Rock core pressure-maintaining sampling device for geological exploration

Abstract

The utility model provides a rock core pressure-maintaining sampling device for geological exploration, which comprises an outer sleeve, a rotary drill bit, a central channel, a pressure-maintaining cavity, a vacuum cavity and a pressurizing cavity, the rotary drill bit is arranged at the bottom of the outer sleeve, the central channel extends from the center of the rotary drill bit to the inside of the outer sleeve, and the vacuum cavity is arranged in the pressure-maintaining cavity. The pressure maintaining cavity is arranged in a space formed by the outer side of the center channel and the inner side of the outer sleeve in a sleeved mode, the vacuum cavity is arranged above the pressure maintaining cavity, the pressurizing cavity is arranged above the vacuum cavity, and a passing air channel is arranged between the pressurizing cavity and the vacuum cavity. The sampled rock core can keep the original oil-gas pressure state in a pressure compensation manner, so that the physical property of the rock core is prevented from being changed.

Description

A core pressure-maintaining sampling device for geological exploration Technical Field

[0001] This utility model belongs to the field of geological exploration, specifically relating to a core pressure-maintaining sampling device for geological exploration. Background Technology

[0002] In order to obtain core samples from downhole for the analysis and research of shale gas reservoirs and coalbed methane reservoirs in the formation, core samples are drilled at certain strata using core-taking tools. During the drilling process, due to the decrease in pressure, the fluidity of oil, gas and water in the core increases, and gas is released from the voids in the core. The physical properties of the core also change, which affects the decision-making of subsequent analysis and research. Therefore, there is an urgent need in this field for a core sampling device that can maintain pressure. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] In view of the above-mentioned technical problems, this utility model provides a core pressure-maintaining sampling device for geological exploration, which maintains the original oil and gas pressure state of the sampled core through pressure compensation, thereby avoiding changes in the physical properties of the core.

[0005] (II) Technical Solution

[0006] This utility model provides a core pressure-maintaining sampling device for geological exploration, including an outer sleeve, a rotary drill bit, a central channel, a pressure-maintaining chamber, a vacuum chamber, and a pressurizing chamber. The rotary drill bit is located at the bottom of the outer sleeve, the central channel extends from the center of the rotary drill bit into the outer sleeve, the pressure-maintaining chamber is fitted within the space formed by the outer side of the central channel and the inner side of the outer sleeve, the vacuum chamber is located above the pressure-maintaining chamber, the pressurizing chamber is located above the vacuum chamber, and an air passage is provided between the pressurizing chamber and the vacuum chamber.

[0007] In some embodiments of this utility model, the bottom diameter of the rotary drill bit is larger than the diameter of the outer sleeve, the rotary drill bit is provided with a rock-walking channel inside, the rock-walking channel is connected to the central channel, and when the rotary drill bit rotates, the rock core enters the interior of the central channel through the rock-walking channel. The outer surface of the central channel and the inner surface of the outer sleeve are both provided with rotary threads.

[0008] In some embodiments of this utility model, the pressure-holding cavity includes a rotating annular portion, a channel fitting portion, and a sealing portion. The rotating annular portion is hollow cylindrical and rotates on a rotating thread on the inner surface of the outer sleeve to achieve vertical displacement. The channel fitting portion extends upward from the bottom end of the rotating annular portion and is connected to the central channel via a rotating thread. The sealing portion has a right-angled triangular vertical section and is arranged around the top end of the channel fitting portion.

[0009] In some embodiments of this utility model, the top of the rotating ring portion is provided with a sealing device and a one-way pressure control valve. The sealing device includes a telescopic rotary motor, a rotary telescopic rod, and a sealing head. The rotary telescopic motor is fixedly installed on the top of the rotating ring portion. The rotary telescopic rod extends downward from the output end of the rotary telescopic motor into the interior of the rotating ring portion. The sealing head is fixedly installed on the bottom end of the rotary telescopic rod. The sealing head and the sealing portion are connected by a rotary thread, and the sealing head and the sealing portion are matched.

[0010] In some embodiments of this utility model, multiple one-way pressure control valves are provided, and the one-way pressure control valves are arranged around the outer ring of the sealing device. Each one-way pressure control valve includes an air inlet, an elastic closing balloon, a transverse support plate, and a tension spring. The air inlet passes through the top of the rotating ring portion, and the bottom of the air inlet is arc-shaped. The elastic closing balloon is located at the bottom of the air inlet and is fixedly installed on the transverse support plate. One end of the tension spring is located on the transverse support plates on the left and right sides of the elastic closing balloon, and the other end of the tension spring is fixedly installed on the inner surface of the top of the rotating ring portion.

