Energy-gathered expansion metal pipe patching device

Abstract

The invention discloses an energy-gathered expansion metal pipe patching device, which utilizes chemical energy released by explosive detonation to extrude a high-elongation special steel pipe to an underground casing damage well section through directional overpressure shock waves generated by modular energy-gathered charging, and expands the original drift diameter to achieve the purposes of diameter expansion and sealing. A hydraulic power source and a conveying pipe column are not needed, the outer diameter of the sealing patching pipe is small, the sealing patching pipe can be lowered to a target patching position easily, and the sealing patching pipe has the advantages of being high in energy utilization rate, high in sealing pressure-bearing index, convenient in construction process, low in cost, high in work efficiency and short in operation period and is suitable for large-scale industrial use and popularization.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of downhole casing plugging, and particularly relates to a poly-energized expansion metal pipe patching device. BACKGROUND

[0002] In view of the casing integrity damage caused by the reasons such as mis-shot hole, corrosion perforation, rupture, sand hole, thread leakage and decoupling of the downhole casing, the commonly used casing plugging methods include gas power patching reinforcement technology, hydraulic power casing patching reinforcement technology and the like. These patching methods all adopt the expansion reinforcement of both ends of the metal patching pipe or the full-section expansion reinforcement of the patching pipe, and have a certain plugging effect, but different technical principles have different advantages and disadvantages, are only applicable to different downhole environmental conditions, and the application range is restricted to a certain extent.

[0003] The gas power patching reinforcement technology utilizes the chemical energy conversion into mechanical energy of the composite propellant combustion, and realizes the plugging purpose through the principle that the piston pushes the high-strength cone to extrude the metal anchor. The disadvantage is that the sealing pressure index is low, and the inner diameter after patching is restricted by the inner diameter of the patching pipe.

[0004] The hydraulic expansion pipe patching technology all adopts the downward expansion cone, and realizes the patching and plugging by means of the pressure of the ground pump liquid pushing the expansion cone to extrude the patching pipe. The disadvantage is that the cost is high, the sealing pressure index of the oil pipe is high, and if the pipe string sealing fails in the working process of the expansion cone, the patching pipe will stop in the middle of the expansion process, the expansion cone is difficult to be taken out from the downhole, and a secondary accident will occur.

[0005] In general, the patching device of the prior art cannot meet the multiple index requirements of the cost, process and operation convenience, inner diameter and sealing pressure. SUMMARY

[0006] The application aims to provide a poly-energized expansion metal pipe patching device, so as to solve the multiple index requirements of the cost, process and operation convenience, inner diameter and sealing pressure of the patching device of the prior art In order to solve the above technical problems, the application adopts the following technical scheme: A poly-energized expansion metal pipe patching device, comprising an initiator, a patching pipe, an expander and an elastic bottom support. The initiator comprises a booster joint and a detonating cord, the booster joint is internally provided with an elastic plug, the elastic plug is internally provided with a booster tube, and the upper end of the detonating cord is connected with the booster tube. The patching pipe comprises an outer pipe and a center pipe coaxially arranged in the inner part of the outer pipe. The lower outer wall of the booster joint is clamped into the inner wall of the outer pipe, and the upper outer wall of the center pipe is clamped into the inner wall of the bottom of the booster joint. The outer wall of the lower part of the central tube is clamped into the inner wall of the elastic bottom support, and the outer wall of the elastic bottom support is clamped into the inner wall of the lower part of the outer tube. The detonating cord line passes through the expander, and the bottom of the detonating cord line extends into the recess. A plurality of charge devices are uniformly arranged on the expander in the vertical direction, and a tapered recess is formed in the charge device.

[0007] The application also has the following characteristics: Further, an O-shaped sealing ring is arranged between the outer wall of the lower part of the detonating adapter and the inner wall of the outer tube.

[0008] Further, the central tube comprises a plurality of sleeve tubes connected end to end, and the adjacent two sleeve tubes are connected through the central tube coupling.

[0009] Further, a spiral groove is formed in the outer wall of the central tube. The outer wall of the outer tube is wrapped with a covering rubber, and a spiral groove is formed in the covering rubber.

[0010] Further, the elastic bottom support comprises a connecting tube, and a guide cone is coaxially arranged at the bottom of the connecting tube. A connecting groove is formed in the outer wall of the upper part of the connecting tube, and the connecting tube is clamped into the inner wall of the lower part of the outer tube through the connecting groove.

