Positioning and self-sealing perforating gun structure and sealing method

Abstract

The invention discloses a positioning and self-sealing perforating gun structure and a sealing method. The positioning and self-sealing perforating gun structure comprises a perforating gun, a positioning device, a magnetic sensing device, a packer device, a magnetic sensor and a water swelling type air bag. The packer device is located above the magnetic sensing device and is in buckled connection with a fixing groove in the oil pipe through a buckling piece on the device, and the packer device is convenient to mount and dismount; the magnetic sensing device is matched and connected with the gun head through a bolt and a nut, and the gun head is connected with the gun body. The invention provides a perforating gun structure capable of positioning and self-sealing and a sealing method to solve the problems that in the prior art, a perforating gun is inaccurate in positioning, the position of the whole structure deviates due to impact force generated by explosion in the perforating process, and a packer needs to be used for setting after perforating is finished, mutual cooperation between the structures is achieved, and the sealing efficiency is improved. Perforation setting work is efficiently completed, and the labor cost and the time cost are reduced.

Description

Technical Field

[0001] The invention relates to a perforating gun and an isolation method, and in particular to a perforating gun structure capable of positioning and self-isolating and an isolation method. Background Art

[0002] Perforation is crucial to oil and gas exploration and development. Since the 1930s, the technology has evolved from bullet-type and torpedo-type to energy-gathering type, which has greatly promoted the efficient development of oil and gas wells. Currently, more than 90% of oil and gas wells are completed by perforation. The perforating gun is a device used in oil well completion operations. It descends to the oil layer and detonates the perforating bullet, penetrating the casing to form an oil flow channel, allowing crude oil to flow into the casing and complete the well completion.

[0003] The perforating gun usually reaches the specified depth, that is, the appropriate perforating position, with the cooperation of the guidance system and the depth control method. The perforating gun is usually rotated to adjust the trajectory of the perforating bullet so that the perforating bullet can perforate in the direction of better permeability. However, the following problems still exist in the subsequent use of the perforating gun: the perforating gun fails to reach a certain appropriate perforating position due to inaccurate positioning during the downhole process; when the perforating gun is started, the impact of the explosion of the perforating bullet is large, which may cause the position of the perforating gun to shift from the original position; after the perforation is completed, a packer is used to set the seal to make each oil layer independent, but the number of layers that can be divided is limited. For wells with multiple oil layers and long well sections, multiple constructions are required, which is inefficient. Therefore, it is necessary to design a perforating gun structure and a sealing method that can be positioned and self-sealed. Summary of the invention

[0004] The purpose of the present invention is to provide a perforating gun structure and a sealing method that can be positioned and self-sealed. This device that provides integrated downhole perforating positioning and sealing realizes sealing by the principle of expansion of the inflatable airbag when it meets water, uses magnetic sensing to achieve positioning, and uses positioning claws to achieve fixed position. The purpose of the present invention is to solve the problem that the perforating gun position is displaced due to the strong impact force caused by the explosion of the downhole perforating bullet, and multiple constructions are required after the explosion to achieve sealing between oil layers. The present invention has the advantages of simple structure, stability and reliability.

