Device and method for changing crustal stress and expanding capacity of oil and gas well

Abstract

The invention relates to the technical field of oil and gas wells, and discloses an oil and gas well crustal stress changing expansion device and method.The device comprises a connecting rod and a perforating bullet connected with the connecting rod, the outer side of the connecting rod is sleeved with a sealing shell, and a sealing assembly is arranged on the inner side of the sealing shell; the sealing assembly comprises a connecting disc arranged on the outer side of the connecting rod in a sleeving mode and an external expansion plate arranged on the side portion of the connecting disc in a sliding mode, and a motor used for driving the external expansion plate is installed on the outer side of the sealing shell. A motor drives a second gear to rotate, the first gear rotates through meshing of the second gear and the first gear, so that a sliding block slides in a track groove, an insertion rod drives an external expansion plate to slide outwards to abut against the inner wall of an oil well, the lower end of the oil well is sealed, and then the inner wall of the oil well is perforated through a perforating bullet; the impact force of the perforating bullets is prevented from collapsing through the wellhead of the oil well as much as possible, so that the impact force of the perforating bullets on perforation of the inner wall of the oil well is larger, large-range holes can be conveniently formed in the inner wall of the oil well, and the fracturing capacity expansion effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas wells, and in particular to a device and method for changing geostress and expanding capacity of oil and gas wells. Background Art

[0002] The geostress of oil and gas wells refers to the various stresses generated inside the earth's crust due to the existence of rocks and fluids. The geostress can be divided into three main types: 1. Horizontal geostress: usually related to the bedding, lithology and structure of the strata; 2. Vertical geostress: generated by the deadweight of the strata, usually related to the depth and density of the strata; 3. Pore pressure: this refers to the fluid pressure existing in the pores of the rock, which has an important influence on the calculation of geostress and the stability of the wellbore.

[0003] Changing the geostress expansion of oil and gas wells is mainly used to improve the production capacity and safety of oil and gas wells, and to improve the oil and gas extraction effect by adjusting the downhole geostress conditions. The following are some commonly used devices and methods: 1. Hydraulic fracturing device: By injecting high-pressure liquid (usually a mixture of water and certain additives) into the formation, cracks are formed. These cracks help to improve the fluidity of oil and gas, and are widely used in shale gas, tight oil and gas and other reservoirs; 2. Nitric acid fracturing device: Using nitric acid as a fracturing fluid, it creates cracks and increases the permeability of the reservoir through chemical reactions. It is suitable for oil and gas wells with certain specific geological conditions; 3. CO2 injection device: Injecting carbon dioxide into the formation to increase the pressure of the reservoir and reduce the viscosity of crude oil, thereby increasing the recovery rate of oil and gas; in addition, it also includes: thermal recovery devices, chemical displacement devices and wellhead control devices to ensure the safe and stable operation of oil and gas wells.

[0004] Before hydraulic fracturing, it is necessary to use oil perforating bullets to drill holes on the side walls of the oil wells. Then, hydraulic fracturing methods are used to inject high-pressure liquid into the oil wells and holes to fracture the holes. Oil perforating bullets are a tool used for oil and natural gas extraction, mainly used for drilling holes in oil wells. Their working principle is to use perforating bullets to launch high-pressure jets (usually produced by high-energy explosives) to penetrate the rock layers or tubing of the well wall so that oil and gas can flow into the wellbore. This process is a key step in oil and gas well extraction because it helps to increase the production and fluidity of the oil wells.

[0005] At present, the existing technology usually uses petroleum perforating bullets to perforate the sidewalls of oil wells, and the petroleum perforating bullets need to be placed at different heights of the oil well, so as to perforate multiple locations in the oil well to facilitate subsequent fracturing and expansion. However, the sidewalls of oil wells usually include wellbores and hard rock formations. It is difficult to form large-scale holes in the oil well by only using petroleum perforating bullets for a single perforation, which can easily affect the expansion effect. Therefore, it does not meet the existing needs. In this regard, we propose a device and method for changing the ground stress of oil and gas wells to expand the capacity. Summary of the invention

[0006] The present invention provides an apparatus and method for changing ground stress and expanding oil and gas wells, which has the beneficial effect of forming large-scale holes in the oil well, thereby improving the expansion effect, and solves the problem of the prior art mentioned in the above-mentioned background technology, that is, usually using oil perforating bullets to perforate the side wall of the oil well, and the oil perforating bullets need to be placed at different heights of the oil well, so as to perforate multiple positions in the oil well, so as to facilitate subsequent fracturing and expansion. However, the side wall of the oil well usually includes a wellbore and a hard rock formation. Only a single perforation with oil perforating bullets is used, which makes it difficult to form large-scale holes in the oil well, thereby easily affecting the expansion effect.

