A simulation device and method for monitoring damage of overburden rock during in-situ pyrolysis of oil-rich coal

Abstract

The present invention discloses a simulation device and simulation method for monitoring the damage of overburden during in-situ pyrolysis of oil-rich coal, which belongs to the technical field of in-situ pyrolysis of oil-rich coal, and solves the problem that the existing device does not consider the damage deformation of overburden and the dynamic evolution of geological structure under the condition of confining ground stress during the simulation of in-situ pyrolysis of oil-rich coal. Its modular pyrolysis reaction chamber includes a reaction chamber module and a heating component; the reaction chamber module is filled with simulated strata and oil-rich coal seams, the vertical stress loading system includes a reaction frame and a stress loading component, the pyrolysis oil and gas collection system includes an oil and gas collection component and an inert gas filling component connected to the reaction chamber module, and a multi-parameter collaborative monitoring and acquisition system is connected to the reaction chamber module to monitor the fracture characteristics and dynamic evolution process of the simulated strata. The present invention simulates the vertical ground stress of the surrounding rock through the vertical stress loading system, simulates the fracture characteristics and dynamic evolution process of the surrounding rock under in-situ conditions, and is conducive to guiding the in-situ pyrolysis process of oil-rich coal.

Description

Technical Field

[0001] The present invention relates to the technical field of in-situ pyrolysis of rich oil coal, and particularly relates to a simulation device and a simulation method for monitoring the damage of overlying strata during in-situ pyrolysis of rich oil coal. Background Technique

[0002] Rich oil coal, as a special coal resource integrating the properties of coal, oil, and gas, has extremely rich reserves. In-situ pyrolysis of rich oil coal is a new approach and technology for obtaining oil and gas resources by heating coal seams in an airtight environment, featuring small mining disturbance, less ground pollution, and being green and low-carbon. It can alleviate the external dependence on oil and gas and increase domestic oil and gas supply.

[0003] During the in-situ pyrolysis of rich oil coal, a large amount of tar and coal gas with complex compositions are produced. Along with the overall expansion or contraction of the coal seam, the balance of the in-situ stress field is disrupted. The high temperature generated by pyrolysis will bake the overlying strata of the coal seam, causing significant changes in the rock mass structure and mechanical properties, which may lead to a series of geological environment problems such as overlying strata deformation, crack development, ground settlement, oil and gas dissipation, and groundwater leakage. In addition, compared with the traditional coal surface pyrolysis oil production technology, the in-situ underground pyrolysis of rich oil coal is also restricted by factors such as geological conditions and underground engineering capabilities, and the heating processes such as heating methods, temperatures, and heating rate used in surface pyrolysis are no longer applicable.

[0004] At present, the in-situ pyrolysis technology of rich oil coal is still in the stage of theoretical exploration and field trials. There is a lack of a physical simulation device for in-situ pyrolysis development of rich oil coal that can comprehensively monitor the geological structure evolution process and the law of pyrolysis oil and gas production with multi-parameter collaboration in the whole space, which brings great difficulties to the design and implementation of in-situ pyrolysis mining of rich oil coal, geological risk assessment, and efficient production of pyrolysis oil and gas. Therefore, mastering the geological structure evolution law and damage mode under the mining conditions of in-situ pyrolysis of rich oil coal, obtaining the optimal in-situ pyrolysis process parameters, and clarifying the best production efficiency of pyrolysis oil and gas have important practical significance for guiding the in-situ pyrolysis technology of rich oil coal. Summary of the Invention

[0005] Aiming at the above problems in the prior art, the present invention provides a simulation device and a simulation method for monitoring the damage of overlying strata during in-situ pyrolysis of rich oil coal, which solves the problem that the existing device does not consider the overlying strata damage deformation and dynamic evolution of geological structure under the condition of confining pressure in-situ stress during the simulation of in-situ pyrolysis of rich oil coal.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] On the one hand, a simulation device for monitoring the damage of overlying strata during in-situ pyrolysis of rich oil coal is provided, which includes:

[0008] Modular pyrolysis reaction chamber, the modular pyrolysis reaction chamber includes a reaction chamber module and a heating component placed at the bottom inside the reaction chamber module; the reaction chamber module is filled with simulated strata and oil-rich coal seams from top to bottom;

[0009] Vertical stress loading system, the vertical stress loading system includes a reaction frame for placing the reaction chamber module and a stress loading component acting on the upper opening of the reaction chamber module and installed on the reaction frame;

[0010] Pyrolysis oil and gas collection system, the pyrolysis oil and gas collection system includes an oil and gas collection component and an inert gas filling component communicated with the reaction chamber module;

[0011] Multi-parameter collaborative monitoring and acquisition system, the multi-parameter collaborative monitoring and acquisition system is connected to the reaction chamber module to collect the temperature, pressure, stress, strain, apparent resistivity and acoustic emission signals of the simulated strata, so as to monitor the fracture characteristics and dynamic evolution process of the simulated strata.

