Natural gas hydrate rock core sample in-situ detection decomposition device and detection method

Abstract

The invention discloses a natural gas hydrate rock core sample in-situ detection and decomposition device and a detection method, and particularly relates to the technical field of energy exploitation, the natural gas hydrate rock core sample in-situ detection and decomposition device comprises a sample cavity for providing a high-pressure and low-temperature stable environment for a rock core sample; the core barrel trepanning unit is used for forming a plurality of detection holes in the core liner tube; the conductivity detection unit is used for penetrating through the detection hole to measure the conductivity of the rock core sample; the shear strength detection unit is used for measuring the shear strength of the rock core sample by penetrating through the detection hole; the heat conductivity coefficient detection unit is used for penetrating through the detection hole to measure the heat conductivity coefficient of the rock core sample; the expansion cavity can independently store the detected rock core sample in the sample cavity; and the rock core decomposition and gas collection unit is used for decomposing the rock core sample in the expansion cavity and collecting decomposed gas. The device can be matched with a pressure maintaining transfer system to complete in-situ measurement of various physical and mechanical parameters of the hydrate core sample, the analysis efficiency and accuracy are improved, and the hydrate reserves can be rapidly evaluated.

Description

Technical Field

[0001] The invention relates to the technical field of energy mining, and in particular to an in-situ detection and decomposition device and a detection method for a natural gas hydrate core sample. Background Art

[0002] Natural gas hydrate is a high-quality clean energy with great development potential. Natural gas hydrate is mostly present in the pores of marine sediments in the form of cementation, pore filling, and support. The decomposition of hydrates will destroy the original skeleton cementation structure and weaken the bearing capacity of the formation. At the same time, the decomposition of hydrates will produce a large amount of gas and water, and generate a large number of pores. The original stress state will be changed, causing reservoir deformation, affecting the gas production rate, and greatly increasing the risk of geological disasters such as submarine landslides. Therefore, before developing and utilizing hydrate resources, it is of great significance to evaluate the hydrate reservoir and fully understand the various mechanical properties of the hydrate reservoir for the study of hydrate exploration and mining methods. Conventional land laboratories can conduct targeted physical and chemical property analysis of each component in the sample, but the disadvantage is that they cannot complete the online detection of fidelity samples. The shipboard field laboratory can perform in-situ online detection of fidelity sampling cores to improve analysis efficiency and accuracy, but it has high requirements for related fidelity sampling technology and shipboard detection systems.

[0003] At present, due to the limitations of equipment systems and technical systems, my country's natural gas hydrate core detection technology is still limited to the analysis and evaluation of non-authentic samples in onshore laboratories, and there is a lack of natural gas hydrate core shipborne detection systems and equipment suitable for field analysis. Summary of the invention

[0004] The purpose of the present invention is to provide a natural gas hydrate core sample in-situ detection decomposition device and detection method to solve the problems existing in the above-mentioned prior art. It can adapt to the pressure-maintaining transfer system to complete the in-situ measurement of various physical and mechanical parameters of the hydrate core sample, improve the analysis efficiency and accuracy, and can also quickly evaluate the hydrate reserves.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a natural gas hydrate core sample in-situ detection and decomposition device, comprising: a sample chamber, the sample chamber is sealed and connected to a pressure-maintaining transfer system, the pressure-maintaining transfer system pushes the core sample to the sample chamber, the sample chamber is used to provide a high-pressure, low-temperature stable environment for the core sample; a core tube opening unit, the core tube opening unit is connected to the sample chamber, the core tube opening unit is used to open a plurality of detection holes for a core liner; an electrical conductivity detection unit, the electrical conductivity detection unit is connected to the sample chamber, the electrical conductivity detection unit passes through the detection holes and is used to measure the electrical conductivity of the core sample; a shear strength detection unit, the shear strength detection unit is connected to the sample chamber, the A shear strength detection unit passes through the detection hole to measure the shear strength of the core sample; a thermal conductivity detection unit, the thermal conductivity detection unit is connected to the sample cavity, and the thermal conductivity detection unit passes through the detection hole to measure the thermal conductivity of the core sample; an expansion cavity, the expansion cavity is sealed and connected to the sample cavity, and a valve is provided between the expansion cavity and the sample cavity, and when all the core samples after the detection in the sample cavity enter the expansion cavity, the valve is closed; a core decomposition and gas collection unit, the core decomposition and gas collection unit is connected to the expansion cavity, and the core decomposition and gas collection unit is used to decompose the core sample in the expansion cavity and collect the decomposed gas.

[0007] Preferably, the core barrel opening unit includes a first ball valve, a first casing, a first threaded guide tube, a first drill rod, a first drill bit and a first hand wheel, one end of the first drill rod is fixedly connected to the first hand wheel, and the other end is fixedly connected to the first drill bit, one end of the first ball valve is connected and communicated with the sample chamber through a threaded joint, and the other end is connected and communicated with the first casing, one end of the first casing away from the first ball valve is connected and communicated with the first threaded guide tube, a sealing ring and a watertight connector are installed between the first casing and the first threaded guide tube, the first casing and the first threaded guide tube are sleeved outside the first drill rod, and the first drill rod is threadedly connected to the first threaded guide tube, and by turning the first hand wheel, the first drill rod can move relative to the first casing and the first threaded guide tube along the axial direction of the first drill rod, and the first drill bit can drill a plurality of the detection holes in the core liner.

