Shale gas core sampling device

Abstract

The invention discloses a shale gas core sampling device which structurally comprises a supporting top plate, a protection mechanism, a motor, a supporting gas rod and a guide ring, the protection mechanism is arranged at the top of the supporting top plate, and the motor is arranged on the upper surface of the supporting top plate. Inert gas and heat preservation gas in the inert gas box and the heat preservation gas box can be evenly conveyed and guided into the drilling barrel through the multiple flow dividing grooves, the periphery of a rock core is wrapped with the inert gas and the heat preservation gas, the protection effect on the rock core is improved, and the situation that the rock core in the drilling barrel is broken in the lifting process is prevented; by rotating the grounding pad to be matched with the screw rod at the bottom of the supporting gas rod, the height of the grounding pad can be adjusted at the bottom of the supporting gas rod, by independently adjusting the height of the four supporting gas rods, the four supporting gas rods can stably support the supporting top plate on the uneven rock stratum surface, and the stability of subsequent rock core sampling is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of shale gas, and more specifically, to a shale gas core sampling device. Background Art

[0002] Shale gas is an unconventional natural gas resource, mainly composed of methane (CH4), occurring in shale formations; shale gas is generated through complex biochemical changes and thermal cracking processes, mainly existing in the micro-nano pores of shale, with part in free state and part adsorbed on the surface of kerogen and clay particles. A core sampling device is used to drill and obtain a core as a sample. Through core sampling, the rock properties of the shale gas reservoir can be analyzed in detail. However, the existing shale gas core sampling devices have the following deficiencies in use: After the core sampling device drives the drill bit and the drill pipe into the rock formation for sampling and then lifts the core out of the rock formation, the temperature of the core inside the drill pipe becomes lower and the sealing performance decreases, which easily causes the core inside the drill pipe to crack and reduces the integrity after core sampling. Summary of the Invention

[0003] The technical solution adopted by the present invention to achieve the technical purpose is: A shale gas core sampling device, the structure of which includes a support top plate, a protection mechanism, a motor, support air rods and a guide ring. The protection mechanism is placed on the top of the support top plate, the motor is arranged on the upper surface of the support top plate, four support air rods are provided and fixedly installed at the four corners of the bottom of the support top plate. Four connecting rods are arranged at the outer end of the guide ring, and the four connecting rods are respectively connected to the lower end of a support air rod, so that the guide ring is located directly below the drilling cylinder arranged on the protection mechanism. A driven wheel is also installed on the protection mechanism, and the driven wheel is fixed on the top of the drilling cylinder. The driven wheel is driven to rotate through the driving wheel arranged at the output end of the motor and belt transmission, so that the drill bit arranged at the bottom of the drilling cylinder performs drilling work. An inert gas tank and a heat preservation gas tank are also arranged inside the upper end of the protection mechanism. The inert gas tank and the heat preservation gas tank are both connected to the conduction cavity at the upper end inside the drilling cylinder through a gas guide pipe, and the gas guide pipe is installed inside the fixed pipe arranged on the protection mechanism. The fixed pipe penetrates through the driven wheel, and the lower end of the fixed pipe is connected to the conduction cavity. The fixed pipe abuts against the ball arranged inside the driven wheel, and the inner part of the driven wheel is connected to the center of the ball through the arranged bracket. The inert gas tank and the heat preservation gas tank can simultaneously transmit inert gas and heat preservation gas into the drilling cylinder to seal and heat preserve the core drilled inside the drilling cylinder.

[0004] As a further improvement of the present invention, a buffer tube is further provided at the upper end of the interior of the drill tube, and a top plate is connected to the bottom of the buffer tube, which limits the upper end of the core sampled by the drill tube, and the outer side of the conduction cavity is through-connected with the air guide cavity provided at the upper end of the interior of the drill tube, and the air guide cavity is through-connected with the diversion groove embedded in the inner wall of the drill tube, and a plurality of the diversion grooves are provided, and are distributed in an inclined state with the inner end being low and the outer end being high.