[0012] In the present invention, the reaction chamber module is filled with simulated strata and oil-rich coal seams from top to bottom. While piling up the simulated strata and oil-rich coal seams, a multi-parameter collaborative monitoring and acquisition system is arranged, and the vertical in-situ stress of the surrounding rock is simulated through the vertical stress loading system. Thus, the temperature, pressure, stress, strain, apparent resistivity and acoustic emission signals of the simulated strata and oil-rich coal seams under the simulated in-situ stress condition are collected through the multi-parameter collaborative monitoring and acquisition system, and the fracture characteristics and dynamic evolution process of the simulated surrounding rock are simulated, which is beneficial to guiding the in-situ pyrolysis process of oil-rich coal.

[0013] Furthermore, the reaction chamber module includes a plurality of reaction chamber units connected up and down. The reaction chamber unit includes two relatively connected reaction sub-chambers. The left and right sides of the reaction sub-chamber are provided with first connecting plates, and the upper and lower sides of the reaction sub-chamber are provided with second connecting plates; two opposite reaction sub-chambers are relatively connected through the first connecting plates to form a reaction chamber unit, and adjacent reaction chamber units are connected through the second connecting plates to form a reaction chamber module.

[0014] Furthermore, a first heat insulation layer is provided on the inner wall of the reaction chamber module, and a seepage isolation layer is provided inside the first heat insulation layer; a second heat insulation layer is provided on the outer wall of the reaction chamber module.

[0015] Furthermore, the heating component includes a pressure-resistant heat insulation plate installed at the bottom inside the reaction chamber module. An electric heating plate is placed on the pressure-resistant heat insulation plate, and the electric heating plate is electrically connected to a temperature controller; the temperature controller is connected to the multi-parameter collaborative monitoring and acquisition system; a heat transfer copper plate is sleeved on the electric heating plate.

[0016] Furthermore, the reaction frame includes a support bottom plate and a support top plate, which are connected by support columns; the reaction sub-chamber at the bottom of the reaction chamber module is connected to the support bottom plate through the second connecting plate;

[0017] The stress loading component includes a hydraulic jack installed on the support top plate. A stress cover plate that fits the reaction chamber unit is provided at the output end of the hydraulic jack, and the hydraulic jack is connected to a pressure controller.

[0018] Furthermore, the oil and gas collection component includes a condenser. The condenser is connected to a pyrolysis tar collection bottle and a pyrolysis gas collector placed on an electronic balance through oil and gas pipelines respectively. The collection end of the condenser is connected to a pyrolysis oil and gas output pipeline, and the pyrolysis oil and gas output pipeline passes through the reaction chamber module and inserts into the oil-rich coal seam.

[0019] The inert gas filling component includes an inert gas cylinder and a gas filling pipeline connected to the inert gas cylinder. The gas filling pipeline passes through the reaction chamber module and inserts into the oil-rich coal seam. Pressure sensors and vortex flow meters are provided between the condenser and the pyrolysis tar collection bottle, the pyrolysis gas collector, and the pyrolysis oil and gas output pipeline.

[0020] Furthermore, the multi-parameter collaborative monitoring and acquisition system includes a temperature data acquisition instrument, a network parallel electrical method instrument, an optical fiber strain analyzer, an acoustic emission signal acquisition instrument, and a host computer. The temperature data acquisition instrument, the network parallel electrical method instrument, the optical fiber strain analyzer, and the acoustic emission signal acquisition instrument are all connected to the host computer.

[0021] The temperature data acquisition instrument is connected to a thermocouple tree buried in layers in advance in the simulated formation and the oil-rich coal seam through a cable.

[0022] The network parallel electrical method instrument is connected to an electrode survey line buried in advance in the simulated formation and the oil-rich coal seam through a cable. Electrodes are arranged in layers on the electrode survey line.

[0023] The optical fiber strain analyzer is connected to an optical fiber buried in advance in the simulated formation and the oil-rich coal seam through a cable. FBG fiber gratings are arranged at intervals on the optical fiber.

[0024] The acoustic emission signal acquisition instrument is connected to an acoustic emission probe installed on a waveguide rod through a cable. The waveguide rod is inserted into the wall of the reaction chamber module so that the acoustic emission probe fits the simulated formation and the oil-rich coal seam.

[0025] On the other hand, a simulation method for a simulation device based on in-situ pyrolysis of oil-rich coal and overlying rock damage monitoring is provided, which includes the following steps:

[0026] Step S1: According to the combined relationship between the oil-rich coal to be simulated and the surrounding rock formation, assemble the reaction chamber module, lay a heating component at the bottom inside the reaction chamber module, and then install the reaction chamber module on the support bottom plate of the reaction frame.

[0027] Step S2: Sequentially fill the rich oil coal seam and the simulated formation in the reaction chamber module. While filling, thermocouple trees, optical fibers, and electrode survey lines are buried in layers. Insert waveguide rods into the wall of the reaction chamber module, and insert the pyrolysis oil and gas production pipeline and the gas injection pipeline through the reaction chamber module into the rich oil coal seam, and seal the wiring channels and pipeline channels;

[0028] Step S3: Start the pressure controller, and apply a predetermined vertical ground stress to the top of the rich oil coal seam and the simulated formation through the stress loading component;

[0029] Step S4: Start the temperature controller to heat the rich oil coal seam in the reaction chamber module. At the same time, open the valve of the inert gas cylinder, and fill the inert gas into the rich oil coal seam in the reaction chamber module through the gas injection pipeline to achieve the displacement of pyrolysis oil and gas;

[0030] Step S5: Start the temperature data collector, network parallel electrical method instrument, and fiber optic strain analyzer in the multi-parameter collaborative monitoring and acquisition system to monitor the temperature, strain, and apparent resistivity parameter information of the rich oil coal seam and the simulated formation respectively; Start the acoustic emission signal collector to monitor the fracture characteristics and dynamic evolution process of the geological structure during pyrolysis in real time, and use the pyrolysis oil and gas collection system to measure the pressure and flow rate of the pyrolysis tar and pyrolysis gas mixture in real time, and collect and record the tar production and pyrolysis oil and gas;

[0031] Step S6: Collect and analyze the data.