[0007] The present invention provides the following technical solution: a device for changing the ground stress expansion capacity of an oil and gas well, comprising a connecting rod and a perforating bullet connected to the connecting rod, the connecting rod being used to send the perforating bullet into the oil well, a sealing shell being sleeved on the outer side of the connecting rod, the sealing shell being arranged on the upper side of the perforating bullet, and a sealing assembly being arranged on the inner side of the sealing shell, the sealing assembly comprising a connecting disk sleeved on the outer side of the connecting rod, and an outward expansion plate being slidably arranged on the side of the connecting disk, the outward expansion plate intermittently abutting against the inner wall of the oil well, and a motor for driving the outward expansion plate being installed on the outer side of the sealing shell.

[0008] As an optional solution of the device for changing ground stress and expanding capacity of an oil and gas well described in the present invention, the sealing assembly also includes a sleeve rod installed on the side of the connecting plate, a plug rod slidably inserted inside the sleeve rod and connected to the external expansion plate, a sealing strip installed on the outside of the external expansion plate, a first gear rotatably sleeved on the outside of the connecting rod, a track groove opened on the side of the first gear, a slider installed on the outside of the plug rod and slidably inserted inside the track groove, and a second gear rotatably installed on the outside of the sleeve rod and meshing with the first gear, and the output shaft of the motor passes through the sealing shell and is inserted in the middle of the second gear.

[0009] As an optional solution of the device for changing ground stress and expanding capacity of an oil and gas well described in the present invention, the number of the sleeve rods is set to be several, and the several sleeve rods are evenly arranged circumferentially on the side of the connecting plate, the insertion rods are slidably inserted on the inner side of the sleeve rods, the ends of the insertion rods are installed with the outward expansion plates, the outward expansion plates are set to be arc plates, the two ends of the outward expansion plates are slidably inserted in the ends of the outward expansion plates adjacent to them, and the outward expansion plates are all on the same circular ring.

[0010] As an optional solution of the device for changing ground stress and expanding capacity of oil and gas wells described in the present invention, the first circular plate is provided on the sliding sleeve outside the connecting rod, the first circular plate is located between the perforating bullet and the sealing shell, and a first spring is provided between the first circular plate and the sealing shell, the two ends of the first spring are respectively connected to the first circular plate and the sealing shell, a punching shell is installed on the outside of the connecting rod, the punching shell is located on the upper side of the sealing shell, punching nails are slidably provided on the inside of the punching shell, the number of the punching nails is set to several, the ends of the punching nails are all installed with a first wedge block, a second wedge block is slidably provided on the inside of the punching shell, the second wedge block is used in conjunction with the first wedge block, a driving rod is installed on the outside of the second wedge block, the driving rod is slidably inserted into the sides of the punching shell and the sealing shell, and the lower end of the driving rod is connected to the first circular plate.

[0011] As an optional solution of the device for changing ground stress and expanding capacity of oil and gas wells described in the present invention, a limiting ball is installed on the inclined surface of the first wedge block, and a groove body used in conjunction with the limiting ball is opened on the inclined surface of the second wedge block, and the limiting ball is slidably inserted in the groove body of the second wedge block.

[0012] As an optional solution of the device for changing ground stress and expanding capacity of an oil and gas well described in the present invention, a shell is installed on the outside of the connecting rod, the shell is located on the lower side of the perforating bullet, a support tube is arranged on the inside of the shell, the support tube is used to be inserted into the hole punched by the perforating bullet, the number of the support tubes is set to be several, the support tubes are vertically arranged on the inside of the shell, a discharge cavity is opened at the bottom of the shell, and the lowermost support tube is located in the discharge cavity.

[0013] As an optional solution of the device for changing ground stress and expanding capacity of oil and gas wells described in the present invention, a third wedge block is slidably arranged on the inner side of the shell, the third wedge block is close to the discharge chamber, a fourth wedge block used in conjunction with the third wedge block is also arranged on the inner side of the shell, a limiting ball is also installed on the inclined surface of the third wedge block, a groove body slidably matched with the limiting ball is opened on the inclined surface of the fourth wedge block, and the limiting ball is slidably inserted in the groove body of the fourth wedge block.

[0014] As an optional solution of the device for changing ground stress and expanding capacity of oil and gas wells described in the present invention, the second circular plate is provided on the sliding sleeve outside the connecting rod, and the second circular plate is located between the perforating bullet and the shell; a push rod is installed on the upper side of the fourth wedge block, and the push rod is slidably inserted in the side of the shell, and the top of the push rod is connected to the second circular plate; a second spring is provided on the outside of the fourth wedge block, and the two ends of the second spring are respectively connected to the fourth wedge block and the inner wall of the shell.

