A quick connector for a perforating gun

Abstract

The present application relates to the technical fields of perforating gun, especially relates to a quick connector of perforating gun, which comprises a male head of perforating gun and a female head of perforating gun, a sealing cavity is formed on the male head of perforating gun, a fluorine rubber sealing layer is arranged on the inner wall of the sealing cavity, a connecting rod is slidably sleeved in the sealing cavity and extends out of the male head of perforating gun, a connecting cavity corresponding to the connecting rod is formed on the female head of perforating gun, and a first fixing plate and a second fixing plate are abuttingly arranged on the female head of perforating gun. The fluorine rubber sealing layer is used to expand in volume under the high temperature environment in the well, the expansion force generated by the volume expansion is used to drive the connecting rod, the expansion force is transmitted to the female joint of perforating gun through the limiting plate, so that the male joint of perforating gun and the female joint of perforating gun are more tightly connected under the high temperature environment in the well.

Description

Technical Field

[0001] This invention relates to the field of perforating gun technology, and more particularly to a quick connector for a perforating gun. Background Technology

[0002] Perforating guns are critical tools in oilfield well completion operations, primarily used to create channels within the casing and cement sheath, allowing formation fluids to flow into the wellbore. In practical applications, perforating gun connectors are required to reliably connect adjacent sections of the perforating gun barrel. This method allows multiple components to be safely and securely assembled into a continuous gun string of the desired length.

[0003] Currently, the tubing connection of perforating guns mainly relies on mature threaded connection methods, whose structure includes precise male and female threads. During connection operations, operators must use specialized torque wrenches and other tools to tighten the connection in stages until a preset torque value is precisely achieved. This ensures that the connection strength and sealing meet the stringent requirements of downhole high-pressure and high-impact conditions. However, this operation is relatively slow, requires high operator skill, and is highly dependent on precise torque control. Insufficient torque may lead to loosening of the connection or failure of the seal, causing accidents, while excessive torque can easily damage the threads, also posing safety hazards. These factors, to some extent, increase the complexity of the operation and limit operational efficiency. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of complex operation and low efficiency of threaded connection in the prior art, and to propose a quick connector for a perforating gun.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A quick connector for a perforating gun includes a male perforating gun head and a female perforating gun head. The male perforating gun head has a sealing cavity, and a fluororubber sealing layer is provided on the inner wall of the sealing cavity. A connecting rod extending outside the male perforating gun head is slidably fitted in the sealing cavity. A force-bearing ring that movably abuts against the bottom end of the fluororubber sealing layer is fixedly connected to one end of the connecting rod located in the sealing cavity. A return spring is fixedly connected between the force-bearing ring and the sealing cavity.

[0007] The female head of the perforating gun has a connecting cavity corresponding to the connecting rod. A first fixing plate and a second fixing plate are mounted on the female head of the perforating gun, and a fixing part is provided between the first fixing plate and the second fixing plate.

[0008] Preferably, the male head of the perforating gun is formed by connecting two coaxial hollow cylinders with different diameters, and the connection between the two hollow cylinders is an annular concave arc-shaped slope.

[0009] Preferably, the perforating gun mother head is connected by two coaxially arranged hollow cylinders with different diameters, and the lower end of the hollow cylinder with a larger diameter is provided with an annular outer convex arc slope surface which abuts against the annular inner concave arc slope surface.

[0010] Preferably, the outer wall of the connecting rod is provided with two symmetrically arranged rectangular plates, the top end of the connecting rod is rotatably installed with a limiting plate, the limiting plate is a circular end rectangular structure, the cross-sectional shape of the connecting cavity is formed by the intersection of a rectangle and a circle, and the shape of the connecting cavity is matched with the connecting rod.

[0011] Preferably, the first fixed plate and the second fixed plate are both semicircular arc plates, and the first fixed plate and the second fixed plate are both provided with a contact cavity which movably contacts the limiting plate.

