Ultra-deep layer carbonate rock corrosion simulation experiment device and method

Abstract

The invention provides an ultra-deep layer carbonate rock corrosion simulation experiment device and method.The experiment device comprises at least two reaction kettles arranged in series, each reaction kettle comprises a confining pressure mechanism and an axial pressure mechanism, the confining pressure mechanism is provided with a rock core cavity used for containing a rock core and can apply confining pressure to the rock core, and the axial pressure mechanism is used for applying axial pressure to the rock core; the axial pressure mechanism is used for applying axial pressure to the rock core in the rock core cavity, and the axial pressure mechanism is provided with a reaction solution interface communicated with the rock core cavity; the solution pressure container system can provide a reaction solution and inject the reaction solution into the rock core cavity through the reaction solution interface; the outlet ends of the core cavities of the reaction kettles are connected with the back pressure control devices; a detection system; the core cavities of the reaction kettles are communicated in series, a reaction solution provided by the solution pressure container system can sequentially flow through the core cavities which are communicated in series, the detection system is used for detecting each core cavity, and the technical problem that simulation experiment on corrosion of a 10000-meter ultra-deep layer-strong modified carbonate rock is difficult to perform is solved.

Description

Technical Field

[0001] The invention 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

[0002] With the exploitation of oil and gas resources in medium and shallow layers (burial depth <4500m) and the decline of resource quantity, entering the deep layers (burial depth 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 today's oil and gas exploration.

[0003] 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 law 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.

[0004] Water-rock reaction simulation experiment is an important method to study the mechanism of carbonate rock dissolution. It can reproduce the carbonate rock dissolution process under temperature, pressure and fluid control by setting different experimental conditions, thus providing a basis for identifying the laws of carbonate rock dissolution and predicting favorable reservoir development areas.

[0005] Chinese invention patent application CN102435716A discloses a diagenesis simulation experimental device, and Chinese invention patent application CN104407118A discloses an analysis method for carbonate rock dissolution and dissolution benefits, which realizes the use of actual rock plunger samples to carry out rock internal dissolution experimental simulation. 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, cracks, etc. The pore structure often changes during the dissolution process and forms a dominant channel for fluid migration, which will cause the contact area between the fluid and the rock to change, resulting in a decrease in the amount of rock dissolution, which will inevitably affect the accurate understanding of the temperature, pressure and fluid factors on the dissolution effect, and the dolomite water-rock reaction data is not repeatable and reproducible.

[0006] Chinese invention patent application CN105137033A discloses a quantitative evaluation method and device for the surface karst effect of gypsum-carbonate reservoirs, which only focuses on the dissolution effect and quantitative evaluation of gypsum-carbonate rocks in the surface environment, and is not suitable for the high temperature and high pressure conditions of dolomite water-rock reaction in the burial stage; although it takes into account the influence of gypsum components in rock samples 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 form of immersing rock samples in solution is adopted, and the water-rock ratio and hydrodynamic mode do not conform to the actual underground situation, and the chemical connotation represented by the rock dissolution amount is unclear.

[0007] Chinese invention patent CN106323812B (patent number: CN201510387709.6) discloses a test device for water-rock simulation flow test, including a control unit; a reactor with multiple sample tubes arranged inside; a constant flow pump, which includes multiple piston cylinders, multiple reversing units and a driving mechanism. In this device, multiple groups of water-rock simulation flow control tests can be carried out simultaneously, and the test device can ensure that multiple groups of rock samples react with the reaction liquid under the same test conditions. However, the shortcomings of this device are: the artificially configured CO2 fluid, acetic acid fluid, and H2S solution react with the rock in the simulation experiment, without considering that the underground fluid crosses different strata and the fluid properties change during the migration process; the fluid entering the reactor and reacting with the rock has only a single mode of constant flow pump driving, and the type of fluid driving force is not distinguished, and the diagenetic effects such as dissolution, cementation or replacement of the fluid and the reservoir under geological boundary conditions cannot be objectively simulated.

[0008] Carbonate rocks are widely distributed underground, and the reaction between carbonate rocks and acidic fluids quickly reaches chemical equilibrium.