[0032] Further, the arrangement methods of the thermocouple trees, optical fibers, and electrode survey lines in Step S2 are as follows:

[0033] The thermocouple trees are distributed horizontally and are arranged in multiple layers at different heights in the rich oil coal seam and the simulated formation. Multiple K-type thermocouples are set on each thermocouple tree to monitor the temperature at different positions of the rich oil coal seam and the simulated formation during the in-situ pyrolysis of rich oil coal in real time;

[0034] The optical fibers are longitudinally distributed at the middle position of the simulated formation, and multiple FBG fiber Bragg gratings are set on the optical fibers to monitor the strain at different positions of the simulated formation during the in-situ pyrolysis of rich oil coal in real time;

[0035] The electrode survey lines are longitudinally distributed at the middle position of the rich oil coal seam and the simulated formation, and multiple electrodes are set on the electrode survey lines to monitor the apparent resistivity at different positions of the rich oil coal seam and the simulated formation during the in-situ pyrolysis of rich oil coal in real time.

[0036] The present invention discloses a simulation device and a simulation method for monitoring overburden damage during in-situ pyrolysis of rich oil coal, and its beneficial effects are:

[0037] In the reaction chamber module of the present invention, simulated strata and oil-rich coal seams are filled from top to bottom. While filling the simulated strata and oil-rich coal seams, a multi-parameter collaborative monitoring and acquisition system is arranged, and the vertical in-situ stress of the surrounding rock is simulated through a vertical stress loading system. Thus, the temperature, pressure, stress, strain, apparent resistivity and acoustic emission signals of the simulated strata and oil-rich coal seams under the simulated in-situ stress are collected through the multi-parameter collaborative monitoring and acquisition system, and the fracture characteristics and dynamic evolution process of the surrounding rock are monitored, which is beneficial to mastering the geological structure evolution law and damage mode under the condition of in-situ pyrolysis mining of oil-rich coal, obtaining the optimal in-situ pyrolysis process parameters, and clarifying the best production efficiency of pyrolysis oil and gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic structural diagram of a simulation device for monitoring overburden damage in in-situ pyrolysis of oil-rich coal of the present invention.

[0039] Figure 2 It is a schematic structural diagram of the vertical stress loading system of the present invention.

[0040] Figure 3 It is a schematic structural diagram of the multi-parameter collaborative monitoring and acquisition system and the heating component of the present invention.

[0041] Figure 4 It is a schematic structural diagram of the pyrolysis oil and gas collection system of the present invention.

[0042] Figure 5 It is a schematic structural diagram of the multi-parameter collaborative monitoring and acquisition system of the present invention.

[0043] Figure 6 It is a schematic structural diagram of the reaction chamber module of the present invention.

[0044] Figure 7 It is a schematic structural diagram of the reaction chamber unit of the present invention.

[0045] Figure 8 It is a schematic structural diagram of the thermocouple tree of the present invention.

[0046] Figure 9 It is a schematic structural diagram of the electrode measuring line of the present invention.

[0047] Figure 10 It is a schematic structural diagram of the optical fiber of the present invention.

[0048] Among them, 1. Modular pyrolysis reaction chamber;

[0049] 2. Vertical stress loading system; 21. Reaction frame; 22. Stress loading component; 23. Support bottom plate; 24. Support top plate; 25. Hydraulic jack; 26. Stress cover plate; 27. Pressure controller; 28. Support column;

[0050] 3. Pyrolysis oil and gas collection system; 31. Oil and gas collection component; 32. Inert gas filling component; 33. Condenser; 34. Electronic balance; 35. Pyrolysis tar collection bottle; 36. Pyrolysis gas collector; 37. Pyrolysis oil and gas output pipeline; 38. Inert gas bottle; 39. Gas filling pipeline; 310. Pressure sensor; 311. Vortex flowmeter;

[0051] 4. Multi-parameter collaborative monitoring and acquisition system; 41. Temperature data acquisition instrument; 411. Thermocouple tree; 412. K-type thermocouple; 42. Network parallel electrical method instrument; 421. Electrode survey line; 422. Electrode; 43. Fiber optic strain analyzer; 431. Optical fiber; 432. FBG fiber grating; 44. Acoustic emission signal acquisition instrument; 441. Waveguide rod; 442. Acoustic emission probe; 45. Host computer;

[0052] 5. Reaction chamber module; 51. Reaction chamber unit; 52. Reaction sub-chamber; 53. First connecting plate; 54. Second connecting plate; 55. First insulation layer; 56. Impermeable layer; 57. Second insulation layer;

[0053] 6. Heating component; 61. Pressure-resistant heat insulation plate; 62. Electric heating plate; 63. Heat transfer copper plate; 64. Temperature controller;

[0054] 7. Simulated formation; 8. Oil-rich coal seam. Specific embodiments

[0055] The specific embodiments of the present invention will be described to facilitate those skilled in the art of the present technology to understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art of the present technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions and creations using the concept of the present invention are within the scope of protection.