[0011] In some embodiments of this utility model, an air inlet channel is provided on the right side of the outer sleeve. The air inlet channel extends downward from the inside of the pressurizing chamber to the outer sleeve above the rotary drill bit and extends outward. The pressurizing chamber is provided with a support frame, a bidirectional suction pressurizer, and a shut-off valve. The support frame is fixedly installed inside the pressurizing chamber, and the bidirectional suction pressurizer is fixedly installed on the support frame. The two ends of the bidirectional suction pressurizer are respectively connected to the air passage and the air inlet channel. The shut-off valve is located at the connection between the air inlet channel, the air passage and the bidirectional suction pressurizer.

[0012] In some embodiments of this utility model, pressure monitoring devices are provided inside the pressure holding chamber and on the outer wall of the outer sleeve, and the pressure monitoring devices are electrically connected to the bidirectional suction and pressurization machine.

[0013] (III) Beneficial Effects

[0014] As can be seen from the above technical solution, this utility model has the following beneficial effects:

[0015] (1) In this utility model, the outer sleeve rotates to drive the rotary drill bit to rotate. During the rotation of the rotary drill bit, it goes deeper into the ground. The core falls into the pressure-holding chamber through the central channel. When the core sampling amount reaches the preset weight, the telescopic rotary motor controls the sealing head and sealing part to rotate and close through the rotating telescopic rod. At this time, the pressure-holding chamber becomes a sealed space. The pressure monitoring device set inside the pressure-holding chamber and on the outer wall of the outer sleeve monitors the pressure difference between the two. When the underground pressure is greater than the pressure inside the pressure-holding chamber, the bidirectional pumping pressurizer pressurizes the underground gas through the air inlet channel and sends it into the vacuum chamber through the air passage. The pressurized underground gas enters the pressure-holding chamber through the one-way pressure control valve. When the pressure inside the pressure-holding chamber is the same as the underground pressure, the bidirectional pumping pressurizer reverses the operation and discharges the gas inside the vacuum chamber into the ground through the air passage and the air inlet channel. This utility model enables the sampled core to maintain the original oil and gas pressure state through pressure compensation.

[0016] (2) In this invention, when the gas inside the vacuum chamber enters the pressure-holding chamber through the one-way pressure control valve, the air-closing valve of the air passage closes, and the pressure-holding chamber rotates upward within the rotating outer sleeve. The gas inside the vacuum chamber is compressed by the pressure-holding chamber, and the pressure increases. The gas with increased pressure then enters the pressure-holding chamber through the one-way pressure control valve. When the pressure inside the pressure-holding chamber is the same as the underground pressure, the bidirectional pumping and pressurizing machine reverses its operation, and the pressure-holding chamber rotates in the opposite direction and moves downward within the outer sleeve. The gas inside the vacuum chamber stops entering the pressure-holding chamber. This invention increases the air intake speed of the pressure-holding chamber by compressing the gas inside the vacuum chamber, thus effectively improving the pressure compensation efficiency of the pressure-holding chamber. Attached Figure Description

[0017] Figure 1 is a schematic diagram of the structure of this utility model.

[0018] Figure 2 is a schematic diagram of the pressure holding chamber and the central channel structure.

[0019] Figure 3 is a schematic diagram of the one-way pressure control valve.

[0020] [Explanation of symbols for main components of this utility model]

[0021] 1. Outer sleeve; 2. Rotary drill bit; 3. Center channel;

[0022] 4. Pressure holding chamber; 5. Vacuum chamber; 6. Pressurization chamber;

[0023] 7. Air inlet channel; 8. Support frame; 9. Two-way air extraction and pressurization unit;

[0024] 10. Air passage; 4-1. Rotating annular part; 4-2. Channel fitting part;

[0025] 4-3. Sealed section; 4-4. One-way pressure control valve; 4-5. Telescopic rotary motor; 4-6. Rotary telescopic rod; 4-7. Sealing head; 4-41. Air intake duct;

[0026] 4-42. Elastic closing balloon; 4-43. Horizontal support plate; 4-44. Tension spring. Detailed Implementation

[0027] This utility model provides a core pressure-maintaining sampling device for geological exploration. To make the purpose, technical solution and advantages of this utility model clearer, the following describes this utility model in further detail with reference to specific embodiments and accompanying drawings.

