阅读说明：本技术 模拟二氧化碳饱和流体-围岩相互作用的实验装置及方法 (Experimental device and method for simulating interaction of carbon dioxide saturated fluid and surrounding rock ) 是由 丁茜 何治亮 刘全有 朱东亚 王静彬 于 2020-06-04 设计创作，主要内容包括：本发明提供一种模拟二氧化碳饱和流体-围岩相互作用的实验装置,二氧化碳气源和反应流体源分别与中间容器连接,预热器分别与中间容器和反应釜连接,化学信号采集装置与反应釜连接。二氧化碳气源与中间容器中间设有增压泵。反应流体源与中间容器之间设有恒压恒流泵。二氧化碳气源与增压泵之间、增压泵与中间容器之间、中间容器与预热器之间、预热器与反应釜之间均设有控制阀。反应釜与化学信号采集装置之间设有回压阀。本发明还提供一种实验方法。本发明涉及的装置及方法能够模拟深层地层至地表二氧化碳饱和流体-围岩体系中,二氧化碳饱和流体改造不同深度不同层位地层围岩的过程,并且对该反应过程进行实时在线监测,并进行记录和储存。(The invention provides an experimental device for simulating carbon dioxide saturated fluid-surrounding rock interaction. A booster pump is arranged between the carbon dioxide gas source and the intermediate container. A constant-pressure constant-flow pump is arranged between the reaction fluid source and the intermediate container. Control valves are arranged between the carbon dioxide gas source and the booster pump, between the booster pump and the intermediate container, between the intermediate container and the preheater and between the preheater and the reaction kettle. A back pressure valve is arranged between the reaction kettle and the chemical signal acquisition device. The invention also provides an experimental method. The device and the method can simulate the process of reforming the surrounding rock of the stratum at different depths of different layers by the carbon dioxide saturated fluid in a carbon dioxide saturated fluid-surrounding rock system from a deep stratum to the surface, and carry out real-time online monitoring, recording and storing on the reaction process.)

1. An experimental device for simulating carbon dioxide saturated fluid-surrounding rock interaction is characterized by comprising a carbon dioxide gas source, a reaction fluid source, an intermediate container, a preheater, a reaction kettle and a chemical signal acquisition device; wherein the content of the first and second substances,

the carbon dioxide gas source and the reaction fluid source are respectively connected with the intermediate container, the preheater is respectively connected with the intermediate container and the reaction kettle, and the chemical signal acquisition device is connected with the reaction kettle;

a booster pump is arranged between the carbon dioxide gas source and the intermediate container;

a constant-pressure and constant-flow pump is arranged between the reaction fluid source and the intermediate container;

the carbon dioxide air source with between the booster pump, the booster pump with between the intermediate container, intermediate container with between the pre-heater, the pre-heater with all be equipped with the control valve between the reation kettle, reation kettle with be equipped with the back pressure valve between the chemical signal collection system.

2. The experimental device for simulating the carbon dioxide saturated fluid-surrounding rock interaction as claimed in claim 1, further comprising a gas-liquid separator connected with the chemical signal acquisition device, wherein a control valve is arranged at the bottom of the gas-liquid separator.

3. The experimental facility for simulating carbon dioxide saturated fluid-surrounding rock interaction according to claim 1 or 2, wherein the carbon dioxide gas source comprises carbon dioxide gas stored in a gas cylinder.

4. The experimental facility for simulating carbon dioxide saturated fluid-surrounding rock interaction according to claim 1 or 2, wherein the reactive fluid source comprises a reactive fluid stored in a pressure vessel.

5. The experimental device for simulating the carbon dioxide saturated fluid-surrounding rock interaction as claimed in claim 1 or 2, wherein a pressure measuring device is arranged in each of the intermediate container and the reaction kettle.

6. The experimental device for simulating the carbon dioxide saturated fluid-surrounding rock interaction as claimed in claim 1 or 2, wherein the reaction kettle body is made of hastelloy materials.