[0009] Yang Yunkun et al. (Re-understanding of deep dissolution of carbonate rocks based on in-situ observations of simulation experiments [J], Journal of Peking University (Natural Science Edition), 2014, 50(2): 316-322) used the diamond anvil cell (DAC) technology to design a set of water-rock interaction simulation experiments for carbonate rocks with increasing burial depth. Although obvious cementation (precipitation) can be observed in situ, it is not possible to quantitatively analyze the amount of dissolution of carbonate rock water-rock reaction, let alone analyze the specific role of formation water properties in the dolomite water-rock reaction process.

[0010] Fan Ming et al. (The transformation of carbonate reservoirs by acidic fluids [J], Geochemistry, 2009, 38(1): 20-26) independently designed a carbonate dissolution rate measuring instrument. However, this experimental device and experimental method are dedicated to evaluating the dissolution rate of carbonate rocks, which requires that the results of carbonate rock water-rock reactions are far from chemical equilibrium. Due to the small amount of rock samples, the fluid generated by the reaction still has the ability to react with the rock.

[0011] Looking at the current research status at home and abroad, according to the water-rock reaction mode, carbonate rock dissolution simulation experimental devices can be divided into rock surface dissolution and rock internal dissolution: rock surface dissolution experimental devices mainly include acid-rock reaction rotating rock disk instrument, high-temperature and high-pressure tubular flow reaction device, diamond pressure chamber and molten capillary silica tube; rock internal dissolution experimental devices include high-temperature and high-pressure core seepage simulation device.

[0012] Obviously, the samples of rock surface dissolution experiments are mostly rock particles or blocks. The water-rock reaction mainly occurs on the surface of the rock, with the characteristics of "water wrapped in rock". The water-rock ratio and hydrodynamic conditions are quite different from the burial environment, and the focus is mainly on the chemical reaction in the carbonate rock water-rock reaction experiment. However, just as some geologists have questioned the burial dissolution and porosity increase of carbonate reservoirs, they believe that the chemical mechanism of dissolution and porosity increase of carbonate rocks and acidic fluids is beyond doubt. The question is what is the mechanism for acidic fluids to retain 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 laws of burial dissolution? Therefore, the burial dissolution of carbonate rocks cannot be simplified as a chemical reaction. It is necessary to focus on the core geological problem of the formation mechanism and distribution law of ultra-deep carbonate reservoirs, and carry out carbonate rock dissolution simulation experiments under the constraints of geological models from the perspective of geological systems.

[0013] 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.

[0014] At present, previous carbonate dissolution simulation experiments have mostly focused on burial depths shallower than 6,000 meters, and the experimental fluids are mainly organic acid solutions. There has been no systematic carbonate dissolution simulation experiment in ultra-deep layers (burial depth > 6,000m) and under strong transformation geological backgrounds. The mineral dissolution-precipitation mechanism and its reservoir effect in ultra-deep burial environments are still unclear. For example, can carbonate rocks undergo large-scale dissolution in ultra-deep environments? Can deep-source hot fluids (hydrothermal fluids) improve reservoir performance? How to quantitatively simulate the evolution law and main controlling factors of the dynamic process of carbonate dissolution-increasing porosity-cementation-reducing porosity? Can corrosive fluids retain acidity during long-distance migration across tectonic periods?

[0015] These mechanistic issues are the focus and difficulty of the research on the formation mechanism and distribution law of ultra-deep carbonate reservoirs, which puts forward higher requirements for the simulation experimental device of carbonate rock dissolution under the coupling of ultra-deep temperature-stress-fluid. It is necessary to meet the requirements of higher working temperature, pressure and corrosion resistance, and to achieve the necessary functions such as water-rock ratio and hydrodynamic mode close to geological reality, quantitative evaluation of dissolution porosity increase effect, characterization of the dynamic evolution process of rock internal pore structure under dissolution-precipitation, cross-tectonic period migration of fluid, and in-situ analysis of high-temperature and high-pressure fluid properties.

[0016] 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. Summary of the invention

[0017] The purpose of the present invention is to provide an ultra-deep carbonate rock dissolution simulation experiment 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.

[0018] The above-mentioned purpose of the present invention can be achieved by adopting the following technical solutions:

[0019] The present invention provides an ultra-deep carbonate rock dissolution simulation experimental device, comprising:

[0020] 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;

[0021] 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;

[0022] 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;

[0023] Detection system;

[0024] 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.

[0025] In a preferred embodiment, the detection system includes at least two in-situ window detection mechanisms, and the in-situ window detection mechanism includes 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.