[0008] Preferably, the conductivity detection unit comprises a second ball valve, a second casing, a second threaded guide tube, a conductivity probe mounting rod, a conductivity probe and a second hand wheel, one end of the conductivity probe mounting rod is fixedly connected to the second hand wheel, and the other end is fixedly connected to the conductivity probe, one end of the second ball valve is connected and communicated with the sample chamber through a threaded joint, and the other end is connected and communicated with the second casing, one end of the second casing away from the second ball valve is connected and communicated with the second threaded guide tube, a sealing ring and a watertight connector are installed between the second casing and the second threaded guide tube, the second casing and the second threaded guide tube are sleeved outside the conductivity probe mounting rod, and the conductivity probe mounting rod is threadedly connected to the second threaded guide tube, and by rotating the second hand wheel, the conductivity probe mounting rod can move relative to the second casing and the second threaded guide tube along the axial direction of the conductivity probe mounting rod, and drive the conductivity probe to pass through the detection hole to measure the conductivity of the core sample.

[0009] Preferably, the thermal conductivity detection unit comprises a third ball valve, a third sleeve, a third threaded guide tube, a thermal conductivity probe mounting rod, a thermal conductivity probe and a third hand wheel, one end of the thermal conductivity probe mounting rod is fixedly connected to the third hand wheel, and the other end is fixedly connected to the thermal conductivity probe, one end of the third ball valve is connected and communicated with the sample chamber through a threaded joint, and the other end is connected and communicated with the third sleeve, one end of the third sleeve away from the third ball valve is connected and communicated with the third threaded guide tube, a sealing ring and a watertight connector are installed between the third sleeve and the third threaded guide tube, the third sleeve and the third threaded guide tube are sleeved outside the thermal conductivity probe mounting rod, the thermal conductivity probe mounting rod is threadedly connected to the third threaded guide tube, and by rotating the third hand wheel, the thermal conductivity probe mounting rod can move relative to the third sleeve and the third threaded guide tube along the axial direction of the thermal conductivity probe mounting rod, and drive the thermal conductivity probe to pass through the detection hole to measure the thermal conductivity of the core sample.

[0010] Preferably, the shear strength detection unit includes a fourth ball valve, a fourth sleeve, a fourth threaded guide tube, a shear probe mounting rod, a shear probe, a torque sensor, a drive assembly and a guide rail, one end of the shear probe mounting rod is connected to the torque sensor, and the other end is fixedly connected to the shear probe, one end of the torque sensor away from the shear probe mounting rod is connected to the output end of the drive assembly, the torque sensor and the drive assembly are both slidably connected to the guide rail, one end of the fourth ball valve is connected and communicated with the sample chamber through a threaded joint, and the other end is connected and communicated with the fourth sleeve, One end of the fourth sleeve away from the fourth ball valve is connected to and communicated with the fourth threaded guide tube, a sealing ring and a watertight connector are installed between the fourth sleeve and the fourth threaded guide tube, the fourth sleeve and the fourth threaded guide tube are sleeved outside the shear probe mounting rod, and the shear probe mounting rod is threadedly connected to the fourth threaded guide tube, and the driving assembly can drive the shear probe mounting rod to move along the axial direction of the shear probe mounting rod relative to the fourth sleeve and the fourth threaded guide tube, and drive the shear probe to pass through the detection hole to measure the shear strength of the core sample.

[0011] Preferably, the shear strength detection unit also includes a coupling, the driving assembly includes a reducer and a motor, the two ends of the torque sensor are respectively connected to the shear probe mounting rod and the reducer through the coupling, the end of the reducer away from the torque sensor is fixedly connected to the output shaft of the motor through the coupling, and the torque sensor, the reducer and the motor are all slidably connected to the guide rail through a mounting bracket.

[0012] Preferably, the core decomposition and gas collection unit includes a three-way connector, a drill pipe casing, a second drill pipe, a second drill bit, a handle and a gas collection device, the first port of the three-way connector is sealed and communicated with the expansion chamber, the second port of the three-way connector is connected to the drill pipe casing, and the third port of the three-way connector is connected and communicated with the gas collection device, the drill pipe casing is sleeved outside the second drill pipe, and the drill pipe casing is threadedly connected to the second drill pipe, one end of the second drill pipe is fixedly connected to the handle, and the other end is fixedly connected to the second drill bit, by rotating the handle, the second drill pipe can move relative to the drill pipe casing along the axial direction of the second drill pipe, and drive the second drill bit to drill a through hole through the core sample, thereby decomposing the core sample, and the gas collection device is used to collect the gas after the decomposition of the core sample.

[0013] Preferably, the core decomposition gas collection unit also includes a three-way valve, a first port of the three-way valve is connected and communicated with the three-way connector, a second port of the three-way valve is connected and communicated with the gas collecting device, and a third port of the three-way valve is communicated with the outside world, and a scale is provided on the gas collecting device.

[0014] Preferably, it further comprises a mounting panel, and the core barrel opening unit, the conductivity detection unit, the shear strength detection unit and the thermal conductivity detection unit are all fixedly connected to the mounting panel via a mounting bracket.

[0015] The present invention also provides a detection method of the natural gas hydrate core sample in-situ detection and decomposition device, and the operation steps are as follows:

[0016] Step 1: After the pressure-maintaining transfer system pushes the core sample wrapped in the core liner into the sample cavity for a certain distance, the core tube opening unit drills the first detection hole on the core liner. After the drilling is completed, the core liner is further pushed into the sample cavity for a certain distance, and then the core tube opening unit drills the second detection hole on the core liner. At this time, the first detection hole is close to the conductivity detection unit.

[0017] Step 2: The conductivity detection unit passes through the first detection hole of the core liner and performs conductivity detection on the core sample at the first detection hole. After the conductivity detection is completed, the core liner is pushed into the sample cavity for a certain distance, and then the third detection hole is drilled on the core liner through the core tube opening unit. At this time, the first detection hole is close to the shear strength detection unit, and the second detection hole is close to the conductivity detection unit.