7. An experimental method implemented by using the experimental device for simulating the carbon dioxide saturated fluid-surrounding rock interaction as claimed in any one of the claims 1 to 6, characterized by comprising the following steps:

s01, pushing a reaction fluid source into an intermediate container by using a constant-pressure constant-flow pump, and simultaneously pushing a carbon dioxide gas source into the intermediate container by using a booster pump according to a preset pressure until carbon dioxide is saturated to obtain a saturated carbon dioxide solution under a preset pressure condition;

s02, putting the core sample into a reaction kettle;

s03, inputting the saturated carbon dioxide solution in the intermediate container into a preheater to preheat to a preset temperature, inputting the saturated carbon dioxide solution in the intermediate container into a reaction kettle at a preset flow rate through a constant-pressure constant-flow pump after the temperature and the pressure are stable, keeping the temperature in the reaction kettle at a non-preset temperature, and closing a control valve between the preheater and the reaction kettle to start reaction after the temperature and the pressure in the reaction kettle are stable;

s04, after the reaction is finished, inputting the fluid after the reaction in the reaction kettle into a chemical signal acquisition device, and monitoring Ca in the fluid²⁺Concentration, Mg²⁺Concentration and pH;

s05, after the reaction is finished, detecting the core sample, including microscopic morphology analysis, mineral composition analysis and three-dimensional CT scanning;

s06, calculating the change trend of calcium carbonate ion product of the reaction fluid according to the monitoring data obtained in S04, estimating the component change of the fluid moving along the fracture, evaluating the interaction degree of the fluid and the carbonate rock in the reaction system, and exploring the relationship among temperature, pressure, fluid, lithology and surrounding rock dissolution-precipitation trend;

and S07, analyzing the evolution process of holes, holes and seams of reservoir spaces in the reservoir under the open environment according to the detection data obtained in the S05, and analyzing the process of reforming different lithologic strata by carbon dioxide saturated fluid.

8. The experimental method as claimed in claim 7, wherein the steps S01 to S04 are repeated at least once before the step S05.

9. The experimental method as claimed in claim 7, further comprising, before step S01, step S00: the sealing performance of the experimental device for simulating the carbon dioxide saturated fluid-surrounding rock interaction is tested.

10. The experimental method as claimed in claim 7, wherein the reacted fluid is treated with a gas-liquid separator after completion of step S04.

Technical Field

The invention relates to the technical field of water rock reaction process research, in particular to an experimental device and method for simulating carbon dioxide saturated fluid-surrounding rock interaction.

Background

China's main basin with oil and gas has experienced large-scale deep-source CO₂And (6) moving. Containing CO₂The fluid may act to erode the deep reservoir. Current oil and gas exploration practices reveal important oil and gas values for carbon dioxide reforming of hydrocarbon reservoirs. And the carbon dioxide fluid is transported along the fracture system and continuously modifies the surrounding rock, so that the storage performance of the modified surrounding rock is improved and promoted. The source of the fluid may be deep hydrothermal, formation or pore water, etc., and the source of the carbon dioxide may be a mantle source, or may be atmospheric carbon dioxide. The carbonate reservoir modified by the carbon dioxide fluid is very extensive, and is particularly important in the deep fields of two major marine basins, namely a Tarim basin and a Sichuan basin, and the carbon dioxide fluid-surrounding rock reaction mechanism/process is also a crucial ring in the problems of carbon dioxide capture and carbon sequestration which are global concerns. However, the dissolution/precipitation mechanism of the modified surrounding rock and the material change and energy change in the fluid rock interaction process are not clear, and the problems need to be solved by carrying out experiments simulating the interaction between the deep stratum to the superficial stratum and the carbon dioxide fluid and the surrounding rock.

Carbon dioxide has unique physical and chemical properties, and the solubility of carbon dioxide in water is reduced along with the increase of temperature; as the pressure increases, the solubility of carbon dioxide in water increases. In actual geological environments, as the depth of the formation increases, the corresponding temperature and pressure also increase synchronously. In a saturated carbon dioxide fluid surrounding rock experiment for simulating a formation environment, the biggest difficulty is that a conventional carbon dioxide saturated solution is only saturated at normal temperature and normal pressure, once the conventional carbon dioxide saturated solution enters a high-temperature and high-pressure experiment system, carbon dioxide in the fluid enters an unsaturated state, the setting of the carbon dioxide fluid saturated in the simulation experiment is inconsistent with that of the carbon dioxide fluid saturated in the simulation experiment, and a corresponding means and a method for continuously keeping the carbon dioxide saturated state in the carbon dioxide fluid along with the change of experiment pressure are not available at present.

