Ultra-deep carbonate rock dissolution simulation experiment device and method

Abstract

An ultra-deep carbonate rock dissolution simulation experiment device and method. The experiment device comprises: at least two reaction kettles (1) arranged in series connection, the reaction kettles (1) each comprising a confining pressure mechanism (10) and an axial pressure mechanism (20), wherein the confining pressure mechanism (10) is provided with a rock core cavity for accommodating a rock core (2) and can apply confining pressure to the rock core (2), the axial pressure mechanism (20) is used for applying axial pressure to the rock core (2) in the rock core cavity, and the axial pressure mechanism (20) is provided with a reaction solution interface communicating with the rock core cavity; a solution pressure vessel system (40), capable of providing a reaction solution and injecting the reaction solution into the rock core cavities by means of the reaction solution interfaces; at least two back pressure control devices (30), outlet ends of the rock core cavities of the reaction kettles (1) being connected to the back pressure control devices (30); and a detection system (50). The rock core cavities of the reaction kettles (1) are in series connection, and the reaction solution provided by the solution pressure vessel system (40) can sequentially flow through the rock core cavities in series connection, and the detection system (50) is used for separately performing detection on each rock core cavity, thereby solving the technical problem of the difficulty in conducting simulation experiments with respect to the dissolution of strongly altered carbonate rocks in ten-thousand-meter ultra-deep conditions.

Description

Ultra-deep carbonate rock dissolution simulation experimental device and method

[0001] Related applications

[0002] This application claims priority to Chinese patent application No. 202311416415.2 filed on October 27, 2023, and cites the contents disclosed in the above patent application as part of this application. Technical Field

[0003] The present application relates to the field of petroleum and natural gas geology, and in particular to an ultra-deep carbonate rock dissolution simulation experimental device and method. Background Art

[0004] With the exploitation of oil and gas resources in shallow and medium layers (burial depth <4500m) and the decline of resource quantity, entering the deep layers (burial depth of 4500-6000m) and even ultra-deep layers (burial depth >6000m) of the earth to search for oil and gas resources has become a real need and an important trend in oil and gas exploration today.

[0005] However, the geological conditions of ultra-deep carbonate rocks are complex, the level of understanding is low, and exploration is difficult. Therefore, the formation mechanism and distribution pattern of large-scale reservoirs in ultra-deep carbonate rocks have become key scientific issues that need to be urgently solved in oil and gas exploration.

[0006] Water-rock reaction simulation experiments are an important method for studying the mechanism of carbonate rock dissolution. By setting different experimental conditions, the carbonate rock dissolution process under temperature, pressure and fluid control can be reproduced, thus providing a basis for identifying the laws of carbonate rock dissolution and predicting favorable reservoir development areas.

[0007] Chinese invention patent application CN102435716A discloses a diagenetic simulation experimental device, and Chinese invention patent application CN104407118A discloses a method for analyzing carbonate rock dissolution and dissolution benefits. The method uses actual rock plunger samples to simulate internal rock dissolution experiments. The advantage is that the water-rock ratio and hydrodynamic mode during the experiment are relatively close to underground conditions, and the pore evolution inside the rock before and after dissolution can be analyzed. However, the pore types of dolomite samples are complex and diverse, including intercrystalline pores, oolitic pores, caves, and cracks. During the dissolution process, the pore structure often changes and forms a dominant channel for fluid migration. This will cause the contact area between the fluid and the rock to change, resulting in a decrease in the amount of rock dissolution. This will inevitably affect the accurate understanding of the effects of temperature, pressure, and fluid factors on dissolution. In addition, the dolomite water-rock reaction data is not repeatable and reproducible.

[0008] Chinese invention patent application CN105137033A discloses a method and device for quantitatively evaluating the surface karstification effect of gypsum-carbonate reservoirs. This method focuses only on the dissolution effect and quantitative evaluation of gypsum-carbonate rocks in a surface environment and is not applicable to the high-temperature and high-pressure conditions of dolomite water-rock reactions during the burial stage. Although it considers the effect of the gypsum-salt component in the rock sample on dissolution, it ignores the factors of formation water properties. However, dolomite is widely present in the formation, and fluid properties are the key factors affecting dolomite dissolution and precipitation. The method uses the form of immersing rock samples in a solution, and the water-rock ratio and hydrodynamic mode do not conform to the actual underground situation. In addition, the chemical connotation represented by the amount of rock dissolution is unclear.

[0009] Chinese invention patent CN106323812B (patent number: CN201510387709.6) discloses a test apparatus for simulated water-rock flow tests, comprising a control unit; a reactor containing multiple sample tubes; and a constant-flow pump comprising multiple piston cylinders, multiple reversing units, and a drive mechanism. This apparatus allows for simultaneous control of multiple sets of simulated water-rock flow tests, ensuring that multiple sets of rock samples react with the reaction fluid under identical experimental conditions. However, the apparatus has several shortcomings: the artificially configured CO2 fluid, acetic acid fluid, and H2S solution react with the rock during the simulation, failing to account for the fact that subsurface fluids migrate across different strata and the changes in fluid properties during migration. Furthermore, the fluid entering the reactor and reacting with the rock is driven solely by the constant-flow pump, without distinguishing between the types of fluid driving forces. Consequently, it cannot objectively simulate diagenetic processes such as dissolution, cementation, or replacement between fluids and reservoirs under geological boundary conditions.

[0010] Carbonate rocks are widely distributed underground, and the reaction between carbonate rocks and acidic fluids quickly reaches chemical equilibrium.

[0011] Yang Yunkun et al. (Re-understanding of deep carbonate dissolution based on in-situ observations of simulation experiments [J], Journal of Peking University (Science and Technology), 2014, 50(2): 316-322) designed a set of water-rock interaction simulation experiments for carbonate rocks with increasing burial depth using the diamond anvil cell (DAC) technique. Although obvious cementation (precipitation) could be observed in situ, it was not possible to quantitatively analyze the amount of dissolution in the carbonate rock water-rock reaction, let alone analyze the specific role of formation water properties in the dolomite water-rock reaction process.