[0005] As a further improvement of the present invention, an intercepting mechanism is also provided at the lower end of the drilling barrel, and the intercepting mechanism is composed of a conductive disk, an outer ring, a vibration guide plate and a contact end. The conductive disk is embedded in the lower end of the drilling barrel, and the conductive disk is electrically connected to the vibration guide plate arranged inside the outer ring through a wire. The outer ring is embedded in the lower end of the drilling barrel, and a contact end is arranged on the inner side of the outer ring, and the contact end is located on the inner wall of the drilling barrel, and the vibration is transmitted to the contact end through the vibration guide plate. The outer ring, the vibration guide plate and the contact end are all annular structures, and the inner width of the contact end is smaller than the outer width, which can concentrate the vibration so that the contact end can quickly break the lower end of the core.

[0006] As a further improvement of the present invention, a buffer frame is also provided at the upper end of the motor, and a spring is provided inside the edge end of the buffer frame, the lower end of the spring is connected to a support rod, and the upper end of the support rod is installed inside the edge end of the buffer frame with a clearance fit, the lower end of the support rod is fixed to the upper surface of the support top plate, and a resistance end is provided on the bottom surface of the middle part of the buffer frame, and the resistance end is against the center of the upper end of the motor, and four springs and support rods are provided, and two are in a group, which are respectively installed at the two edge ends of the buffer frame, and under the elastic support of the four springs and the support rod, the resistance end is against the center of the upper end of the motor.

[0007] As a further improvement of the present invention, a connecting head is provided at the upper end of the supporting gas rod to be fixed to the ground of the supporting top plate, and a screw is provided at the bottom of the supporting gas rod, which is connected to the internal thread of a grounding pad provided at the bottom of the supporting gas rod through the screw. An internal thread is provided on the inner side of the grounding pad, and the grounding pad is matched with the screw at the bottom of the supporting gas rod by rotating the grounding pad so that the height of the grounding pad can be adjusted at the bottom of the supporting gas rod, thereby independently adjusting the height of the four supporting gas rods.

[0008] The beneficial effects of the present invention are: 1. The gas is transmitted into the drilling tube through the inert gas box and the insulation gas box. The inert gas and insulation gas in the inert gas box and the insulation gas box can be evenly transmitted into the drilling tube through multiple diversion grooves, wrapped around the outer periphery of the core, thereby improving the protection effect of the core and preventing the core inside the drilling tube from being broken during the lifting process; 2. By rotating the grounding pad to cooperate with the screw at the bottom of the supporting gas rod, the grounding pad can be adjusted in height at the bottom of the supporting gas rod. By independently adjusting the height of the four supporting gas rods, the four supporting gas rods can stably support the supporting top plate on the uneven rock surface, thereby improving the stability of subsequent core sampling. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 The present invention is a schematic structural diagram of a shale gas core sampling device.

[0010] Figure 2 It is a three-dimensional structural schematic diagram of the protection mechanism of the present invention.

[0011] Figure 3 It is a schematic diagram of the top structure of the protection mechanism of the present invention.

[0012] Figure 4 It is a schematic diagram of the internal structure of the drilling tube of the present invention.

[0013] Figure 5 It is a schematic diagram of the three-dimensional structure of the intercepting mechanism of the present invention.

[0014] Figure 6 It is a structural schematic diagram of the buffer frame of the present invention.

[0015] Figure 7 It is a schematic diagram of the three-dimensional disassembled structure of the supporting gas rod of the present invention.

[0016] In the figure: supporting top plate-1, protection mechanism-2, driven wheel-21, bracket-211, ball-212, drilling tube-22, conduction cavity-221, buffer tube-222, top plate-223, air guide cavity-224, diversion groove-225, intercepting mechanism-226, conductive disk-2261, outer ring-2262, vibration guide plate-2263, contact end-2264, drill bit-227, inert gas box-201, insulation gas box-202, air guide tube-203, fixed tube-204, motor-3, buffer frame-31, spring-311, support rod-312, contact end-313, driving wheel-32, belt-33, supporting gas rod-4, connector-41, screw rod-42, grounding pad-43, guide ring-5, connecting rod-51. DETAILED DESCRIPTION