The existing water rock chemical reaction device mostly adopts a continuous flow method, a granular rock sample or a rock core sample is assembled in a reaction kettle, and fluid enters the reaction kettle through a pipeline to react with the sample for a period of time. And calculating and inferring the reaction process through the change of the microscopic morphology and the structural composition of the rock sample after the reaction and the change of the concentration of the ion components in the fluid after the reaction.

The device only designs a reaction kettle and a fluid booster pump, and can only simulate the water-rock reaction under the conditions of temperature and pressure at a certain depth, and the reaction pressure condition is single. Meanwhile, due to the lack of a corresponding carbon dioxide gas pressurization system, saturated carbon dioxide fluid corresponding to formation pressure conditions cannot be prepared, and the reaction environment cannot be truly reproduced. However, the method only simulates the saturated carbon dioxide fluid-rock reaction under the normal temperature and pressure environment of the earth surface, and obviously cannot meet the requirements of deep exploration and exploration of the deep fluid-rock reaction process/mechanism.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides an experimental device and method for simulating the interaction of carbon dioxide saturated fluid and surrounding rock, which can simulate the process of reforming the surrounding rock of the stratum with different depths at different depths from a deep stratum to an earth surface carbon dioxide saturated fluid-surrounding rock system, carry out real-time online monitoring on the reaction process, record and store the reaction process and provide an effective means and method for reservoir reforming and prediction.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

an experimental device for simulating the interaction between carbon dioxide saturated fluid and surrounding rock comprises a carbon dioxide gas source, a reaction fluid source, an intermediate container, a preheater, a reaction kettle and a chemical signal acquisition device. Wherein, the carbon dioxide gas source and the reaction fluid source are respectively connected with the intermediate container, the preheater is respectively connected with the intermediate container and the reaction kettle, and the chemical signal acquisition device is connected with the reaction kettle. A booster pump is arranged between the carbon dioxide gas source and the intermediate container. A constant-pressure constant-flow pump is arranged between the reaction fluid source and the intermediate container. Control valves are arranged between the carbon dioxide gas source and the booster pump, between the booster pump and the intermediate container, between the intermediate container and the preheater and between the preheater and the reaction kettle. A back pressure valve is arranged between the reaction kettle and the chemical signal acquisition device.

According to the experimental device disclosed by the invention, the migration of saturated carbon dioxide fluid along a crack and the continuous transformation of the water-rock action process of surrounding rocks at different depths and different layers can be simulated and reproduced from a deep stratum under the conditions of high temperature and high pressure to the surface of the earth under the conditions of normal temperature and normal pressure, the progress of water-rock reaction in the system can be monitored in real time, and the sampling detection does not influence the reaction process. The key point is that even if the value of the pressure parameter changes in the reaction, the concentration of carbon dioxide in the fluid can keep a saturated state along with the pressure change, so that the interaction between the carbon dioxide saturated fluid and the surrounding rock from the deep stratum to the earth surface in different stratums with different depths can be comprehensively measured, the dynamic process of the reaction between the saturated carbon dioxide fluid and the surrounding rock in the deep/shallow stratum environment can be monitored, the evolution process of the reservoir space along with time, stratum depth, lithology and other influence factors can be investigated, and effective experimental means and experimental techniques are provided for reservoir transformation and reservoir prediction.

Specifically, a reaction fluid is pressurized by a constant-pressure constant-flow pump and then enters an intermediate container, carbon dioxide gas is increased to a set pressure by a gas booster pump and then enters the intermediate container to be mixed with the fluid and fully saturated, the saturated carbon dioxide fluid is preheated by a preheater at a constant flow rate by the constant-pressure constant-flow pump and then enters a high-temperature high-pressure reaction kettle, the saturated carbon dioxide fluid reacts with a rock sample and then enters a real-time chemical signal acquisition device, and Ca in the fluid²⁺，Mg²⁺，H⁺The change in the isocationic concentration is detected and recorded. During the whole experiment, the pressure is returnedThe valve can ensure that the pressure of the whole experiment system is stable and unchanged after reaching the preset pressure. The set of devices