[0011] Further, a grommet is arranged on the connecting groove of the connecting tube. The outer diameter of the grommet is greater than the outer diameter of the connecting tube, a compression spring is further arranged on the connecting tube, and the compression spring is located between the bottom of the grommet and the upper end surface of the guide cone.

[0012] Further, a plurality of adjusting pads are arranged on the expander. The plurality of adjusting pads are arranged one by one between the adjacent two charge devices.

[0013] Further, the taper of the recess of the charge device is 50-70°, the pass diameter of the recess is 5-7mm, and the amount of explosive in a single charge device is 3-100g.

[0014] The inner diameter of the central tube is 18mm-100mm, the outer diameter is 24mm-106mm, the length is 200-1000mm, the wall thickness of the central tube is 3mm, 4mm or 5mm, and the material of the central tube is magnesium-aluminum alloy or aluminum alloy. The depth of the spiral groove in the outer wall of the central tube is 0.2-1mm. The rubber coating of the outer tube adopts nitrile rubber with a thickness of 1-5 mm, and the spiral groove depth of the rubber coating is not greater than 1 mm. The thickness of the rubber coating is 1-5 mm, the tensile strength is 2-10 MPa, the volume expansion ratio is 2000%-600%, and the Shore A hardness is 50-80.

[0015] Further, the elastic bottom support adopts a soluble magnesium-aluminum alloy material.

[0016] Compared with the prior art, the present application has the following technical effects: The energy-gathering expansion metal pipe patching device utilizes chemical energy released by explosive detonation, and a directional overpressure shock wave generated by modular energy-gathering charges to extrude a high-elongation special steel pipe to a downhole casing damage well section and expand the original drift diameter, so as to achieve the purposes of expansion and sealing. The energy-gathering expansion metal pipe patching device does not need a hydraulic power source, and the outer diameter of the delivery pipe string is small, so that the device can be easily lowered to a target patching position. The device has the advantages of high energy utilization rate, high sealing pressure index, convenient construction process, low cost, high work efficiency, short operation cycle, and the like, and is suitable for large-scale use and promotion in industry. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic diagram of the energy-gathering expansion metal pipe patching device of the present application installed in a stratum; Figure 2 is a schematic diagram of the overall structure of the energy-gathering expansion metal pipe patching device of the present application; Figure 3 is a schematic diagram of the center pipe connection structure in the present application; Figure 4 is a schematic diagram of the initiator structure in the present application.

[0018] The meanings of the various reference numerals in the drawings are as follows: 1, initiator; 2, patching pipe; 3, expander; 4, elastic bottom support; 5, charger; 6, O-ring; 7, center pipe coupling; 8, adjusting pad; 101, booster joint; 102, detonating cord; 201, outer tube; 202, center tube; 401, groove; 402, guide cone; 403, spacer ring; 404, compression spring. DETAILED DESCRIPTION

[0019] It should be noted that all components in the present application, such as the expander, are known components in the prior art, unless otherwise specified.

[0020] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0021] like Figures 1-4 As shown, a shaped charge expansion metal tube supplement device includes an initiator 1, a supplement tube 2, an expander 3, and an elastic base 4. The detonator 1 includes a detonation connector 101 and a detonating cord 102. The detonation connector 101 is provided with an elastic plug inside, and the elastic plug is provided with a detonation tube inside. The upper end of the detonating cord 102 is connected to the detonation tube. Subsidy tube 2 includes an outer tube 201 and a central tube 202 coaxially disposed inside the outer tube 201; The lower outer wall of the detonation connector 101 is fitted into the inner wall of the outer tube 201, and the upper outer wall of the central tube 202 is fitted into the bottom inner wall of the detonation connector 101. The lower outer wall of the central tube 202 is fitted into the inner wall of the elastic base 4, and the outer wall of the elastic base 4 is fitted into the lower inner wall of the outer tube 201; the bottom of the elastic base 4 is a conical structure, and a groove 401 is provided at the bottom of the inner wall of the elastic base 4; the elastic base 4 includes a connecting tube, and a guide cone 402 is coaxially provided at the bottom of the connecting tube. The expander 3 is coaxially disposed inside the central tube 202; the detonating cord 102 passes through the expander 3, and the bottom of the detonating cord 102 extends into the groove 401. Multiple explosive chargers 5 are evenly mounted vertically along the upper edge of the expander 3, and the explosive chargers 5 can be filled with explosives.