[0017] The present invention is further described below in conjunction with the accompanying drawings: Example

[0018] As attached Figure 1 To Attachment Figure 7 As shown: A shale gas core sampling device of the present invention, the structure of which comprises a support top plate 1, a protection mechanism 2, a motor 3, a support air rod 4 and a guide ring 5. The protection mechanism 2 is placed on the top of the support top plate 1, the motor 3 is arranged on the upper surface of the support top plate 1, four support air rods 4 are provided and fixedly installed at the four corner positions of the bottom of the support top plate 1. Four connecting rods 51 are arranged at the outer end of the guide ring 5, and the four connecting rods 51 are respectively connected to the lower end of a support air rod 4, so that the guide ring 5 is located directly below the drilling cylinder 22 arranged on the protection mechanism 2. A driven wheel 21 is also installed on the protection mechanism 2, and the driven wheel 21 is fixed at the top of the drilling cylinder 22. The driven wheel 21 is driven to rotate through the driving wheel 32 arranged at the output end of the motor 3 and the transmission of the belt 33, so that the drill bit 227 arranged at the bottom of the drilling cylinder 22 performs drilling work; An inert gas box 201 and a heat preservation gas box 202 are also arranged inside the upper end of the protection mechanism 2. Both the inert gas box 201 and the heat preservation gas box 202 are connected to the conduction cavity 221 at the upper end of the interior of the drilling cylinder 22 through a gas guide pipe 203. And the gas guide pipe 203 is installed inside the fixed pipe 204 arranged on the protection mechanism 2. The fixed pipe 204 penetrates through the interior of the driven wheel 21, and the lower end of the fixed pipe 204 is connected to the conduction cavity 221. The fixed pipe 204 abuts against the rolling balls 212 arranged inside the driven wheel 21, and the interior of the driven wheel 21 is connected to the axis of the rolling balls 212 through the arranged bracket 211. A buffer pipe 222 is also arranged at the upper end of the interior of the drilling cylinder 22, and the bottom of the buffer pipe 222 is connected to a top plate 223. The top plate 223 limits the upper end of the core sampled by the drilling cylinder 22. The outside of the conduction cavity 221 is connected to the air guide cavity 224 arranged at the upper end of the interior of the drilling cylinder 22, and the air guide cavity 224 is connected to the diversion groove 225 embedded in the inner wall of the drilling cylinder 22. An intercepting mechanism 226 is also arranged at the lower end of the drilling cylinder 22. The intercepting mechanism 226 is composed of a conductive disk 2261, an outer ring 2262, a vibration conducting plate 2263 and a contact end 2264. The conductive disk 2261 is embedded in the middle and lower part of the drilling cylinder 22, and the conductive disk 2261 is electrically connected to the vibration conducting plate 2263 arranged inside the outer ring 2262 through a wire. The outer ring 2262 is embedded in the lower end of the drilling cylinder 22. A contact end 2264 is arranged inside the outer ring 2262, and the contact end 2264 is located on the inner wall of the drilling cylinder 22. The vibration is conducted to the contact end 2264 through the vibration conducting plate 2263.

