Water-rock reaction mechanism in-situ measurement device and method

Abstract

The invention relates to a water-rock reaction mechanism in-situ measurement device and method, and belongs to the field of carbon dioxide geological sequestration experiment determination. The device comprises a formation water tank, a Raman probe, a reaction kettle, a vacuum pump, a gas tank, a formation water pipeline, a liquid circulating pump, a vacuum pipeline, a gas pipeline, a gas circulating pump, a connecting piece, a gas-liquid circulating pipeline and a sampling pipeline, wherein a sampler is arranged on the sampling pipeline. According to the invention, through combined arrangement of the formation water pipeline, the gas pipeline, the Raman probe and the pipeline where the connecting piece is located, real-time measurement of Raman spectrum data in the whole water-rock reaction process is realized; liquid and gas are mixed and circulated in the device in the water-rock reaction process by utilizing the combined arrangement of a gas-liquid circulating pipeline, a gas circulating pump and a liquid circulating pump, so that the accuracy of detection data is improved.

Description

Technical Field

[0001] This invention belongs to the field of experimental determination of carbon dioxide geological sequestration, and specifically relates to an in-situ measurement device and method for water-rock reaction mechanism. Background Technology

[0002] CO2 geological sequestration is currently the most direct, effective, and potentially significant technological means for large-scale reduction of greenhouse gas emissions. It is generally believed that after CO2 injection, it is deposited in the formation in the forms of tectonic sequestration, dissolution sequestration, residual gas sequestration, and mineral sequestration. When CO2 dissolves in formation water, it reacts chemically with minerals, resulting in mineral dissolution and precipitation. On the one hand, mineral reactions can alter the CO2 plume by affecting local formation porosity and permeability, thus influencing tectonic and residual gas sequestration; on the other hand, mineral reactions alter the ionic composition of formation water and the composition of formation minerals, thus affecting dissolution and mineral sequestration. Therefore, clarifying the types, sequence, and total amount of mineral reactions after CO2 or CO2-rich gas mixtures (including residual gaseous impurities from flue gas and other waste gas treatment processes) are crucial for understanding the contributions of different CO2 storage mechanisms and assessing the safety of CO2 sequestration. Currently, micro Raman spectroscopy experiments on mineral reactions involving fluid inclusions exist. However, these experiments require sample loading using millimeter or micrometer-scale capillaries. Loading a single capillary with solid particles, gaseous samples, and liquid samples simultaneously is challenging, making the experimental procedure complex. Furthermore, due to the small sample volume measured in a single measurement, it is difficult to assess the relationship between the total amount of dissolved and precipitated substances produced by the reaction of CO2 with minerals and parameters such as temperature, pressure, and reactant contact area. To address these issues, there is an urgent need to establish a laboratory experimental method that enables quantitative analysis. Summary of the Invention

[0003] To address the above problems, this invention provides an in-situ measurement device and method for water-rock reaction mechanism.

[0004] The first objective of this invention is to provide an in-situ measurement device for water-rock reaction mechanisms, comprising a formation water tank, a Raman probe, a reaction vessel, a vacuum pump, and a gas tank;

[0005] The formation water tank and the reaction vessel are connected by a formation water pipeline, and a liquid circulation pump is installed on the formation water pipeline;

[0006] The reactor is connected to the vacuum pump via a vacuum pipeline;

[0007] The reaction vessel and the gas tank are connected by a gas pipeline, and a gas circulation pump is installed on the gas pipeline;

[0008] The Raman probe is connected to the formation water tank and the reaction vessel via connectors, with one end of the connector connected to the formation water tank and the other end connected to the reaction vessel.

[0009] Gas-liquid circulation pipelines are connected in parallel at both ends of the connector. One end of the gas-liquid circulation pipeline merges with the connection point between the connector and the formation water tank, and the other end merges with the connection point between the connector and the reactor.

[0010] Several sampling lines are provided between the vacuum line and the gas line. One end of each sampling line is connected to the vacuum line, and the other end is connected to the gas line. Each sampling line is equipped with a sampler.

[0011] Furthermore, a formation water switch is also provided on the formation water pipeline, and the formation water switch is located near the formation water tank.