[0015] As an optional solution of the device for changing ground stress and expanding capacity of oil and gas wells described in the present invention, a baffle is rotatably installed on the inner side of the shell, the baffle is arranged on the upper side of the discharge chamber, and the baffle is located between the two lowest support tubes, a third spring is installed on the lower side of the second circular plate, the lower end of the third spring is inserted into the side of the shell, and a lower pressure plate is installed at the bottom of the third spring, the lower pressure plate is in contact with the uppermost support tube, and the third spring is always in a compressed state.

[0016] The present invention also proposes a method for changing the geostress capacity of an oil and gas well, comprising the following specific steps: S1. Pre-drilling of the inner wall of the oil well: When the perforating bullet perforates the inner wall of the oil well, the violent impact force generated by the explosion of the explosive rapidly pushes the first circular plate upward, and the first wedge block and the second wedge block cooperate to drive the punching nail to violently impact the inner wall of the oil well, so that the punching nail penetrates into the inner wall of the oil well to form a hole, thereby pre-drilling the inner wall of the oil well, and then the punching nail retracts into the punching shell; S2. Re-perforating the inner wall of the oil well: The device is driven to move upward as a whole by the connecting rod, so that the perforations of the perforating bullet correspond to the positions of the holes pre-formed by the punching nails, so that the perforating bullets impact and perforate the holes again on this basis, expanding the diameter and depth of the holes, thereby improving the effect of the next step of fracturing and expansion, and when the perforating bullets are perforating, the punching nails also pre-perforate the upper side of the inner wall of the oil well; S3. Preventing the hole from closing: The impact force generated by the perforating bullet during perforation also drives the second circular plate to move downward. Through the coordinated use of the third wedge block and the fourth wedge block, the support tube in the shell is pushed into the hole to provide a certain support to the hole, thereby avoiding the hole from closing as much as possible and causing adverse effects on the next step of fluid injection fracturing.

[0017] The present invention has the following beneficial effects: 1. The device and method for changing the ground stress expansion capacity of the oil and gas well, the device is placed in the oil well through a connecting rod, the motor drives the second gear to rotate, and the first gear is rotated through the meshing of the second gear and the first gear, so that the slider slides in the track groove, so that the insertion rod drives the outer expansion plate to slide outward, so that the outer diameter of the ring formed by the outer expansion plate is expanded, and the sealing strip is pressed against the inner wall of the oil well, so that the lower end of the oil well is sealed; Subsequently, the perforating bullets are used to perforate the inner wall of the oil well, so as to avoid the impact force of the perforating bullets from dissipating through the wellhead of the oil well as much as possible, so that the impact force of the perforating bullets on the inner wall of the oil well is greater, which facilitates the formation of large-scale holes on the inner wall of the oil well, thereby improving the effect of subsequent fracturing and expansion.

[0018] 2. The device and method for changing the ground stress expansion capacity of the oil and gas well, when the perforating bullet perforates the inner wall of the oil well, the violent impact force generated pushes the first circular plate upward rapidly, and the first spring is compressed, and the first wedge block is driven to move upward rapidly through the driving rod, so that the punching nail is driven to violently impact the inner wall of the oil well through the cooperation of the first wedge block and the second wedge block, so that the punching nail is inserted into the inner wall of the oil well to form a hole, thereby pre-punching the inner wall of the oil well, and then under the action of the rebound force of the first spring, the punching nail is retracted into the punching shell; Subsequently, the device is driven to move upward as a whole by the connecting rod, so that the perforation bullets correspond to the positions of the holes pre-formed by the punching nails, so that the perforation bullets impact and perforate the holes again on this basis, thereby expanding the diameter and depth of the holes, and when the perforation bullets are perforating, the punching nails also pre-drill holes on the upper side of the inner wall of the oil well again; Moreover, the impact force generated when the perforating bullet shoots a hole also drives the second circular plate and the push rod to move downward. Through the coordinated use of the third wedge block and the fourth wedge block, the support tube in the discharge cavity is pushed into the above-mentioned hole by the third wedge block, providing a certain support for the hole, thereby avoiding the hole from closing as much as possible, further improving the perforating effect on the inner wall of the oil well, and further improving the effect of fracturing and expansion of the oil and gas well.

[0019] 3. The device and method for changing the ground stress expansion capacity of the oil and gas well. When the perforating bullet is used to perforate, the support tube in the discharge chamber is pushed into the hole on the inner wall of the oil well. At the same time, the rebound force of the third spring presses down the remaining support tubes, causing the blocking piece to flip, so that the support tube at the bottom passes over the blocking piece and enters the discharge chamber. When the device moves to the next perforating position, it is convenient to push the support tube into the corresponding hole again, so it is convenient to push the support tube into different holes in turn. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0021] Figure 2 For the present invention Figure 1 Enlarged structural diagram at A in the middle.