Secondly, a step-type pressure increasing/reducing reaction technology is adopted, the gas pressure is adjusted by adjusting the parameters of the gas booster pump, the pressure of the intermediate container reaches a set value, and the intermediate container is fully saturated with the fluid under the pressure. In addition to simulating a single stratum, if continuous saturated carbon dioxide fluid-surrounding rock reaction of two groups of strata, three groups of strata and multiple groups of strata is simulated, a step pressure increasing/reducing program can be set, the pressure parameter of a gas booster pump is changed, pressurized gas with a set pressure value is input into an intermediate container, and after the intermediate container and the fluid are fully saturated for a period of time, the saturated carbon dioxide fluid enters a subsequent high-temperature high-pressure reaction kettle and a surrounding rock sample for reaction. The design solves the problem that the prior experimental device can not truly and effectively simulate the continuous reaction process of the saturated carbon dioxide fluid-surrounding rock of different depth formations.

Furthermore, according to the experimental device provided by the invention, an experimental scheme can be designed aiming at a geological object which is actually researched, the process of continuously transforming the surrounding rock by using the saturated carbon dioxide fluid is simulated, and the corrosion-precipitation law of carbonate rocks in different geological environments of different layers is contrastively investigated, so that the experimental device has important scientific significance for exploring the formation and maintenance of a reservoir space in a deep stratum fracture system. The application range of the invention can be expanded to different lithologic samples, and the invention is applied to the fields of reservoir origin, reservoir prediction, reservoir transformation, carbon capture, carbon sequestration and the like.

With respect to the above technical solution, further improvements as described below can be made.

The experimental device for simulating the carbon dioxide saturated fluid-surrounding rock interaction further comprises a gas-liquid separator connected with the chemical signal acquisition device, and a control valve is arranged at the bottom of the gas-liquid separator.

Through setting up vapour and liquid separator, can carry out the separation processing to fluid and gas after the reaction, be convenient for follow-up collection and analysis and test.

Specifically, in a preferred embodiment, the carbon dioxide gas source comprises carbon dioxide gas stored in a gas cylinder.

In particular, in a preferred embodiment, the source of reaction fluid comprises a reaction fluid stored within a pressure vessel.

Further, in a preferred embodiment, pressure measuring devices are arranged in the intermediate container and the reaction kettle.

Through setting up pressure measurement device, can real time monitoring in the experimentation whether overall system's pressure maintains at the stable invariant of preset pressure value to effectively ensure that the experimentation is reliable and stable.

Specifically, in a preferred embodiment, the reactor body of the reaction kettle is made of hastelloy materials.

The reactor body of the reaction kettle is made of hastelloy, so that the reaction kettle is high in strength, resistant to acid and alkali corrosion, high-temperature resistant and high-pressure resistant, and the reaction kettle can meet the experimental requirements of high-temperature high-pressure and different types of fluid.

The experimental method implemented by adopting the experimental device for simulating the carbon dioxide saturated fluid-surrounding rock interaction according to the second aspect of the invention comprises the following steps: and S01, pushing a reaction fluid source into an intermediate container by using a constant-pressure constant-flow pump, and simultaneously pushing a carbon dioxide gas source into the intermediate container by using a booster pump according to a preset pressure until carbon dioxide is saturated to obtain a saturated carbon dioxide solution under a preset pressure condition. And S02, putting the core sample into a reaction kettle. And S03, inputting the saturated carbon dioxide solution in the intermediate container into a preheater to be preheated to a preset temperature, inputting the saturated carbon dioxide solution in the intermediate container into a reaction kettle at a preset flow rate through a constant-pressure constant-flow pump after the temperature and the pressure are stable, keeping the temperature in the reaction kettle at a non-preset temperature, and closing a control valve between the preheater and the reaction kettle to start reaction after the temperature and the pressure in the reaction kettle are stable. S04, after the reaction is finished, inputting the fluid after the reaction in the reaction kettle into a chemical signal acquisition device, and monitoring Ca in the fluid²⁺Concentration, Mg²⁺Concentration and pH. And S05, after the reaction is finished, detecting the core sample, including microscopic morphology analysis, mineral composition analysis and three-dimensional CT scanning. S06 obtained according to S04The monitoring data of the system calculates the change trend of the calcium carbonate ion product of the reaction fluid, estimates the component change of the fluid moving along the fracture, estimates the interaction degree of the fluid-carbonate rock in the reaction system and explores the relationship among temperature, pressure, fluid, lithology and surrounding rock dissolution-precipitation trend. And S07, analyzing the evolution process of holes, holes and seams of reservoir spaces in the reservoir under the open environment according to the detection data obtained in the S05, and analyzing the process of reforming different lithologic strata by carbon dioxide saturated fluid.