[0018] Step three, the shear strength detection unit passes through the first detection hole of the core liner, and performs shear strength detection on the core sample at the first detection hole position, and at the same time, the conductivity detection unit passes through the second detection hole of the core liner, and performs conductivity detection on the core sample at the second detection hole position. After the shear strength at the first detection hole position and the conductivity at the second detection hole position are detected, the core liner is pushed into the sample cavity for a certain distance, and then the fourth detection hole is drilled on the core liner through the core tube opening unit. At this time, the first detection hole is close to the thermal conductivity detection unit, the second detection hole is close to the shear strength detection unit, and the third detection hole is close to the conductivity detection unit;

[0019] Step 4: The thermal conductivity detection unit passes through the first detection hole of the core liner and performs thermal conductivity detection on the core sample at the first detection hole. At the same time, the shear strength detection unit passes through the second detection hole of the core liner and performs shear strength detection on the core sample at the second detection hole. The conductivity detection unit passes through the third detection hole of the core liner and performs conductivity detection on the core sample at the third detection hole. After the thermal conductivity at the first detection hole, the shear strength at the second detection hole and the conductivity at the third detection hole are all detected, the core liner is pushed into the sample cavity for a certain distance, and then the fifth detection hole is drilled on the core liner through the core tube opening unit. At this time, the first detection hole has completed all the detections. At this time, the second detection hole is close to the thermal conductivity detection unit, the third detection hole is close to the shear strength detection unit, and the fourth detection hole is close to the conductivity detection unit.

[0020] Step 5, and so on, until all tests on the entire core sample are completed;

[0021] Step six, push all the core samples that have been tested into the expansion chamber, close the valve between the expansion chamber and the sample chamber, decompose the core samples in the expansion chamber through the core decomposition and gas collection unit, collect the decomposed gas, and then quickly evaluate the hydrate reserves based on the gas collection amount.

[0022] Compared with the prior art, the present invention has achieved the following technical effects:

[0023] The present invention provides an in-situ detection and decomposition device for a natural gas hydrate core sample. The sample chamber is connected to a pressure-maintaining transfer system and is used to provide a high-pressure and low-temperature stable environment for the core sample. The sample chamber can adapt to the pressure-maintaining transfer system to complete the in-situ measurement of various physical and mechanical parameters of the hydrate core sample, thereby avoiding the situation where the hydrate core sample is decomposed during transportation to the laboratory, resulting in inaccurate measurement results; the conductivity detection unit, the shear strength detection unit and the thermal conductivity detection unit can perform three different physical and mechanical parameter tests on the core sample, with high integration and convenient operation, and is suitable for being carried on a scientific research vessel for rapid measurement at a drilling site; the core decomposition and gas collection unit can reduce the pressure and decompose the hydrate core sample, and collect and analyze the gas generated by the decomposition, thereby obtaining the gas content of the hydrate core sample in the in-situ state, thereby facilitating accurate evaluation of the hydrate reserves. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a front view of a decomposition device for in-situ detection of a natural gas hydrate core sample;

[0026] Figure 2 It is a schematic diagram of the structure of the in-situ detection and decomposition device for natural gas hydrate core samples;

[0027] Figure 3 A cross-sectional view of the in-situ detection and decomposition device for natural gas hydrate core samples.

[0028] In the figure: 1-sample chamber; 2-core tube opening unit; 21-first ball valve; 22-first casing; 23-first threaded guide tube; 24-first drill rod; 25-first drill bit; 26-first hand wheel; 3-conductivity detection unit; 31-second ball valve; 32-second casing; 33-second threaded guide tube; 34-conductivity probe mounting rod; 35-conductivity probe; 36-second hand wheel; 4-shear strength detection unit; 41-fourth ball valve; 42-fourth casing; 43-fourth threaded guide tube; 44-shear probe mounting rod; 45-shear probe; 46-torque Torque sensor; 47-coupling; 48-reducer; 49-motor; 410-guide rail; 5-thermal conductivity detection unit; 51-third ball valve; 52-third casing; 53-third threaded guide tube; 54-thermal conductivity probe mounting rod; 55-thermal conductivity probe; 56-third handwheel; 6-expansion chamber; 7-core decomposition gas collection unit; 71-three-way connector; 72-drill pipe casing; 73-second drill pipe; 74-second drill bit; 75-handle; 76-gas collection device; 77-three-way valve; 8-installation panel; 9-clamp; 10-installation bracket; 11-end cover. DETAILED DESCRIPTION

[0029] 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.

[0030] The purpose of the present invention is to provide a natural gas hydrate core sample in-situ detection decomposition device and detection method to solve the problems existing in the above-mentioned prior art. It can adapt to the pressure-maintaining transfer system to complete the in-situ measurement of various physical and mechanical parameters of the hydrate core sample, improve the analysis efficiency and accuracy, and can also quickly evaluate the hydrate reserves.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Example 1