[0012] Furthermore, the connection point between the connector and the formation water tank is located between the formation water switch and the liquid circulation pump, and a first gas-liquid circulation switch is provided between the connection point between the connector and the formation water tank and the liquid circulation pump. One end of the connector is connected to the gas-liquid circulation pipeline through a third gas-liquid circulation switch, and the other end is connected to the gas-liquid circulation pipeline through a fourth gas-liquid circulation switch. A second gas-liquid circulation switch is provided on the gas-liquid circulation pipeline.

[0013] Furthermore, a vacuum switch is provided on the vacuum line;

[0014] The connection point between the sampling line and the vacuum line is located between the vacuum switch and the reactor.

[0015] Furthermore, the gas pipeline is also equipped with an injection pump and an injection first switch, and the injection pump, the injection first switch and the gas circulation pump are arranged in sequence in the direction of gas flow.

[0016] The connection point between the sampling pipeline and the gas pipeline is located between the first gas injection switch and the gas circulation pump.

[0017] Furthermore, a pressure sensor is also provided on the gas pipeline, and the gas injection pump, the first gas injection switch, the gas circulation pump and the pressure sensor are arranged in sequence in the direction of gas flow.

[0018] Furthermore, the gas pipeline is also equipped with a second gas injection switch, and in the direction of gas flow, the gas injection pump, the first gas injection switch, the second gas injection switch, the gas circulation pump and the pressure sensor are arranged in sequence;

[0019] The connection point between the sampling pipeline and the gas pipeline is located between the first gas injection switch and the second gas injection switch.

[0020] Furthermore, the sampling pipeline is also equipped with a sampling switch group, the number of which is at least two, and at least two switches are respectively located at both ends of the sampler.

[0021] Furthermore, the sampling pipelines include a first sampling pipeline and a second sampling pipeline. The first sampling pipeline is provided with a first sampler and a first sampling switch group. The first sampling switch group includes a first sampling first switch and a first sampling second switch. The first sampling first switch and the first sampling second switch are respectively disposed at both ends of the first sampler.

[0022] The second sampling pipeline is provided with a second sampler and a second sampling switch group. The second sampling switch group includes a second sampling first switch and a second sampling second switch. The second sampling first switch and the second sampling second switch are respectively located at both ends of the second sampler.

[0023] Furthermore, the reactor has a lining inside its peripheral wall, and a heating jacket is provided on the side wall of the lining away from the reactor; a stirring impeller is provided inside the reactor; and a thermocouple is also provided inside the reactor.

[0024] Furthermore, the reactor is also connected to a venting line, and a venting switch is installed on the venting line.

[0025] The second objective of this invention is to provide an in-situ measurement method for water-rock reaction mechanisms, comprising:

[0026] Connect the formation water tank, gas tank, reaction vessel, vacuum pump, Raman probe and sampler according to the above-mentioned in-situ measurement device;

[0027] Formation water with known water quality characteristics is loaded into a formation water tank;

[0028] The gas sample to be injected, with a known gas composition, is loaded into the gas container;

[0029] A rock sample with a known mineral composition is loaded into the bottom of the reaction vessel;

[0030] Turn on the vacuum pump to evacuate the formation water pipeline, vacuum pipeline, gas pipeline, pipeline where the Raman probe is located, sampling pipeline and reaction vessel. After completion, turn off the vacuum pump.

[0031] Open the gas cylinder and inject the gas sample into the reaction vessel until the target gas pressure is reached;

[0032] Turn on the liquid circulation pump and the gas circulation pump to circulate the liquid and gas internally.

[0033] Heat the reactor to the target temperature;

[0034] The reaction of water and rock was carried out at the target temperature and target pressure, and the spectral data of the reaction process was recorded by Raman probe;

[0035] Remove the sampler from any sampling line and perform gas phase composition analysis on the gas in the sampler;

[0036] Turn off the liquid circulation pump and gas circulation pump, stop heating the reactor, remove the rock sample after the reaction is complete, and perform whole-rock and clay composition analysis on the rock sample after the reaction is complete.

[0037] Furthermore, the target air pressure is 15-35 MPa.

[0038] Furthermore, the target temperature is 20-120℃.

[0039] Further, the step of removing the sampler from any sampling pipeline and performing gas phase composition analysis on the gas in the sampler includes:

[0040] When the pressure in the gas pipeline no longer decreases, take a sampler from a sampling pipeline and perform gas phase composition analysis on the gas in the sampler.