[0026] 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, wherein 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, and the light in the solution cavity can be transmitted to the spectrometer through the window portion.

[0027] 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 in the metal cylinder.

[0028] 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.

[0029] 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.

[0030] In a preferred embodiment, 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 around the outside of 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.

[0031] In a preferred embodiment, the confining pressure fluid channel is connected to a confining pressure pump, and the confining pressure pump is used to transport the confining pressure fluid to the confining pressure fluid channel.

[0032] In a preferred embodiment, the confining pressure pump and the back-pressure pump are connected to the same water container.

[0033] In a preferred embodiment, the reactor comprises a temperature controller, and the temperature controller is used to control the temperature of the confining pressure fluid.

[0034] 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.

[0035] In a preferred embodiment, the solution pressure container system includes a pressure container, 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 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.

[0036] In a preferred embodiment, the detection system comprises an electronic balance; the ends of all the reaction kettles connected in series are connected to a sampler, and the sampler is arranged on the electronic balance.

[0037] The present invention provides an ultra-deep carbonate rock dissolution simulation experimental method, using the ultra-deep carbonate rock dissolution simulation experimental device, the experimental method comprises:

[0038] The reactor applies confining pressure and axial pressure to the core in the core cavity;

[0039] 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;

[0040] The detection system detects each of the core cavities respectively.

[0041] The characteristics and advantages of the present invention are:

[0042] In the 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-layer-strongly modified carbonate rock dissolution simulation experiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, 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 invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0044] Figure 1 The overall schematic diagram of the ultra-deep carbonate rock dissolution simulation experimental device provided by the present invention;

[0045] Figure 2 for Figure 1 The pipeline connection diagram of a single reactor in the ultra-deep carbonate rock dissolution simulation experimental device shown;

[0046] Figure 3 for Figure 1 The pipeline connection diagram of multiple reactors in the ultra-deep carbonate rock dissolution simulation experimental device shown;

[0047] Figure 4 for Figure 1 A schematic diagram of a solution pressure vessel system in an ultra-deep carbonate rock dissolution simulation experimental device is shown;

[0048] Figure 5 A schematic diagram of another embodiment of the solution pressure container system in the ultra-deep carbonate rock dissolution simulation experimental device provided by the present invention;

[0049] Figure 6 A schematic diagram of the structure 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 invention;

[0050] Figure 7 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 invention;

[0051] Figure 8 for Figure 7 The AA section view;

[0052] Fig. 9 for Figure 7 The cross-sectional view along the BB direction;

[0053] Fig.10 A schematic diagram of the explosion of the window portion in the ultra-deep carbonate rock dissolution simulation experimental device provided by the present invention;

[0054] Fig.11 A schematic diagram of the structure of a reactor in the ultra-deep carbonate rock dissolution simulation experimental device provided by the present invention;

[0055] Fig.12 The overall structure diagram of the ultra-deep carbonate rock dissolution simulation experimental device provided by the present invention;

[0056] Fig.13 for Fig.12 The rear view of the ultra-deep carbonate rock dissolution simulation experimental device is shown.

[0057] Description of Figure Numbers:

[0058] 1. Reactor; 2. Core;

[0059] 161. kettle cover; 162. ultra-high pressure kettle body; 163. self-sealing plug; 164. reactor support;

[0060] 18. Temperature control box; 181. Tracking heating jacket;

[0061] 10. Confining pressure mechanism; 101. Core cavity; 11. Copper sleeve; 12. Support sleeve;

[0062] 121, confining pressure fluid channel; 122, confining pressure port; 13, confining pressure pump; 131, second valve; 132, safety valve; 14, temperature controller;

[0063] 151. first temperature measuring probe; 152. second temperature measuring probe; 20. axial pressure mechanism; 21. hydraulic push rod plug;

[0064] 22, reaction solution interface; 221, fluid injection port; 222, fluid outlet;

[0065] 23. Sampler;

[0066] 30. Back pressure control device; 31. Back pressure controller; 32. Back pressure pump; 33. Water container;

[0067] 34. Back pressure buffer device;

[0068] 40. Solution pressure vessel system;

[0069] 41. Pressure vessel; 411. First valve; 42. Gas cylinder; 43. Gas booster pump; 44. Gas buffer tank; 45. Double plunger pump;