[0056] Example 1

[0057] Refer to Figures 1 - 7 , this embodiment provides a simulation device for monitoring the damage of overlying strata during in-situ pyrolysis of oil-rich coal, aiming to solve the problem that the existing device does not consider the damage deformation of overlying strata and the dynamic evolution of geological structure under the condition of confining pressure and in-situ stress during the simulation of in-situ pyrolysis of oil-rich coal. The specific structure in this embodiment will be described in detail below.

[0058] A simulation device for monitoring the damage of overlying strata during in-situ pyrolysis of oil-rich coal, which includes a modular pyrolysis reaction chamber 1, a vertical stress loading system 2, a pyrolysis oil and gas collection system 3, and a multi-parameter collaborative monitoring and acquisition system 4.

[0059] Among them, the modular pyrolysis reaction chamber 1 includes a reaction chamber module 5 and a heating component 6 placed at the bottom inside the reaction chamber module 5. The reaction chamber module 5 includes a plurality of reaction chamber units 51 connected up and down. The specific number of the reaction chamber units 51 can be assembled for the reaction chamber module 5 according to the height of the actual simulated formation.

[0060] The reaction chamber unit 51 includes two relatively connected reaction sub-chambers 52. The reaction sub-chamber 52 is a steel structure chamber body. First connecting plates 53 are arranged on the left and right sides of the reaction sub-chamber 52, and second connecting plates 54 are arranged on the upper and lower sides of the reaction sub-chamber 52. Both the first connecting plates 53 and the second connecting plates 54 are flange plates. Thus, two first connecting plates 53 at corresponding positions are connected by bolts, so that two opposite reaction sub-chambers 52 are relatively connected through the first connecting plates 53 to form the reaction chamber unit 51. Two second connecting plates 54 at corresponding positions are connected by bolts, so that adjacent reaction chamber units 51 are connected through the second connecting plates 54 to form the reaction chamber module 5.

[0061] Specifically, a first heat insulation layer 55 is arranged on the inner wall of the reaction chamber module 5, a seepage isolation layer 56 is arranged inside the first heat insulation layer 55, a second heat insulation layer 57 is arranged on the outer wall of the reaction chamber module 5. The reaction chamber module 5 is filled with a simulated formation 7 and an oil-rich coal seam 8 from top to bottom. Among them, the first heat insulation layer 55 can adopt a high-temperature insulating, fireproof and heat-insulating mica board, the second heat insulation layer 57 can adopt a silica-aluminum refractory ceramic fiber felt, and the seepage isolation layer 56 can adopt a thin stainless steel plate.

[0062] Specifically, the heating component 6 includes a pressure-resistant heat insulation plate 61 installed at the bottom inside the reaction chamber module 5. An electric heating plate 62 is placed on the pressure-resistant heat insulation plate 61. The electric heating plate 62 is electrically connected to a temperature controller 64. The temperature controller 64 is connected to the multi-parameter collaborative monitoring and acquisition system 4. A heat transfer copper plate 63 is sleeved on the electric heating plate 62. The multi-parameter collaborative monitoring and acquisition system 4 starts the electric heating plate 62 through the temperature controller 64 to heat the oil-rich coal seam 8 inside the reaction chamber module 5.

[0063] Specifically, the vertical stress loading system 2 includes a reaction frame 21 for placing the reaction chamber module 5 and a stress loading component 22 acting on the upper opening of the reaction chamber module 5 and installed on the reaction frame 21; the pyrolysis oil and gas collection system 3 includes an oil and gas collection component 31 communicated with the reaction chamber module 5 and an inert gas filling component 32; the multi-parameter collaborative monitoring and acquisition system 4 is connected to the reaction chamber module 5 to collect the temperature, pressure, stress, strain, apparent resistivity and acoustic emission signals of the simulated formation 7, so as to monitor the fracture characteristics and dynamic evolution process of the simulated formation 7.

[0064] Specifically, the reaction force frame 21 includes a support bottom plate 23 and a support top plate 24. The support bottom plate 23 and the support top plate 24 are connected by support columns 28. The reaction sub-chamber 52 at the bottom of the reaction chamber module 5 is connected to the support bottom plate 23 through a second connecting plate 54. The second connecting plate 54 and the support bottom plate 23 at the corresponding positions are connected by bolts, so as to install the reaction chamber module 5 on the reaction force frame 21.

[0065] The stress loading assembly 22 includes a hydraulic jack 25 installed on the support top plate 24. The output end of the hydraulic jack 25 is provided with a stress cover plate 26 that fits the reaction chamber unit 51, and the hydraulic jack 25 is connected to a pressure controller 27.