[0012] Preferably, the fixed part comprises:

[0013] a first fixed cavity and a second fixed cavity, the first fixed cavity is arranged in the first fixed plate, and the second fixed cavity is arranged in the second fixed plate;

[0014] a first heat shield and a second heat shield, the first heat shield is fixedly connected to the inner wall of the first fixed cavity, and the second heat shield is fixedly connected to the inner wall of the second fixed cavity;

[0015] a horseshoe-shaped magnet, which is fixedly installed in the first heat shield;

[0016] a heating ring, which is fixedly installed in the second heat shield;

[0017] a thermal expansion dismounting ring, which is fixedly installed on the heating ring.

[0018] Preferably, the end of the horseshoe-shaped magnet close to the thermal expansion dismounting ring is composed of a samarium-cobalt magnet layer, a rubber magnet layer and a neodymium-iron-boron magnet layer, the samarium-cobalt magnet layer is a working surface, the rubber magnet layer is an intermediate layer, and the neodymium-iron-boron magnet layer is a base layer.

[0019] Preferably, the outermost ring of the thermal expansion dismounting ring is a magnetic steel ring, the middle ring of the thermal expansion dismounting ring is a yin steel ring, and the innermost ring of the thermal expansion dismounting ring is an aluminum alloy ring.

[0020] Preferably, the interface of the yin steel ring and the interface of the aluminum alloy ring are sprayed with a Ni-Al intermetallic compound transition layer, and the interface of the yin steel ring is provided with a wavy undulating structure which is perpendicular to the radial displacement caused by thermal expansion.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] 1. This invention utilizes the characteristic of the fluororubber sealing layer to expand in volume under high-temperature conditions downhole. The expansion force generated by the expansion drives the connecting rod, which transmits the expansion force to the perforating gun female connector via the limiting plate, thereby enabling a tighter connection between the perforating gun male connector and the perforating gun female connector in high-temperature conditions downhole.

[0023] 2. The present invention covers the upper end of the perforation gun female head with the first fixing plate and the second fixing plate, so that the perforation gun male head and the perforation gun female head are assembled into a cylindrical structure. The smooth cylindrical surface has no stress concentration points. When subjected to complex downhole loads, the cylindrical cross section can distribute stress more evenly, reducing the risk of yielding or fatigue failure caused by excessive local stress, which helps to extend the service life of the perforation gun connector. Furthermore, the first fixing plate and the second fixing plate limit the angle of the limiting plate, which further improves the connection stability of the perforation gun male head and the perforation gun female head.

[0024] 3. The present invention uses a horseshoe magnet to achieve magnetic connection and fixation between the first fixing piece and the second fixing piece, and utilizes the thermal expansion of the aluminum alloy ring of the disassembly ring to achieve rapid disassembly between the first fixing piece and the second fixing piece. Attached Figure Description

[0025] Figure 1 This is a three-dimensional structural diagram of a quick-connect head for a perforating gun proposed in this invention;

[0026] Figure 2 For the present invention Figure 1 The proposed explosion diagram;

[0027] Figure 3 This is a schematic diagram of the male head structure of the perforating gun proposed in this invention;

[0028] Figure 4 For the present invention Figure 3 A cross-sectional view obtained by cutting along half of the sealed cavity;

[0029] Figure 5 For the present invention Figure 4 A schematic diagram of the proposed A-part enlarged structure;

[0030] Figure 6 This is a schematic diagram of the perforation gun head structure proposed in this invention;

[0031] Figure 7 For the present invention Figure 6 The proposed bottom view;

[0032] Figure 8 This is a schematic diagram of the connection structure between the first fixing plate and the second fixing plate proposed in this invention;

[0033] Figure 9 For the present invention Figure 8The proposed view from above;

[0034] Figure 10 For the present invention Figure 8 The proposed section view along one half of the first fixed cavity and the second fixed cavity;

[0035] Figure 11 For the present invention Figure 10 The proposed B local enlarged structure schematic diagram;

[0036] Figure 12 The proposed schematic diagram of the thermal expansion disassembly ring structure for the present invention.