[0070] 46, flow meter; 471, first safety valve; 472, pressure reducing valve; 48, air compressor;

[0071] 49. Pressure sensor;

[0072] 50. Detection system;

[0073] 51. pressure detection mechanism; 511. inlet pressure sensor; 512. outlet pressure sensor; 513. differential pressure sensor;

[0074] 52. Electronic balance;

[0075] 6. In-situ window detection mechanism;

[0076] 60. High temperature and high pressure fluid in-situ detection cell;

[0077] 61, solution cavity; 611, solution inlet; 612, solution outlet;

[0078] 62. Window part; 621. Thermal insulation ceramic sleeve;

[0079] 63. Metal cylinder; 631. Metal nut; 632. First metal washer;

[0080] 64, sapphire glass; 641, large diameter portion; 642, small diameter portion;

[0081] 651, second metal gasket; 652, graphite gasket; 653, metal O-ring;

[0082] 66. Fixing mechanism; 661. Fixing frame; 662. Metal jacket; 663. Heat insulation jacket;

[0083] 67. Spectrometer;

[0084] 71. Mounting frame; 72. Control cabinet. DETAILED DESCRIPTION

[0085] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0086] Solution 1

[0087] The present invention provides an ultra-deep carbonate rock dissolution simulation experimental device, such as Figure 1-Figure 11 As shown, the experimental device includes: a solution pressure container 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 the 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 container 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 reactor 1 are connected in series, the reaction solution provided by the solution pressure container 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 respectively.

[0088] In the ultra-deep carbonate rock dissolution simulation experimental device, multiple reactors 1 are arranged in series, and the reaction solution provided by the solution pressure container 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, so as to load the simulated static rock pressure and fluid pressure on the core 2 at the same time, and the fluid can be driven to cross two or more reactors 1 with temperature and pressure conditions, so as to 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-strongly modified carbonate rock dissolution simulation experiments.

[0089] In the ultra-deep carbonate rock dissolution simulation experimental device provided by the present invention, the core can be clamped under ultra-high temperature and high pressure triaxial stress 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 contents, providing an experimental device for the high temperature and high pressure carbonate rock dissolution simulation experiment under the coupling of ultra-deep temperature-stress-fluid, so as to realize ultra-deep oil and gas exploration as deep ground exploration, and advance support for the basic theoretical research of ultra-deep oil and gas exploration of 10,000 meters.

[0090] In one embodiment, the detection system 50 includes at least two in-situ window detection mechanisms 6, which include a high-temperature and high-pressure fluid in-situ detection cell 60 and a spectrometer 67. The high-temperature and high-pressure fluid in-situ detection cell 60 is connected in series between the outlet end 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 and high-pressure fluid in-situ detection cell 60, and the spectrometer 67 performs in-situ detection on it, which can provide real-time continuous measurement of water-rock reaction products under different temperature and pressure conditions. For carbonate rock dissolution reaction, Raman spectroscopy can be used to "in-situ" semi-quantitatively measure the amount of dissolution under equilibrium conditions, and then comprehensively study the dissolution / precipitation trend of carbonate rock with increasing burial depth.

[0091] like Figure 2 , Figure 3 and Figure 6 As shown, the high temperature and high pressure fluid in-situ detection pool 60 includes a solution cavity 61, a fixing mechanism 66 and a window portion 62. The solution cavity 61 is fixed between the outlet end of the core cavity 101 and the back pressure control device 30 through the fixing mechanism 66; the solution cavity 61 is provided with a solution inlet 611 and a solution outlet 612, the solution inlet 611 is connected to the outlet end of the core cavity 101, and the solution outlet 612 is connected to the back pressure control device 30; the window portion 62 is provided in the solution cavity 61, and the spectrometer 67 is provided outside the window portion 62, and the light in the solution cavity 61 can be transmitted to the spectrometer 67 through the window portion 62. The reaction solution flows into the solution cavity 61 through the solution inlet 611, and can flow to the next reactor 1 through the solution outlet 612; through the window portion 62, the spectrometer 67 detects the reaction solution in the solution cavity 61. Preferably, the solution cavity 61 is made of hafnium alloy material, with a hollow structure, used to accommodate the reaction generated solution, and a thermocouple is connected externally to control the temperature in the cavity. like Figure 7-Figure 9 As shown, the two ends are connected to the pipelines of the solution inlet 611 and the solution outlet 612 by metal cone threads, and the other two ends are connected to the window part 62, which are the signal source transmitting end and the signal source receiving end respectively.