[0028]

[0029] As shown in Figures 1-3, this utility model provides a core pressure-maintaining sampling device for geological exploration, including an outer sleeve 1, a rotary drill bit 2, a central channel 3, a pressure-maintaining chamber 4, a vacuum chamber 5, and a pressurizing chamber 6. The rotary drill bit 2 is located at the bottom of the outer sleeve 1. The central channel 3 extends from the center of the rotary drill bit 2 into the outer sleeve 1. The bottom diameter of the rotary drill bit 2 is larger than the diameter of the outer sleeve 1. A rock-walking channel is provided inside the rotary drill bit 2, which is connected to the central channel 3. When the rotary drill bit 2 rotates, the core sample enters the central channel 3 through the rock-walking channel. Rotary threads are provided on both the outer surface of the central channel 3 and the inner surface of the outer sleeve 1. The pressure-maintaining chamber 4 is sleeved on the outer side of the central channel 3 and the outer side of the outer sleeve 1. Within the space formed inside the sleeve 1, the pressure-holding chamber 4 includes a rotating annular portion 4-1, a channel fitting portion 4-2, and a sealing portion 4-3. The rotating annular portion 4-1 is a hollow cylinder and rotates on a rotating thread on the inner surface of the outer sleeve 1 to achieve vertical displacement. The channel fitting portion 4-2 extends upward from the bottom end of the rotating annular portion 4-1 and is connected to the central channel 3 via a rotating thread. The sealing portion 4-3 has a right-angled triangular cross-section and is arranged around the top end of the channel fitting portion 4-2. The top 4-1 of the rotating annular portion is provided with a sealing device and a one-way pressure control valve 4-4. The sealing device includes a telescopic rotating mechanism. The system includes a motor 4-5, a rotating telescopic rod 4-6, and a sealing head 4-7. The rotating telescopic motor 4-5 is fixedly installed on the top of the rotating ring part 4-1. The rotating telescopic rod 4-6 extends downward from the output end of the rotating telescopic motor 4-5 into the interior of the rotating ring part 4-1. The sealing head 4-7 is fixedly installed on the bottom end of the rotating telescopic rod 4-6. The sealing head 4-7 is connected to the sealing part 4-3 by a rotating thread, and the sealing head 4-7 matches the sealing part 4-3. The pressure holding chamber 4 can be rotated by a rotating magnetic ring sleeved outside the outer sleeve 1, or it can be rotated inside the vacuum chamber 5 by a rotating motor. Multiple one-way pressure control valves 4-4 are provided. A pressure valve 4-4 is arranged around the outer ring of the sealing device. The one-way pressure control valve 4-4 includes an air inlet 4-41, an elastic closing balloon 4-42, a transverse support plate 4-43, and a tension spring 4-44. The air inlet 4-41 passes through the top of the rotating ring 4-1, and the bottom of the air inlet 4-41 is arc-shaped. The elastic closing balloon 4-42 is located at the bottom of the air inlet 4-41 and is fixedly installed on the transverse support plate 4-43. One end of the tension spring 4-44 is located on the transverse support plates 4-43 on the left and right sides of the elastic closing balloon 4-42, and the other end of the tension spring 4-44 is fixedly installed on the inner surface of the top of the rotating ring 4-1.

[0030] The vacuum chamber 5 is located above the pressure holding chamber 4, and the pressurizing chamber 6 is located above the vacuum chamber 5. An air passage 10 is provided between the pressurizing chamber 6 and the vacuum chamber 5. An air inlet channel 7 is provided on the right side of the outer sleeve 1. The air inlet channel 7 extends downward from the inside of the pressurizing chamber 6 to the outer sleeve 1 above the rotary drill bit 2 and extends outward. The pressurizing chamber 6 is equipped with a support frame 8, a bidirectional suction pressurizer 9, and a shut-off valve. The support frame 8 is fixedly installed inside the pressurizing chamber 6, and the bidirectional suction pressurizer 9 is fixedly installed on the support frame 8. The two ends of the bidirectional suction pressurizer 9 are respectively connected to the air passage 10 and the air inlet channel 7. The shut-off valve is located at the connection between the air inlet channel 7, the air passage 10, and the bidirectional suction pressurizer 9. Pressure monitoring devices are provided inside the pressure holding chamber 4 and on the outer wall of the outer sleeve 1. The pressure monitoring devices are electrically connected to the bidirectional suction pressurizer 9.

[0031] This concludes the detailed description of the embodiment with reference to the accompanying drawings. Based on the above description, those skilled in the art should have a clear understanding of the present invention.

[0032] It should be noted that implementations not shown or described in the accompanying drawings or the main text of the specification are all forms known to those skilled in the art and are not described in detail. Furthermore, the definitions of the elements and methods described above are not limited to the various specific structures, shapes, or methods mentioned in the embodiments.