[0022] Figure 3 It is a schematic diagram of the internal three-dimensional structure of the present invention.

[0023] Figure 4 It is a schematic diagram of the three-dimensional structure of the sealing component of the present invention.

[0024] Figure 5 It is a schematic diagram of the back structure of the sealing component of the present invention.

[0025] Figure 6 It is a schematic diagram of the internal three-dimensional structure of the punching shell of the present invention.

[0026] Figure 7 It is a schematic diagram of the cross-section structure of the first wedge block of the present invention.

[0027] Figure 8 It is a schematic diagram of the internal three-dimensional structure of the shell of the present invention.

[0028] Fig. 9 It is a schematic diagram of the cutaway structure of the shell of the present invention.

[0029] In the figure: 100, connecting rod; 110, perforating bullet; 120, sealing shell; 130, sealing assembly; 131, connecting plate; 132, sleeve rod; 133, plug rod; 134, expansion plate; 135, sealing strip; 136, first gear; 137, track groove; 138, slider; 139, second gear; 140, motor; 150, first round plate; 151, first spring; 152, punching hole Shell; 153, punching nail; 154, first wedge block; 155, second wedge block; 156, driving rod; 160, limiting ball; 170, shell; 171, support tube; 172, discharge cavity; 180, third wedge block; 181, fourth wedge block; 190, second circular plate; 191, push rod; 192, second spring; 200, blocking piece; 201, third spring; 202, lower pressure piece. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Embodiment 1: This embodiment is intended to promote the solution of the existing technology, which usually uses oil perforating bullets to perforate the sidewall of the oil well, and needs to place the oil perforating bullets at different heights of the oil well, so as to perforate multiple locations in the oil well, so as to facilitate subsequent fracturing and expansion. However, the sidewall of the oil well usually includes the wellbore and hard rock formations. It is difficult to form a large range of holes in the oil well by only using oil perforating bullets for a single perforation, which easily affects the expansion effect. Please refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 A device for changing ground stress and expanding capacity of an oil and gas well includes a connecting rod 100 and a perforating bullet 110 connected to the connecting rod 100. The top of the connecting rod 100 is arranged on the outside of the oil well port. The connecting rod 100 is used to send the perforating bullet 110 into the oil well and drive the perforating bullet 110 to rise and fall in the oil well.

[0032] The structure of the perforating bullet 110 generally includes an ammunition shell filled with explosives, which is usually installed in a long tube, can be placed in a wellbore, and the explosives are detonated by electric shock, which will produce a strong impact force. During operation, the perforating bullet 110 is placed in the wellbore, and then the explosives are detonated by electrical signals or other means, thereby forming holes on the well wall. These holes allow oil and gas to flow from the formation into the wellbore for further exploitation; the perforations of the oil perforating gun are generally distributed on one or more circles of the gun body, and these perforations are usually evenly distributed to ensure the uniformity and efficiency of the perforating effect. According to different needs and designs, the perforations can be distributed on one circle or on multiple circles to adapt to different wellbore structures and formation conditions. The perforations of the perforating bullet 110 in the device are set to one circle.

[0033] A sealing shell 120 is fixedly sleeved on the outside of the connecting rod 100, and the sealing shell 120 is arranged on the upper side of the perforating bullet 110, and a sealing assembly 130 is arranged on the inside of the sealing shell 120. The sealing assembly 130 includes a connecting disk 131 fixedly sleeved on the outside of the connecting rod 100, and an outward expansion plate 134 slidably arranged on the side of the connecting disk 131, and the outward expansion plate 134 is slidably inserted into the side of the sealing shell 120, and the outward expansion plate 134 intermittently contacts the inner wall of the oil well. A wellbore can also be inserted inside the oil well, and the outward expansion plate 134 intermittently contacts the inner wall of the wellbore in the oil well, thereby sealing the oil well. A motor 140 for driving the outward expansion plate 134 is fixedly installed on the outside of the sealing shell 120.

[0034] The sealing assembly 130 also includes a sleeve rod 132 fixedly mounted on the side of the connecting disk 131, an insertion rod 133 slidably inserted into the inner side of the sleeve rod 132 and fixedly connected to the outer expansion plate 134, a sealing strip 135 installed on the outer side of the outer expansion plate 134, a first gear 136 rotatably sleeved on the outer side of the connecting rod 100 through a bearing, a track groove 137 opened on the side of the first gear 136, a slider 138 fixedly mounted on the outer side of the insertion rod 133 and slidably inserted into the inner side of the track groove 137, and a second gear 139 rotatably mounted on the outer side of the sleeve rod 132 and meshing with the first gear 136. The output shaft of the motor 140 passes through the sealing shell 120 and is interference-inserted in the middle of the second gear 139.