[0092] 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 arranged at the two ends of the metal cylinder 63, and the sapphire glass 64 has a large diameter portion 641 and a small diameter portion 642. The small diameter portion 642 is at least partially inserted into the metal cylinder 63. The window portion 62 takes into account both the pressure resistance and the good transmittance of the spectral signal, thereby improving the structural stability of the window portion 62. The light in the solution cavity 61 is transmitted to the spectrometer 67 through the sapphire glass 64, ensuring detection under high temperature and high pressure conditions. The sapphire glass 64 can be a nut-type sapphire glass 64. Specifically, the metal cylinder 63 includes a metal nut 631 and a first metal washer 632. The first metal washer 632 is arranged at one end of the metal nut 631; as shown in FIG. Fig.10 As shown, the window portion 62 further includes a second metal gasket 651 , a graphite gasket 652 and a metal O-ring 653 , and the second metal gasket 651 is disposed between the graphite gasket 652 and the first metal gasket 632 .

[0093] like Fig. 9 As shown, the fixing mechanism 66 includes a fixing frame 661, a metal jacket 662, and a heat insulating sleeve 663. The solution chamber 61 is fixed under high pressure by the fixing frame 661. The outside of the fixing frame 661 is wrapped with a heat insulating sleeve 663, which is made of fire-resistant heat-insulating material for heat insulation and heat preservation, and a metal jacket 662 is installed on the outside.

[0094] Both ends of the high temperature and high pressure fluid in-situ detection pool 60 are connected to the spectrometer through optical fiber probes. The high temperature and high pressure fluid in-situ detection pool 60 can withstand high temperature and high pressure. The generated liquid of the reactor 1 will flow through the high temperature and high pressure fluid in-situ detection pool 60. The composition and content of the generated liquid in the high temperature and high pressure fluid in-situ detection pool 60 can be analyzed by the spectrometer under high temperature and high pressure in-situ conditions. The spectrometer 67 can be a laser Raman spectrometer 67.

[0095] In one embodiment, the detection system 50 includes a pressure detection mechanism 51 corresponding to each of the reaction kettles 1; Figure 1 and Figure 2As shown, 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 arranged at the inlet end of the core chamber 101, and the outlet pressure sensor 512 is arranged at the outlet end of the core chamber 101; the differential pressure sensor 513 is arranged between the inlet end and the outlet end of the core chamber 101 to detect the fluid pressure difference between the inlet end and the outlet end. For each reactor 1, the fluid pressure at the inlet end and the outlet end of the core chamber 101 is detected in real time through the inlet pressure sensor 511 and the outlet pressure sensor 512; and the differential pressure sensor 513 is used to realize the real-time detection of the fluid pressure difference between the inlet end and the outlet end, and the fluid pressure and the difference at the inlet end and the outlet end of the core 2 are obtained in real time.

[0096] 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, and the sampler 23 is arranged 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 generated solution in real time.

[0097] 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 by 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 realized, and the real-time evolution characteristic curve of the permeability of the core 2 is generated through the control software.

[0098] The control system can coordinately control the various hardware mechanical structures and circuit systems in the detection system 50 through the control software, so as to realize the 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 connectivity properties of rocks during the dissolution process with the reaction time.

[0099] In one embodiment, if Figure 2 and Figure 3 As shown, 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. 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 pool 60. The outlet end of each reactor 1 controls the fluid pressure inside the rock through the back pressure controller 31 and the back pressure pump 32 to achieve multi-stage cross-tectonic period dissolution simulation. In another embodiment, as Figure 5As shown, 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. The back pressure controller 31 can specifically be a back pressure valve.

[0100] 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 outside 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, and can clamp the core 2 under high temperature and high pressure conditions. The confining pressure fluid channel 121 has a confining pressure port 122, such as Figure 2 and Fig.11 As shown, the confining pressure fluid channel 121 is connected to the confining pressure pump 13 , and the confining pressure pump 13 is used to transport the confining pressure fluid to the confining pressure fluid channel 121 .

[0101] Preferably, if Figure 3 As shown, the confining pressure pump 13 and the back pressure pump 32 are connected to the same water container 33, which is beneficial to simplify the structure of the experimental device and reduce operational failures.