[0033] This embodiment provides a natural gas hydrate core sample in-situ detection and decomposition device, such as Figure 1 As shown, it includes a sample chamber 1, a core tube opening unit 2, a conductivity detection unit 3, a shear strength detection unit 4, a thermal conductivity detection unit 5, an expansion chamber 6 and a core decomposition gas collection unit 7. The sample chamber 1 is sealed and connected to the pressure-maintaining transfer system. The pressure-maintaining transfer system pushes the core sample to the sample chamber 1. The sample chamber 1 is used to provide a high-pressure and low-temperature stable environment for the core sample; the core tube opening unit 2 is connected to the sample chamber 1, and the core tube opening unit 2 is used to open a plurality of detection holes in the core liner; the conductivity detection unit 3 is connected to the sample chamber 1, and the conductivity detection unit 3 passes through the detection holes to measure the conductivity of the core sample; the shear strength detection unit 4 is connected to the sample chamber 1 The shear strength detection unit 4 passes through the detection hole to measure the shear strength of the core sample; the thermal conductivity detection unit 5 is connected to the sample chamber 1, and the thermal conductivity detection unit 5 passes through the detection hole to measure the thermal conductivity of the core sample; the expansion chamber 6 is sealed and connected to the sample chamber 1 through a clamp 9, and the end of the expansion chamber 6 away from the sample chamber 1 is sealed by an end cover 11; and a valve is provided between the expansion chamber 6 and the sample chamber 1, and when all the core samples after the detection in the sample chamber 1 enter the expansion chamber 6, the valve is closed; the core decomposition and gas collection unit 7 is connected to the expansion chamber 6, and the core decomposition and gas collection unit 7 is used to decompose the core sample in the expansion chamber 6 and collect the decomposed gas. The sample chamber 1 is connected to the pressure-maintaining transfer system and is used to provide a stable environment of high pressure and low temperature for the core sample. The sample chamber 1 can adapt to the pressure-maintaining transfer system to complete the in-situ measurement of various physical and mechanical parameters of the hydrate core sample, thereby avoiding the inaccurate measurement results caused by the decomposition of the hydrate core sample during transportation to the laboratory; the conductivity detection unit 3, the shear strength detection unit 4 and the thermal conductivity detection unit 5 can perform three different physical and mechanical parameter tests on the core sample, with high integration and convenient operation, and are suitable for rapid measurement on the drilling site on scientific research vessels; the core decomposition and gas collection unit 7 can reduce the pressure on the hydrate core sample and decompose it, and collect and analyze the gas generated by the decomposition, so as to obtain the gas content of the hydrate core sample in the in-situ state, which is conducive to the accurate assessment of the hydrate reserves.

[0034] In the implementation of this embodiment, it is further preferred that Figure 2-3As shown, the core tube opening unit 2 includes a first ball valve 21, a first casing 22, a first threaded guide tube 23, a first drill rod 24, a first drill bit 25 and a first hand wheel 26. One end of the first drill rod 24 is fixedly connected to the first hand wheel 26, and the other end is fixedly connected to the first drill bit 25 through a screw. One end of the first ball valve 21 is connected and communicated with the sample chamber 1 through a threaded joint, and the other end is connected and communicated with the first casing 22. One end of the first casing 22 away from the first ball valve 21 is connected and communicated with the first threaded guide tube 23. There is a first casing 22 and the first threaded guide tube 23. Equipped with a sealing ring and a watertight connector, after the first ball valve 21 is opened, the first drill rod 24 drives the first drill bit 25 to move while ensuring the internal pressure of the first sleeve 22 is stable, thereby not destroying the high-pressure environment in the sample chamber 1. The first sleeve 22 and the first threaded guide tube 23 are sleeved outside the first drill rod 24, and the first drill rod 24 is threadedly connected with the first threaded guide tube 23. By turning the first hand wheel 26, the first drill rod 24 can move relative to the first sleeve 22 and the first threaded guide tube 23 along the axial direction of the first drill rod 24, and the first drill bit 25 can drill multiple detection holes in the core liner. By rotating the first hand wheel 26 forward, the first drill rod 24 moves forward along the thread on the first threaded guide tube 23, driving the first drill bit 25 thereon to rotate and move forward, thereby drilling detection holes on the core liner. After the detection holes are opened, the first hand wheel 26 is reversed to make the first drill bit 25 withdraw from the sample chamber 1.

[0035] It is further preferred in the implementation of this embodiment that the conductivity detection unit 3 includes a second ball valve 31, a second sleeve 32, a second threaded guide tube 33, a conductivity probe mounting rod 34, a conductivity probe 35 and a second hand wheel 36, one end of the conductivity probe mounting rod 34 is fixedly connected to the second hand wheel 36, and the other end is fixedly connected to the conductivity probe 35 by a screw, one end of the second ball valve 31 is connected and communicated with the sample chamber 1 through a threaded joint, and the other end is connected and communicated with the second sleeve 32, one end of the second sleeve 32 away from the second ball valve 31 is connected and communicated with the second threaded guide tube 33, and a second sleeve 32 is installed between the second sleeve 32 and the second threaded guide tube 33. The sealing ring and the watertight connector can ensure the stability of the internal pressure of the second sleeve 32 when the conductivity probe mounting rod 34 drives the conductivity probe 35 to move after the second ball valve 31 is opened, so as not to destroy the high-pressure environment in the sample chamber 1. The second sleeve 32 and the second threaded guide tube 33 are sleeved outside the conductivity probe mounting rod 34, and the conductivity probe mounting rod 34 is threadedly connected to the second threaded guide tube 33. By turning the second hand wheel 36, the conductivity probe mounting rod 34 can move relative to the second sleeve 32 and the second threaded guide tube 33 along the axial direction of the conductivity probe mounting rod 34, and drive the conductivity probe 35 to pass through the detection hole to measure the conductivity of the core sample. When the detection hole is directly opposite to the second ball valve 31, the second hand wheel 36 is turned, and the conductivity probe mounting rod 34 moves forward along the thread on the second threaded guide tube 33, driving the conductivity probe 35 thereon to rotate and move forward, passing through the detection hole on the core liner, and the conductivity probe 35 contacts the core sample to detect the conductivity of the core sample. After the detection is completed, the second hand wheel 36 is reversed to withdraw the conductivity probe 35 from the sample chamber 1.