[0035] The sealing strips 135 are all configured as rubber strips, the number of sleeve rods 132 is set to be several, and the several sleeve rods 132 are evenly arranged on the side of the connecting plate 131 in a circumferential direction, and the inner side of the sleeve rods 132 is slidably inserted with plug rods 133, and the ends of the plug rods 133 are installed with outward expansion plates 134, which are all configured as arc plates, and the two ends of the outward expansion plates 134 are slidably inserted in the ends of the outward expansion plates 134 adjacent to them, and the outward expansion plates 134 are all on the same circular ring.

[0036] In this embodiment: the device is placed into the oil well through the connecting rod 100, the motor 140 drives the second gear 139 to rotate, and the first gear 136 is rotated by the meshing of the second gear 139 and the first gear 136, so that the slider 138 slides in the track groove 137, so that the insertion rod 133 drives the outer expansion plate 134 to slide outward, so that the outer diameter of the ring formed by the outer expansion plate 134 is expanded, and the sealing strip 135 is pressed against the inner wall of the oil well, so that the lower end of the oil well is sealed; Subsequently, the perforating bullet 110 perforates the inner wall of the oil well, and the impact force of the perforating bullet 110 is avoided as much as possible from dissipating through the wellhead of the oil well, so that the impact force of the perforating bullet 110 on the inner wall of the oil well is greater, which is convenient for forming a large range of holes on the inner wall of the oil well, thereby improving the effect of subsequent fracturing and expansion, and solving the problem of the prior art as much as possible, usually using oil perforating bullets to drill holes in the side wall of the oil well, and it is necessary to place the oil perforating bullets at different heights of the oil well, so as to drill holes in multiple positions in the oil well, so as to facilitate subsequent fracturing and expansion. However, the side wall of the oil well usually includes a wellbore and a hard rock formation. It is difficult to form a large range of holes in the oil well by only using an oil perforating bullet for a single drilling, which is easy to affect the expansion effect. After the perforation is completed, the motor 140 is reversed, so that the outer expansion plate 134 is retracted into the sealing shell 120 again, so that the device can be lifted and moved in the oil well.

[0037] Embodiment 2: This embodiment is intended to further promote the solution of the problem that the inner wall of the oil well is usually a hard rock formation, and the use of a perforating bullet 110 for a single perforation has limited damage to the rock formation, which is easy to affect the perforation effect of the inner wall of the oil well, and thus the effect of fracturing and expansion. This embodiment is an improvement made on the basis of embodiment 1. For details, please refer to Figure 1 , Figure 2 , Figure 3 , Figure 6 , Figure 7 , Figure 8 and Fig. 9A first circular plate 150 is provided on the outer side of the connecting rod 100 for sliding sleeve, and the first circular plate 150 is located between the perforating bullet 110 and the sealing shell 120, and a first spring 151 is provided between the first circular plate 150 and the sealing shell 120, and the two ends of the first spring 151 are respectively fixedly connected to the first circular plate 150 and the sealing shell 120, and a punching shell 152 is fixedly installed on the outer side of the connecting rod 100, and the punching shell 152 is located on the upper side of the sealing shell 120, and a punching nail 153 is slidably provided on the inner side of the punching shell 152, and the number of the punching nails 153 is set to be several, and the ends of the punching nails 153 are fixedly installed with a first wedge block 154, and the inside of the punching shell 152 is fixedly installed with a punching nail 153. A second wedge block 155 is provided for side sliding, and the second wedge block 155 is used in conjunction with the first wedge block 154. A driving rod 156 is fixedly installed on the lower side of the second wedge block 155. The driving rod 156 is slidably inserted into the sides of the punching shell 152 and the sealing shell 120. The lower end of the driving rod 156 is fixedly connected to the first circular plate 150. A limiting ball 160 is fixedly installed on the inclined surface of the first wedge block 154. A groove body used in conjunction with the limiting ball 160 is opened on the inclined surface of the second wedge block 155. The limiting ball 160 is slidably inserted in the groove body of the second wedge block 155 to prevent the first wedge block 154 and the second wedge block 155 from separating.

[0038] A shell 170 is fixedly installed on the outside of the connecting rod 100. The shell 170 is located at the lower side of the perforating bullet 110. A support tube 171 is placed inside the shell 170. The support tube 171 is used to be inserted into the hole punched by the perforating bullet 110. The number of support tubes 171 is set to be several. The support tubes 171 are vertically arranged on the inside of the shell 170. A discharge cavity 172 is opened at the bottom of the shell 170, and the lowermost support tube 171 is located in the discharge cavity 172.