[0012] Fan Ming et al. (Effects of acidic fluids on carbonate reservoirs [J], Geochemistry, 2009, 38(1): 20-26) independently designed a carbonate dissolution rate measuring instrument. However, this experimental device and method are dedicated to evaluating the dissolution rate of carbonate rocks, requiring the carbonate rock water-rock reaction results to be far from chemical equilibrium. Due to the small amount of rock sample, the fluid generated by the reaction still has the ability to react with the rock.

[0013] Looking at the current research status at home and abroad, carbonate rock dissolution simulation experimental devices can be divided into rock surface dissolution and rock internal dissolution according to the water-rock reaction mode: the rock surface dissolution experimental device mainly includes an acid-rock reaction rotating rock disk instrument, a high-temperature and high-pressure tubular flow reaction device, a diamond pressure chamber and a molten capillary silica tube; the rock internal dissolution experimental device includes a high-temperature and high-pressure core seepage simulation device.

[0014] Obviously, most rock surface dissolution experiment samples are rock particles or blocks. Water-rock reactions mainly occur on the surface of the rock, with a "water-encapsulated rock" characteristic. The water-rock ratio and hydrodynamic conditions differ greatly from the burial environment, and the main focus is on chemical reactions in carbonate rock water-rock reaction experiments. However, as some geologists have questioned the burial dissolution and porosity increase in carbonate reservoirs, they believe that the chemical mechanism of dissolution and porosity increase between carbonate rocks and acidic fluids is unquestionable. The question is how the acidic fluid retains its acidity during long-distance migration, how large is the scale of burial dissolution and porosity increase, and what are the main controlling factors and distribution patterns of favorable burial dissolution? Therefore, burial dissolution of carbonate rocks cannot be simplified to chemical reactions. It is necessary to focus on the core geological issue of the formation mechanism and distribution patterns of ultra-deep carbonate reservoirs and conduct carbonate rock dissolution simulation experiments under the constraints of geological models from the perspective of geological systems.

[0015] Judging from the current technological status, although the existing equipment cannot meet the needs of China's ultra-deep and strongly modified carbonate rock dissolution simulation experiments, after long-term research and accumulation, the above-mentioned experimental equipment has laid a solid foundation for the research and development of ultra-deep carbonate rock dissolution simulation experimental equipment.

[0016] Currently, previous carbonate rock dissolution simulation experiments have mostly focused on burial depths shallower than 6,000 meters, and the experimental fluids have primarily been organic acid solutions. Systematic carbonate rock dissolution simulation experiments in ultra-deep layers (burial depths > 6,000 meters) and in highly modified geological settings have not yet been conducted. The mineral dissolution-precipitation mechanisms and their reservoir-forming effects in ultra-deep burial environments remain unclear. For example, can carbonate rocks undergo large-scale dissolution in ultra-deep environments? Can deep-source thermal fluids (hydrothermal fluids) improve reservoir performance? How can the evolution of the dynamic process of carbonate rock dissolution-induced porosity increase and cementation-induced porosity reduction be quantitatively simulated, along with its main controlling factors? Can aggressive fluids retain their acidity during long-distance migration across tectonic periods?

[0017] These mechanistic issues are the focus and difficulty of the research on the formation mechanism and distribution law of ultra-deep carbonate reservoirs, and thus put forward higher requirements for the simulation experimental device of carbonate rock dissolution under the coupling of ultra-deep temperature-stress-fluid. It must not only meet the requirements of higher working temperature, pressure and corrosion resistance, but also achieve the necessary functions such as water-rock ratio and hydrodynamic mode close to geological reality, quantitative evaluation of dissolution porosity effect, characterization of the dynamic evolution process of the internal pore structure of the rock under dissolution-precipitation, cross-tectonic migration of fluids, and in-situ analysis of high-temperature and high-pressure fluid properties.

[0018] In summary, it is difficult to conduct simulation experiments on the dissolution of ultra-deep and strongly modified carbonate rocks at a depth of 10,000 meters using existing technologies.

[0019] Summary of the Invention

[0020] The purpose of this application is to provide an ultra-deep carbonate rock dissolution simulation experimental device and method to solve the technical problem in the prior art that it is difficult to conduct simulation experiments on the dissolution of ultra-deep and strongly modified carbonate rocks of 10,000 meters.

[0021] The above-mentioned purpose of this application can be achieved by adopting the following technical solutions:

[0022] The present application provides an ultra-deep carbonate rock dissolution simulation experimental device, comprising:

[0023] At least two reactors arranged in series, the reactors comprising a confining pressure mechanism and an axial pressure mechanism, the confining pressure mechanism having a core cavity for accommodating a core and capable of applying confining pressure to the core, the axial pressure mechanism for applying axial pressure to the core in the core cavity, the axial pressure mechanism being provided with a reaction solution interface communicating with the core cavity;

[0024] a solution pressure vessel system capable of providing a reaction solution and injecting the reaction solution into the core cavity through a reaction solution interface;

[0025] At least two back pressure control devices, the outlet end of the core chamber of each reactor is connected to the back pressure control device;

[0026] Detection system;

[0027] The core cavities of the reactor are connected in series, and the reaction solution provided by the solution pressure container system can flow through the core cavities connected in series in sequence. The detection system is used to detect each core cavity respectively.

[0028] In a preferred embodiment, the detection system includes at least two in-situ window detection mechanisms, which include a high-temperature and high-pressure fluid in-situ detection cell and a spectrometer. The high-temperature and high-pressure fluid in-situ detection cell is connected in series between the outlet end of the core cavity and the back pressure control device.