With respect to the above technical solution, further improvements as described below can be made.

According to the experimental method for simulating the carbon dioxide saturated fluid-surrounding rock interaction, in a preferred embodiment, the steps S01 to S04 are repeated at least once before the step S05.

By setting different pressure and temperature values and adopting a step-type pressure increasing/reducing reaction technology, the continuous reaction of saturated carbon dioxide fluid-rock of a single stratum, two groups of strata, three groups of strata and a plurality of groups of strata can be simulated respectively. By adopting the technology, an experimental scheme can be designed aiming at a geological object of practical research, the process of continuously transforming the surrounding rock by saturated carbon dioxide fluid is simulated, and the carbonate rock corrosion-precipitation rules in different geological environments of different layers are contrastingly investigated, so that the method has important scientific significance for exploring the formation and maintenance of a reservoir space in a deep stratum fracture system.

Further, in a preferred embodiment, before the step S01, the method further includes a step S00: the sealing performance of the experimental device for simulating the carbon dioxide saturated fluid-surrounding rock interaction is tested.

Before the experiment, through carrying out the sealing performance test to whole experimental apparatus, can guarantee that the experimentation is stable smooth.

Further, in a preferred embodiment, the reacted fluid is treated with a gas-liquid separator after completion of step S04.

After the experiment is finished, the reacted fluid is separated by the gas-liquid separator, so that the influence on the environment can be effectively avoided.

Compared with the prior art, the invention has the advantages that: the system can simulate the process of migration of saturated carbon dioxide fluid along a fracture system and continuous modification of fluid-rock interaction of surrounding rocks at different depths and different layers under the conditions of high temperature and high pressure of a deep stratum to the surface of the earth under the conditions of normal temperature and normal pressure, can monitor the progress of water-rock reaction in the system in real time, does not influence the reaction process by sampling detection, can be applied to rock samples with different quantities and different lithologies, can also research the physical property change of a carbonate reservoir along with temperature and pressure in the continuous multi-stage structure lifting-settling process and the process of corrosion of the surrounding rocks by the saturated carbon dioxide fluid-filling pores, investigate and research the migration rule of the saturated carbon dioxide fluid in the water-rock reaction process, monitor the expansion or filling degree of a reservoir space under different temperature and pressure conditions, judge the occurrence trend of dissolution/precipitation, and monitor the modification/construction degree of the saturated carbon dioxide fluid at different depths to the reservoir, judging the effective degree of the carbon sequestration engineering and finding out the interaction rule of the saturated carbon dioxide fluid and the surrounding rock have important scientific significance. The invention has strong practical application significance, can be used in the research fields of reservoir cause, reservoir transformation, reservoir prediction, carbon capture/carbon sequestration and the like, and is convenient for application and popularization.

Drawings

The invention will be described in more detail hereinafter on the basis of embodiments and with reference to the accompanying drawings. Wherein:

fig. 1 schematically shows the framework structure principle of an experimental apparatus for simulating carbon dioxide saturated fluid-surrounding rock interaction according to an embodiment of the present invention.

In the drawings, like parts are provided with like reference numerals. The figures are not drawn to scale.

Detailed Description

The invention will be further explained in detail with reference to the figures and the embodiments without thereby limiting the scope of protection of the invention.

Fig. 1 schematically shows the framework structure principle of an experimental apparatus 10 for simulating carbon dioxide saturated fluid-surrounding rock interaction according to an embodiment of the present invention.