[0066] In this embodiment, the simulated formation 7 and the rich oil coal seam 8 are filled in the reaction chamber module 5 from top to bottom. While filling the simulated formation 7 and the rich oil coal seam 8, a multi-parameter collaborative monitoring and acquisition system 4 is arranged, and a vertical stress loading system 2 is used to apply vertical pressure to the simulated formation 7 and the rich oil coal seam 8 in the reaction chamber module 5 to simulate the vertical in-situ stress of the surrounding rock. Thus, the temperature, pressure, stress, strain, apparent resistivity and acoustic emission signals of the simulated formation 7 and the rich oil coal seam 8 under the simulated in-situ stress condition are collected through the multi-parameter collaborative monitoring and acquisition system 4, and the fracture characteristics and dynamic evolution process of the simulated surrounding rock are simulated, which is beneficial to mastering the geological structure evolution law and damage mode under the condition of in-situ pyrolysis mining of rich oil coal, obtaining the optimal in-situ pyrolysis process parameters, and clarifying the best output efficiency of pyrolysis oil and gas.

[0067] Embodiment 2

[0068] Reference Figures 2 - 4 Based on Embodiment 1, this embodiment gives a further solution for the oil and gas collection assembly 31 and the inert gas filling assembly 32. The purpose is to collect the tar and pyrolysis gas generated during the in-situ pyrolysis process and assist the oil and gas collection assembly 31. The specific structures of the oil and gas collection assembly 31 and the inert gas filling assembly 32 in this embodiment will be described in detail below.

[0069] The oil and gas collection assembly 31 includes a condenser 33, a pyrolysis tar collection bottle 35 and a pyrolysis gas collector 36.

[0070] Among them, the condenser 33 is connected to the pyrolysis tar collection bottle 35 and the pyrolysis gas collector 36 respectively through an oil and gas pipeline. The pyrolysis tar collection bottle 35 is placed on an electronic balance 34, and the tar production is recorded in real time through the electronic balance 34.

[0071] The collection end of the condenser 33 is connected to the pyrolysis oil and gas output pipeline 37. The pyrolysis oil and gas output pipeline 37 passes through the reaction chamber module 5 and is inserted into the rich oil coal seam 8, and the insertion part of the pyrolysis oil and gas output pipeline 37 passing through the reaction chamber module 5 is sealed by a pipeline sealing sleeve.

[0072] The inert gas filling assembly 32 includes an inert gas cylinder 38 and a gas filling pipeline 39 communicating with the inert gas cylinder 38. The gas filling pipeline 39 passes through the reaction chamber module 5 and inserts into the rich oil coal seam 8.

[0073] Pressure sensors 310 and vortex flow meters 311 are provided between the condenser 33, the pyrolysis tar collection bottle 35, the pyrolysis gas collector 36 and the pyrolysis oil and gas output pipeline 37. The pressure sensors 310 and the vortex flow meters 311 are respectively used to measure the pressure and flow rate of the pyrolysis gas in real time.

[0074] In this embodiment, the mixture of pyrolysis tar and pyrolysis gas generated by the pyrolysis of rich oil coal is discharged from the pyrolysis oil and gas output pipeline 37 in the reaction chamber module 5, passes through the pressure sensor 310 and the vortex flow meter 311 in sequence, and then enters the condenser 33. The pressure sensor 310 and the vortex flow meter 311 are respectively used to measure the pressure and flow rate of the mixture of pyrolysis tar and pyrolysis gas in real time; the condenser 33 is used to separate the mixture of pyrolysis tar and pyrolysis gas. Among them, the pyrolysis tar enters the pyrolysis tar collection bottle 35, and the tar production is recorded in real time by the electronic balance 34. The pyrolysis gas passes through the vortex flow meter 311 and the pressure sensor 310 and then enters the pyrolysis gas collector 36. The pressure sensor 310 and the vortex flow meter 311 are respectively used to measure the pressure and flow rate of the pyrolysis gas in real time; the pyrolysis gas collector 36 can be connected to a gas chromatograph analyzer (not shown in the figure) to analyze the components of the pyrolysis gas.

[0075] In order to accurately obtain the yields of pyrolysis tar and pyrolysis gas generated by the pyrolysis of rich oil coal, the inert gas in the inert gas cylinder 38 can be transported to the rich oil coal seam 8 through the inert gas filling pipeline 39 while the rich oil coal is pyrolyzed, so as to carry out the pyrolysis tar and pyrolysis gas and avoid retention.

[0076] Embodiment 3

[0077] Reference Figure 3 and Figure 5 Based on Embodiment 1, this embodiment gives a further solution for the multi-parameter collaborative monitoring and acquisition system 4. Its purpose is to collect the temperature, pressure, strain, apparent resistivity and acoustic emission signals of the simulated formation 7 or the rich oil coal seam 8 during the in-situ pyrolysis process, as well as the fracture characteristics and dynamic evolution process of the geological structure during the pyrolysis process. The specific structure of the multi-parameter collaborative monitoring and acquisition system 4 in this embodiment will be described in detail below.

[0078] The multi-parameter collaborative monitoring and acquisition system 4 includes a temperature data collector 41, a network parallel electrical method instrument 42, an optical fiber strain analyzer 43, an acoustic emission signal collector 44 and a host computer 45.

[0079] Among them, a temperature data collector 41, a network parallel electrical prospecting instrument 42, an optical fiber strain analyzer 43, and an acoustic emission signal collector 44 are all connected to a host computer 45. The host computer 45 can be a computer, and the computer is electrically connected to the temperature data collector 41, the network parallel electrical prospecting instrument 42, the optical fiber strain analyzer 43, and the acoustic emission signal collector 44.