[0102] Furthermore, the reactor 1 includes a temperature controller 14, which is used to control 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.

[0103] In one embodiment, if Fig.11 As shown, 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 plug 21. The hydraulic push rod plug 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.

[0104] Reactor 1 has the function of a high-temperature and high-pressure triaxial stress core holder. At least two reactors 1 are connected in series through pipelines. Each reactor 1 carries out water-rock reaction simulation under the corresponding tectonic period diagenetic environment. Therefore, independent temperature controllers 14, confining pressure pumps 13, back pressure controllers 31 and back pressure pumps 32 are respectively configured. The temperature controller 14 controls the water-rock reaction temperature in the reactor 1, and the confining pressure pump 13 controls the confining pressure of the core 2 sample. In each stage, the outlet of the reactor 1 controls the fluid pressure inside the rock through the back pressure controller 31 and the back pressure pump 32 to carry out multi-stage-continuous flow simulation. In the experimental process of fluid dissolution simulation across tectonic periods, by simulating the temperature, pressure, fluid chemical properties, mineral composition and flow characteristics of different tectonic periods during the diagenesis process, it is possible to effectively simulate the diagenesis such as dissolution, cementation, and replacement caused by changes in temperature, pressure, and fluid properties in the actual strata due to basin tectonic activities. Figure 2 As shown, 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 .

[0105] The reactor 1 is an ultra-high temperature and high pressure triaxial stress reactor. The present invention optimizes the structure of the reactor 1: Fig.11 As shown, the reactor 1 is provided with a temperature control box 18, a reactor support 164 and an ultra-high pressure reactor body 162 from outside to inside, and is also provided with a self-sealing plug 163 and a sample chamber fixing frame 661. A detachable reactor cover 161 is installed on the top of the ultra-high pressure reactor body 162, and a metal piston is arranged inside. The metal piston separates the ultra-high pressure reactor body 162 into two spaces, an upper part and a lower part. The upper part has a fluid injection port 221, a fluid outlet 222, a confining pressure port 122, a first temperature measuring probe 151 and a self-sealing plug 163, and the lower part has a second temperature measuring probe 152. The ultra-high pressure reactor body 162 includes a tracking heating sleeve 181, and the tracking heating sleeve 181 and the two temperature measuring probes are controlled by the temperature control box 18 to track the temperature of the core 2. In addition, the fluid injection port 221, the core cavity 101, and the fluid outlet 222 are connected.

[0106] The reaction solution interface 22 includes a fluid injection port 221 and a fluid outlet 222. The core 2 is used as a sample, the core cavity 101 is used as a 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, one end of the hydraulic push rod plug 21 is connected to the reaction solution inlet 611, and the other end of the hydraulic push rod plug 21 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, wrapped around the outside of the hollow copper cylindrical sample tube, and each support sleeve 12 contains 2 circular holes, so that the confining pressure fluid wraps the hollow copper cylindrical sample tube through the support sleeve 12 and applies confining pressure; the confining pressure fluid channel 121 is connected to the circular hole. The self-sealing plug 163 is placed at both ends of the sample chamber to fix the support sleeve 12 and the hollow copper cylindrical sample tube; the sample chamber fixing frame 661 is used to fix the sample chamber to the sealing cap of the high temperature and high pressure cavity to ensure that the position of the sample chamber is fixed under high temperature and high pressure conditions. One end of the sample chamber fixing frame 661 is connected to the self-sealing plug 163, and the other end is fixed to the sample chamber by screws; the ultra-high pressure autoclave body 162 is hollow and can carry the confining pressure fluid, and is equipped with electric heating and temperature thermocouples, which provide the temperature of the water-rock reaction in the sample chamber by heating the confining pressure fluid; the confining pressure port 122 is connected to the confining pressure pump and the pressure control system.

[0107] In one embodiment, the solution pressure container system 40 includes a pressure container 41, a gas cylinder 42, a gas booster pump 43, a gas buffer tank 44, a gas flow meter 46 and a double plunger pump 45, the gas booster pump 43 is connected to the pressure container 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 container 41, and the pressure container 41 is connected to the reaction solution interface 22. The pressure container 41 can be a piston container, the double plunger pump 45 can be a constant speed constant pressure pump, CO2 can be stored in the gas cylinder 42, and the solution pressure container system 40 can quantitatively prepare a highly saturated CO2 solution, simulate the CO2-rich hydrothermal fluid components deep in the earth, and realize the highly saturated CO2 dissolution simulation. The various hardware mechanical structures in the solution pressure container system 40 can be collaboratively controlled by the host computer control software.

