Liquid oxygen fracturing pipe upper end cover suitable for underwater rock mass

Abstract

The utility model provides an upper end cover of a liquid oxygen fracturing pipe suitable for underwater rock mass, and relates to the technical field of expansion fracturing, the upper end cover comprises an end cover body, the upper surface of the end cover body is provided with counter-force petals, the counter-force petals are annularly arranged on the upper surface of the end cover body, and the counter-force petals are arranged on the lower surface of the end cover body. The counter-force petals are arranged on the upper end cover, an acute included angle alpha is formed between the counter-force petals and the axial direction of the end cover body, the counter-force petals are made of semi-rigid materials, the end cover body is used for being detachably connected with a fracturing pipe, and the counter-force petals are arranged on the upper end cover, so that the counter-force petals can be clamped to the inner wall of a blast hole, the buoyancy effect of water on the fracturing pipe is counteracted, and the fracturing effect is improved. And therefore, an operator can mount the fracturing pipe at the bottom of the blast hole.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of inflation fracturing, especially relates to an upper end cover of liquid oxygen fracturing pipe suitable for underwater rock mass. BACKGROUND

[0002] Liquid oxygen phase change fracturing technology has gradually matured, and the structure of the fracturing pipe, as the most important content, has a relatively mature design process.

[0003] The liquid oxygen phase change fracturing technology on land has the characteristics of low sealing requirement for the fracturing pipe, and mainly stores liquid oxygen through the sealed space formed by drilling and filling. However, when this technology is used underwater, the situation will be completely different. The fracturing pipe body has a small mass, and has the characteristics of portability and flexibility when the operation is carried out on land. However, when the operation is carried out underwater, the self-gravity of the fracturing pipe body cannot offset the buoyancy, and the fracturing pipe will float upward along the large blast hole during the lower pipe construction. This will make it difficult for the operator to place the pipe body at the bottom of the blast hole, and thus the subsequent work cannot be carried out efficiently and conveniently.

[0004] Based on the above reasons, the present application provides an upper end cover of a liquid oxygen fracturing pipe suitable for underwater rock mass and a manufacturing method thereof, aiming to solve the problem that the fracturing pipe is not easy to fix when operating underwater. UTILITY MODEL CONTENTS

[0005] The utility model provides an upper end cover of a liquid oxygen fracturing pipe suitable for underwater rock mass, and aims to solve the problem that the fracturing pipe is not easy to fix when operating underwater.

[0006] In order to achieve the above purpose, the embodiment of the utility model provides an upper end cover of a liquid oxygen fracturing pipe suitable for underwater rock mass, which comprises:

[0007] The upper surface of the end cover body is provided with a counterforce petal, the counterforce petal is annularly arranged on the upper surface of the end cover body, the counterforce petal and the axial direction of the end cover body form an acute angle α, the counterforce petal is made of semi-rigid material, and the end cover body is used for detachable connection with the fracturing pipe.

[0008] Preferably, the end cover body comprises a surrounding plate and an end plate, the end plate is arranged above the surrounding plate so that the end cover body forms a semi-closed structure, and the surrounding plate is used for detachable connection with the fracturing pipe.

[0009] The end plate is provided with a liquid inlet, an exhaust port and a threading hole, the liquid inlet is used for threading the infusion tube of the oxygen absorption medium, the exhaust port is provided with an exhaust pipe or a one-way valve allowing liquid oxygen to flow from the inner cavity of the fracturing pipe to the atmosphere, and the threading hole is used for threading the cable of the electronic excitation device.

[0010] Preferably, one side of the end plate facing the surrounding plate is provided with a ring groove, and a sealing ring is arranged in the ring groove.

[0011] When the surrounding plate is connected with the fracturing tube, the upper end of the fracturing tube abuts against the sealing ring.

[0012] Preferably, the other side of the end plate away from the surrounding plate is provided with a protective ring, and the liquid inlet, the exhaust port and the threading port are located in the protection range formed by the protective ring.

[0013] Preferably, the liquid inlet is a threaded hole, and a double-pass quick connector is screwed on the liquid inlet, one end of the double-pass quick connector located in the fracturing tube is used for communicating with the infusion tube of the oxygen absorption medium, and the other end of the double-pass quick connector located outside the fracturing tube is used for communicating with the extension tube.

[0014] Preferably, the threading port is a double-concave threading port, the diameter of the threading port on the upper and lower surfaces of the end plate is greater than the diameter of the threading port on the middle surface of the end plate, and the middle surface is located between the upper surface and the lower surface of the end plate.