[0029] In a preferred embodiment, the high-temperature and high-pressure fluid in-situ detection cell includes a solution cavity, a fixing mechanism and a window portion, wherein the solution cavity is fixed between the outlet end of the core cavity and the back pressure control device by the fixing mechanism; the solution cavity is provided with a solution inlet and a solution outlet, the solution inlet is connected to the outlet end of the core cavity, and the solution outlet is connected to the back pressure control device; the window portion is provided in the solution cavity, and the spectrometer is provided outside the window portion, so that light in the solution cavity can be transmitted to the spectrometer through the window portion.

[0030] In a preferred embodiment, the window portion includes a metal cylinder, an insulating ceramic sleeve and a sapphire glass, the insulating ceramic sleeve and the sapphire glass are respectively arranged at both ends of the metal cylinder, and the sapphire glass has a large diameter portion and a small diameter portion, and the small diameter portion is at least partially inserted into the metal cylinder.

[0031] In a preferred embodiment, the detection system includes a pressure detection mechanism corresponding to the reactor one by one; the pressure detection mechanism includes an inlet pressure sensor, an outlet pressure sensor and a differential pressure sensor, the inlet pressure sensor is arranged at the inlet end of the core cavity, and the outlet pressure sensor is arranged at the outlet end of the core cavity; the differential pressure sensor is arranged between the inlet end and the outlet end of the core cavity to detect the fluid pressure difference between the inlet end and the outlet end.

[0032] In a preferred embodiment, the back pressure control device includes a back pressure controller and a back pressure pump, the back pressure pump is connected to the back pressure controller, and the back pressure controller is arranged between the inlet end of the latter core cavity and the high temperature and high pressure fluid in situ detection pool.

[0033] In a preferred embodiment, the confining pressure mechanism includes a copper sleeve and a support sleeve. The inner cavity of the copper sleeve forms a core cavity. The support sleeve is wrapped around the outside of the copper sleeve. The support sleeve is provided with a confining pressure fluid channel. The confining pressure fluid enters between the support sleeve and the copper sleeve through the confining pressure fluid channel so that the copper sleeve applies confining pressure to the core.

[0034] In a preferred embodiment, the confining pressure fluid channel is connected to a confining pressure pump, and the confining pressure pump is used to deliver confining pressure fluid to the confining pressure fluid channel.

[0035] In a preferred embodiment, the confining pressure pump and the back-pressure pump are connected to the same water container.

[0036] In a preferred embodiment, the reactor includes a temperature controller, which is used to regulate the temperature of the confining pressure fluid.

[0037] In a preferred embodiment, the axial pressure mechanism includes hydraulic push rod plugs provided at both ends of the copper sleeve, and the reaction solution interface is provided at the hydraulic push rod plugs.

[0038] In a preferred embodiment, the solution pressure vessel system includes a pressure vessel, a gas cylinder, a gas booster pump, a volume flow meter, a gas buffer tank and a double-plunger pump, the gas booster pump is connected to the pressure vessel, the gas cylinder, the gas booster pump, the gas buffer tank and the gas flow meter are connected in series to the pressure vessel in sequence, and the pressure vessel is connected to the reaction solution interface.

[0039] In a preferred embodiment, the detection system includes an electronic balance; the ends of all the reactors connected in series are connected to samplers, and the samplers are arranged on the electronic balance.

[0040] The present application provides an ultra-deep carbonate rock dissolution simulation experimental method, using the ultra-deep carbonate rock dissolution simulation experimental device described above. The experimental method includes:

[0041] The reactor applies confining pressure and axial pressure to the core in the core cavity;

[0042] The solution pressure vessel system provides the reaction solution and injects it into the core cavity, and the back pressure control device controls the outlet pressure of each core cavity;

[0043] The detection system detects each core cavity separately.

[0044] The features and advantages of this application are:

[0045] In this ultra-deep carbonate rock dissolution simulation experimental device, multiple reactors are arranged in series, and the reaction solution provided by the solution pressure vessel system flows through the cores in each reactor in turn; the back pressure control device independently controls the fluid pressure in each reactor, and the confining pressure mechanism and axial pressure mechanism in each reactor respectively apply confining pressure and axial pressure to the core therein, thereby simultaneously loading the core with simulated static rock pressure and fluid pressure, driving the fluid to cross two or more reactors with temperature and pressure conditions, realizing the cross-tectonic period dissolution simulation of carbonate rocks under the constraints of geological models, and conducting multi-stage-continuous flow simulation, which is conducive to meeting the needs of ultra-deep and strongly modified carbonate rock dissolution simulation experiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0047] FIG1 is an overall schematic diagram of the ultra-deep carbonate rock dissolution simulation experimental device provided in this application;

[0048] FIG2 is a pipeline connection diagram of a single reactor in the ultra-deep carbonate rock dissolution simulation experimental device shown in FIG1 ;

[0049] FIG3 is a pipeline connection diagram of multiple reactors in the ultra-deep carbonate rock dissolution simulation experimental device shown in FIG1 ;

[0050] FIG4 is a schematic diagram of a solution pressure vessel system in the ultra-deep carbonate rock dissolution simulation experimental device shown in FIG1 ;

[0051] FIG5 is a schematic diagram of another embodiment of the solution pressure vessel system in the ultra-deep carbonate rock dissolution simulation experimental device provided by the present application;

[0052] FIG6 is a schematic structural diagram of a high-temperature and high-pressure fluid in-situ detection cell in the ultra-deep carbonate rock dissolution simulation experimental device provided by the present application;

[0053] FIG7 is a top view of a high-temperature and high-pressure fluid in-situ detection pool in the ultra-deep carbonate rock dissolution simulation experimental device provided by the present application;

[0054] FIG8 is a cross-sectional view taken along line AA in FIG7 ;

[0055] FIG9 is a cross-sectional view taken along line BB in FIG7 ;

[0056] FIG10 is a schematic diagram of the explosion of a window portion in the ultra-deep carbonate rock dissolution simulation experimental device provided by the present application;

[0057] FIG11 is a schematic structural diagram of a reactor in the ultra-deep carbonate rock dissolution simulation experimental device provided in this application;

[0058] FIG12 is an overall structural diagram of the ultra-deep carbonate rock dissolution simulation experimental device provided by the present application;

[0059] FIG13 is a rear view of the ultra-deep carbonate rock dissolution simulation experimental device shown in FIG12 .