[0036] In the implementation of the present embodiment, it is further preferred that the thermal conductivity detection unit 5 includes a third ball valve 51, a third sleeve 52, a third threaded guide tube 53, a thermal conductivity probe mounting rod 54, a thermal conductivity probe 55 and a third hand wheel 56, one end of the thermal conductivity probe mounting rod 54 is fixedly connected to the third hand wheel 56, and the other end is fixedly connected to the thermal conductivity probe 55 through a screw, one end of the third ball valve 51 is connected and communicated with the sample chamber 1 through a threaded joint, and the other end is connected and communicated with the third sleeve 52, one end of the third sleeve 52 away from the third ball valve 51 is connected and communicated with the third threaded guide tube 53, and a sealing member is installed between the third sleeve 52 and the third threaded guide tube 53. The ring and the watertight connector can ensure the internal pressure of the third sleeve 52 to be stable during the movement of the thermal conductivity probe 55 driven by the thermal conductivity probe mounting rod 54 after the third ball valve 51 is opened, so as not to destroy the high-pressure environment in the sample chamber 1. The third sleeve 52 and the third threaded guide tube 53 are sleeved outside the thermal conductivity probe mounting rod 54, and the thermal conductivity probe mounting rod 54 is threadedly connected with the third threaded guide tube 53. By turning the third hand wheel 56, the thermal conductivity probe mounting rod 54 can move relative to the third sleeve 52 and the third threaded guide tube 53 along the axial direction of the thermal conductivity probe mounting rod 54, and drive the thermal conductivity probe 55 to pass through the detection hole to measure the thermal conductivity of the core sample. When the detection hole is directly opposite to the third ball valve 51, the third hand wheel 56 is turned, and the thermal conductivity probe mounting rod 54 moves forward along the thread on the third threaded guide tube 53, driving the thermal conductivity probe 55 thereon to rotate and move forward, passing through the detection hole on the core liner, and the thermal conductivity probe 55 contacts the core sample to detect the thermal conductivity of the core sample. After the detection is completed, the third hand wheel 56 is reversed to withdraw the thermal conductivity probe 55 from the sample chamber 1.

[0037] It is further preferred in the implementation manner of the present embodiment that the shear strength detection unit 4 includes a fourth ball valve 41, a fourth sleeve 42, a fourth threaded guide tube 43, a shear probe mounting rod 44, a shear probe 45, a torque sensor 46, a drive assembly and a guide rail 410, one end of the shear probe mounting rod 44 is connected to the torque sensor 46, and the other end is fixedly connected to the shear probe 45 by a screw, the end of the torque sensor 46 away from the shear probe mounting rod 44 is connected to the output end of the drive assembly, the torque sensor 46 and the drive assembly are both slidably connected to the guide rail 410, one end of the fourth ball valve 41 is connected and communicated with the sample chamber 1 through a threaded joint, and the other end is connected and communicated with the fourth sleeve 42, and the end of the fourth sleeve 42 away from the fourth ball valve 41 It is connected and communicated with the fourth threaded guide tube 43, and a sealing ring and a watertight connector are installed between the fourth sleeve 42 and the fourth threaded guide tube 43, which can ensure the internal pressure of the fourth sleeve 42 to be stable during the movement of the shear probe 45 driven by the shear probe mounting rod 44 after the fourth ball valve 41 is opened, thereby not destroying the high-pressure environment in the sample chamber 1. The fourth sleeve 42 and the fourth threaded guide tube 43 are sleeved outside the shear probe mounting rod 44, and the shear probe mounting rod 44 is threadedly connected to the fourth threaded guide tube 43. The driving assembly can drive the shear probe mounting rod 44 to move along the axial direction of the shear probe mounting rod 44 relative to the fourth sleeve 42 and the fourth threaded guide tube 43, and drive the shear probe 45 to pass through the detection hole to measure the shear strength of the core sample. The shear strength detection unit 4 also includes a coupling 47, and the driving assembly includes a reducer 48 and a motor 49. The two ends of the torque sensor 46 are respectively connected to the shear probe mounting rod 44 and the reducer 48 through the coupling 47. The end of the reducer 48 away from the torque sensor 46 is fixedly connected to the output shaft of the motor 49 through the coupling 47. The torque sensor 46, the reducer 48 and the motor 49 are all slidably connected to the guide rail 410 through the mounting bracket 10. Preferably, the shear probe 45 is a cross-plate shear probe. When the detection hole is directly opposite to the fourth ball valve 41, the motor 49 is started, and the motor 49 drives the reducer 48, the torque sensor 46, the shear probe mounting rod 44 and the cross-plate shear probe to rotate and move forward through the coupling 47, so that the cross-plate shear probe passes through the detection hole on the core liner, and the cross-plate shear probe contacts the core sample and completes the shear strength detection. After the detection is completed, the motor 49 is reversed to make the cross-plate shear probe withdraw from the sample chamber 1.