[0015] The above scheme of the utility model has the following beneficial effects:

[0016] In the application, the counterforce petal is arranged on the upper end cover, so that the counterforce petal can be clamped on the inner wall of the blast hole, the buoyancy effect of water on the fracturing tube is offset, and it is guaranteed that the operating personnel installs the fracturing tube at the bottom of the blast hole.

[0017] Other features and advantages of the utility model will be described in detail in the subsequent specific embodiment part. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is the schematic view of the utility model;

[0019] Figure 2 is the top view of the utility model;

[0020] Figure 3 is the sectional view of A-A direction;

[0021] Figure 4 is the parameter schematic view of the application in the blast hole.

[0022] LEGEND

[0023] 10-end cover body, 11-surrounding plate, 12-end plate, 13-sealing ring, 14-protective ring, 16-one-way valve, 17-double-pass quick connector, 18-nut, 19-threading port,

[0024] 20-counterforce petal. DETAILED DESCRIPTION

[0025] In order to make the technical problems, technical schemes and advantages of the utility model clearer, specific embodiments will be described in detail below with reference to the drawings.

[0026] As Figures 1-4 shown, the utility model discloses an upper end cover of liquid oxygen induced cracking pipe suitable for underwater rock mass, including end cover body 10, the upper surface of this end cover body 10 is provided with counterforce petal 20, the counterforce petal 20 is annular and is arranged on the upper surface of end cover body 10, and the axial direction of the counterforce petal 20 and end cover body 10 forms an acute angle α, more exactly, the axial direction of the counterforce petal 20 and end cover body 10 forms an acute angle, and the counterforce ring plate is made of semi-rigid material, such as PE, and can be deformed under stress. The end cover body 10 is detachably connected with the cracking pipe.

[0027] Further, the end cover body 10 includes a surrounding plate 11 and an end plate 12, the end plate 12 is arranged above the surrounding plate 11 to form a semi-closed structure of the end cover body 10, when the surrounding plate 11 is detachably connected with the cracking pipe, the end plate 12 seals the cracking pipe at the upper end of the cracking pipe.

[0028] Since the oxygen-absorbing medium needs to be arranged in the cracking pipe and the liquid oxygen needs to be filled for the oxygen-absorbing medium, the liquid inlet is arranged on the end plate 12, the oxygen-absorbing medium includes a liquid delivery pipe, and the liquid delivery pipe is arranged in the liquid inlet. The electronic excitation device also needs to be installed in the cracking pipe, and the cable of the electronic excitation device is arranged in the wire hole 19 arranged on the end plate 12. The exhaust port is also arranged on the end plate 12, the exhaust pipe 15 or the one-way valve 16 allowing the liquid oxygen to flow from the cracking pipe to the atmosphere is arranged on the exhaust port. The exhaust pipe 15 is used to observe whether the liquid oxygen is filled enough.

[0029] Further, the ring groove is arranged on one side of the end plate 12 facing the surrounding plate 11, and the sealing ring 13 is arranged in the ring groove. When the surrounding plate 11 is connected with the cracking pipe, the upper end of the cracking pipe abuts against the sealing ring 13 to seal the upper end of the cracking pipe.

[0030] Preferably, the fastening bolts are arranged on the circumferential direction of the surrounding plate 11, the fastening bolts are screwed with the surrounding plate 11 and the cracking pipe, and the blind hole is formed on the cracking pipe to avoid punching the cracking pipe and affecting the sealing performance.

[0031] Further, the protective ring 14 is arranged on the side of the end plate 12 away from the surrounding plate 11, the two ends of the protective ring 14 are open, the port of the protective ring 14 is fixedly connected with the end plate 12, and the air inlet, the exhaust port and the wire hole 19 are located in the protection range formed by the protective ring 14.

[0032] Preferably, the protective ring 14 is square or circular, the protective ring 14 is integrally formed with the end plate 12 and the surrounding plate 11, and is made of semi-rigid material, such as PE material.

[0033] In the present application, the protective ring 14 can avoid large-angle bending of the infusion tube, the cable and the exhaust pipe 15, and prevent the tube from breaking or being blocked due to bending.