[0022] To address the challenge of preventing the auxiliary tube from rupturing under multi-point detonation overpressure plastic deformation and expansion, an approach was adopted: adding aluminum powder to conventional explosives to reduce detonation velocity and enhance their heat of combustion, work capacity, and volumetric power. The aluminum powder absorbs a large amount of heat in the initial stages of the explosion, undergoing sublimation and oxidation reactions, which lag behind the main detonation process. This slows down the propagation speed of the shock wave and allows for better control of the detonation wave overpressure.

[0023] Meanwhile, since there is liquid water or other mixed liquid between the sleeve and the auxiliary tube 2 when the auxiliary tube 2 expands, and given the instantaneous incompressibility of water, the outer tube 201 of the auxiliary tube 2 is designed to be made of low-carbon steel, stainless steel and other low-strength steel, and the outer surface is covered with high-temperature resistant and oil-resistant rubber, which has a certain compressibility and buffers the collision speed between the expansion of the auxiliary tube and the inner wall of the sleeve. In addition, a rubber seal is used between the sleeve and the auxiliary tube 2.

[0024] In order to solve the problem of small clamping force of the rubber and the outer tube 201, a plurality of coarse thread grooves are processed on the outer surface of the patch pipe 2, and the rubber is embedded and vulcanized in the thread grooves, so that the patch pipe 2 can be tightly compacted with the inner wall of the casing pipe after the diameter expansion, and in order to further improve the sealing pressure index, water and oil expandable rubber material can be selected to completely solve the sealing and pressure problem.

[0025] In this embodiment, a mixed explosive containing 5-50% of RDX, HMX and HNS is used, and a mold and a press are used to press the charging device 5. The taper of the charging device 5 is 50°-70°, and the inner diameter is 5mm-7mm, which is convenient for connecting the detonating cord 102. The charging capacity of a single charging device 5 is 3-100g.

[0026] As a preferred solution, an O-shaped sealing ring 6 is arranged between the lower outer wall of the booster joint 101 and the inner wall of the outer tube 201.

[0027] As a preferred solution, the center tube 202 includes a plurality of casing pipes connected end to end, and the adjacent two casing pipes are connected by a center tube coupling 7. The purpose of this is to enable the center tube 202 to be not limited by the length of the outer tube 201, to prevent leakage and to be able to be flexibly selected.

[0028] As a preferred solution, a spiral groove is formed on the outer wall of the center tube 202. The outer wall of the outer tube 201 is wrapped with a covering rubber, and a spiral groove is formed on the covering rubber. The spiral groove is arranged to facilitate cracking and releasing energy after explosion.

[0029] As a preferred solution, the elastic base 4 is made of a soluble magnesium-aluminum alloy material. The design of the guide cone 404 facilitates the lowering to the preset patching work section.

[0030] A connecting groove is formed on the upper outer wall of the connecting pipe, and the connecting pipe is clamped into the lower inner wall of the outer tube 201 through the connecting groove.

[0031] As a preferred solution, a grommet 403 is sleeved on the connecting groove of the connecting pipe. The outer diameter of the grommet 403 is greater than the outer diameter of the connecting pipe, and a compression spring 404 is further sleeved on the connecting pipe, and the compression spring 404 is located between the bottom of the grommet 403 and the upper end surface of the guide cone 402.

[0032] As a preferred solution, a plurality of adjusting pads 8 are further arranged on the expander 3. The plurality of adjusting pads 8 are arranged one by one between the adjacent two charging devices 5. This arrangement can flexibly adjust the number of charging devices 5 and ensure the stability of the installation.

[0033] The center tube 202 has an inner diameter of 18-100 mm, an outer diameter of 24-106 mm, a length of 200-1000 mm, a wall thickness of 3 mm, 4 mm or 5 mm, and is made of magnesium-aluminum alloy or aluminum alloy; The spiral groove of the outer wall of the center tube 202 has a depth of 0.2-1 mm; The covering rubber of the outer tube 201 is made of butyronitrile rubber with a thickness of 1-5 mm, and the spiral groove of the covering rubber has a depth of not more than 1 mm; The covering rubber has a thickness of 1-5 mm, a tensile strength of 2-10 MPa, a volume expansion ratio of 2000%-600%, and a Shore A hardness of 50-80.

[0034] In the implementation of the embodiment, the coiled tubing operation mode is taken as an example, the coiled tubing operation equipment is connected with a pressure initiator, the energy-gathering expansion metal tube patching device of the embodiment is lowered to a target layer, the wellhead is pressurized to a set initiation pressure, a firing pin triggers a detonator to detonate the detonating cord 201, the chemical energy released by the detonation of the explosive carried in the charger 5 generates a directional overpressure shock wave, the high-elongation patching tube 2 is adhered to the downhole casing damage section, and the original drift diameter is expanded, and the anchoring and sealing functions of the patching tube 2 are completed.