[0037] In the figure: 1, perforating gun male head; 2, perforating gun female head; 3, sealing cavity; 4, fluororubber sealing layer; 5, connecting rod; 6, force ring; 7, reset spring; 8, connecting cavity; 9, first fixed plate; 10, second fixed plate; 11, rectangular plate; 12, limiting plate; 13, abutting cavity; 14, first fixed cavity; 15, second fixed cavity; 16, first heat shield; 17, second heat shield; 18, horseshoe magnet; 19, heating ring; 20, thermal expansion disassembly ring. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be apparently and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0039] With reference to Figures 1-11 A perforating gun quick connector, comprising a perforating gun male head 1 and a perforating gun female head 2, the perforating gun male head 1 is connected by two coaxial hollow cylinders with different diameters, the connecting part of the two hollow cylinders is an annular concave arc slope surface, the perforating gun female head 2 is connected by two coaxial hollow cylinders with different diameters, the lower end of the hollow cylinder with larger diameter is provided with an annular convex arc slope surface abutting against the annular concave arc slope surface, the curvatures of the annular concave arc slope surface and the annular convex arc slope surface are matched, the annular concave arc slope surface and the annular convex arc slope surface can generate high local contact pressure, effectively block the leakage path, and the curved surface design allows a certain degree of self-centering, compensates for the shaft deflection or thermal deformation, reduces the leakage caused by misalignment, and the temperature rise generated in the downhole environment is non-uniform, which can cause thermal expansion of the annular concave arc slope surface and the annular convex arc slope surface, but the annular concave arc slope surface and the annular convex arc slope surface can compensate for the displacement through the contact band migration, and the converging gap structure generated by the curved surface contact of the annular concave arc slope surface and the annular convex arc slope surface has a damping effect on vibration, further improving the adaptability of the perforating gun male head 1 and the perforating gun female head 2 to the downhole environment.

[0040] The sealing cavity 3 is arranged on the perforating gun male head 1, and a fluororubber sealing layer 4 is arranged on the inner wall of the sealing cavity 3. Since the perforating gun is used in the downhole, the downhole environment is different from the ground environment, and the downhole environment is generally a high-temperature and high-pressure environment. The fluororubber will reversibly physically expand under such conditions. The volume slightly increases when the temperature rises, and the volume will return after the temperature decreases. Therefore, the fluororubber sealing layer 4 is reusable.

[0041] The connecting rod 5 is sleeved in the sealing cavity 3 and extends out of the perforating gun male head 1. The outer wall of the connecting rod 5 is provided with two symmetrical rectangular plates 11. The top end of the connecting rod 5 is rotatably provided with a limiting plate 12 in a circular end rectangular structure. The perforating gun female head 2 is provided with a connecting cavity 8 corresponding to the connecting rod 5. The shape of the connecting cavity 8 is matched with the connecting rod 5. The cross-sectional shape of the connecting cavity 8 is formed by the intersection of a rectangle and a circle. One end of the connecting rod 5 located in the sealing cavity 3 is fixedly connected with a stress ring 6 movably abutting the bottom end of the fluororubber sealing layer 4. It should be noted that when the perforating gun male head 1 and the perforating gun female head 2 are in a connected state, the end of the rectangular plate 11 away from the stress ring 6 is in the same horizontal plane as the end of the connecting cavity 8 away from the stress ring 6. At this time, the side of the limiting plate 12 close to the connecting cavity 8 movably abuts the perforating gun female head 2. The stress ring 6 and the sealing cavity 3 are fixedly connected with a return spring 7. When the stress ring 6 is not affected by external force, the return spring 7 can be used to reset. When the perforating gun enters the downhole environment, the fluororubber sealing layer 4 will physically expand due to the downhole environmental factors. At this time, the fluororubber sealing layer 4 will apply a force to the connecting rod 5 in the direction of the stress ring 6 through the stress ring 6. The force will be transmitted to the perforating gun female head 2 through the limiting plate 12 on the connecting rod 5, so as to improve the tightness when the perforating gun male head 1 and the perforating gun female head 2 are connected.