[0039] A third wedge block 180 is slidably arranged on the inner side of the shell 170, and the third wedge block 180 is close to the discharge chamber 172. A fourth wedge block 181 used in conjunction with the third wedge block 180 is also arranged on the inner side of the shell 170. A limiting ball 160 is also installed on the inclined surface of the third wedge block 180. A groove body slidably cooperated with the limiting ball 160 is opened on the inclined surface of the fourth wedge block 181. The limiting ball 160 is slidably inserted in the groove body of the fourth wedge block 181 to prevent the third wedge block 180 and the fourth wedge block 181 from separating.

[0040] A second circular plate 190 is provided on the outer sliding sleeve of the connecting rod 100, and the second circular plate 190 is located between the perforating bullet 110 and the shell 170. A push rod 191 is fixedly installed on the upper side of the fourth wedge block 181, and the push rod 191 is slidably inserted in the side of the shell 170. The top of the push rod 191 is fixedly connected to the second circular plate 190. A second spring 192 is provided on the outer side of the fourth wedge block 181, and the two ends of the second spring 192 are respectively fixedly connected to the fourth wedge block 181 and the inner wall of the shell 170. A sealing assembly 130 can also be provided between the shell 170 and the second circular plate 190 to further improve the sealing performance in the oil well when the perforating bullet 110 perforates, thereby further improving the perforating effect.

[0041] In this embodiment: when the perforating bullet 110 perforates the inner wall of the oil well, the violent impact force generated pushes the first circular plate 150 upward rapidly, and the first spring 151 is compressed, and the first wedge block 154 is driven to move upward rapidly through the driving rod 156, so that the punching nail 153 is driven to violently impact the inner wall of the oil well through the cooperation of the first wedge block 154 and the second wedge block 155, so that the punching nail 153 is inserted into the inner wall of the oil well to form a hole, thereby pre-punching the inner wall of the oil well, and then under the action of the rebound force of the first spring 151, the punching nail 153 is retracted into the punching shell 152; Subsequently, the device is driven to move upward as a whole by the connecting rod 100, so that the perforations of the perforating bullet 110 correspond to the positions of the holes preformed by the punching nails 153, so that the perforating bullet 110 impacts and perforates the holes again on this basis, expanding the diameter and depth of the holes, and when the perforating bullet 110 is perforating, the punching nails 153 also pre-drill holes on the upper side of the inner wall of the oil well again; Moreover, the impact force generated when the perforating bullet 110 perforates also drives the second circular plate 190 and the push rod 191 to move downward. Through the coordinated use of the third wedge block 180 and the fourth wedge block 181, the support tube 171 in the discharge cavity 172 is pushed into the above-mentioned hole by the third wedge block 180, so as to provide a certain support for the hole, thereby avoiding the hole from closing as much as possible, further improving the perforating effect on the inner wall of the oil well, and further improving the effect of fracturing and expansion of the oil and gas well.

[0042] Embodiment 3: This embodiment is intended to facilitate solving the problem that it is necessary to perform multiple perforations at different heights on the inner wall of the oil well, so it is inconvenient to push the support pipe 171 into different holes in sequence. This embodiment is an improvement made on the basis of embodiment 1. For details, please refer to Figure 1 , Figure 3 , Figure 8 and Fig. 9A blocking piece 200 is rotatably installed on the inner side of the shell 170, and the blocking piece 200 can only be flipped downward. The blocking piece 200 is arranged on the upper side of the discharge chamber 172, and the blocking piece 200 is located between the two lowest support tubes 171 to support the support tubes 171 thereon. A third spring 201 is fixedly installed on the lower side of the second circular plate 190, and the lower end of the third spring 201 is plugged into the upper side of the shell 170, and a lower pressing piece 202 is fixedly installed on the bottom of the third spring 201, and the lower pressing piece 202 is in contact with the uppermost support tube 171. The third spring 201 is always in a compressed state, and the rebound force of the third spring 201 is always greater than the resistance to the flipping of the blocking piece 200.

[0043] In this embodiment: when the perforating bullet 110 perforates, the support tube 171 in the discharge chamber 172 is pushed into the hole on the inner wall of the oil well. At the same time, the rebound force of the third spring 201 presses the remaining support tube 171 downward, causing the blocking piece 200 to flip, so that the support tube 171 at the bottom passes over the blocking piece 200 and enters the discharge chamber 172. When the device moves to the next perforating position, it is convenient to push the support tube 171 into the corresponding hole again, so it is convenient to push the support tube 171 into different holes in turn.

[0044] It should be noted that during the first perforation, since there is no hole on the inner wall of the oil well corresponding to the discharge cavity 172, the support tube 171 in the discharge cavity 172 contacts the inner wall of the oil well, but this will not affect the reuse of the device.