[0041] When the spectral data recorded by the Raman probe no longer changes, take a sampler from one of the remaining sampling lines and perform gas phase composition analysis on the gas in the sampler.

[0042] The beneficial effects of this invention are:

[0043] This invention discloses an in-situ measurement device and method for water-rock reaction mechanism. Through the combined arrangement of formation water pipelines, gas pipelines, and the pipeline containing the Raman probe and connectors, real-time measurement of Raman spectral data is achieved throughout the entire water-rock reaction process. Furthermore, the combined arrangement of gas-liquid circulation pipelines and gas and liquid circulation pumps enables the mixing and circulation of liquids and gases within the device during the water-rock reaction process, improving the accuracy of the detection data. Additionally, the installation of several sampling pipelines allows for independent gas sampling at multiple reaction stages within the water-rock reaction.

[0044] Furthermore, by setting up a gas-liquid circulation switch group consisting of a first gas-liquid circulation switch, a second gas-liquid circulation switch, a third gas-liquid circulation switch, and a fourth gas-liquid circulation switch, the control of the specific mixing and circulation position of liquid and gas is realized;

[0045] Furthermore, by setting up the sampling switch group, it is ensured that independent sampling is carried out in multiple reaction stages, while ensuring that the sampling process does not affect the water-rock reaction process, the circulation and mixing of liquid and gas, and the detection data of the Raman probe, thus ensuring the accuracy of the experiment.

[0046] Furthermore, by setting pressure sensors, the timing of gas sampling during the gas dissolution stage of the water-rock reaction was clarified, thus improving the accuracy of the sampling data.

[0047] The method of the present invention obtains the characteristic parameter data of the liquid during the water-rock reaction process through the above-mentioned in-situ measurement device and the liquid Raman spectroscopy data analysis during the water-rock reaction process. Through the sampler, the gas composition data of different reaction stages during the water-rock reaction process are obtained. Then, combined with the original rock composition data and the original liquid and gas data, the relationship between the above data is analyzed. Furthermore, it enables indoor simulation study of the water-rock reaction mechanism during CO2 geological sequestration.

[0048] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 A schematic diagram of an in-situ measurement device for water-rock reaction mechanism according to an embodiment of the present invention is shown.

[0051] In the diagram: 10. Formation water tank; 11. Formation water switch; 12. Liquid circulation pump; 20. Raman generator; 21. Raman probe; 22. Connector; 30. Reactor; 31. Lining; 32. Agitator impeller; 33. Heating jacket; 40. Vacuum pump; 41. Vacuum switch; 50. First sampler; 51. Second sampler; 60. First sampling switch group; 61. First sampling first switch; 62. First sampling second switch; 70. Second sampling switch group; 71. Second... 72. First sampling switch; 80. Second sampling switch; 81. Gas-liquid circulation switch group; 82. First gas-liquid circulation switch; 83. Third gas-liquid circulation switch; 84. Fourth gas-liquid circulation switch; 90. Gas tank; 91. Gas injection pump; 92. First gas injection switch; 93. Second gas injection switch; 94. Gas circulation pump; 95. Pressure sensor; 110. Vent line; 111. Vent switch; 120. Thermocouple; 130. Rock sample. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] like Figure 1 As shown, an in-situ measurement device for water-rock reaction mechanism according to an embodiment of the present invention includes a formation water tank 10, a Raman probe 21, a reaction vessel 30, a vacuum pump 40, and a gas tank 90;

[0054] The formation water tank 10 and the reaction vessel 30 are connected by a formation water pipeline, and a liquid circulation pump 12 is provided on the formation water pipeline.

[0055] The reactor 30 is connected to the vacuum pump 40 via a vacuum pipeline;

[0056] The reaction vessel 30 is connected to the gas tank 90 through a gas pipeline, and a gas circulation pump 94 is provided on the gas pipeline;

[0057] The Raman probe 21 is connected to the formation water tank 10 and the reaction vessel 30 respectively via a connector 22. One end of the connector 22 is connected to the formation water tank 10 and the other end is connected to the reaction vessel 30.

[0058] The two ends of the connector 22 are connected in parallel with gas-liquid circulation pipelines. One end of the gas-liquid circulation pipeline is connected to the connection point between the connector 22 and the formation water tank 10, and the other end is connected to the connection point between the connector 22 and the reaction vessel 30.