[0019] As a further improvement of the present invention, a buffer frame 31 is further provided at the upper end of the motor 3, and a spring 311 is provided inside the edge end of the buffer frame 31. The lower end of the spring 311 is connected to a support rod 312, and the upper end of the support rod 312 is installed inside the edge end of the buffer frame 31 by clearance fit. The lower end of the support rod 312 is fixed on the upper surface of the support top plate 1. A contact end 313 is provided on the bottom surface of the middle part of the buffer frame 31, and the contact end 313 abuts against the center of the upper end of the motor 3. A connection head 41 is provided at the upper end of the support air rod 4 and is fixed to the ground surface of the support top plate 1, and a screw rod 42 is provided at the bottom of the support air rod 4, and the screw rod 42 is threadedly connected to the inside of a grounding pad 43 provided at the bottom of the support air rod 4; In the present invention, the device is moved to the position of core sampling. The guiding ring 5 positions the sampling center. And before core sampling, by rotating the screw rod 42 at the bottom of the support air rod 4 and the grounding pad 43 in cooperation, the grounding pad 43 can adjust the height at the bottom of the support air rod 4. By independently adjusting the height of the four support air rods 4, the four support air rods 4 can stably support the support top plate 1 on the uneven rock formation surface, improving the stability of subsequent core sampling. Then, the motor 3 is started to drive the drilling cylinder 22 and the drill bit 227 to rotate. Then, the support air rod 4 is started to drive the support top plate 1 to descend. At this time, the drill bit 227 penetrates into the inside of the guiding ring 5 and vertically drills the core downward. When the core enters the inside of the drilling cylinder 22, then the conductive disk 2261 is started to energize the vibration guide plate 2263. At this time, the contact end 2264 can quickly break the lower end of the core, so as to intercept the core inside the rock formation. Then, the inert gas tank 201 and the heat preservation gas tank 202 are used to transmit gas into the inside of the drilling cylinder 22. Through a plurality of diversion grooves 225, the inert gas and the heat preservation gas inside the inert gas tank 201 and the heat preservation gas tank 202 can be evenly transmitted into the inside of the drilling cylinder 22 and wrapped around the outer periphery of the core, improving the protection effect on the core and preventing the core inside from breaking when the drilling cylinder 22 is lifted.

[0020] In a preferred technical solution, the inert gas tank 201 and the heat preservation gas tank 202 can simultaneously transmit inert gas and heat preservation gas into the inside of the drilling cylinder 22 to perform sealing and heat preservation work on the core drilled inside the drilling cylinder 22, avoiding the situation of cracking during the lifting of core sampling. And with the auxiliary sliding of the four balls 212, it is ensured that the fixed tube 204 can remain on the same axis as the driven wheel 21 during the rotation of the driven wheel 21 and will not collide, improving the protection effect of the fixed tube 204 on the internal air guide tube 203; A preferred technical solution is that a plurality of diversion grooves 225 are provided and are distributed in an inclined state with the inner end lower and the outer end higher. Through the plurality of diversion grooves 225, the inert gas and the heat-insulating gas inside the inert gas box 201 and the heat-insulating gas box 202 can be evenly transmitted into the drill core barrel 22 and wrapped around the outer periphery of the core, improving the protection effect on the core. A preferred technical solution is that the outer ring 2262, the vibration guide plate 2263 and the contact end 2264 are all of annular structures, and the inner width of the contact end 2264 is smaller than the outer width, which can concentrate the vibration, so that the contact end 2264 can quickly break the lower end of the core, thereby intercepting the core inside the rock formation, facilitating the lifting of the core from the rock formation, and eliminating the need for subsequent manual knocking to break the core for extraction, improving the integrity of core sampling. A preferred technical solution is that four springs 311 and four support rods 312 are provided, and two of them are in a group and are respectively installed at the two edge ends of the buffer frame 31. Under the elastic support of the four springs 311 and the support rods 312 and the abutment of the abutting end 313 against the center of the upper end of the motor 3, the damping and buffering effect of the buffer frame 31 on the rotation of the motor 3 is improved, avoiding large vibrations of the motor 3 and affecting the sampling stability of the core. A preferred technical solution is that internal threads are provided on the inner side of the grounding pad 43. By rotating the grounding pad 43 to cooperate with the screw 42 at the bottom of the support air rod 4, the height of the grounding pad 43 can be adjusted at the bottom of the support air rod 4. By independently adjusting the height of the four support air rods 4, the four support air rods 4 can stably support the support top plate 1 on the uneven rock formation surface, and the lifting of the support top plate 1 can be adjusted through the four support air rods 4. Lowering drives the drill core barrel 22 and the drill bit 227 to enter the rock formation for core drilling, thereby improving the stability during core sampling. Using the technical solution of the present invention, or those skilled in the art being inspired by the technical solution of the present invention to design similar technical solutions and achieving the above technical effects shall fall within the protection scope of the present invention.