[0108] like Figure 4 As shown, the gas booster pump 43 is connected to the air compressor 48, the 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. Figure 5 As shown, a pressure sensor 49 is also connected to the outlet of the solution pressure container system 40 .

[0109] like Fig.12 and Fig.13As shown, the reaction kettle 1, the solution pressure container system 40 and the in-situ window detection mechanism 6 and other structures are installed on the mounting frame 71 and are electrically connected to the control cabinet 72 to coordinately control the various components.

[0110] The ultra-deep carbonate rock dissolution simulation experimental device provided by the present invention 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, thus solving 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.

[0111] Solution 2

[0112] The present invention provides a carbonate rock dissolution simulation experimental method, using the ultra-deep carbonate rock dissolution simulation experimental device, the experimental method includes: the reactor 1 applies confining pressure and axial pressure to the core 2 in the core cavity 101; the solution pressure container system 40 provides a reaction solution and injects it into the core cavity 101, the back pressure control device 30 controls the outlet pressure of each core cavity 101; the detection system 50 respectively detects each core cavity 101. The experimental method has the technical features and beneficial effects of the above-mentioned experimental device, which will not be repeated here.

[0113] This experimental method can be used to simulate the seepage of ultra-high temperature and high pressure core 2 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 work, the functional requirements of ultra-high temperature and high pressure core 2 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 components and content, and high saturated CO2 dissolution simulation can be achieved. The host computer control software in the software control system completes the control of experimental parameters, data acquisition, spectrum analysis and evaluation of each unit.

[0114] The carbonate rock dissolution simulation experimental method provided by the present invention has the following characteristics:

[0115] (1) Simulation of water-rock reaction environment in ultra-deep carbonate rock formations at 10,000 meters:

[0116] 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, such as a maximum working temperature of 450°C and a maximum working pressure of 150MPa. 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 in the reactor 1, realizing the cross-tectonic period dissolution simulation of carbonate rocks under the constraints of geological models.

[0117] (2) Quantitative evaluation of the dissolution reservoir effect and characterization of pore structure evolution characteristics:

[0118] A core 2 plug sample simulation experiment is provided, and the pore-forming effect of dissolution on the rock can be quantitatively evaluated through parameters such as porosity, permeability and weight before and after the experiment; CT analysis before and after the experiment is used to in-situ compare and characterize the dynamic evolution process of the pore structure inside the rock under dissolution.

[0119] (3) Quantitative characterization of the evolution of connectivity properties during rock dissolution:

[0120] 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.

[0121] (4) Real-time determination of fluid composition and content during rock dissolution:

[0122] Provides real-time continuous measurement of water-rock reaction products under different temperature and pressure conditions. For carbonate rock dissolution reaction, Raman spectroscopy can be used to semi-quantitatively measure the amount of dissolution under equilibrium conditions "in situ", and then comprehensively study the dissolution / precipitation trend of carbonate rocks with increasing burial depth.

[0123] The above are only several embodiments of the present invention. Those skilled in the art may make various changes or modifications to the embodiments of the present invention based on the contents disclosed in the application documents without departing from the spirit and scope of the present invention.

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; Detection system; 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 detection system includes at least two in-situ window detection mechanisms, which include a high-temperature and high-pressure fluid in-situ detection pool and a spectrometer. The high-temperature and high-pressure fluid in-situ detection pool is connected in series between the outlet end of the core cavity and the back pressure control device.

3. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 2, 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.

4. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 3 is 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.

5. The ultra-deep carbonate rock dissolution simulation experimental device according to any one of claims 1 to 4, 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 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.

6. The carbonate rock dissolution simulation experimental device according to claim 5, 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.

7. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 2, 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.

8. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 7, 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.

9. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 8, 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.

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

11. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 8, characterized in that: The reactor comprises a temperature controller, and the temperature controller is used to regulate the temperature of the confining pressure fluid.

12. The ultra-deep carbonate rock dissolution simulation experimental device according to claim 8, 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.

13. 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.

14. 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 13 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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