[0033] It should also be noted that this document provides examples of parameters containing specific values, but these parameters need not be exactly equal to the corresponding values, but can approximate the corresponding values ​​within acceptable error tolerances or design constraints. Directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the accompanying drawings and are not intended to limit the scope of protection of this utility model. Furthermore, unless specifically described or steps must occur in sequence, the order of the above steps is not limited to those listed above and can be varied or rearranged according to the desired design. Moreover, the above embodiments can be used in combination with each other or with other embodiments based on design and reliability considerations; that is, technical features from different embodiments can be freely combined to form more embodiments.

[0034] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above descriptions are merely specific embodiments of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A core sampling device for geological exploration, characterized in that, It includes an outer sleeve, a rotary drill bit, a central channel, a pressure holding chamber, a vacuum chamber, and a pressurizing chamber. The rotary drill bit is located at the bottom of the outer sleeve. The central channel extends from the center of the rotary drill bit into the outer sleeve. The pressure holding chamber is fitted within the space formed by the outer side of the central channel and the inner side of the outer sleeve. The vacuum chamber is located above the pressure holding chamber. The pressurizing chamber is located above the vacuum chamber. An air passage is provided between the pressurizing chamber and the vacuum chamber.

2. The core pressure-maintaining sampling device for geological exploration according to claim 1, characterized in that, The bottom diameter of the rotary drill bit is larger than the diameter of the outer sleeve. The rotary drill bit has a rock-walking channel inside, which is connected to the central channel. When the rotary drill bit rotates, the rock core enters the central channel through the rock-walking channel. The outer surface of the central channel and the inner surface of the outer sleeve are both provided with rotary threads.

3. The core pressure-maintaining sampling device for geological exploration according to claim 2, characterized in that, The pressure-holding cavity includes a rotating annular portion, a channel fitting portion, and a sealing portion. The rotating annular portion is hollow cylindrical and rotates on the rotating thread on the inner surface of the outer sleeve to achieve vertical displacement. The channel fitting portion extends upward from the bottom end of the rotating annular portion and is connected to the central channel through a rotating thread. The sealing portion has a right-angled triangular vertical section and is arranged around the top end of the channel fitting portion.

4. The core pressure-maintaining sampling device for geological exploration according to claim 3, characterized in that, The top of the rotating ring is equipped with a sealing device and a one-way pressure control valve. The sealing device includes a rotary telescopic motor, a rotary telescopic rod, and a sealing head. The rotary telescopic motor is fixedly installed on the top of the rotating ring. The rotary telescopic rod extends downward from the output end of the rotary telescopic motor into the interior of the rotating ring. The sealing head is fixedly installed at the bottom end of the rotary telescopic rod. The sealing head and the sealing part are connected by a rotary thread, and the sealing head and the sealing part are matched.

5. A core pressure-maintaining sampling device for geological exploration according to claim 4, characterized in that, Multiple one-way pressure control valves are provided, and the one-way pressure control valves are arranged around the outer ring of the sealing device. Each one-way pressure control valve includes an air inlet, an elastic closing balloon, a transverse support plate, and a tension spring. The air inlet passes through the top of the rotating ring and the bottom of the air inlet is arc-shaped. The elastic closing balloon is located at the bottom of the air inlet and is fixedly installed on the transverse support plate. One end of the tension spring is located on the transverse support plates on the left and right sides of the elastic closing balloon, and the other end of the tension spring is fixedly installed on the inner surface of the top of the rotating ring.

6. The core pressure-maintaining sampling device for geological exploration according to claim 1, characterized in that, An air inlet channel is provided on the right side of the outer sleeve. The air inlet channel extends downward from the inside of the pressurization chamber to the outer sleeve above the rotary drill bit and extends outward. The pressurization chamber is provided with a support frame, a bidirectional suction pressurizer, and an air shut-off valve. The support frame is fixedly installed inside the pressurization chamber, and the bidirectional suction pressurizer is fixedly installed on the support frame. The two ends of the bidirectional suction pressurizer are respectively connected to the air passage and the air inlet channel. The air shut-off valve is located at the connection between the air inlet channel, the air passage and the bidirectional suction pressurizer.

7. The core pressure-maintaining sampling device for geological exploration according to claim 1, characterized in that, Pressure monitoring devices are installed inside the pressure holding chamber and on the outer wall of the outer sleeve. The pressure monitoring devices are electrically connected to the bidirectional air extraction and pressurization machine.

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