Example 1

As shown in fig. 1, an experimental apparatus 10 for simulating carbon dioxide saturated fluid-surrounding rock interaction according to an embodiment of the present invention includes a gas cylinder 1 for storing carbon dioxide gas, a pressure vessel 2 for storing reaction fluid, an intermediate vessel 3, a preheater 4, a high-temperature high-pressure reaction vessel 5, and a chemical signal acquisition device 6. Wherein, gas cylinder 1 and pressure vessel 2 are connected with intermediate container 3 respectively, and pre-heater 4 is connected with intermediate container 3 and high temperature high pressure reation kettle 5 respectively, and chemical signal collection system 6 is connected with high temperature high pressure reation kettle 5. A booster pump 7 is arranged between the gas cylinder 1 and the intermediate container 3. A constant pressure and constant flow pump 8 is arranged between the pressure container 2 and the intermediate container 3. Stop valves 9 are arranged between the gas cylinder 1 and the booster pump 7, between the booster pump 7 and the intermediate container 3, between the intermediate container 3 and the preheater 4, and between the preheater 4 and the high-temperature high-pressure reaction kettle 5. A back pressure valve 101 is arranged between the high-temperature high-pressure reaction kettle 5 and the chemical signal acquisition device 6.

According to the experimental device provided by the embodiment of the invention, the migration of saturated carbon dioxide fluid along a crack and the continuous transformation of the water-rock action process of surrounding rocks at different depths and different layers can be simulated and reproduced from a deep stratum under the conditions of high temperature and high pressure to the surface normal temperature and normal pressure, the water-rock reaction progress in the system can be monitored in real time, and the sampling detection does not influence the reaction process. The key point is that even if the value of the pressure parameter changes in the reaction, the concentration of carbon dioxide in the fluid can keep a saturated state along with the pressure change, so that the interaction between the carbon dioxide saturated fluid and the surrounding rock from the deep stratum to the earth surface in different stratums with different depths can be comprehensively measured, the dynamic process of the reaction between the saturated carbon dioxide fluid and the surrounding rock in the deep/shallow stratum environment can be monitored, the evolution process of the reservoir space along with time, stratum depth, lithology and other influence factors can be investigated, and effective experimental means and experimental techniques are provided for reservoir transformation and reservoir prediction.

Specifically, the reaction fluid is pressurized by a constant-pressure constant-flow pump and then enters an intermediate container, the carbon dioxide gas is increased to a set pressure by a gas booster pump and then enters the intermediate container to be mixed with the fluid and fully saturated, and the saturated carbon dioxide fluid is preheated at a constant flow rate by the constant-pressure constant-flow pumpPreheating the reactor, then feeding the preheated fluid into a high-temperature high-pressure reaction kettle, reacting the saturated carbon dioxide fluid with a rock sample, feeding the reacted saturated carbon dioxide fluid into a chemical signal acquisition device, and collecting Ca in the fluid²⁺，Mg²⁺，H⁺The change in the isocationic concentration is detected in real time and recorded. In the whole experiment process, the pressure of the whole experiment system can be guaranteed to be stable and unchanged after reaching the preset pressure through the action of the back pressure valve. The set of devices

Secondly, a step-type pressure increasing/reducing reaction technology is adopted, the gas pressure is adjusted by adjusting the parameters of the gas booster pump, the pressure of the intermediate container reaches a set value, and the intermediate container is fully saturated with the fluid under the pressure. In addition to simulating a single stratum, if continuous saturated carbon dioxide fluid-surrounding rock reaction of two groups of strata, three groups of strata and multiple groups of strata is simulated, a step pressure increasing/reducing program can be set, the pressure parameter of a gas booster pump is changed, pressurized gas with a set pressure value is input into an intermediate container, and after the intermediate container and the fluid are fully saturated for a period of time, the saturated carbon dioxide fluid enters a subsequent high-temperature high-pressure reaction kettle and a surrounding rock sample for reaction. The design solves the problem that the prior experimental device can not truly and effectively simulate the continuous reaction process of the saturated carbon dioxide fluid-surrounding rock of different depth formations.