[0035] The device uses the energy-gathering effect of the explosive, generates circumferential overpressure after initiation, uniformly extrudes the metal patching tube, and expands the metal patching tube into the inner wall of the target damaged casing to complete the casing patching operation. The technology can overcome the shortcomings of the prior art, has simple construction process and convenient operation, and can be adaptively adjusted according to different casing specifications, downhole casing environmental conditions and sealing index requirements.

Claims

1. A device for attaching a condensing expansion metal tube, characterized in that, It includes an initiator (1), a supplement tube (2), an expander (3), and an elastic base (4). The detonator (1) includes a detonation connector (101) and a detonating cord (102). The detonation connector (101) is provided with an elastic plug inside, and the elastic plug is provided with a detonation tube inside. The upper end of the detonating cord (102) is connected to the detonation tube. The subsidy tube (2) includes an outer tube (201) and a central tube (202) coaxially disposed inside the outer tube (201); The lower outer wall of the detonation connector (101) is fitted into the inner wall of the outer tube (201), and the upper outer wall of the central tube (202) is fitted into the bottom inner wall of the detonation connector (101). The lower outer wall of the central tube (202) is fitted into the inner wall of the elastic base (4), and the outer wall of the elastic base (4) is fitted into the lower inner wall of the outer tube (201); the bottom of the elastic base (4) is a conical structure, and a groove (401) is provided at the bottom of the inner wall of the elastic base (4). The expander (3) is coaxially disposed inside the central tube (202); the detonating cord (102) passes through the expander (3), and the bottom of the detonating cord (102) extends into the groove (401); The expander (3) is uniformly fitted with multiple chargers (5) along the vertical direction. Each charger (5) has a conical groove, and explosives can be filled inside the groove.

2. The shaped charge liner assembly of claim 1 wherein, An O-ring (6) is provided between the lower outer wall of the explosion transmission joint (101) and the inner wall of the outer tube (201).

3. The shaped charge liner assembly of claim 2 wherein, The central tube (202) includes multiple sleeves connected end to end, and adjacent sleeves are connected by a central tube coupling (7).

4. The shaped charge liner assembly of claim 3 wherein, The outer wall of the central tube (202) is provided with a spiral groove; The outer wall of the outer tube (201) is covered with rubber, and the rubber is provided with spiral grooves.

5. The shaped charge liner assembly of claim 4 wherein, The elastic base (4) includes a connecting tube, and a guide cone (402) is coaxially provided at the bottom of the connecting tube. A connecting groove is formed on the upper outer wall of the connecting pipe, and the connecting pipe is inserted into the lower inner wall of the outer pipe (201) through the connecting groove.

6. The shaped charge liner assembly of claim 5 wherein, A gasket (403) is fitted onto the connecting groove of the connecting pipe. The outer diameter of the washer (403) is larger than the outer diameter of the connecting pipe, and a compression spring (404) is also sleeved on the connecting pipe. The compression spring (404) is located between the bottom of the washer (403) and the upper end face of the guide cone (402).

7. The shaped charge liner assembly of claim 6 wherein, The expander (3) is also provided with multiple adjusting pads (8); Multiple adjustment pads (8) are arranged one-to-one between two adjacent loading devices (5).

8. The shaped charge liner assembly of claim 7 wherein, The loading device (5) has a groove taper of 50-70° and a groove diameter of 5-7mm. Each loading device (5) holds 3-100g of explosives. The central tube (202) has an inner diameter of 18mm-100mm, an outer diameter of 24mm-106mm, a length of 200-1000mm, a wall thickness of 3mm, 4mm or 5mm, and is made of magnesium-aluminum alloy or aluminum alloy. The spiral groove depth on the outer wall of the central tube (202) is 0.2-1mm; The rubber coating of the outer tube (201) is made of butyronitrile rubber with a thickness of 1-5 mm, and the spiral groove depth of the rubber coating is not more than 1 mm. The thickness of the rubber coating is 1-5 mm, the tensile strength is 2-10 MPa, the volume expansion ratio is 2000%-600%, and the Shore A hardness is 50-80.

9. The shaped charge liner assembly of claim 8 wherein, The elastic bra (4) is made of soluble magnesium-aluminum alloy material.

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