[0038] In the implementation manner of the present embodiment, it is further preferred that the core decomposition gas collection unit 7 includes a three-way connector 71, a drill pipe casing 72, a second drill pipe 73, a second drill bit 74, a handle 75 and a gas collection device 76, the first port of the three-way connector 71 is sealed and connected to the expansion chamber 6, the second port of the three-way connector 71 is connected to the drill pipe casing 72, the third port of the three-way connector 71 is connected and connected to the gas collection device 76, the drill pipe casing 72 is sleeved outside the second drill pipe 73, and the drill pipe casing 72 is threadedly connected to the second drill pipe 73, one end of the second drill pipe 73 is fixedly connected to the handle 75, and the other end is fixedly connected to the handle 75. The end is fixedly connected to the second drill bit 74 by a screw, and the handle 75 is turned so that the second drill rod 73 can move relative to the drill rod casing 72 along the axial direction of the second drill rod 73, and drive the second drill bit 74 to drill a through hole penetrating the core sample, thereby decomposing the core sample. The gas collecting device 76 is used to collect the gas after the decomposition of the core sample. The core decomposition and gas collecting unit 7 also includes a three-way valve 77. The first port of the three-way valve 77 is connected and communicated with the three-way connector 71, the second port of the three-way valve 77 is connected and communicated with the gas collecting device 76, and the third port of the three-way valve 77 is communicated with the outside world. A scale is provided on the gas collecting device 76. The handle 75 on the second drill rod 73 is rotated to push the second drill bit 74 through the threaded screw of the drill rod on the drill rod casing 72, thereby drilling a through hole in the core liner and the core sample. After the drilling is completed, the overall pressure in the expansion chamber 6 is reduced, and the core sample begins to decompose as the pressure drops. The gas generated after the decomposition will enter the gas collecting device 76 through the pipeline, and the generated liquid can flow to the outside through the three-way valve 77 for preservation.

[0039] It is further preferred that the implementation of this embodiment further includes a mounting panel 8, and the core barrel opening unit 2, the conductivity detection unit 3, the shear strength detection unit 4 and the thermal conductivity detection unit 5 are all fixedly connected to the mounting panel 8 via a mounting bracket 10.

[0040] Example 2

[0041] This embodiment provides a detection method of the natural gas hydrate core sample in-situ detection and decomposition device of embodiment 1, and the operation steps are as follows:

[0042] Step 1: After the pressure-maintaining transfer system pushes the core sample wrapped in the core liner into the sample chamber 1 for a certain distance, the first hand wheel 26 is turned, and the first drill rod 24 drives the first drill bit 25 to drill the first detection hole on the core liner. After the drilling is completed, the first hand wheel 26 is reversed to withdraw the first drill bit 25 from the sample chamber 1, and the core liner is continuously pushed into the sample chamber 1 for a certain distance, and the first hand wheel 26 is turned again, and the first drill rod 24 drives the first drill bit 25 to drill the second detection hole on the core liner. At this time, the first detection hole is close to the conductivity detection unit 3;

[0043] Step 2: When the first detection hole is directly opposite to the second ball valve 31, the second hand wheel 36 is turned, and the conductivity probe installation rod 34 drives the conductivity probe 35 to pass through the first detection hole on the core liner, so that the conductivity probe 35 contacts the core sample and completes the conductivity detection. After the conductivity detection is completed, the second hand wheel 36 is reversed to withdraw the conductivity probe 35 from the sample cavity 1, and the core liner is continuously pushed into the sample cavity 1 for a certain distance, and then the first hand wheel 26 is turned, and the first drill rod 24 drives the first drill bit 25 to drill the third detection hole on the core liner. At this time, the first detection hole is close to the shear strength detection unit 4, and the second detection hole is close to the conductivity detection unit 3.

[0044] Step 3: When the first detection hole is directly opposite to the fourth ball valve 41, and the second detection hole is directly opposite to the second ball valve 31, the motor 49 is started, the shear probe mounting rod 44 drives the shear probe 45 to pass through the first detection hole of the core liner, and the shear strength test is performed on the core sample at the first detection hole position; at the same time, the second hand wheel 36 is turned, the conductivity probe mounting rod 34 drives the conductivity probe 35 to pass through the second detection hole of the core liner, and the conductivity test is performed on the core sample at the second detection hole position. When the shear strength at the first detection hole position is After the conductivity of the first and second detection holes are detected, the motor 49 is reversed to withdraw the shear probe 45 from the sample chamber 1, and the second hand wheel 36 is reversed to withdraw the conductivity probe 35 from the sample chamber 1, and the core liner is continuously pushed into the sample chamber 1 for a certain distance, and then the first hand wheel 26 is turned, and the first drill rod 24 drives the first drill bit 25 to drill the fourth detection hole on the core liner. At this time, the first detection hole is close to the thermal conductivity detection unit 5, the second detection hole is close to the shear strength detection unit 4, and the third detection hole is close to the conductivity detection unit 3;

[0045] Step 4, when the first detection hole is opposite to the third ball valve 51, the second detection hole is opposite to the fourth ball valve 41, and the third detection hole is opposite to the second ball valve 31, turn the third hand wheel 56, the thermal conductivity probe mounting rod 54 drives the thermal conductivity probe 55 to pass through the first detection hole of the core liner, and perform thermal conductivity detection on the core sample at the first detection hole position; at the same time, start the motor 49, the shear probe mounting rod 44 drives the shear probe 45 to pass through the second detection hole of the core liner, and perform shear strength detection on the core sample at the second detection hole position; turn the second hand wheel 36, the conductivity probe mounting rod 34 drives the conductivity probe 35 to pass through the third detection hole of the core liner, and perform conductivity detection on the core sample at the third detection hole position After the thermal conductivity of the first detection hole, the shear strength of the second detection hole and the electrical conductivity of the third detection hole are all detected, the third hand wheel 56 is reversed to withdraw the thermal conductivity probe 55 from the sample chamber 1, the motor 49 is reversed to withdraw the shear probe 45 from the sample chamber 1, the second hand wheel 36 is reversed to withdraw the electrical conductivity probe 35 from the sample chamber 1, and the core liner is continuously pushed into the sample chamber 1 for a certain distance, and then the first hand wheel 26 is turned, the first drill rod 24 drives the first drill bit 25 to drill the fifth detection hole on the core liner. At this time, all the tests of the first detection hole are completed. At this time, the second detection hole is close to the thermal conductivity detection unit 5, the third detection hole is close to the shear strength detection unit 4, and the fourth detection hole is close to the electrical conductivity detection unit 3;

[0046] Step 5, and so on, until all tests on the entire core sample are completed;

[0047] Step six, push all the core samples that have been tested into the expansion chamber 6, close the valve between the expansion chamber 6 and the sample chamber 1, rotate the second handle 75, and drive the second drill bit 74 through the drill pipe to drill a through hole in the core liner and the core sample. After the drilling is completed, reduce the overall pressure in the expansion chamber 6 to decompose the core sample in the expansion chamber 6. The decomposed gas is collected by the gas collection device 76, and then the hydrate reserves are quickly evaluated based on the gas collection amount. The generated liquid can flow to the outside through the three-way valve 77 for storage.