[0060] Description of Figure Numbers:

[0061] 1. Reactor; 2. Core;

[0062] 161. Reactor cover; 162. Ultra-high pressure reactor body; 163. Self-sealing plug; 164. Reactor support;

[0063] 18. Temperature control box; 181. Tracking heating jacket;

[0064] 10. Confining pressure mechanism; 101. Core cavity; 11. Copper sleeve; 12. Support sleeve;

[0065] 121. Confining pressure fluid channel; 122. Confining pressure port; 13. Confining pressure pump; 131. Second valve; 132. Safety valve; 14. Temperature controller;

[0066] 151. First temperature probe; 152. Second temperature probe; 20. Axial pressure mechanism; 21. Hydraulic push rod plug;

[0067] 22, reaction solution interface; 221, fluid injection port; 222, fluid outlet;

[0068] 23. Sampler;

[0069] 30. Back pressure control device; 31. Back pressure controller; 32. Back pressure pump; 33. Water container;

[0070] 34. Back pressure buffer device;

[0071] 40. Solution pressure vessel system;

[0072] 41. Pressure vessel; 411. First valve; 42. Gas cylinder; 43. Gas booster pump; 44. Gas buffer tank; 45. Double plunger pump;

[0073] 46. ​​Flow meter; 471. First safety valve; 472. Pressure reducing valve; 48. Air compressor;

[0074] 49. Pressure sensor;

[0075] 50. Detection system;

[0076] 51. Pressure detection mechanism; 511. Inlet pressure sensor; 512. Outlet pressure sensor; 513. Differential pressure sensor;

[0077] 52. Electronic balance;

[0078] 6. In-situ window detection mechanism;

[0079] 60. High temperature and high pressure fluid in-situ detection cell;

[0080] 61, solution cavity; 611, solution inlet; 612, solution outlet;

[0081] 62. Window portion; 621. Thermal insulation ceramic sleeve;

[0082] 63. Metal cylinder; 631. Metal nut; 632. First metal washer;

[0083] 64, sapphire glass; 641, large diameter portion; 642, small diameter portion;

[0084] 651, second metal washer; 652, graphite washer; 653, metal O-ring;

[0085] 66. Fixing mechanism; 661. Fixing frame; 662. Metal jacket; 663. Thermal insulation sleeve;

[0086] 67. Spectrometer;

[0087] 71. Mounting frame; 72. Control cabinet. DETAILED DESCRIPTION

[0088] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0089] Option 1

[0090] The present application provides an ultra-deep carbonate rock dissolution simulation experimental device, as shown in Figures 1 to 11, the experimental device includes: a solution pressure vessel system 40, a detection system 50, at least two reactors 1 arranged in series, and at least two back pressure control devices 30, the reactor 1 includes a confining pressure mechanism 10 and an axial pressure mechanism 20, the confining pressure mechanism 10 has a core cavity 101 for accommodating a core 2 and can apply confining pressure to the core 2, the axial pressure mechanism 20 is used to apply axial pressure to the core 2 in the core cavity 101, and the axial pressure mechanism 20 is provided with a reaction solution interface 22 connected to the core cavity 101; the solution pressure vessel system 40 can provide a reaction solution and inject it into the core cavity 101 through the reaction solution interface 22; the outlet end of the core cavity 101 of each reactor 1 is connected to the back pressure control device 30; the core cavities 101 of the reactors 1 are connected in series, and the reaction solution provided by the solution pressure vessel system 40 can flow through the core cavities 101 connected in series in sequence, and the detection system 50 is used to detect each core cavity 101 separately.

[0091] In this ultra-deep carbonate rock dissolution simulation experimental device, multiple reactors 1 are arranged in series, and the reaction solution provided by the solution pressure vessel system 40 flows through the core 2 in each reactor 1 in turn; the back pressure control device 30 independently controls the fluid pressure in each reactor 1, and the confining pressure mechanism 10 and the axial pressure mechanism 20 in each reactor 1 respectively apply confining pressure and axial pressure to the core 2 therein, thereby simultaneously loading the core 2 with simulated static rock pressure and fluid pressure, which can drive the fluid to cross two or more reactors 1 with temperature and pressure conditions, realize the cross-tectonic period dissolution simulation of carbonate rocks under the constraints of geological models, and perform multi-stage-continuous flow simulation, which is conducive to meeting the needs of ultra-deep and strongly modified carbonate rock dissolution simulation experiments.

[0092] In the ultra-deep carbonate rock dissolution simulation experimental device provided in the present application, the core can be subjected to ultra-high temperature and high pressure triaxial stress clamping through the reactor 1, and the solution pressure vessel system 40 can provide highly saturated CO2 and realize multi-stage-continuous flow reaction, thereby realizing highly saturated CO2 dissolution simulation. The detection system 50 can perform real-time online detection of ultra-high temperature and high pressure permeability, and realize in-situ detection of high temperature and high pressure fluid components and content, providing an experimental device for high temperature and high pressure carbonate rock dissolution simulation experiments under ultra-deep temperature-stress-fluid coupling, so as to realize ultra-deep oil and gas exploration as deep ground exploration, and advance support the basic theoretical research of ultra-deep oil and gas exploration of 10,000 meters.

