationships indicated by “upper”, “lower”, “inside”, “outside”, “top”, “bottom”, etc. are all based on the orientations or positional relationships shown in the accompanying drawings. The purpose is only to facilitate the description of the present invention and simplify the description. It does not indicate or imply that the referred parts must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0015] like Figure 1-3 As shown, the present invention provides a self-pressure relief intermediate joint for oil pipe transmission perforating, which specifically comprises: a plurality of upper-stage perforating guns with bullets 1, a self-pressure relief intermediate joint 6 and a lower-stage perforating gun 7 without bullets; One end of each of the self-depressurizing intermediate joints 6 is threadedly connected to the upper-level ejection perforating gun 1 with a bullet, and the other end is threadedly connected to the lower-level ejection perforating gun 7 without a bullet; the self-depressurizing intermediate joint 6 connects the upper-level ejection perforating gun 1 with a bullet and the lower-level ejection perforating gun 7 without a bullet to facilitate the transmission of the explosion from the upper-level ejection perforating gun 1 with a bullet to the lower-level ejection perforating gun 7 without a bullet.

[0016] Among them, a detonating cord 3 is respectively provided in the upper-level perforating gun 1 with a bullet and the lower-level perforating gun 7 without a bullet. After the two detonating cords 3 are docked, when one of the detonating cords 3 is detonated, the explosion will be transmitted to the other detonating cord 3 along the first detonating cord, thereby transmitting the explosion. An axial through hole is provided in the middle of the self-pressure relief intermediate joint 6. The detonating cords 3 in the upper-level perforating gun 1 with a bullet and the lower-level perforating gun 7 without a bullet are respectively inserted into the axial through hole of the self-pressure relief intermediate joint 6 from the top and bottom. The two detonating cords 3 are docked in the self-pressure relief intermediate joint 6. The self-pressure relief intermediate joint 6 connects the upper-level single perforating gun 1 and the lower-level perforating gun 7 without a bullet and provides an environment for the detonating cord 3 to transmit the explosion.

[0017] It should be noted that each detonating cord 3 is provided with a stabilizing tube 2, into which the detonating cord 3 is inserted. The stabilizing tube 2 fixes the direction and position of the detonating cord 3, thereby preventing the detonating cord 3 from bending out of the docking state due to its soft texture during movement and installation, thereby improving the stability of the device and ensuring the normal operation of the device.

[0018] like Figure 2As shown, both ends of the self-pressure relief intermediate joint 6 are respectively provided with threads for connecting with the upper stage with ejection hole 1 or the lower stage without ejection hole gun 7, and the inner sides of the threads on both sides are processed with threaded back grooves, and a number of axial pressure relief holes are evenly arranged on the two end surfaces of the self-pressure relief intermediate joint 6, and the depth of the pressure relief hole is flush with the position of the threaded back groove. A radial through hole is provided at the end of each pressure relief hole to connect to the threaded back groove, and each of the pressure relief holes and the radial through hole at the end thereof form an L-shaped pressure relief channel, and when the joint is connected to the upper stage with ejection hole 1 or the lower stage without ejection hole gun 7, the pressure relief channel is sealed by the upper and lower perforating guns, and the pressure in the gun string will not escape outward at this time. After the detonation is completed, the self-pressure relief intermediate joint 6 needs to be disassembled. During the disassembly process, the upper-level perforating gun 1 with bullets and the lower-level perforating gun 7 without bullets are first screwed out along the thread but not separated from the self-pressure relief intermediate joint 6. At this time, the radial through hole of the L-shaped pressure relief hole is separated from the inner wall of the upper and lower perforating guns, and the internal pressure gas is discharged from the radial through hole part of the L-shaped pressure relief hole along the pressure relief hole, and then the device is completely disassembled. In this process, the pressure in the gun string is released and relieved before the device is disassembled to prevent the higher pressure in the gun string from suddenly escaping during disassembly to cause harm to the staff, effectively reducing the incidence of high-pressure injuries in the gun string, reducing the danger of construction operations, and greatly improving the safety of the device.

[0019] Among them, the two ends of the axial through hole in the middle of the self-pressure relief intermediate joint 6 are trumpet-mouth structures. When installing the device, it is necessary to first install the straightening tube 2, detonating cord 3 and detonating tube 5 and then extend them into the self-pressure relief intermediate joint 6 for docking. At this time, the detonating tubes at both ends are aligned in the self-pressure relief intermediate joint 6. When the detonating cord 3 in the upper-level ejection hole gun 1 explodes, the detonation energy is transferred between the detonating tube 5 at its end and the detonating tube 5 in the lower-level non-ejection hole gun 7 to achieve the effect of explosion transfer. Setting the two ends of the through hole as trumpet-mouth structures can facilitate the coordination between the detonating cord 3, the straightening tube 2 and the detonating tube 5 and the self-pressure relief intermediate joint 6 during installation. When the device is assembled, the trumpet-mouth structure plays a guiding role in guiding the straightening tube 2 into the axial through hole in the self-pressure relief intermediate joint 6, saving the alignment steps of the straightening tube 2 and the self-pressure relief intermediate joint 6 during installation, reducing the operating difficulty of workers, reducing working hours, and improving work efficiency.

[0020] It should be noted that a card plate groove is provided on the outside of the self-pressure relief intermediate joint 6. After the device is assembled, a card plate is provided at the wellhead. The card plate groove outside the self-pressure relief intermediate joint 6 cooperates with the card plate to fix the device above the wellhead to prevent the position of the device from changing after installation, causing the explosion position to deviate from the predetermined position, thereby improving the accuracy and stability of the device detonation.