[0080] Specifically, the temperature data collector 41 is connected to a thermocouple tree 411 that is pre-stratified and buried in the simulated formation 7 and the rich oil coal seam 8 through a cable.

[0081] The network parallel electrical prospecting instrument 42 is connected to an electrode survey line 421 that is pre-buried in the simulated formation 7 and the rich oil coal seam 8 through a cable. Electrodes 422 are arranged in layers on the electrode survey line 421.

[0082] The optical fiber strain analyzer 43 is connected to an optical fiber 431 that is pre-buried in the simulated formation 7 and the rich oil coal seam 8 through a cable. FBG fiber gratings 432 are arranged at intervals on the optical fiber 431.

[0083] The acoustic emission signal collector 44 is connected to an acoustic emission probe 442 installed on a waveguide rod 441 through a cable. The waveguide rod 441 is inserted into the wall of the reaction chamber module 5 so that the acoustic emission probe 442 is in contact with the simulated formation 7 and the rich oil coal seam 8.

[0084] In this embodiment, the reaction chamber module 5 is a steel structure chamber body. A reserved orifice is provided on the wall of the steel structure chamber body. The reserved orifice is used for the layout of the pyrolysis oil and gas production pipeline 37, the gas filling pipeline 39, the thermocouple tree 411, and the waveguide rod 441. At the same time, the reserved orifice is sealed through a cable seal.

[0085] The thermocouple tree 411, the electrode survey line 421, and the optical fiber 431 are all arranged in layers, and the simulated formation 7 and the rich oil coal seam 8 are also filled in layers. That is, when filling a layer of the simulated formation 7 or the rich oil coal seam 8, a layer of the thermocouple tree 411, the electrode survey line 421, and the optical fiber 431 is arranged.

[0086] Embodiment 4

[0087] Based on Embodiment 1, this embodiment provides a simulation method for a simulation device for monitoring overlying rock damage during in-situ pyrolysis of rich oil coal. The purpose is to solve the problem that the existing device does not consider the confining pressure ground stress during the simulation of the in-situ pyrolysis of rich oil coal. The specific steps of the simulation method in this embodiment will be described in detail below.

[0088] A simulation method for a simulation device for monitoring overlying rock damage during in-situ pyrolysis of rich oil coal includes the following steps:

[0089] Step S1: Assemble the reaction chamber module 5 according to the combined relationship between the rich oil coal and the surrounding rock strata to be simulated, lay a heating component 6 at the bottom inside the reaction chamber module 5, and then install the reaction chamber module 5 on the support bottom plate 23 of the reaction frame 21.

[0090] Step S2: Sequentially fill the rich oil coal layer 8 and the simulated strata 7 in the reaction chamber module 5. While filling, thermocouple trees 411, electrode measurement lines 421, and optical fibers 431 are buried in layers. Insert the waveguide rod 441 into the wall of the reaction chamber module 5, and insert the pyrolysis oil and gas production pipeline 37 and the gas filling pipeline 39 through the reaction chamber module 5 into the rich oil coal layer 8, and seal the wiring channels and pipeline channels.

[0091] Among them, the arrangement methods of the thermocouple trees 411, electrode measurement lines 421, and optical fibers 431 in step S2 are as follows:

[0092] Reference Figure 8 , the thermocouple trees 411 are distributed horizontally and multiple layers are set at different heights in the rich oil coal layer 8 and the simulated strata 7. Multiple K-type thermocouples 412 are set on each bundle of thermocouple trees 411 to monitor the temperatures at different positions of the rich oil coal layer 8 and the simulated strata 7 in real time during the in-situ pyrolysis process of the rich oil coal.

[0093] Reference Figure 10 , the optical fibers 431 are longitudinally distributed at the middle position of the simulated strata 7. Multiple FBG fiber gratings 432 are set on the optical fibers 431 to monitor the strains at different positions of the simulated strata 7 in real time during the in-situ pyrolysis process of the rich oil coal.

[0094] Reference Figure 9 , the electrode measurement lines 421 are longitudinally distributed at the middle position of the rich oil coal layer 8 and the simulated strata 7. Multiple electrodes 422 are set on the electrode measurement lines 421 to monitor the apparent resistivity at different positions of the rich oil coal layer 8 and the simulated strata 7 in real time during the in-situ pyrolysis process of the rich oil coal.

[0095] Step S3: Start the pressure controller 27 and apply a predetermined vertical in-situ stress to the tops of the rich oil coal layer 8 and the simulated strata 7 through the stress loading component 22.

[0096] Step S4: Start the temperature controller 64 to heat the rich oil coal layer 8 in the reaction chamber module 5. At the same time, open the valve of the inert gas cylinder 38 and fill the inert gas into the rich oil coal layer 8 in the reaction chamber module 5 through the gas filling pipeline 39 to achieve the displacement of the pyrolysis oil and gas.

[0097] Step S5: Start the temperature data collector 41, network parallel electrical resistivity instrument 42, and fiber optic strain analyzer 43 in the multi-parameter collaborative monitoring and acquisition system 4 to monitor the temperature, strain, and apparent resistivity parameter information of the rich oil coal seam 8 and the simulated formation 7; start the acoustic emission signal collector 44 to monitor the fracture characteristics and dynamic evolution process of the geological structure during pyrolysis in real time, and use the pyrolysis oil and gas collection system 3 to measure the pressure and flow rate of the pyrolysis tar and pyrolysis gas mixture in real time, and collect and record the tar production and pyrolysis oil and gas.