[0093] In one embodiment, the detection system 50 includes at least two in-situ window detection mechanisms 6, each comprising a high-temperature, high-pressure fluid in-situ detection cell 60 and a spectrometer 67. The high-temperature, high-pressure fluid in-situ detection cell 60 is connected in series between the outlet of the core cavity 101 and the back-pressure control device 30. The reaction solution flowing out of the core cavity 101 flows through the high-temperature, high-pressure fluid in-situ detection cell 60, where it is detected in situ by the spectrometer 67. This provides real-time, continuous measurement of water-rock reaction products under varying temperature and pressure conditions. For carbonate rock dissolution reactions, Raman spectroscopy can be used to semi-quantitatively measure the amount of dissolution under equilibrium conditions "in situ," enabling a comprehensive study of the dissolution / precipitation trends of carbonate rocks with increasing burial depth.

[0094] As shown in Figures 2, 3, and 6, the high-temperature, high-pressure fluid in-situ detection cell 60 includes a solution chamber 61, a fixing mechanism 66, and a window 62. The solution chamber 61 is fixed between the outlet of the core chamber 101 and the back-pressure control device 30 via the fixing mechanism 66. The solution chamber 61 is provided with a solution inlet 611 and a solution outlet 612. The solution inlet 611 is connected to the outlet of the core chamber 101, and the solution outlet 612 is connected to the back-pressure control device 30. The window 62 is provided in the solution chamber 61, and a spectrometer 67 is disposed outside the window 62. Light within the solution chamber 61 can propagate toward the spectrometer 67 through the window 62. The reaction solution flows into the solution chamber 61 through the solution inlet 611 and can flow to the next reactor 1 through the solution outlet 612. The spectrometer 67 detects the reaction solution in the solution chamber 61 through the window 62. Preferably, the solution chamber 61 is made of hafnium alloy and has a hollow structure. It is used to accommodate the reaction solution and is externally connected to a thermocouple to control the temperature within the chamber. As shown in Figures 7-9, its two ends are connected to the solution inlet 611 and solution outlet 612 pipelines via metal tapered threads. The other two ends are connected to the window portion 62, respectively serving as the signal source transmitter and signal source receiver.

[0095] Furthermore, the window portion 62 includes a metal cylinder 63, an insulating ceramic sleeve 621, and a sapphire glass 64. The insulating ceramic sleeve 621 and the sapphire glass 64 are respectively disposed at both ends of the metal cylinder 63. The sapphire glass 64 has a large-diameter portion 641 and a small-diameter portion 642, with the small-diameter portion 642 at least partially inserted into the metal cylinder 63. The window portion 62 is designed to balance compressive strength with good spectral signal transmittance, improving the structural stability of the window portion 62. Light in the solution chamber 61 is transmitted through the sapphire glass 64 to the spectrometer 67, ensuring detection under high-temperature and high-pressure conditions. The sapphire glass 64 can be a nut-shaped sapphire glass 64. Specifically, the metal cylinder 63 includes a metal nut 631 and a first metal washer 632, and the first metal washer 632 is arranged at one end of the metal nut 631; as shown in Figure 10, the window portion 62 also includes a second metal washer 651, a graphite washer 652 and a metal O-ring 653, and the second metal washer 651 is arranged between the graphite washer 652 and the first metal washer 632.

[0096] As shown in Figure 9, the fixing mechanism 66 includes a fixing frame 661, a metal jacket 662, and an insulating sleeve 663. The fixing frame 661 ensures that the solution chamber 61 is fixed under high pressure. The fixing frame 661 is wrapped with an insulating sleeve 663, which is made of fire-resistant and heat-insulating material for thermal insulation and heat preservation. The metal jacket 662 is installed on the outside of the insulating sleeve 663.

[0097] Both ends of the high-temperature, high-pressure fluid in-situ detection cell 60 are connected to a spectrometer via fiber optic probes. The cell 60 is capable of withstanding high temperatures and high pressures. The generated liquid from the reactor 1 flows through the cell 60. The spectrometer can analyze the composition and content of the generated liquid within the cell 60 under in-situ high-temperature, high-pressure conditions. The spectrometer 67 can be a laser Raman spectrometer.

[0098] In one embodiment, the detection system 50 includes a pressure detection mechanism 51 corresponding to each reactor 1. As shown in Figures 1 and 2, the pressure detection mechanism 51 includes an inlet pressure sensor 511, an outlet pressure sensor 512, and a differential pressure sensor 513. The inlet pressure sensor 511 is located at the inlet of the core chamber 101, and the outlet pressure sensor 512 is located at the outlet of the core chamber 101. The differential pressure sensor 513 is located between the inlet and outlet of the core chamber 101 to detect the difference in fluid pressure at the inlet and outlet. For each reactor 1, the inlet pressure sensor 511 and the outlet pressure sensor 512 detect the fluid pressure at the inlet and outlet of the core chamber 101 in real time. The differential pressure sensor 513 also detects the difference in fluid pressure at the inlet and outlet in real time, thereby obtaining the fluid pressure and its difference at the inlet and outlet of the core 2 in real time.

[0099] Furthermore, the detection system 50 includes an electronic balance 52; the ends of all the reactors 1 connected in series are connected to a sampler 23, which is mounted on the electronic balance 52. The electronic balance 52 can record the fluid flow of the sampler 23 and collect the unit time flow of the reaction solution in real time.

[0100] The differential pressure sensor 513 directly measures the fluid pressure difference between the inlet and outlet ends of the core 2, while the inlet pressure sensor 511 and the outlet pressure sensor 512 respectively test the fluid pressure at the inlet and outlet ends of the core 2; the fluid pressure difference is then obtained through calculation; the electronic balance records the fluid flow of the sampler 23 and collects the unit time flow of the solution generated by the reaction in real time; according to the Darcy formula, the liquid permeability value of the core 2 is calculated in real time, and finally the real-time online continuous measurement of the liquid permeability value of the rock plunger sample during the water-rock reaction process is achieved, and the real-time permeability evolution characteristic curve of the core 2 is generated through the control software.

[0101] The control system can coordinately control the various hardware mechanical structures and circuit systems in the detection system 50 through the control software to achieve real-time online measurement of ultra-high temperature and high pressure permeability values. The software collects quantitative parameters of the connectivity properties of carbonate rocks during the dissolution process in real time and generates a characteristic curve of the evolution of the rock connectivity properties with the reaction time during the dissolution process.