[0034] The infusion tube and the liquid inlet will generate a gap during assembly, and therefore the liquid inlet is optimized in the present application. Specifically, the liquid inlet is a threaded hole, and a double-pass quick connector 17 is screwed on the liquid inlet. The double-pass quick connector 17 has two ends, one of which is located in the cracking tube, and the other of which is located outside the cracking tube. The end located in the cracking tube is in communication with the infusion tube of the oxygen absorption medium, and the end located outside the cracking tube is in communication with the extension tube. The extension tube is used to communicate with the liquid oxygen supply device, so that the liquid oxygen enters the cracking tube through the extension tube, the double-pass quick connector 17 and the infusion tube, and is absorbed by the oxygen absorption medium.

[0035] Preferably, the double-pass quick connector 17 further includes nuts 18 for fixing the double-pass quick connector 17. The nuts 18 are two, and are respectively screwed with the double-pass quick connector 17, and the two nuts 18 are respectively located on the upper and lower surfaces of the end plate 12. Another sealing ring 13 is arranged between the nuts 18 and the end plate 12.

[0036] Further, the threading hole 19 is a double-concave threading hole 19, and the diameter of the threading hole 19 on the upper and lower surfaces of the end plate 12 is greater than the diameter of the threading hole 19 on the middle surface of the end plate 12. The middle surface is located between the upper surface and the lower surface of the end plate 12.

[0037] Preferably, the double-concave threading hole 19 can be drop-glued and sealed after the cable is threaded, and the sealing glue is concentrated in the threading hole 19, avoiding leakage.

[0038] The present application also provides a manufacturing method of the upper end cover, comprising the following steps:

[0039] S10. Pour a batch of upper end covers, which have the end cover body 10 and the counterforce petals 20. It should be noted that the length direction of the counterforce petals 20 is parallel to the axial direction of the end cover body 10 at this time. For the convenience of description, the end of the counterforce petals 20 fixed on the end plate 12 is defined as the fixed end, and the end of the counterforce petals 20 away from the end plate 12 is defined as the free end.

[0040] Bend one of the counterforce petals 20 of the upper end to any angle, and ensure that the free end of the counterforce petals 20 can contact the inner wall of the blast hole after being bent outward. Measure the following parameters of the upper end cover: the radius difference between the outermost radius of the counterforce petals 20 and the radius of the test blast hole, the outer diameter of the virtual circle formed by the bottom ends of the counterforce petals 20 on the end cover body 10, the inner diameter of the virtual circle formed by the bottom ends of the counterforce petals 20 on the end cover body 10, the length of the counterforce petals 20 and the number of the counterforce petals 20;

[0041] S20. Drilling a plurality of blast holes in the area where cracking is needed, including a test blast hole. Since the plurality of blast holes are located in the same area, the friction coefficient of the inner wall of the blast hole is considered to be the same.

[0042] Placing the upper end cover in the test blast hole so that the free end is in contact with the inner wall of the test blast hole, and measuring the sliding friction force on the upper end cover in the test blast hole using a tension meter.

[0043] S30. Based on the cantilever beam model, obtaining the proportional relationship between the sliding friction force and the elastic modulus of the reaction force petal 20 and the friction coefficient of the reaction force ring plate and the inner wall of the blast hole.

[0044] The cantilever beam model is:

[0045]

[0046] In the formula, f is the sliding friction force between the upper end cover and the blast hole, E is the elastic modulus of the upper end cover, μ is the friction coefficient of the upper end cover and the blast hole, y is the radius difference between the outermost radius of the reaction force petal 20 and the radius of the test blast hole, R is the outer diameter of the virtual circle formed by the bottom ends of the reaction force petals 20 on the end cover body 10, r is the inner diameter of the virtual circle formed by the bottom ends of the reaction force petals 20 on the end cover body 10, L is the length of the reaction force petal 20, and n is the number of reaction force petals 20.

[0047] In the formula, f is the sliding friction force between the upper end cover and the blast hole, E is the elastic modulus of the upper end cover, μ is the friction coefficient of the upper end cover and the blast hole, y is the radius difference between the outermost radius of the reaction force petal 20 and the radius of the test blast hole, R is the outer diameter of the virtual circle formed by the bottom ends of the reaction force petals 20 on the end cover body 10, r is the inner diameter of the virtual circle formed by the bottom ends of the reaction force petals 20 on the end cover body 10, L is the length of the reaction force petal 20, and n is the number of reaction force petals 20.

[0048] The cantilever beam model can obtain the proportional relationship between the sliding friction force and K.