[0005] A perforating gun structure and a sealing method that can be positioned and self-sealed, the present invention comprises: an oil pipe, a sealing device, a piston, a buffer pad, a slider, a magnetic sensor device, a gun head, a gun body, a perforating bullet, a blind hole, a gun tail, a positioning device, a bullet rack, a slide rail, a fixed groove, a fine-pore filter, a fastener, a sealing block, a formation water inlet and outlet, an expansion air bag, a sealing ring, a first fixed rod, a support rod, a connecting rod, an "I-shaped" iron core, a magnetic steel, a magnetic sensor mounting seat, an outer shell, a bolt, a nut, a shock-absorbing support, a support rod, a three-hole block, a positioning claw, a second fixed rod, a reset spring, a movable connecting rod, a knob, and a shell. The oil pipe is equipped with a slide rail and a fixed groove, the sealing device is fixed with the fixed groove on the oil pipe by a fastener, and a piston is installed on the slider. The magnetic sensor device is connected to the gun head by bolts and nuts, and a buffer pad is installed between the magnetic sensor device and the gun head, and the gun head is connected to the gun body. The expansion airbag inside the packer device is connected to the outer shell through a support rod, and a sealing ring is installed at the connection. The magnets inside the magnetic sensor device are connected through an "I-shaped" iron core, and the magnets on both sides are fixed through a magnetic sensor mounting seat. The positioning device is divided into two parts, the upper and lower parts, which are connected and fixed by a shock-absorbing support. The inside of the device is connected to the outer shell of the device through a support rod, and a knob is installed between the movable connecting rods inside. The outer shell is connected to the gun body through a second fixed rod. There are multiple blind holes of uniform size on the gun body corresponding to the positions of the perforating bullets on the bullet rack. The bullet rack is equipped with several perforating bullets. The positioning device is fixed between the gun body and the tail of the gun.

[0006] The slide rails are installed on the upper and lower sides of the oil pipe. The fixing grooves are installed on the left and right sides of the oil pipe. The slide rails are equipped with sliders. Formation water outlets are installed on the upper and lower ends of the outer side of the packer device. The blind holes are evenly and randomly distributed on the gun body. The outer shell of the magnetic sensor device is fixedly connected to the inside through a connecting rod, and the connecting rod is installed on the upper and lower sides of the inside of the magnetic sensor device. The positioning claws inside the positioning device are installed on the upper and lower sides of the positioning device.

[0007] There is one set of slide rails and fixed grooves installed on the oil pipe. The slider is equipped with a piston, the size of which corresponds to the formation water inlet and outlet on the packer device. The formation water inlet and outlet are installed on the upper and lower sides of one end of the packer device, and a fine-pore filter is installed inside the formation water inlet and outlet channel. The blind hole position corresponds to the perforating bullet on the bullet rack. There is one set of positioning claws and they are respectively installed on the three-hole blocks of the upper and lower parts of the positioning device.

[0008] An expansion airbag is installed inside the packer device, and a first fixing rod and a blocking block are installed at the upper and lower ends of the same side of the expansion airbag. A magnetic sensor mounting seat is installed inside the magnetic sensor device, and the same poles of the magnetic steel are placed on the magnetic sensor mounting seat opposite to each other, and are connected and fixed by an "I-shaped" iron core. The outer shell of the magnetic sensor device is connected to the internal device by a connecting rod.

[0009] The method comprises the following steps: The magnetic sensor device is connected to the gun head through bolts and nuts. The radial curve of the ground equipment is observed through the magnetic sensor device, and the positioning device is started. There are two sets of reset springs, one end of which is connected to the positioning claw fixed on the three-hole block, and the other end is connected to the movable connecting rod. The positioning claw is extended, and the reset spring is stretched. The movable connecting rod connected to the positioning claw is bent, and the fine-aperture filter is fixed in the internal channel of the formation water inlet and outlet. Formation water enters the packer device, and the expansion airbag expands when it encounters water. The support rod connected to the expansion airbag and the outer shell of the packer device supports the expansion of the entire device. The first fixed rod is fixed to the expansion airbag and the blocking block. The expansion pushes the first fixed rod together with the blocking block to move toward the formation water inlet and outlet, slowing down the speed of formation water in and out, and finally achieving sealing.

[0010] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention uses magnetic steel and an outer shell with the same polarities facing each other in the magnetic sensor device, which not only plays an anti-interference role but also facilitates the generation of signals.

[0011] 2. The present invention realizes a positioning device, which cooperates with a magnetic sensor device to fix the perforating gun at a suitable perforating position, and at the same time solves the problem of the sound position of the perforating gun being offset due to the large impact force generated by the explosion of the perforating bullet.

[0012] 3. The present invention arranges two groups of reset springs and one group of shock-absorbing supports inside the positioning device, which can protect the positioning device from explosion damage while fixing the position of the perforating gun and accelerate the reset speed of the positioning claw.