[0059] Several sampling lines are provided between the vacuum line and the gas line. One end of each sampling line is connected to the vacuum line, and the other end is connected to the gas line. Each sampling line is equipped with a sampler.

[0060] In this embodiment of the invention, the combination of the formation water pipeline, the gas pipeline, and the pipeline containing the Raman probe 21 and the connector 22 enables real-time measurement of Raman spectral data throughout the water-rock reaction process. Furthermore, the combination of the gas-liquid circulation pipeline, the gas circulation pump 94, and the liquid circulation pump 12 enables internal mixing and circulation of liquid and gas during the water-rock reaction process, thereby improving the accuracy of the detection data.

[0061] In this embodiment of the invention, the reactor 30 is used to provide a container for water-rock reaction, therefore, the rock sample 130 in the water-rock reaction is placed at the bottom of the reactor 30;

[0062] In this embodiment of the invention, the formation water pipeline is used to inject formation water samples into the reactor 30 to restore the formation water in the CO2 geological sequestration site;

[0063] In this embodiment of the invention, the gas pipeline is used to inject a gas sample into the reactor 30 to reduce the CO2 or CO2-rich mixture involved in CO2 geological sequestration.

[0064] In this embodiment of the invention, the vacuum line is used for evacuating the measuring device;

[0065] In this embodiment of the invention, several of the sampling pipelines are used for independent gas sampling at multiple reaction stages in the water-rock reaction;

[0066] In this embodiment of the invention, the sampler is used to store gas samples obtained through the sampling pipeline.

[0067] In some embodiments of the present invention, the Raman probe 21 is connected to a Raman host 20, which facilitates the real-time recording and analysis of the detection data of the Raman probe 21.

[0068] In some embodiments of the present invention, a formation water switch 11 is also provided on the formation water pipeline. The formation water switch 11 is close to the formation water tank 10. The arrangement of the formation water switch 11 improves the control of the water sample injected into the formation water pipeline.

[0069] In some embodiments of the present invention, a vacuum switch 41 is provided on the vacuum pipeline, and the vacuum switch 41 enables the opening and closing of the vacuum pipeline.

[0070] The connection point between the sampling line and the vacuum line is located between the vacuum switch 41 and the reactor 30.

[0071] In some embodiments of the present invention, the gas pipeline is further provided with an injection pump 91 and an injection first switch 92. In the flow direction of the injected gas, the injection pump 91, the injection first switch 92 and the gas circulation pump 94 are arranged in sequence. The combination of the injection pump 91 and the injection first switch 92 improves the control of the opening and closing of the injected gas in the gas pipeline and the speed.

[0072] The connection point between the sampling pipeline and the gas pipeline is located between the first gas injection switch 92 and the gas circulation pump 94.

[0073] In some embodiments of the present invention, a pressure sensor 95 is also provided on the gas pipeline. The pressure sensor 95 is provided to monitor the reaction stages (including the gas dissolution stage and the rock-mineral reaction stage according to time) between the injected gas, formation water and rock in the reactor 30. When the reading of the pressure sensor 95 no longer decreases, it indicates that the gas dissolution stage has ended and the rock-mineral reaction stage has begun.

[0074] In some embodiments of the present invention, the gas injection pump 91, the first gas injection switch 92, the gas circulation pump 94 and the pressure sensor 95 are arranged in sequence in the flow direction of the injected gas;

[0075] The connection point between the sampling pipeline and the gas pipeline is located between the first gas injection switch 92 and the gas circulation pump 94.

[0076] In some embodiments of the present invention, the gas pipeline is further provided with a second gas injection switch 93. In the direction of gas flow, the gas injection pump 91, the first gas injection switch 92, the second gas injection switch 93, the gas circulation pump 94 and the pressure sensor 95 are arranged in sequence. The setting of the second gas injection switch 93 improves the accuracy of the pressure sensor 95 in monitoring the reaction pressure.

[0077] The connection point between the sampling line and the gas line is located between the first gas injection switch 92 and the second gas injection switch 93. This arrangement ensures the independence of the sampling line.

[0078] In some embodiments of the present invention, the sampling pipeline is further provided with a sampling switch group, the number of which is at least two, and at least two switches are respectively disposed at both ends of the sampler to ensure that the replacement of the sampler does not affect the gas inside the measuring device.