[0048] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A natural gas hydrate core sample in-situ detection and decomposition device, characterized by: include: A sample chamber, wherein the sample chamber is sealed and connected to the pressure-maintaining transfer system, and the pressure-maintaining transfer system pushes the core sample into the sample chamber, and the sample chamber is used to provide a high-pressure, low-temperature stable environment for the core sample; A core tube opening unit, the core tube opening unit is connected to the sample chamber, and the core tube opening unit is used to open a plurality of detection holes in the core liner; A conductivity detection unit, the conductivity detection unit is connected to the sample chamber, and the conductivity detection unit passes through the detection hole to measure the conductivity of the core sample; A shear strength detection unit, the shear strength detection unit is connected to the sample cavity, and the shear strength detection unit passes through the detection hole to measure the shear strength of the core sample; A thermal conductivity detection unit, the thermal conductivity detection unit is connected to the sample cavity, and the thermal conductivity detection unit passes through the detection hole to measure the thermal conductivity of the core sample; An expansion chamber, the expansion chamber is sealed and connected to the sample chamber, and a valve is provided between the expansion chamber and the sample chamber. When all the core samples after the detection in the sample chamber enter the expansion chamber, the valve is closed; A core decomposition and gas collection unit is connected to the expansion chamber and is used to decompose the core sample in the expansion chamber and collect the decomposed gas.

2. The natural gas hydrate core sample in-situ detection and decomposition device according to claim 1, characterized in that: The core barrel opening unit includes a first ball valve, a first casing, a first threaded guide tube, a first drill rod, a first drill bit and a first hand wheel. One end of the first drill rod is fixedly connected to the first hand wheel, and the other end is fixedly connected to the first drill bit. One end of the first ball valve is connected and communicated with the sample chamber through a threaded joint, and the other end is connected and communicated with the first casing. An end of the first casing away from the first ball valve is connected and communicated with the first threaded guide tube. A sealing ring and a watertight connector are installed between the first casing and the first threaded guide tube. The first casing and the first threaded guide tube are sleeved outside the first drill rod. The first drill rod is threadedly connected to the first threaded guide tube. By turning the first hand wheel, the first drill rod can move relative to the first casing and the first threaded guide tube along the axial direction of the first drill rod, and the first drill bit can drill a plurality of the detection holes in the core liner.

3. The natural gas hydrate core sample in-situ detection and decomposition device according to claim 1, characterized in that: The conductivity detection unit includes a second ball valve, a second sleeve, a second threaded guide tube, a conductivity probe mounting rod, a conductivity probe and a second hand wheel. One end of the conductivity probe mounting rod is fixedly connected to the second hand wheel, and the other end is fixedly connected to the conductivity probe. One end of the second ball valve is connected and communicated with the sample chamber through a threaded joint, and the other end is connected and communicated with the second sleeve. One end of the second sleeve away from the second ball valve is connected and communicated with the second threaded guide tube. A sealing ring and a watertight connector are installed between the second sleeve and the second threaded guide tube. The second sleeve and the second threaded guide tube are sleeved outside the conductivity probe mounting rod. The conductivity probe mounting rod is threadedly connected to the second threaded guide tube. By rotating the second hand wheel, the conductivity probe mounting rod can move relative to the second sleeve and the second threaded guide tube along the axial direction of the conductivity probe mounting rod, and drive the conductivity probe to pass through the detection hole to measure the conductivity of the core sample.

4. The natural gas hydrate core sample in-situ detection and decomposition device according to claim 1, characterized in that: The thermal conductivity detection unit includes a third ball valve, a third sleeve, a third threaded guide tube, a thermal conductivity probe mounting rod, a thermal conductivity probe and a third hand wheel. One end of the thermal conductivity probe mounting rod is fixedly connected to the third hand wheel, and the other end is fixedly connected to the thermal conductivity probe. One end of the third ball valve is connected and communicated with the sample chamber through a threaded joint, and the other end is connected and communicated with the third sleeve. One end of the third sleeve away from the third ball valve is connected and communicated with the third threaded guide tube. A sealing ring and a watertight connector are installed between the third sleeve and the third threaded guide tube. The third sleeve and the third threaded guide tube are sleeved outside the thermal conductivity probe mounting rod. The thermal conductivity probe mounting rod is threadedly connected to the third threaded guide tube. By rotating the third hand wheel, the thermal conductivity probe mounting rod can move relative to the third sleeve and the third threaded guide tube along the axial direction of the thermal conductivity probe mounting rod, and drive the thermal conductivity probe to pass through the detection hole to measure the thermal conductivity of the core sample.