[0045] Embodiment 4, a method for changing geostress and expanding capacity of an oil and gas well, comprising the following specific steps: S1. Pre-drilling of the inner wall of the oil well: When the perforating bullet 110 perforates the inner wall of the oil well, the violent impact force generated by the explosion of the explosive rapidly pushes the first circular plate 150 upward, and the first wedge block 154 and the second wedge block 155 cooperate to drive the punching nail 153 to violently impact the inner wall of the oil well, so that the punching nail 153 penetrates into the inner wall of the oil well to form a hole, thereby pre-drilling the inner wall of the oil well, and then the punching nail 153 retracts into the punching shell 152; S2. Re-perforating the inner wall of the oil well: The connecting rod 100 drives the device to move upward as a whole, so that the perforations of the perforating bullet 110 correspond to the positions of the holes pre-formed by the punching nails 153, so that the perforating bullet 110 perforates the holes again on this basis, expanding the diameter and depth of the holes, thereby improving the effect of the next fracturing expansion. When the perforating bullet 110 is perforating, the punching nails 153 also pre-perforate the upper side of the inner wall of the oil well again; S3. Preventing the hole from closing: The impact force generated by the perforating bullet 110 during perforation also drives the second circular plate 190 to move downward. Through the coordinated use of the third wedge block 180 and the fourth wedge block 181, the support tube 171 in the shell 170 is pushed into the above-mentioned hole through the discharge cavity 172, and the hole is supported to a certain extent, thereby avoiding the hole from closing as much as possible and causing adverse effects on the next step of injection fracturing. The support tube 171 can be evenly provided with mesh holes on the tube body to facilitate the passage of fracturing liquid and minimize the obstruction to the flow of oil.

[0046] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0047] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A device for changing ground stress and expanding capacity of an oil and gas well, comprising a connecting rod (100) and a perforating charge (110) connected to the connecting rod (100), wherein the connecting rod (100) is used to send the perforating charge (110) into the oil well, characterized in that: A sealing shell (120) is sleeved on the outside of the connecting rod (100), the sealing shell (120) is arranged on the upper side of the perforating bullet (110), and a sealing assembly (130) is arranged on the inside of the sealing shell (120), the sealing assembly (130) comprises a connecting disk (131) sleeved on the outside of the connecting rod (100), and an outward expansion plate (134) slidably arranged on the side of the connecting disk (131), the outward expansion plate (134) intermittently abuts against the inner wall of the oil well, and a motor (140) for driving the outward expansion plate (134) is installed on the outside of the sealing shell (120).

2. The device for changing geostress and expanding capacity of oil and gas wells according to claim 1, characterized in that: The sealing assembly (130) further comprises a sleeve rod (132) mounted on the side of the connecting plate (131), an insertion rod (133) slidably inserted inside the sleeve rod (132) and connected to the outer expansion plate (134), a sealing strip (135) mounted on the outer side of the outer expansion plate (134), a first gear (136) rotatably sleeved on the outer side of the connecting rod (100), a track groove (137) provided on the side of the first gear (136), a sliding block (138) mounted on the outer side of the insertion rod (133) and slidably inserted inside the track groove (137), and a second gear (139) rotatably mounted on the outer side of the sleeve rod (132) and meshing with the first gear (136), and an output shaft of the motor (140) passes through the sealing shell (120) and is inserted in the middle of the second gear (139).

3. The device for changing geostress and expanding capacity of oil and gas wells according to claim 2, characterized in that: The number of the sleeve rods (132) is set to be a plurality, and the plurality of sleeve rods (132) are uniformly arranged in a circumferential direction on the side of the connecting plate (131), the insertion rods (133) are slidably inserted into the inner side of the sleeve rods (132), the ends of the insertion rods (133) are installed with the outer expansion plates (134), the outer expansion plates (134) are set to be arc plates, the two ends of the outer expansion plates (134) are slidably inserted into the ends of the outer expansion plates (134) adjacent thereto, and the outer expansion plates (134) are all on the same circular ring.

4. The device for changing geostress and expanding capacity of oil and gas wells according to claim 1, characterized in that: A first circular plate (150) is slidably sleeved on the outer side of the connecting rod (100), the first circular plate (150) is located between the perforating bullet (110) and the sealing shell (120), and a first spring (151) is provided between the first circular plate (150) and the sealing shell (120), the two ends of the first spring (151) are respectively connected to the first circular plate (150) and the sealing shell (120), a punching shell (152) is installed on the outer side of the connecting rod (100), the punching shell (152) is located on the upper side of the sealing shell (120), and a first spring (151) is provided on the inner side of the punching shell (152). A punching pin (153) is arranged, the number of the punching pins (153) is set to be several, the end of each punching pin (153) is installed with a first wedge block (154), a second wedge block (155) is slidably arranged inside the punching shell (152), the second wedge block (155) is used in conjunction with the first wedge block (154), a driving rod (156) is installed outside the second wedge block (155), the driving rod (156) is slidably inserted into the side of the punching shell (152) and the sealing shell (120), and the lower end of the driving rod (156) is connected to the first circular plate (150).