[0102] In one embodiment, as shown in Figures 2 and 3, the back pressure control device 30 includes a back pressure controller 31 and a back pressure pump 32, the back pressure pump 32 is connected to the back pressure controller 31, and the back pressure controller 31 is arranged between the inlet end of the next core cavity 101 and the high temperature and high pressure fluid in-situ detection tank 60. The outlet end of each reactor 1 controls the internal fluid pressure of the rock through the back pressure controller 31 and the back pressure pump 32, thereby realizing multi-stage cross-tectonic period dissolution simulation. In another embodiment, as shown in Figure 5, the back pressure control device 30 includes a back pressure controller 31, a back pressure pump 32 and a back pressure buffer device 34, the back pressure pump 32 is connected to the back pressure controller 31 through the back pressure buffer device 34, and the back pressure controller 31 can specifically be a back pressure valve.

[0103] In one embodiment, the confining pressure mechanism 10 includes a copper sleeve 11 and a support sleeve 12. The inner cavity of the copper sleeve 11 forms a core cavity 101. The support sleeve 12 is wrapped around the outside of the copper sleeve 11. The support sleeve 12 is provided with a confining pressure fluid channel 121. The confining pressure fluid enters between the support sleeve 12 and the copper sleeve 11 through the confining pressure fluid channel 121, so that the copper sleeve 11 applies confining pressure to the core 2, which can clamp the core 2 under high temperature and high pressure conditions. The confining pressure fluid channel 121 has a confining pressure port 122, as shown in Figures 2 and 11. The confining pressure fluid channel 121 is connected to the confining pressure pump 13, which is used to deliver the confining pressure fluid to the confining pressure fluid channel 121.

[0104] Preferably, as shown in FIG3 , the confining pressure pump 13 and the back pressure pump 32 are connected to the same water container 33 , which is beneficial to simplifying the structure of the experimental device and reducing operational failures.

[0105] Furthermore, the reactor 1 includes a temperature controller 14, which is used to regulate the temperature of the confining pressure fluid, thereby controlling the ambient temperature of the core 2 and simulating the high-temperature environment of the formation, which is conducive to more direct and efficient control of temperature conditions and improving the accuracy of temperature control.

[0106] In one embodiment, as shown in FIG11 , the axial pressure mechanism 20 includes hydraulic push rod plugs 21 disposed at both ends of the copper sleeve 11, and the reaction solution interface 22 is disposed on the hydraulic push rod plugs 21. The hydraulic push rod plugs 21 can be controlled by the axial hydraulic control system of the reactor 1 to axially squeeze the core 2 in the core cavity 101, thereby providing axial pressure.

[0107] Reactor 1 functions as a high-temperature, high-pressure, triaxial stress core holder. At least two reactors 1 are connected in series via pipelines, and each reactor 1 simulates water-rock reactions under the corresponding tectonic diagenetic environment. Therefore, each reactor 1 is equipped with an independent temperature controller 14, confining pressure pump 13, back-pressure controller 31, and back-pressure pump 32. The temperature controller 14 controls the water-rock reaction temperature within reactor 1, while the confining pressure pump 13 controls the confining pressure surrounding the core 2 sample. At each stage, the back-pressure controller 31 and back-pressure pump 32 control the fluid pressure within the rock at the outlet of reactor 1, enabling multi-stage, continuous flow simulation. During the cross-tectonic dissolution simulation experiment, by simulating the temperature, pressure, fluid chemistry, mineral composition, and flow characteristics of different tectonic stages during diagenesis, it is possible to effectively simulate diagenetic processes such as dissolution, cementation, and replacement, resulting from changes in temperature, pressure, and fluid properties in actual strata caused by basin tectonic activity. As shown in FIG2 , the outlet end of the confining pressure pump 13 is connected to a second valve 131 to control the start and stop of conveying the confining pressure fluid; the confining pressure mechanism 10 is also connected to a safety valve 132 .

[0108] This reactor 1 is an ultra-high temperature, high pressure, triaxial stress reactor. This application optimizes the structure of reactor 1: As shown in Figure 11, reactor 1 is equipped, from outside to inside, with a temperature control box 18, a reactor support 164, and an ultra-high pressure reactor body 162. It also features a self-sealing plug 163 and a sample chamber mounting bracket 661. A removable lid 161 is mounted on the top of the ultra-high pressure reactor body 162, which contains a metal piston. The metal piston divides the ultra-high pressure reactor body 162 into two compartments: an upper compartment and a lower compartment. The upper compartment contains a fluid inlet 221, a fluid outlet 222, a confining pressure port 122, a first temperature probe 151, and a self-sealing plug 163. The lower compartment contains a second temperature probe 152. The ultra-high pressure reactor body 162 includes a tracking heating jacket 181. The tracking heating jacket 181 and two temperature probes are controlled by the temperature control box 18 to track the temperature of the core 2. Furthermore, the fluid inlet 221, the core cavity 101, and the fluid outlet 222 are interconnected.