[0049] S40. Obtaining the sliding friction force f1 of the upper end cover installed in the blast hole, obtaining the radius difference between the outermost radius of the reaction force petal 20 and the radius of the installed blast hole, and obtaining the angle α that the reaction force petal 20 needs to deflect.

[0050] Specifically, the sliding friction force is obtained, which is the sliding friction force of the blast hole where the upper end cover needs to be installed, and can be obtained using a tension meter. Since the outer diameter R of the virtual circle formed by the bottom ends of the reaction force petals 20 on the end cover body 10, the inner diameter r of the virtual circle formed by the bottom ends of the reaction force petals 20 on the end cover body 10, the length L of the reaction force petal 20, and the number n of reaction force petals 20 are all fixed and unchanged, the radius difference y between the outermost radius R of the reaction force petal 20 and the radius R of the test blast hole can be inversely deduced through the cantilever beam model. 外 孔 ​​

[0051] Further, since the bore diameter R of the blast hole 孔 The outermost radius R of the counterforce petal 20 can be measured and obtained 外 , R 外 = R 炮 -y.

[0052] The deflection angle a of the counterforce petal 20 is obtained based on the sine function Sin a = R 外 / L.

[0053] S50. A hot-pressing mold is made based on the deflection angle of the counterforce petal 20, and the upper end cover is placed in the hot-pressing mold to deflect the counterforce petal 20 to the angle a.

[0054] S60. After the upper end cover is cooled, drilling is performed on the end plate 12 to obtain

[0055] The above is the preferred embodiment of the present application, it should be noted that for those skilled in the art, without departing from the principles of the present application, can make a number of improvements and refinements, these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. An upper end cap for a liquid oxygen induced fracturing pipe suitable for use in an underwater rock mass, characterised in that, The utility model relates to an end cover body (10) is provided with the counterforce petal (20) on the upper surface, the counterforce petal (20) is arranged on the upper surface of the end cover body (10) in a ring, the counterforce petal (20) forms an acute angle alpha with the axial direction of the end cover body (10), the counterforce petal (20) is made of semi-rigid material, and the end cover body (10) is used for detachable connection with the fracturing tube. The end cover body (10) comprises a surrounding plate (11) and an end plate (12), the end plate (12) is arranged above the surrounding plate (11) to form a semi-closed structure, and the surrounding plate (11) is used for detachable connection with the fracturing tube.

2. The upper end cap of the liquid oxygen induced fracturing pipe suitable for underwater rock mass according to claim 1, characterized in that: The end plate (12) is provided with a liquid inlet, an exhaust port and a threading port (19), the liquid inlet is used for threading the infusion tube of the oxygen absorption medium, the exhaust port is provided with an exhaust pipe (15) or a one-way valve (16) allowing liquid oxygen to flow from the inner cavity of the fracturing tube to the atmosphere, and the threading port (19) is used for threading the cable of the electronic excitation device. The end plate (12) is provided with a ring groove on the side facing the surrounding plate (11), and a sealing ring (13) is arranged in the ring groove.

3. The upper end cap of the liquid oxygen induced fracturing pipe suitable for underwater rock mass according to claim 2, characterized in that: When the surrounding plate (11) is connected with the fracturing tube, the upper end of the fracturing tube abuts against the sealing ring (13). The end plate (12) is provided with a protective ring (14) on the side away from the surrounding plate (11), and the liquid inlet, the exhaust port and the threading port (19) are located within the protection range formed by the protective ring (14).

4. The upper end cap of the liquid oxygen induced fracturing pipe suitable for underwater rock mass according to claim 2, characterized in that: The liquid inlet is a threaded hole, a double-pass quick connector (17) is screwed on the liquid inlet, one end of the double-pass quick connector (17) located in the fracturing tube is used for communication with the infusion tube of the oxygen absorption medium, and the other end of the double-pass quick connector (17) located outside the fracturing tube is used for communication with the extension pipe.

5. The upper end cap of the liquid oxygen induced fracturing pipe suitable for underwater rock mass according to claim 2, characterized in that: The threading port (19) is a double-concave threading port (19), the diameter of the threading port (19) on the upper and lower surfaces of the end plate (12) is greater than the diameter of the threading port (19) on the middle surface of the end plate (12), and the middle surface is located between the upper surface and the lower surface of the end plate (12).

6. The upper end cap of the liquid oxygen induced fracturing pipe suitable for underwater rock mass according to claim 2, characterized in that: ​

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