[0042] The first fixed sheet 9 and the second fixed sheet 10 are arranged on the perforating gun female head 2 in abutment, and the first fixed sheet 9 and the second fixed sheet 10 are both semicircular arc sheets. When the first fixed sheet 9 and the second fixed sheet 10 are arranged on the perforating gun female head 2, the perforating gun male head 1, the perforating gun female head 2, the first fixed sheet 9 and the second fixed sheet 10 form a cylindrical structure, which can guarantee uniform stress distribution, so that the perforating gun joint can better bear the complex high pressure, axial load and torsional load in the well, and help to reduce the failure risk caused by stress concentration. The first fixed sheet 9 and the second fixed sheet 10 are both provided with an abutment cavity 13 in abutment with the limiting plate 12, so as to limit the rotation angle of the limiting plate 12, so that the cross-sectional center line of the limiting plate 12 intersects with the cross-sectional center line of the connecting cavity 8 at this time, so that the limiting plate 12 cannot complete the disassembly operation of the connecting rod 5 by simply plugging at this time, and further guarantee the stability of the perforating gun male head 1 and the perforating gun female head 2 when connected. The first fixed sheet 9 and the second fixed sheet 10 are provided with a fixed part, and the fixed part includes a first fixed cavity 14, a second fixed cavity 15, a first heat shield 16, a second heat shield 17, a horseshoe-shaped magnet 18, a heating ring 19 and a thermal expansion disassembly ring 20. The components are arranged as follows:

[0043] The first fixed cavity 14 is arranged in the first fixed sheet 9, the second fixed cavity 15 is arranged in the second fixed sheet 10, the first heat shield 16 is fixedly connected to the inner wall of the first fixed cavity 14, and the second heat shield 17 is fixedly connected to the inner wall of the second fixed cavity 15. The heat insulation characteristics of the first heat shield 16 and the second heat shield 17 protect the horseshoe-shaped magnet 18, the heating ring 19 and the thermal expansion disassembly ring 20 from the influence of the downhole environment temperature;

[0044] The horse-shoe magnet 18 is fixedly installed in the first heat shield 16, and the horse-shoe magnet 18 is composed of a samarium-cobalt magnet layer, a rubber magnet layer and a neodymium-iron-boron magnet layer near one end of the thermal expansion dismounting ring 20, the samarium-cobalt magnet layer is a working surface, the rubber magnet layer is an intermediate layer, and the neodymium-iron-boron magnet layer is a base layer, two magnetic poles of the horse-shoe magnet 18 are close to each other to form a natural “magnetic circuit”, when it is adsorbed on a ferromagnetic material, the magnetic force line can be shorter and more effective to come out from the N pole, pass through the adsorbed object, and return to the S pole, which greatly reduces the leakage of the magnetic force line in the air, thereby generating a very concentrated and powerful local magnetic field at the magnetic pole gap, significantly improving the adsorption force, the use of the samarium-cobalt magnet layer ensures the stability of the magnetic performance of the magnet in a high-temperature environment, although the rubber magnet layer itself has a low magnetic energy product, but it usually has better flexibility and thermal shock resistance than sintered magnets at high temperatures, by taking the rubber magnet layer as an intermediate layer, on the one hand, it can provide a certain heat insulation buffer to reduce the rapid conduction of heat to the internal neodymium-iron-boron magnet layer, on the other hand, it can absorb the stress generated between different material layers due to the difference in thermal expansion coefficient in a high-temperature environment, prevent the brittle samarium-cobalt magnet layer or the neodymium-iron-boron magnet layer from cracking or peeling due to thermal stress, and improve the thermal mechanical reliability of the overall structure, at the same time, the neodymium-iron-boron magnet layer is far away from the high-temperature position, thereby providing a powerful basic magnetic force, which helps to control the production cost of the horse-shoe magnet 18;