[0013] 4. The present invention realizes a packer device, which can seal the oil layer after the explosion occurs. At the same time, a group of sealing blocks inside the device move horizontally due to the expansion of the expansion air bag when it encounters water, thereby reducing the inflow and outflow speed of the formation water. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of a positionable and self-sealing perforating gun structure and a sealing method of the present invention.

[0015] Figure 2 It is a schematic diagram of the oil pipe structure of the present invention.

[0016] Figure 3 It is a schematic structural diagram of the packer device of the present invention.

[0017] Figure 4 It is a structural schematic diagram of the magnetic sensor device of the present invention.

[0018] Figure 5 It is a schematic diagram of the structure of the positioning device of the present invention.

[0019] In the figure: 1. tubing; 2. packer device; 3. piston; 4. cushion; 5. slider; 6. magnetic sensor device; 7. gun head; 8. gun body; 9. perforating bullet; 10. blind hole; 11. gun tail; 12. positioning device; 13. bullet rack; 101. slide rail; 102. fixing groove; 201. fine-pore filter screen; 202. fastener; 203. blocking block; 204. formation water inlet and outlet; 205. expansion air bag; 206. sealing ring; 207. A fixing rod; 208. Support rod; 701. Connecting rod; 702. "I" iron core; 703. Magnet; 704. Magnetic sensor mounting seat; 705. Outer shell; 706. Bolt; 707. Nut; 1301. Shock-absorbing support; 1302. Support rod; 1303. Three-hole block; 1304. Positioning claw; 1305. Second fixing rod; 1306. Return spring; 1307. Movable connecting rod; 1308. Knob; 1309. Shell. DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with the accompanying drawings. It should be understood that the following embodiments are merely exemplary and non-restrictive: The present invention comprises an oil pipe 1, a packer device 2, a piston 3, a buffer pad 4, a slider 5, a magnetic sensor device 6, a gun head 7, a gun body 8, a perforating bullet 9, a blind hole 10, a gun tail 11, a positioning device 12, a bullet rack 13, a slide rail 101, a fixing groove 102, a fine-pore filter 201, a fastener 202, a blocking block 203, a formation water inlet and outlet 204, an expansion air bag 205, a sealing ring 206, and a first fixing rod. 207, support rod 208, connecting rod 701, "I-shaped" iron core 702, magnetic steel 703, magnetic sensor mounting base 704, outer shell 705, bolt 706, nut 707, shock absorbing support 1301, support rod 1302, three-hole block 1303, positioning claw 1304, second fixing rod 1305, return spring 1306, movable connecting rod 1307, knob 1308, shell 1309.

[0021] like Figure 1-5As shown, when the present invention is working, the magnetic sensor device 6, the positioning device 12 and the packer device 2 cooperate with each other and play a role in sequence before and after the perforating bullet 9 is detonated. The magnetic sensor device 6 and the ground equipment observe the radial curve to determine whether the entire perforating gun structure has reached the appropriate perforating position. Start the positioning device 12, the positioning claw 1304 installed on the three-hole block 1303 extends out to directly contact the well wall, and at the same time the reset spring 1306 is stretched, and the movable connecting rod 1307 moves up and down, so that the knob 1308 is bent. While fixing the positioning claw 1304, the perforating gun structure is prevented from being offset due to the explosion. The second fixing rod 1305 is fixed to the inside of the positioning device 12 and the external gun body 8. Without affecting the overall operation of the structure, the packer device 2 is added, the internal expansion airbag 205 expands when it encounters water, and the fine-aperture filter 201 is installed inside the formation water inlet and outlet 204 channel to filter large-aperture particles to facilitate the free entry and exit of formation water. At the same time, the support rod 208, the first fixed rod 207, and the blocking block 203 are pushed by the expansion. At the same time, a sealing ring 206 is installed at the connection between the support rod 208 and the expansion airbag 205 to prevent formation water from entering the expansion airbag 205 and causing an impact. The support rod 208, the first fixed rod 207, and the blocking block 203 support the entire device and effectively slow down the speed of formation water entering and exiting the packer device 2, reducing the cost of manpower and time.