Furthermore, according to the experimental device provided by the embodiment of the invention, an experimental scheme can be designed aiming at a geological object which is actually researched, the process of continuously transforming the surrounding rock by using the saturated carbon dioxide fluid is simulated, and the carbonate rock corrosion-precipitation rules in different geological environments of different layers are contrastingly investigated, so that the experimental device has important scientific significance for exploring the formation and maintenance of a reservoir space in a deep stratum fracture system. The application range of the invention can be expanded to different lithologic samples, and the invention is applied to the fields of reservoir origin, reservoir prediction, reservoir transformation, carbon capture, carbon sequestration and the like.

As shown in fig. 1, preferably, the experimental apparatus 10 for simulating the carbon dioxide saturated fluid-surrounding rock interaction according to the embodiment of the present invention further includes a gas-liquid separator 102 connected to the chemical signal acquisition device 6, and a stop valve 9 is disposed at the bottom of the gas-liquid separator 102. Through setting up vapour and liquid separator, can carry out the separation processing to fluid and gas after the reaction, be convenient for follow-up collection and analysis and test.

Further, as shown in fig. 1, in the present embodiment, pressure gauges 103 are provided in the intermediate vessel 3, the high-temperature high-pressure reactor 5, and the gas-liquid separator 102. Through setting up pressure measurement device, can real time monitoring in the experimentation whether overall system's pressure maintains at the stable invariant of preset pressure value to effectively ensure that the experimentation is reliable and stable.

Specifically, in this embodiment, the body of the high-temperature high-pressure reaction kettle 5 is made of hastelloy. The reactor body of the reaction kettle is made of hastelloy, so that the reaction kettle is high in strength, resistant to acid and alkali corrosion, high-temperature resistant and high-pressure resistant, and the reaction kettle can meet the experimental requirements of high-temperature high-pressure and different types of fluid.

Example 2

As shown in fig. 1, the experimental method for simulating the carbon dioxide saturated fluid-surrounding rock interaction according to the embodiment of the present invention specifically includes the following steps:

(1) debugging before experiment: connecting pipelines, opening stop valves 9 between the gas cylinder 1 and the booster pump 7, between the booster pump 7 and the intermediate container 3, between the intermediate container 3 and the preheater 4 and between the preheater 4 and the high-temperature high-pressure reaction kettle 5, introducing pure water into the whole system, testing the sealing performance, controlling a constant-pressure constant-flow pump 8 to push liquid in the pressure container 2 into the intermediate container 3, heating the liquid by the preheater 4 and then pushing the liquid into the high-temperature high-pressure reaction kettle 5, and testing the background ion concentration in the blank fluid by a chemical signal acquisition device 6;

(2) preparation of experimental fluid system: a constant-pressure constant-flow pump 8 is adopted to push reaction fluid in the high-pressure container 2 to enter the intermediate container 3, and meanwhile, a booster pump 7 is adopted to push carbon dioxide gas to enter the intermediate container 3 according to a preset pressure of 10Mpa until carbon dioxide is saturated to obtain a saturated carbon dioxide solution under the condition of 10 Mp;

(3) and (3) continuous reaction: the plunger-shaped core sample is put into a high-temperature high-pressure reaction kettle 5. The temperature of the preheater 4 is adjusted to 50 ℃, and the saturated CO is₂The aqueous solution is preheated via an inline preheater 4. After the temperature and the pressure are stabilized, the intermediate container 3 is saturated by the constant pressure and constant flow pump 8 at a speed of 1ml/minAnd CO₂The aqueous solution is pumped into a high-temperature high-pressure reaction kettle 5. The temperature of a heating jacket of the high-temperature high-pressure reaction kettle 5 is adjusted to 50 ℃, and the pressure of the system is adjusted to 10Mpa by a constant-pressure constant-flow pump 8. After the temperature and the pressure of the system are stabilized, the stop valves 9 between the preheater 4 and the high-temperature high-pressure reaction kettle 5 and at the bottom of the separator 102 are closed. Starting to time, after the reaction is carried out for 24 hours, opening stop valves 9 between the preheater 4 and the high-temperature high-pressure reaction kettle 5 and at the bottom of the separator 102, enabling the fluid after the reaction to enter a chemical signal acquisition device 6, and monitoring Ca in the fluid²⁺Concentration, Mg²⁺Concentration, pH value. The detected fluid is processed and collected by a gas-liquid separator 102; then closing the stop valves 9 between the preheater 4 and the high-temperature high-pressure reaction kettle 5 and at the bottom of the separator 102;