[0045] The heating ring 19 is fixedly installed in the second heat shield 17, and it is necessary to note that the heating ring 19 adopts a remote control heating technology to reduce the operation difficulty of the fixed part;

[0046] The thermal expansion dismounting ring 20 is fixedly installed on the heating ring 19, the outermost circle of the thermal expansion dismounting ring 20 is a magnetic steel ring, the magnetic steel ring adopts samarium-cobalt magnetic steel, the low thermal expansion characteristic of the samarium-cobalt magnetic steel is used to keep the shape stable, and thermal deformation is avoided to damage the magnetic circuit, the middle circle of the thermal expansion dismounting ring 20 is an invar ring, and the innermost circle of the thermal expansion dismounting ring 20 is an aluminum alloy ring, the invar ring is used to block the expansion force of the aluminum alloy ring from transmitting outward, the size of the outermost magnetic steel ring is almost unchanged, interlayer shear stress is absorbed, direct contact between the magnetic steel and the aluminum alloy at high temperature is avoided to cause cracking, the aluminum alloy ring generates a great radial expansion force after being heated, the horseshoe-shaped magnet 18 is driven away from the magnetic steel ring, and the interference fit is released, a Ni-Al intermetallic compound transition layer is sprayed on the interface between the invar ring and the aluminum alloy ring, the interface of the invar ring is provided with a wave-shaped undulating structure perpendicular to the radial displacement caused by thermal expansion, the Ni-Al intermetallic compound transition layer buffers the interface stress through a gradient thermal expansion coefficient, and meanwhile, the wave structure absorbs the radial displacement generated by the aluminum alloy ring after being heated through elastic deformation, the safe resolution of the thermal expansion difference under an extreme temperature difference is realized, when the thermal expansion dismounting ring 20 is heated, the high expansion characteristic of the aluminum alloy ring drives the radial expansion of the aluminum alloy ring, at this time, the wave peaks and wave troughs of the wave-shaped invar ring are elastically deformed, the linear expansion displacement of the aluminum alloy ring is converted into the bending strain energy of the wave structure, and the Ni-Al intermetallic compound transition layer gradually transitions the deformation difference between the aluminum alloy and the invar by virtue of the thermal expansion coefficient therebetween, the interface shear crack initiation is inhibited, and finally, the complete absorption of the radial expansion displacement and stress dissipation are realized under the condition of zero plastic deformation.

[0047] The application can be described by the following operation modes to illustrate the functional principle:

[0048] The perforating gun female head 2 is inserted on the perforating gun male head 1, the connecting rod 5 enters the connecting cavity 8, the limiting plate 12 is rotated to make the limiting plate 12 angularly deflect, the first fixed sheet 9 and the second fixed sheet 10 are on the perforating gun female head 2, the abutting cavity 13 abuts against the limiting plate 12, at this time, the first heat shield 16 enters the second fixed cavity 15, and the first heat shield 16 abuts against the second heat shield 17, the first heat shield 16 drives the horseshoe-shaped magnet 18 and the thermal expansion dismounting ring 20 to abut against each other, so that the magnetic force fixation between the first fixed sheet 9 and the second fixed sheet 10 is realized;

[0049] When the perforating gun enters the downhole operation, the temperature of the downhole environment is greatly improved relative to the temperature of the ground environment, the fluorine rubber sealing layer 4 expands in the high-temperature environment, so as to exert a force on the force ring 6 in the direction of the perforating gun male head 1, the force ring 6 drives the limiting plate 12 to move in the direction of the perforating gun male head 1 through the connecting rod 5, so as to exert a force on the perforating gun female head 2 in the direction of the perforating gun male head 1 through the limiting plate 12, and the connection between the perforating gun female head 2 and the perforating gun male head 1 is more close.