[0022] The buckle 202 on the packer device 2 is snap-connected with the fixing groove 102 on the oil pipe, which is convenient for the installation and removal of the packer device 2. The fine-aperture filter 201 is in the middle of the channel of the formation water inlet and outlet 204, and the slider 5 is installed on the slide rail 101 to facilitate the free movement of the slider 5. There is a buffer pad 4 on the end of the gun head 7 close to the magnetic sensor device 6, which plays a certain buffering role after the explosion. The magnetic sensor device 6 and the gun head 7 are connected and fixed by two sets of bolts 706 and nuts 707. Inside the magnetic sensor device 6, there is a pair of magnets 703 with the same poles facing each other, and the magnets 703 are connected by an "I-shaped" iron core 702 to facilitate the generation of signals. The two ends of the magnet 703 are fixed by a magnetic sensor mounting seat 704. At the same time, the outer shell 705 is covered on the outside of the magnetic sensor device 6, which protects the magnetic sensor device 6 and plays an anti-interference role. The gun head 7 is connected to the gun body 8, and a number of randomly distributed and uniformly sized perforating bullets 9 are installed on the bullet rack 13 inside the gun body 8 connected to the oil pipe 1. The perforating bullets 9 can be detonated by the detonating wire, and there are multiple blind holes 10 of uniform size and corresponding to the positions of the perforating bullets 9 on the gun body 8 to ensure that the perforating bullets 9 can directly penetrate the oil layer without affecting their own structure when they explode. A positioning device 12 is fixed between the gun body 8 and the gun tail 11. A group of positioning claws 1304 of the positioning device are extended after activation and directly contact the well wall, which plays a role in fixing the position of the perforating gun and avoiding the position deviation of the perforating gun after the explosion. When the positioning claws 1304 are extended, the two groups of reset springs 1306 are stretched, and the two groups of movable connecting rods 1307 are bent due to the action of the knob 1308 in the middle, which plays a role in fixing the positioning claws 1304. The middle of the upper and lower parts of the device is hollowed out and fixedly connected by a group of shock-absorbing supports 1301, while reducing the damage to the positioning device 12 caused by the impact force generated by the explosion.

Claims

1. A perforating gun structure capable of positioning and self-isolating and an isolation method, the present invention comprises: Oil pipe (1), packer device (2), piston (3), buffer pad (4), slider (5), magnetic sensor device (6), gun head (7), gun body (8), perforating bullet (9), blind hole (10), gun tail (11), positioning device (12), bullet rack (13), slide rail (101), fixing groove (102), fine-pore filter (201), fastener (202), blocking block (203), formation water inlet and outlet (204), expansion air bag (205), sealing ring (206), first fixing rod (207), support rod (208), connecting rod (701), "I" iron core (702), magnetic steel (703), a magnetic sensor mounting seat (704), an outer shell (705), bolts (706), nuts (707), a shock-absorbing support (1301), a support rod (1302), a three-hole block (1303), a positioning claw (1304), a second fixing rod (1305), a return spring (1306), a movable connecting rod (1307), a knob (1308), and a shell (1309); characterized in that: the oil pipe (1) is equipped with a slide rail (101) and a fixing groove (102), the packer device (2) is fixed to the fixing groove (102) on the oil pipe (1) by a fastener (202), and the slider (5) is provided with a piston (3); the magnetic sensor device (6) is connected to the gun head (7) by means of bolts (706) and nuts (707), and a buffer pad (4) is provided between the magnetic sensor device (6) and the gun head (7), and the gun head (7) is connected to the gun body (8); the internal expansion air bag (205) of the packer device (2) is connected to the outer shell (1309) through a support rod (208), and a sealing ring (206) is provided at the connection; the magnetic steel (703) inside the magnetic sensor device (6) is connected through an "I" iron core (702), and the magnetic steels (703) on both sides are fixed through a magnetic sensor mounting seat (704); The positioning device (12) is divided into two parts, an upper part and an lower part, which are connected and fixed by a shock-absorbing support (1301); the inside of the device is connected to the device shell (1309) by a support rod (1302), and a knob (1308) is installed between the movable connecting rods (1307) inside; the shell (1309) is connected to the gun body (8) by a second fixing rod (1305); the gun body (8) is provided with a plurality of blind holes (10) of uniform size corresponding to the positions of the perforating bullets (9) on the bullet rack (13); the bullet rack (13) is provided with a plurality of perforating bullets (9); the positioning device (12) is fixedly connected between the gun body (8) and the gun tail (11).