[0021] like Figure 3As shown, one end of the straightening tube 2 is provided with a thread. During the installation process, the threaded end of the straightening tube 2 is connected to the corresponding upper-level single-perforating gun 1 or the lower-level non-bullet perforating gun 7 to fix the position and direction of the straightening tube 2. During the installation and use process, the direction and position of the straightening tube 2 are fixed, thereby fixing the position and direction of the detonating cord 3, ensuring that the detonating tubes 5 at the top ends of the two sections of detonating cord 3 can be accurately aligned to ensure the normal operation of the device.

[0022] Among them, a plurality of radial through holes are provided on the side of the straightening tube 2, and a rubber top screw 4 is provided in each through hole. The rubber top screw 4 is inserted into the through hole on the straightening tube 2 after the detonating cord 3 and the detonating tube 5 are installed, and the detonating cord 3 is squeezed inward to fix the position of the detonating cord 3, thereby preventing the detonating cord 3 from slipping during operation, resulting in the device being unable to transmit the explosion, thereby improving the stability of the device during operation.

[0023] It should be noted that the outer diameter of the straightening tube 2 is processed with a milled flat structure, which can be matched with external installation tools such as pliers during installation, making installation and disassembly convenient and improving the practicality of the device.

[0024] The self-depressurizing intermediate joint for oil pipe transmission perforation provided by the present invention has a simple structure and is easy to operate. When disassembling, the pressure in the device can be released first to prevent workers from being injured during disassembly. The specific operation process of the device is as follows: Step 1: Connect and install the device according to the work plan, and fix the device by combining the clamping plate groove of the self-pressure relief intermediate joint with the clamping plate of the working wellhead.

[0025] Step 2: Ignite the top of the connected pipe body. At this time, after the detonating cord in each stage of the perforating gun explodes, the explosion is transmitted through the booster tube at the end of the detonating cord in the self-decompression intermediate joint to detonate the booster tube of the detonating cord at the top of the next stage of the perforating gun. This process is repeated until all pre-set explosion points have exploded.

[0026] Step 3, remove the clamping plate at the wellhead, lift the pipe string out of the well and disassemble the perforating gun, rotate the perforating gun to be disassembled so that it is generally separated from the self-pressure relief intermediate joint, at this time, the perforating gun withdraws from the thread of the pressure relief intermediate joint along the thread, and the radial through hole of the L-shaped pressure relief channel of the self-pressure relief intermediate joint is opened from a closed state due to the movement of the perforating gun. At this time, the internal pressure flows out along the pressure relief hole and is discharged through the L-shaped pressure relief hole to relieve the pressure in the gun string.

[0027] Step 4: When the pressure in the gun string is released, continue to rotate the perforating gun to completely separate it from the self-pressure relief intermediate joint. At this time, the pressure in the pipe string has been completely released, and no internal pressure will escape and injure anyone when the perforating gun is separated from the self-pressure relief intermediate joint. Step 5: Repeat steps 3 to 4 until all perforating guns and self-decompression intermediate joints are disassembled, and then recycle and store the disassembled parts.

[0028] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A self-depressurizing intermediate joint for oil pipe transmission perforating, comprising an upper-stage perforating gun with a bullet (1), a self-depressurizing intermediate joint (6) and a lower-stage perforating gun without a bullet (7); One end of the self-pressure relief intermediate joint (6) is threadedly connected to the upper-stage ejection hole gun (1) and the other end is threadedly connected to the lower-stage ejection hole gun (7); the inner sides of the threads at both ends of the self-pressure relief intermediate joint (6) are provided with threaded back grooves; a plurality of radial pressure relief holes are evenly arranged on both end surfaces of the self-pressure relief intermediate joint (6); the bottom end depth of the pressure relief hole is the same as the threaded back groove, and a through hole is arranged at the bottom end of each pressure relief hole and is radially connected to the threaded back groove. The through hole and the pressure relief hole form an L-shaped pressure relief structure; when the two ends of the self-pressure relief intermediate joint (6) are connected and fixed to the upper-stage ejection hole gun (1) or the lower-stage ejection hole gun (7), the through hole on the threaded back groove at the bottom end of the pressure relief hole is closed; The self-depressurizing intermediate joint (6) is provided with an axial through hole in the middle, and the upper-stage ejection hole gun (1) and the lower-stage ejection hole gun (7) are respectively provided with detonating cords (3) which pass through the through hole of the self-depressurizing intermediate joint (6).

2. The self-depressurizing intermediate joint for oil pipe transmission perforation according to claim 1 is characterized in that: The ends of the detonating cords (3) of the upper-stage perforating gun with a bullet (1) and the lower-stage perforating gun without a bullet (7) are respectively provided with booster tubes (5).

3. The self-depressurizing intermediate joint for oil pipe transmission perforation according to claim 1 is characterized in that: The detonating cord (3) is provided with a righting tube (2) outside.

4. The self-depressurizing intermediate joint for oil pipe transmission perforation according to claim 3 is characterized in that: One end of the straightening tube (2) is connected to an upper-stage perforating gun with a bullet (1) or a lower-stage perforating gun without a bullet (7) via a thread.

5. The self-depressurizing intermediate joint for oil pipe transmission perforation according to claim 4 is characterized in that: The straightening tube (2) is provided with a plurality of axial through holes, and rubber top screws (4) are provided in the through holes.

6. The self-depressurizing intermediate joint for oil pipe transmission perforation according to claim 1, characterized in that: Both ends of the through hole in the self-pressure relief intermediate joint (6) are of bell-mouth structure.

7. The self-depressurizing intermediate joint for oil pipe transmission perforation according to claim 3 is characterized in that: The outer diameter of the centralizing tube (2) is provided with a milling flattening structure.

8. The self-depressurizing intermediate joint for oil pipe transmission perforation according to claim 1, characterized in that: The self-pressure relief intermediate joint (6) is provided with a clamping plate groove.

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