[0050] The above description is only the preferred embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can make equivalent replacements or changes according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A quick connector for perforating gun, comprising a male connector (1) and a female connector (2), characterized in that, The sealing cavity (3) is provided on the perforating gun male head (1), a fluororubber sealing layer (4) is arranged on the inner wall of the sealing cavity (3), a connecting rod (5) is slidably sleeved in the sealing cavity (3) and extends out of the perforating gun male head (1), one end of the connecting rod (5) located in the sealing cavity (3) is fixedly connected with a stress ring (6) which is movably abutted with the bottom end of the fluororubber sealing layer (4), and a return spring (7) is fixedly connected between the stress ring (6) and the sealing cavity (3). The perforating gun female head (2) is provided with a connecting cavity (8) corresponding to the connecting rod (5), the perforating gun female head (2) is provided with a first fixed plate (9) and a second fixed plate (10) which are abutted and installed, a fixed part is arranged between the first fixed plate (9) and the second fixed plate (10), the outer wall of the connecting rod (5) is provided with two symmetrically arranged rectangular plates (11), the top end of the connecting rod (5) is rotatably provided with a limiting plate (12), the limiting plate (12) is a circular end rectangular structure, the cross-sectional shape of the connecting cavity (8) is formed by the intersection of a rectangle and a circle, and the shape of the connecting cavity (8) is matched with the connecting rod (5).

2. The quick connect head for a perforating gun of claim 1, wherein, The perforating gun male head (1) is connected by two coaxially arranged hollow cylinders with different diameters, and the connecting part of the two hollow cylinders is an annular concave arc slope.

3. A quick connect for a perforating gun as defined in claim 2, wherein, The perforating gun female head (2) is connected by two coaxially arranged hollow cylinders with different diameters, and the lower end of the hollow cylinder with a larger diameter is provided with an annular convex arc slope which is abutted with the annular concave arc slope.

4. The quick connect of claim 1, wherein, The first fixed plate (9) and the second fixed plate (10) are both semicircular arc plates, and the first fixed plate (9) and the second fixed plate (10) are both provided with an abutting cavity (13) which is movably abutted with the limiting plate (12).

5. The quick connect of claim 1, wherein, The fixed part comprises: A first fixed cavity (14) and a second fixed cavity (15), the first fixed cavity (14) is arranged in the first fixed plate (9), and the second fixed cavity (15) is arranged in the second fixed plate (10); A first heat shield (16) and a second heat shield (17), the first heat shield (16) is fixedly connected to the inner wall of the first fixed cavity (14), and the second heat shield (17) is fixedly connected to the inner wall of the second fixed cavity (15); A horseshoe-shaped magnet (18) is fixedly installed in the first heat shield (16); A heating ring (19) is fixedly installed in the second heat shield (17); A thermal expansion dismounting ring (20) is fixedly installed on the heating ring (19).

6. A quick connect for a perforating gun as defined in claim 5, wherein, The end of the horseshoe-shaped magnet (18) close to the thermal expansion dismounting ring (20) is composed of a samarium-cobalt magnet layer, a rubber magnet layer and a neodymium-iron-boron magnet layer, the samarium-cobalt magnet layer is a working surface, the rubber magnet layer is an intermediate layer, and the neodymium-iron-boron magnet layer is a base layer.

7. A quick connect for a perforating gun as defined in claim 5, wherein, The outermost ring of the thermal expansion dismounting ring (20) is a magnetic steel ring, the middle ring of the thermal expansion dismounting ring (20) is an invar ring, and the innermost ring of the thermal expansion dismounting ring (20) is an aluminum alloy ring.

8. The quick connect of claim 7, wherein, The interface of the invar ring and the interface of the aluminum alloy ring are sprayed with a Ni-Al intermetallic compound transition layer, and the interface of the invar ring is provided with a wavy undulating structure perpendicular to the radial displacement caused by thermal expansion.

Images