[0109] The reaction solution interface 22 includes a fluid injection port 221 and a fluid outlet 222. The core 2 serves as the sample, and the core cavity 101 serves as the sample chamber. The copper sleeve 11 is preferably a hollow copper cylindrical sample tube, which constitutes the main body of the sample chamber. The sample is placed inside the copper cylindrical sample tube, and hollow hydraulic push rod plugs 21 are placed at both ends. The hydraulic push rod plug 21 at one end is connected to the reaction solution inlet 611, and the hydraulic push rod plug 21 at the other end is connected to the reaction dissolution outlet. The support sleeve 12 is mainly used to protect the hollow copper cylindrical sample tube. The support sleeve 12 is an alloy cylinder composed of two pieces, which is wrapped around the outside of the hollow copper cylindrical sample tube. Each support sleeve 12 contains two circular holes, so that the confining pressure fluid can pass through the support sleeve 12 to wrap the hollow copper cylindrical sample tube and apply confining pressure. The confining pressure fluid channel 121 is connected to the circular holes. Self-sealing plugs 163 are placed at both ends of the sample chamber to secure the support sleeve 12 and the hollow copper cylindrical sample tube. A sample chamber mounting bracket 661 secures the sample chamber to the high-temperature, high-pressure chamber sealing cap, ensuring the sample chamber's position remains fixed under high-temperature, high-pressure conditions. One end of the mounting bracket 661 connects to the self-sealing plug 163, while the other end secures the sample chamber via screws. The ultrahigh-pressure autoclave body 162 is hollow and can carry the confining pressure fluid. It is equipped with an electric heater and a temperature thermocouple to heat the confining pressure fluid, thereby maintaining the temperature for the water-rock reaction within the sample chamber. The confining pressure port 122 connects to the confining pressure pump and pressure control system.

[0110] In one embodiment, the solution pressure vessel system 40 includes a pressure vessel 41, a gas cylinder 42, a gas booster pump 43, a gas buffer tank 44, a gas flow meter 46, and a double-piston pump 45. The gas booster pump 43 is connected to the pressure vessel 41. The gas cylinder 42, the gas booster pump 43, the gas buffer tank 44, and the gas flow meter 46 are sequentially connected in series to the pressure vessel 41. The pressure vessel 41 is connected to the reaction solution interface 22. The pressure vessel 41 can be a piston container, the double-piston pump 45 can be a constant speed and constant pressure pump, and CO2 can be stored in the gas cylinder 42. The solution pressure vessel system 40 can quantitatively prepare a highly saturated CO2 solution, simulate the CO2-rich hydrothermal fluid components in the deep earth, and realize highly saturated CO2 dissolution simulation. The various hardware and mechanical structures in the solution pressure vessel system 40 can be collaboratively controlled by the host computer control software.

[0111] As shown in Figure 4 , the gas booster pump 43 is connected to the air compressor 48, a pressure reducing valve 472 is connected in series between the gas buffer tank 44 and the gas flow meter 46, a first safety valve 471 is provided between the gas booster pump 43 and the gas buffer tank 44, and a first valve 411 is connected to the outlet of the solution pressure container system 40. As shown in Figure 5 , a pressure sensor 49 is also connected to the outlet of the solution pressure container system 40.

[0112] As shown in FIG12 and FIG13 , the reaction kettle 1 , the solution pressure vessel system 40 and the in-situ window detection mechanism 6 and other structures are installed on a mounting frame 71 and are electrically connected to a control cabinet 72 to coordinately control the various components.

[0113] The ultra-deep carbonate rock dissolution simulation experimental device provided in this application can realize the simulation of carbonate rock dissolution under the coupled action of temperature-stress-fluid, and simulate the water-rock reaction under the joint control of temperature-stress-fluid in the geological background from near the surface to ultra-deep layers of 10,000 meters, solving the technical problem in the existing technology that it is difficult to conduct simulation experiments on the dissolution of ultra-deep and strongly modified carbonate rocks of 10,000 meters.

[0114] Option 2

[0115] This application provides a carbonate rock dissolution simulation experimental method, utilizing the aforementioned ultra-deep carbonate rock dissolution simulation experimental apparatus. The experimental method comprises: a reactor 1 applies confining pressure and axial pressure to a core 2 within a core cavity 101; a solution pressure vessel system 40 provides a reaction solution and injects it into the core cavity 101; a back pressure control device 30 controls the outlet pressure of each core cavity 101; and a detection system 50 performs separate detection of each core cavity 101. This experimental method shares the technical features and beneficial effects of the aforementioned experimental apparatus and will not be further elaborated upon here.

[0116] This experimental method enables simulation of ultra-high temperature and high pressure core seepage in ultra-deep layers of 10,000 meters. By developing ultra-high temperature and high pressure triaxial stress clamping, automatic tracking and control of confining pressure, ultra-high temperature and high pressure in-situ observation, real-time online measurement of ultra-high temperature and high pressure permeability, automatic tracking of back pressure, and quantitative metering and delivery of saturated CO2, and integrating and coordinating these functions, the functional requirements of ultra-high temperature and high pressure core seepage simulation, multi-stage continuous flow simulation, real-time online detection of ultra-high temperature and high pressure permeability, in-situ detection of high temperature and high pressure fluid composition and content, and highly saturated CO2 dissolution simulation are achieved. The host computer control software in the software control system completes the control of experimental parameters for each unit, data acquisition, spectrum analysis, and evaluation.

[0117] The carbonate rock dissolution simulation experimental method provided in this application has the following characteristics:

[0118] (1) Simulation of water-rock reaction environment in ultra-deep carbonate rock formations at 10,000 meters:

[0119] It provides ultra-deep simulated formation environment (10,000 meters), structural-fluid interaction, and continuous rock-fluid chemical reaction simulation under large-span temperature and pressure conditions. For example, the maximum working temperature is 450°C, the maximum working pressure is 150MPa, and the core 2 is loaded with simulated static rock pressure and fluid pressure at the same time, which can drive the fluid to cross two or more temperature and pressure conditions of the reactor 1, realizing the cross-tectonic period dissolution simulation of carbonate rocks under the constraints of geological models.

[0120] (2) Quantitative evaluation of the dissolution reservoir effect and characterization of pore structure evolution characteristics:

[0121] A core 2-plunger sample simulation experiment is provided. The porosity, permeability, and weight parameters before and after the experiment can be used to quantitatively evaluate the pore-forming effect of dissolution on the rock. CT analysis before and after the experiment is used to compare and characterize the dynamic evolution of the pore structure inside the rock under dissolution in situ.