2. A positionable and self-isolating perforating gun structure and isolation method according to claim 1, characterized in that: The slide rail (101) is installed on the upper and lower sides of the oil pipe (1), the fixing groove (102) is installed on the left and right sides of the oil pipe (1), and a slider (5) is installed on the slide rail (101); the upper and lower ends of the outer side of the packer device (2) are equipped with formation water outlets (204), and the blind holes (10) are evenly and randomly distributed on the gun body (8); the outer shell (705) of the magnetic sensor device (6) is fixedly connected to the interior through a connecting rod (701), and the connecting rod (701) is installed on the upper and lower sides of the interior of the magnetic sensor device (6); the positioning claws (1304) inside the positioning device (12) are installed on the upper and lower sides of the positioning device (12).

3. A positionable and self-isolating perforating gun structure and isolation method according to claim 1, characterized in that: The oil pipe (1) is provided with a set of slide rails (101) and fixed grooves (102), and the slide block (5) is provided with a piston (3) whose size corresponds to the formation water inlet and outlet (204) on the packer device (2); the formation water inlet and outlet (204) is provided on the upper and lower sides of one end of the packer device (2), and a fine-pore filter (201) is provided inside the formation water inlet and outlet (204) channel; the position of the blind hole (10) corresponds to the perforating bullet (9) on the bullet rack (13); the positioning claws (1304) are provided in a set and are respectively provided on the three-hole blocks (1303) at the upper and lower parts of the positioning device (12).

4. A positionable and self-isolating perforating gun structure and isolation method according to claim 1, characterized in that: The packer device (2) is internally installed with an expansion airbag (205), and a first fixing rod (207) and a blocking block (203) are installed at the upper and lower ends on the same side of the expansion airbag (205); the magnetic sensor device (6) is internally installed with a magnetic sensor mounting seat (704), and the magnetic steel (703) is placed on the magnetic sensor mounting seat (704) with the same poles facing each other, and is connected and fixed by an "I-shaped" iron core (702); the outer shell (705) of the magnetic sensor device (6) is connected to the internal device by a connecting rod (701).

5. A positionable and self-isolating perforating gun structure and isolation method as claimed in claims 1 to 4, characterized in that: The method comprises the following steps: The magnetic sensor device (6) is connected to the gun head (7) through the bolts (706) and nuts (707), and the radial curve of the ground equipment is observed through the magnetic sensor device (6); the positioning device (12) is started, and the reset spring (1306) has two groups and one end is connected to the positioning claw (1304) fixed on the three-hole block (1303), and the other end is connected to the movable connecting rod (1307); the positioning claw (1304) is extended, the reset spring (1306) is stretched, and the movable connecting rod (1307) connected to the positioning claw (1304) is bent; the fine-aperture filter (201) is fixedly connected to the internal channel of the formation water inlet and outlet (204), and formation water enters the packer device (2). The expansion airbag (205) expands when it encounters water, and the support rod (208) connected to the expansion airbag (205) and the outer shell (1309) of the packer device (2) supports the expansion of the entire device; the first fixed rod (207) is fixedly connected to the expansion airbag (205) and the blocking block (203), and the expansion pushes the first fixed rod (207) together with the blocking block (203) to move toward the formation water inlet and outlet (204), slowing down the speed of formation water inlet and outlet, and finally achieving sealing.

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