5. The device for changing geostress and expanding capacity of oil and gas wells according to claim 4, characterized in that: A limiting ball (160) is mounted on the inclined surface of the first wedge-shaped block (154), a groove body for use with the limiting ball (160) is provided on the inclined surface of the second wedge-shaped block (155), and the limiting ball (160) is slidably inserted in the groove body of the second wedge-shaped block (155).

6. The device for changing geostress and expanding capacity of oil and gas wells according to claim 1, characterized in that: A shell (170) is installed on the outside of the connecting rod (100), and the shell (170) is located at the lower side of the perforating bullet (110). A support tube (171) is arranged on the inside of the shell (170), and the support tube (171) is used to be inserted into the hole punched by the perforating bullet (110). The number of the support tubes (171) is set to be several, and the support tubes (171) are arranged vertically on the inside of the shell (170). A discharge cavity (172) is opened at the bottom of the shell (170), and the lowest support tube (171) is located in the discharge cavity (172).

7. The device for changing geostress and expanding capacity of oil and gas wells according to claim 6, characterized in that: A third wedge block (180) is slidably disposed inside the shell (170), and the third wedge block (180) is close to the discharge cavity (172). A fourth wedge block (181) for use with the third wedge block (180) is also disposed inside the shell (170). A limiting ball (160) is also installed on the inclined surface of the third wedge block (180). A groove body slidably engaged with the limiting ball (160) is provided on the inclined surface of the fourth wedge block (181), and the limiting ball (160) is slidably inserted in the groove body of the fourth wedge block (181).

8. The device for changing geostress and expanding capacity of oil and gas wells according to claim 7, characterized in that: A second circular plate (190) is slidably sleeved on the outer side of the connecting rod (100), and the second circular plate (190) is located between the perforating bullet (110) and the shell (170). A push rod (191) is installed on the upper side of the fourth wedge block (181), and the push rod (191) is slidably inserted into the side of the shell (170). The top of the push rod (191) is connected to the second circular plate (190). A second spring (192) is arranged on the outer side of the fourth wedge block (181), and two ends of the second spring (192) are respectively connected to the fourth wedge block (181) and the inner wall of the shell (170).

9. The device for changing geostress and expanding capacity of oil and gas wells according to claim 8, characterized in that: A blocking piece (200) is rotatably mounted inside the shell (170), the blocking piece (200) being arranged on the upper side of the discharge cavity (172), and the blocking piece (200) being located between the two lowermost support tubes (171); a third spring (201) is mounted on the lower side of the second circular plate (190), the lower end of the third spring (201) being plugged into the side of the shell (170), and a lower pressing piece (202) is mounted on the bottom of the third spring (201), the lower pressing piece (202) abuts against the uppermost support tube (171), and the third spring (201) is always in a compressed state.

10. A method for changing geostress and expanding capacity of an oil and gas well, according to the device for changing geostress and expanding capacity of an oil and gas well according to any one of claims 1 to 9, characterized in that: The specific steps include: S1. Pre-drilling of the inner wall of the oil well: When the perforating bullet (110) perforates the inner wall of the oil well, the violent impact force generated by the explosion of the explosive rapidly pushes the first circular plate (150) upward, and the first wedge block (154) and the second wedge block (155) cooperate to drive the punching nail (153) to violently impact the inner wall of the oil well, so that the punching nail (153) penetrates into the inner wall of the oil well to form a hole, thereby pre-drilling the inner wall of the oil well, and then the punching nail (153) retracts into the punching shell (152); S2. Re-perforating the inner wall of the oil well: the device is driven to move upward as a whole by the connecting rod (100), so that the perforations of the perforating bullet (110) correspond to the positions of the holes pre-formed by the punching nails (153), so that the perforating bullet (110) impacts and perforates the holes again on this basis, thereby expanding the diameter and depth of the holes, thereby improving the effect of the next step of fracturing and expansion, and when the perforating bullet (110) is perforating, the punching nails (153) also pre-perforate the upper side of the inner wall of the oil well; S3. Preventing the hole from closing: The impact force generated by the perforating bullet (110) during perforation also drives the second circular plate (190) to move downward, and through the coordinated use of the third wedge block (180) and the fourth wedge block (181), the support tube (171) in the shell (170) is pushed into the hole to provide a certain support for the hole, thereby preventing the hole from closing as much as possible and causing adverse effects on the next step of hydraulic fracturing.

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