[0098] Step S6: Collect and analyze the data, and analyze the temperature, strain, and apparent resistivity parameters of the rich oil coal seam 8 and the simulated formation 7 collected in step S5, the fracture characteristics and dynamic evolution process of the geological structure during pyrolysis, and the pressure and flow rate of the tar production and pyrolysis oil and gas during pyrolysis.

[0099] Repeating steps S1 to S6 can realize the simulation of the in-situ pyrolysis process of rich oil coal under different combinations of rich oil coal and surrounding rock formation characteristics, different stress states, different pyrolysis temperatures, and heating rate conditions.

[0100] Although the specific embodiments of the invention have been described in detail with reference to the accompanying drawings, it should not be construed as a limitation on the protection scope of this patent. Within the scope described in the claims, various modifications and deformations that can be made by those skilled in the art without creative efforts still fall within the protection scope of this patent.

Claims

1. A simulation device for monitoring overburden damage during in-situ pyrolysis of oil-rich coal, characterized in that: include: A modular pyrolysis reaction chamber (1), the modular pyrolysis reaction chamber (1) comprising a reaction chamber module (5) and a heating assembly (6) placed at the bottom of the reaction chamber module (5); the reaction chamber module (5) is filled with simulated strata (7) and oil-rich coal seams (8) from top to bottom; A vertical stress loading system (2), the vertical stress loading system (2) comprising a reaction frame (21) for placing a reaction chamber module (5) and a stress loading component (22) acting on an opening above the reaction chamber module (5) and mounted on the reaction frame (21); A pyrolysis oil and gas collection system (3), the pyrolysis oil and gas collection system (3) comprising an oil and gas collection component (31) and an inert gas filling component (32) connected to the reaction chamber module (5); A multi-parameter collaborative monitoring and acquisition system (4), wherein the multi-parameter collaborative monitoring and acquisition system (4) is connected to the reaction chamber module (5) to collect temperature, pressure, stress, strain, apparent resistivity and acoustic emission signals of the simulated stratum (7) to monitor the fracture characteristics and dynamic evolution process of the simulated stratum (7); The reaction chamber module (5) comprises a plurality of reaction chamber units (51) connected up and down, the reaction chamber unit (51) comprises two reaction sub-chambers (52) connected to each other in a relative manner, the left and right sides of the reaction sub-chamber (52) are provided with a first connecting plate (53), and the upper and lower sides of the reaction sub-chamber (52) are provided with a second connecting plate (54); two relative reaction sub-chambers (52) are connected to each other in a relative manner via the first connecting plate (53) to form a reaction chamber unit (51), and adjacent reaction chamber units (51) are connected via the second connecting plate (54) to form a reaction chamber module (5); The heating assembly (6) comprises a pressure-resistant heat-insulating plate (61) installed at the bottom of the reaction chamber module (5); an electric heating plate (62) is placed on the pressure-resistant heat-insulating plate (61); the electric heating plate (62) is electrically connected to a temperature controller (64); the temperature controller (64) is connected to a multi-parameter collaborative monitoring and acquisition system (4); and a heat transfer copper plate (63) is sleeved on the electric heating plate (62).

2. The simulation device for monitoring overburden damage during in-situ pyrolysis of oil-rich coal according to claim 1 is characterized by: A first thermal insulation layer (55) is arranged on the inner wall of the reaction chamber module (5), and a permeation barrier layer (56) is arranged on the inner side of the first thermal insulation layer (55); a second thermal insulation layer (57) is arranged on the outer wall of the reaction chamber module (5).

3. The simulation device for monitoring overburden damage during in-situ pyrolysis of oil-rich coal according to claim 1 is characterized by: The reaction frame (21) comprises a supporting bottom plate (23) and a supporting top plate (24), wherein the supporting bottom plate (23) and the supporting top plate (24) are connected via a supporting column (28); the reaction sub-chamber (52) located at the bottom of the reaction chamber module (5) is connected to the supporting bottom plate (23) via a second connecting plate (54); The stress loading assembly (22) comprises a hydraulic jack (25) mounted on a supporting top plate (24), an output end of the hydraulic jack (25) is provided with a stress cover plate (26) matching the reaction chamber unit (51), and the hydraulic jack (25) is connected to a pressure controller (27).

4. The simulation device for monitoring overburden damage during in-situ pyrolysis of oil-rich coal according to claim 3 is characterized by: The oil and gas collection assembly (31) comprises a condenser (33), and the condenser (33) is respectively connected to a pyrolysis tar collection bottle (35) and a pyrolysis gas collector (36) placed on an electronic balance (34) through oil and gas pipelines; the collection end of the condenser (33) is connected to a pyrolysis oil and gas production pipeline (37), and the pyrolysis oil and gas production pipeline (37) passes through the reaction chamber module (5) and is inserted into the oil-rich coal seam (8); The inert gas filling assembly (32) comprises an inert gas bottle (38) and a gas filling pipeline (39) connected to the inert gas bottle (38), and the gas filling pipeline (39) passes through the reaction chamber module (5) and is inserted into the oil-rich coal seam (8); A pressure sensor (310) and a vortex flowmeter (311) are provided between the condenser (33) and the pyrolysis tar collection bottle (35), the pyrolysis gas collector (36) and the pyrolysis oil and gas output pipeline (37).