[0122] (3) Quantitative characterization of the evolution of connectivity properties during rock dissolution:

[0123] It provides real-time online measurement of ultra-high temperature and high pressure permeability values. The software collects quantitative parameters of carbonate rock connectivity properties during the dissolution process in real time and generates a characteristic curve of the evolution of rock connectivity properties with reaction time during the dissolution process.

[0124] (4) Real-time determination of fluid composition and content during rock dissolution:

[0125] It provides real-time and continuous measurement of water-rock reaction products under different temperature and pressure conditions. For carbonate rock dissolution reactions, Raman spectroscopy can be used to semi-quantitatively measure the amount of dissolution under equilibrium conditions "in situ", thereby comprehensively studying the dissolution / precipitation trends of carbonate rocks with increasing burial depth.

[0126] The above are only a few embodiments of the present application. Those skilled in the art may make various changes or modifications to the embodiments of the present application based on the contents disclosed in the application documents without departing from the spirit and scope of the present application.

Claims

1. An ultra-deep carbonate rock dissolution simulation experimental device, characterized in that: include: At least two reactors arranged in series, the reactors comprising a confining pressure mechanism and an axial pressure mechanism, the confining pressure mechanism having a core cavity for accommodating a core and capable of applying confining pressure to the core, the axial pressure mechanism being used to apply axial pressure to the core in the core cavity, the axial pressure mechanism being provided with a reaction solution interface communicating with the core cavity; a solution pressure container system capable of providing a reaction solution and injecting the reaction solution into the core cavity through the reaction solution interface; At least two back pressure control devices, the outlet end of the core chamber of each reactor is connected to the back pressure control device; A detection system, the detection system comprising at least two in-situ window detection mechanisms, the in-situ window detection mechanisms comprising a high-temperature and high-pressure fluid in-situ detection cell and a spectrometer, the high-temperature and high-pressure fluid in-situ detection cell being connected in series between the outlet end of the core cavity and the back pressure control device; The core cavities of the reactor are connected in series, the reaction solution provided by the solution pressure container system can flow through the core cavities connected in series in sequence, and the detection system is used to detect each of the core cavities respectively.

2. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 1 is characterized in that: The high-temperature and high-pressure fluid in-situ detection cell comprises a solution cavity, a fixing mechanism and a window portion, wherein the solution cavity is fixed between the outlet end of the core cavity and the back pressure control device through the fixing mechanism; The solution cavity is provided with a solution inlet and a solution outlet, the solution inlet is connected to the outlet end of the core cavity, and the solution outlet is connected to the back pressure control device; The window portion is arranged in the solution cavity, the spectrometer is arranged outside the window portion, and the light in the solution cavity can be transmitted to the spectrometer through the window portion.

3. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 2, characterized in that: The window portion includes a metal cylinder, an insulating ceramic sleeve and a sapphire glass, wherein the insulating ceramic sleeve and the sapphire glass are respectively arranged at two ends of the metal cylinder, and the sapphire glass has a large diameter portion and a small diameter portion, wherein the small diameter portion is at least partially inserted into the metal cylinder.

4. The ultra-deep carbonate rock dissolution simulation experimental device according to any one of claims 1 to 3, characterized in that: The detection system includes a pressure detection mechanism corresponding to each of the reaction kettles; The pressure detection mechanism includes an inlet pressure sensor, an outlet pressure sensor and a pressure difference sensor. The sensor is arranged at the inlet end of the core cavity, and the outlet pressure sensor is arranged at the outlet end of the core cavity; the differential pressure sensor is arranged between the inlet end and the outlet end of the core cavity to detect the fluid pressure difference between the inlet end and the outlet end.

5. The carbonate rock dissolution simulation experimental device according to claim 4, characterized in that: The detection system comprises an electronic balance; the ends of all the reaction kettles connected in series are connected to samplers, and the samplers are arranged on the electronic balance.

6. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 1, characterized in that: The back pressure control device comprises a back pressure controller and a back pressure pump, the back pressure pump is connected to the back pressure controller, and the back pressure controller is arranged between the inlet end of the latter core cavity and the high temperature and high pressure fluid in-situ detection pool.

7. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 6, characterized in that: The confining pressure mechanism includes a copper sleeve and a support sleeve, the inner cavity of the copper sleeve forms the core cavity, the support sleeve is wrapped outside the copper sleeve, and the support sleeve is provided with a confining pressure fluid channel. The confining pressure fluid enters between the support sleeve and the copper sleeve through the confining pressure fluid channel so that the copper sleeve applies confining pressure to the core.

8. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 7, characterized in that: The confining pressure fluid channel is connected to a confining pressure pump, and the confining pressure pump is used to transport confining pressure fluid to the confining pressure fluid channel.

9. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 8, characterized in that: The confining pressure pump and the back-pressure pump are connected to the same water container.

10. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 7, characterized in that: The reactor comprises a temperature controller, and the temperature controller is used to regulate the temperature of the confining pressure fluid.

11. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 7, characterized in that: The axial pressure mechanism comprises hydraulic push rod plugs arranged at both ends of the copper sleeve, and the reaction solution interface is arranged on the hydraulic push rod plugs.

12. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 1, characterized in that: The solution pressure container system includes a pressure container, a gas cylinder, a gas booster pump, a gas flow meter, a gas buffer tank and a double-plunger pump, the gas booster pump is connected to the pressure container, the gas cylinder, the gas booster pump, the gas buffer tank and the gas flow meter are sequentially connected in series to the pressure container, and the pressure container is connected to the reaction solution interface.

13. An ultra-deep carbonate rock dissolution simulation experimental method, characterized in that: The ultra-deep carbonate rock dissolution simulation experimental device according to any one of claims 1 to 12 is used, and the experimental method comprises: The reactor applies confining pressure and axial pressure to the core in the core cavity; The solution pressure container system provides a reaction solution and injects it into the core cavity, and the back pressure control device controls the outlet pressure of each core cavity; The detection system detects each of the core cavities respectively.

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