(4) and (3) continuous reaction: the reaction fluid in the high-pressure container 2 is pushed into the intermediate container 3 by adopting a constant-pressure constant-flow pump 8, the pressure of the booster pump 7 is adjusted to be 20Mpa, and the booster pump 7 is controlled to push CO in the gas cylinder 1₂Gas is introduced into the intermediate vessel 3 to CO₂Saturating, adjusting the temperature of the preheater 4 to 80 ℃, opening the stop valves 9 between the preheater 4 and the high-temperature high-pressure reaction kettle 5 and at the bottom of the separator 102 after the temperature and the pressure are stable, and leading the saturated CO in the intermediate container 3 to flow at the speed of 1ml/min through a constant-pressure constant-flow pump 8₂The aqueous solution is pumped into a high-temperature high-pressure reaction kettle 5. The temperature of a heating jacket of the high-temperature high-pressure reaction kettle 5 is adjusted to 80 ℃, and the pressure of the system is adjusted to 20Mpa by a constant-pressure constant-flow pump 8. After the temperature and the pressure of the system are stabilized, the stop valves 9 between the preheater 4 and the high-temperature high-pressure reaction kettle 5 and at the bottom of the separator 102 are closed. Starting to time the reaction, after the reaction is carried out for 24 hours, opening the stop valves 9 between the preheater 4 and the high-temperature high-pressure reaction kettle 5 and at the bottom of the separator 102, enabling the fluid after the reaction to enter the chemical signal acquisition device 6, and monitoring Ca in the fluid in real time²⁺Concentration, Mg²⁺Concentration, pH value. And (4) processing and collecting the detected fluid through a separator 10, and closing a stop valve 9 between the preheater 4 and the high-temperature high-pressure reaction kettle 5 and at the bottom of the separator 102. After the reaction is finished, carrying out subsequent detection on the sample, such as specific surface area, micro morphology, mineral composition and the like;

(5) and (3) data post-processing: based on the obtained post-reaction solution Ca²⁺，Mg²⁺The ion concentration and the pH value can be calculated, the change trend of the calcium carbonate ion product of the reaction fluid can be calculated, the component change of the fluid moving along the fracture can be estimated, the interaction degree of the fluid-carbonate rock in the reaction system can be evaluated, and the relationship among the temperature, the pressure, the fluid, the lithology and the dissolution-precipitation trend of the surrounding rock can be explored. According to the subsequent microscopic morphology analysis, mineral composition analysis and three-dimensional CT scanning of the sample, the evolution process of holes, holes and seams of reservoir spaces in a reservoir under an open environment can be analyzed, and the process of reforming different lithologic strata by carbon dioxide saturated fluid is analyzed.

According to the embodiment, the experimental device for simulating the effect of the saturated carbon dioxide fluid on the surrounding rocks can simulate the process that the saturated carbon dioxide fluid migrates along a fracture system and continuously reforms the fluid-rock interaction of the surrounding rocks at different depths and different layers under the conditions of high temperature and high pressure of a deep stratum and normal temperature and normal pressure of the ground surface, can monitor the progress of the water-rock reaction in the system in real time, can not influence the reaction process by sampling and detection, can be expanded and applied to different quantities of rock samples with different lithologies, can also research the physical property change of a carbonate reservoir along with the temperature and pressure change in the continuous multi-stage structure lifting-settling process and the process that the saturated carbon dioxide fluid erodes the surrounding rocks and fills pores, investigate the migration rule of the saturated carbon dioxide fluid in the water-rock reaction process, monitor the expansion or filling degree of the reservoir space under different temperature and pressure conditions, the method has important scientific significance for monitoring the transformation/construction degree of saturated carbon dioxide fluid in strata at different depths to reservoirs, judging the effective degree of carbon sequestration engineering and finding out the interaction rule of the saturated carbon dioxide fluid and surrounding rocks. The invention has strong practical application significance, can be used in the research fields of reservoir cause, reservoir transformation, reservoir prediction, carbon capture/carbon sequestration and the like, and is convenient for application and popularization.

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.