5. The simulation device for monitoring overburden damage during in-situ pyrolysis of oil-rich coal according to claim 4 is characterized by: The multi-parameter collaborative monitoring and acquisition system (4) comprises a temperature data acquisition instrument (41), a network parallel electrical method instrument (42), an optical fiber strain analyzer (43), an acoustic emission signal acquisition instrument (44) and a host computer (45); the temperature data acquisition instrument (41), the network parallel electrical method instrument (42), the optical fiber strain analyzer (43), and the acoustic emission signal acquisition instrument (44) are all connected to the host computer (45); The temperature data acquisition instrument (41) is connected to a thermocouple tree (411) pre-buried in layers in the simulated stratum (7) and the oil-rich coal seam (8) via a cable; The network parallel electrical method instrument (42) is connected to an electrode measuring line (421) pre-buried in the simulated stratum (7) and the oil-rich coal seam (8) through a cable, and electrodes (422) are arranged in layers on the electrode measuring line (421); The optical fiber strain analyzer (43) is connected to an optical fiber (431) pre-buried in the simulated stratum (7) and the oil-rich coal seam (8) through a cable, and FBG optical fiber gratings (432) are arranged at intervals on the optical fiber (431); The acoustic emission signal collector (44) is connected to an acoustic emission probe (442) installed on a waveguide rod (441) via a cable, and the waveguide rod (441) is inserted into the wall of the reaction chamber module (5) so that the acoustic emission probe (442) fits the simulated stratum (7) and the oil-rich coal seam (8).

6. A simulation method based on the simulation device for monitoring overburden damage during in-situ pyrolysis of oil-rich coal according to claim 5, characterized in that: The following steps are involved: Step S1, assembling a reaction chamber module (5) according to the oil-rich coal and surrounding rock formation to be simulated, laying a heating assembly (6) at the bottom of the reaction chamber module (5), and then installing the reaction chamber module (5) on the supporting bottom plate (23) of the reaction frame (21); Step S2, stacking the oil-rich coal seam (8) and the simulated stratum (7) in layers in the reaction chamber module (5), burying the thermocouple tree (411), the electrode measuring line (421) and the optical fiber (431) in layers while stacking in layers, and inserting the waveguide rod (441) into the chamber wall of the reaction chamber module (5); Then, the pyrolysis oil and gas output pipeline (37) and the gas charging pipeline (39) are inserted into the oil-rich coal seam (8) through the reaction chamber module (5), and the wiring channel and the pipeline channel are sealed; Step S3, starting the pressure controller (27) to apply a predetermined vertical ground stress to the top of the oil-rich coal seam (8) and the simulated formation (7) through the stress loading component (22); Step S4, starting the temperature controller (64) to heat the oil-rich coal layer (8) in the reaction chamber module (5), and at the same time, opening the valve of the inert gas cylinder (38) to charge the inert gas into the oil-rich coal layer (8) in the reaction chamber module (5) through the gas charging pipeline (39), so as to achieve displacement of pyrolysis oil and gas; Step S5, start the temperature data acquisition instrument (41), the network parallel electrical method instrument (42) and the optical fiber strain analyzer (43) in the multi-parameter collaborative monitoring and acquisition system (4) to monitor the temperature, strain and apparent resistivity parameter information of the oil-rich coal seam (8) and the simulated stratum (7) respectively; start the acoustic emission signal acquisition instrument (44) to monitor the fracture characteristics and dynamic evolution process of the geological structure during the pyrolysis process in real time, and use the pyrolysis oil and gas collection system (3) to measure the pressure and flow of the pyrolysis tar and pyrolysis gas mixture in real time, and collect and record the tar production and pyrolysis oil and gas; Step S6: collect and analyze data.

7. The simulation method of the simulation device for monitoring overburden damage during in-situ pyrolysis of oil-rich coal according to claim 6 is characterized by: The arrangement of the thermocouple tree (411), the electrode measuring line (421) and the optical fiber (431) in step S2 is as follows: Thermocouple trees (411) are distributed in the horizontal direction and are arranged in multiple layers at different heights in the oil-rich coal seam (8) and the simulated stratum (7); a plurality of K-type thermocouples (412) are arranged on each bundle of thermocouple trees (411) to monitor the temperature at different positions of the oil-rich coal seam (8) and the simulated stratum (7) in real time during the in-situ pyrolysis of the oil-rich coal; The optical fiber (431) is longitudinally distributed in the middle of the simulated stratum (7), and a plurality of FBG fiber gratings (432) are arranged on the optical fiber (431) for real-time monitoring of strains at different positions of the simulated stratum (7) during in-situ pyrolysis of oil-rich coal; The electrode measuring line (421) is distributed longitudinally in the middle position of the oil-rich coal seam (8) and the simulated stratum (7), and a plurality of electrodes (422) are arranged on the electrode measuring line (421) for real-time monitoring of the apparent resistivity at different positions of the oil-rich coal seam (8) and the simulated stratum (7) during the in-situ pyrolysis process of the oil-rich coal.

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