Claims

1. A shale gas core sampling device, the structure of which comprises a support top plate (1), a protection mechanism (2), a motor (3), a support air rod (4) and a guide ring (5). The protection mechanism (2) is placed on the top of the support top plate (1), the motor (3) is arranged on the upper surface of the support top plate (1), four support air rods (4) are provided and fixedly installed at the four corner positions of the bottom of the support top plate (1), four connecting rods (51) are arranged at the outer side end of the guide ring (5), and the four connecting rods (51) are respectively connected to the lower end of a support air rod (4), so that the guide ring (5) is located directly below the drilling cylinder (22) arranged on the protection mechanism (2). It is characterized in that: A driven wheel (21) is further installed on the protection mechanism (2), and the driven wheel (21) is fixed on the top of the drilling cylinder (22). The driven wheel (21) is driven to rotate through the driving wheel (32) arranged at the output end of the motor (3) and the belt (33), so that the drill bit (227) arranged at the bottom of the drilling cylinder (22) performs drilling work; An inert gas box (201) and a heat preservation gas box (202) are further arranged inside the upper end of the protection mechanism (2). Both the inert gas box (201) and the heat preservation gas box (202) are connected to the conduction cavity (221) at the upper end inside the drilling cylinder (22) through a gas guide pipe (203). The gas guide pipe (203) is installed inside a fixed pipe (204) arranged on the protection mechanism (2). The fixed pipe (204) penetrates through the inside of the driven wheel (21), and the lower end of the fixed pipe (204) is connected to the conduction cavity (221). The fixed pipe (204) abuts against the rolling balls (212) arranged inside the driven wheel (21), and the inside of the driven wheel (21) is connected to the axis of the rolling balls (212) through a bracket (211) arranged therein.

2. The shale gas core sampling device according to claim 1, wherein: A buffer pipe (222) is further arranged at the upper end inside the drilling cylinder (22), and the bottom of the buffer pipe (222) is connected with a top plate (223). The top plate (223) limits the upper end of the core sampled by the drilling cylinder (22). The outside of the conduction cavity (221) is connected to an air guide cavity (224) arranged at the upper end inside the drilling cylinder (22), and the air guide cavity (224) is connected to a diversion groove (225) embedded in the inner wall of the drilling cylinder (22).

3. The shale gas core sampling device according to claim 2, characterized in that: An intercepting mechanism (226) is further arranged at the lower end of the drilling cylinder (22). The intercepting mechanism (226) is composed of a conductive disc (2261), an outer ring (2262), a vibration conducting plate (2263) and a contact end (2264). The conductive disc (2261) is embedded in the middle and lower part of the drilling cylinder (22), and the conductive disc (2261) is electrically connected to the vibration conducting plate (2263) arranged inside the outer ring (2262) through a wire. The outer ring (2262) is embedded in the lower end of the drilling cylinder (22), a contact end (2264) is arranged inside the outer ring (2262), and the contact end (2264) is located on the inner wall of the drilling cylinder (22). The vibration is conducted to the contact end (2264) through the vibration conducting plate (2263).

4. The shale gas core sampling device according to claim 1, wherein: A buffer frame (31) is further provided at the upper end of the motor (3), and a spring (311) is provided inside the edge end of the buffer frame (31). The lower end of the spring (311) is connected to a support rod (312), and the upper end of the support rod (312) is installed inside the edge end of the buffer frame (31) with a clearance fit. The lower end of the support rod (312) is fixed on the upper surface of the support top plate (1). A contact end (313) is provided on the bottom surface of the middle part of the buffer frame (31), and the contact end (313) abuts against the center of the upper end of the motor (3).

5. The shale gas core sampling device according to claim 1, wherein: A connecting head (41) is provided at the upper end of the support air cylinder (4) and is fixed to the ground surface of the support top plate (1). A screw rod (42) is provided at the bottom of the support air cylinder (4), and is threadedly connected to the inside of a grounding pad (43) provided at the bottom of the support air cylinder (4) through the screw rod (42).

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