5. The natural gas hydrate core sample in-situ detection and decomposition device according to claim 1, characterized in that: The shear strength detection unit includes a fourth ball valve, a fourth sleeve, a fourth threaded guide tube, a shear probe mounting rod, a shear probe, a torque sensor, a drive assembly and a guide rail. One end of the shear probe mounting rod is connected to the torque sensor, and the other end is fixedly connected to the shear probe. One end of the torque sensor away from the shear probe mounting rod is connected to the output end of the drive assembly. Both the torque sensor and the drive assembly are slidably connected to the guide rail. One end of the fourth ball valve is connected and communicated with the sample cavity through a threaded joint, and the other end is connected and communicated with the fourth sleeve. One end of the fourth sleeve away from the fourth ball valve is connected and communicated with the fourth threaded guide tube. A sealing ring and a watertight connector are installed between the fourth sleeve and the fourth threaded guide tube. The fourth sleeve and the fourth threaded guide tube are sleeved outside the shear probe mounting rod. The shear probe mounting rod is threadedly connected to the fourth threaded guide tube. The drive assembly can drive the shear probe mounting rod to move relative to the fourth sleeve and the fourth threaded guide tube along the axial direction of the shear probe mounting rod, and drive the shear probe to pass through the detection hole to measure the shear strength of the core sample.

6. The natural gas hydrate core sample in-situ detection and decomposition device according to claim 5, characterized in that: The shear strength detection unit also includes a coupling, the driving assembly includes a reducer and a motor, the two ends of the torque sensor are respectively connected to the shear probe mounting rod and the reducer through the coupling, the end of the reducer away from the torque sensor is fixedly connected to the output shaft of the motor through the coupling, and the torque sensor, the reducer and the motor are all slidably connected to the guide rail through a mounting bracket.

7. The natural gas hydrate core sample in-situ detection and decomposition device according to claim 1, characterized in that: The core decomposition and gas collection unit includes a three-way connector, a drill pipe casing, a second drill pipe, a second drill bit, a handle and a gas collection device. The first port of the three-way connector is sealed and connected to the expansion chamber, the second port of the three-way connector is connected to the drill pipe casing, and the third port of the three-way connector is connected and connected to the gas collection device. The drill pipe casing is sleeved outside the second drill pipe, and the drill pipe casing is threadedly connected to the second drill pipe. One end of the second drill pipe is fixedly connected to the handle, and the other end is fixedly connected to the second drill bit. By rotating the handle, the second drill pipe can move relative to the drill pipe casing along the axial direction of the second drill pipe, and drive the second drill bit to drill a through hole through the core sample, thereby decomposing the core sample. The gas collection device is used to collect the gas after the core sample is decomposed.

8. The natural gas hydrate core sample in-situ detection and decomposition device according to claim 7, characterized in that: The core decomposition gas collection unit also includes a three-way valve, a first port of the three-way valve is connected and communicated with the three-way connector, a second port of the three-way valve is connected and communicated with the gas collection device, and a third port of the three-way valve is communicated with the outside world. A scale is provided on the gas collection device.

9. The natural gas hydrate core sample in-situ detection and decomposition device according to claim 1, characterized in that: It also includes a mounting panel, and the core tube opening unit, the conductivity detection unit, the shear strength detection unit and the thermal conductivity detection unit are all fixedly connected to the mounting panel through a mounting bracket.

10. A detection method using the natural gas hydrate core sample in-situ detection and decomposition device according to any one of claims 1 to 9, characterized in that: The steps are as follows: Step 1: After the pressure-maintaining transfer system pushes the core sample wrapped in the core liner into the sample cavity for a certain distance, the core tube opening unit drills the first detection hole on the core liner. After the drilling is completed, the core liner is further pushed into the sample cavity for a certain distance, and then the core tube opening unit drills the second detection hole on the core liner. At this time, the first detection hole is close to the conductivity detection unit. Step 2: The conductivity detection unit passes through the first detection hole of the core liner and performs conductivity detection on the core sample at the first detection hole. After the conductivity detection is completed, the core liner is pushed into the sample cavity for a certain distance, and then the third detection hole is drilled on the core liner through the core tube opening unit. At this time, the first detection hole is close to the shear strength detection unit, and the second detection hole is close to the conductivity detection unit. Step three, the shear strength detection unit passes through the first detection hole of the core liner, and performs shear strength detection on the core sample at the first detection hole position, and at the same time, the conductivity detection unit passes through the second detection hole of the core liner, and performs conductivity detection on the core sample at the second detection hole position. After the shear strength at the first detection hole position and the conductivity at the second detection hole position are detected, the core liner is pushed into the sample cavity for a certain distance, and then the fourth detection hole is drilled on the core liner through the core tube opening unit. At this time, the first detection hole is close to the thermal conductivity detection unit, the second detection hole is close to the shear strength detection unit, and the third detection hole is close to the conductivity detection unit; Step 4: The thermal conductivity detection unit passes through the first detection hole of the core liner and performs thermal conductivity detection on the core sample at the first detection hole. At the same time, the shear strength detection unit passes through the second detection hole of the core liner and performs shear strength detection on the core sample at the second detection hole. The conductivity detection unit passes through the third detection hole of the core liner and performs conductivity detection on the core sample at the third detection hole. After the thermal conductivity at the first detection hole, the shear strength at the second detection hole and the conductivity at the third detection hole are all detected, the core liner is pushed into the sample cavity for a certain distance, and then the fifth detection hole is drilled on the core liner through the core tube opening unit. At this time, the first detection hole has completed all the detections. At this time, the second detection hole is close to the thermal conductivity detection unit, the third detection hole is close to the shear strength detection unit, and the fourth detection hole is close to the conductivity detection unit. Step 5, and so on, until all tests on the entire core sample are completed; Step six, push all the core samples that have been tested into the expansion chamber, close the valve between the expansion chamber and the sample chamber, decompose the core samples in the expansion chamber through the core decomposition and gas collection unit, collect the decomposed gas, and then quickly evaluate the hydrate reserves based on the gas collection amount.

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