[0079] In some embodiments of the present invention, such as Figure 1 As shown, the sampling pipelines include a first sampling pipeline and a second sampling pipeline. The first sampling pipeline is provided with a first sampler 50 and a first sampling switch group 60. The first sampling switch group 60 includes a first sampling first switch 61 and a first sampling second switch 62. The first sampling first switch 61 and the first sampling second switch 62 are respectively disposed at both ends of the first sampler 50.

[0080] The second sampling pipeline is provided with a second sampler 51 and a second sampling switch group 70. The second sampling switch group 70 includes a second sampling first switch 71 and a second sampling second switch 72. The second sampling first switch 71 and the second sampling second switch 72 are respectively disposed at both ends of the second sampler 51.

[0081] The combination of the first sampler 50, the first sampling switch group 60, the second sampler 51, and the second sampling switch group 70 enables independent sampling of gases in two different stages of water-rock reaction: gas dissolution and rock-mineral reaction, without mutual interference.

[0082] In some embodiments of the present invention, such as Figure 1 As shown, the connector 22 is a tubular object, and the top of the Raman probe 21 is embedded inside the connector 22, which facilitates the Raman probe 21 to contact the gas inside the connector 22 for detection. The connector 22 serves to fix and protect the Raman probe 21.

[0083] In some embodiments of the present invention, the connection point between the connector 22 and the formation water tank 10 is located between the formation water switch 11 and the liquid circulation pump 12, and a gas-liquid circulation first switch 81 is provided between the connection point between the connector 22 and the formation water tank 10 and the liquid circulation pump 12. One end of the connector 22 is connected to the gas-liquid circulation pipeline through a gas-liquid circulation third switch 83, and the other end is connected to the gas-liquid circulation pipeline through a gas-liquid circulation fourth switch 84. A gas-liquid circulation second switch 82 is provided on the gas-liquid circulation pipeline.

[0084] The gas-liquid circulation first switch 81, the gas-liquid circulation second switch 82, the gas-liquid circulation third switch 83, and the gas-liquid circulation fourth switch 84 constitute a gas-liquid circulation switch group 80;

[0085] The combined configuration of the gas-liquid circulation switch group 80, the formation water switch 11, the first gas injection switch 92, the second gas injection switch 93, the vacuum switch 41, the sampling switch group, the liquid circulation pump 12, and the gas circulation pump 94 enables precise control of the internal circulation of gas and liquid within the reactor 30, as well as within the formation water pipeline, the vacuum pipeline, the pipeline where the Raman probe 21 is located, the gas pipeline, and the sampling pipeline.

[0086] Specifically:

[0087] If the formation water switch 11, vacuum switch 41 and first gas injection switch 92 are closed, and the gas-liquid circulation switch group 80, liquid circulation pump 12, gas circulation pump 94, sampling switch group and second gas injection switch 93 are opened, the gas and liquid can be circulated within the reactor 30, as well as within the formation water pipeline, vacuum pipeline, pipeline where the Raman probe 21 is located, gas pipeline and sampling pipeline;

[0088] If the formation water switch 11, vacuum switch 41, first gas injection switch 92, third gas-liquid circulation switch 83, and fourth gas-liquid circulation switch 84 are closed, and the first gas-liquid circulation switch 81, second gas-liquid circulation switch 82, liquid circulation pump 12, gas circulation pump 94, sampling switch group, and second gas injection switch 93 are opened, the gas and liquid can be internally circulated in the reactor 30, as well as in the formation water pipeline, vacuum pipeline, gas pipeline, and sampling pipeline;

[0089] Similarly, through the opening and closing of the formation water switch 11, vacuum switch 41, first gas injection switch 92, third gas-liquid circulation switch 83, fourth gas-liquid circulation switch 84, first gas-liquid circulation switch 81, second gas-liquid circulation switch 82, liquid circulation pump 12, gas circulation pump 94, sampling switch group and second gas injection switch 93, the precise control of gas and liquid at specific locations can be achieved.

[0090] In some embodiments of the present invention, the interior of the peripheral wall of the reaction vessel 30 is provided with a lining 31, and a heating sleeve 33 is provided on the side wall of the lining 31 away from the reaction vessel 30. The heating sleeve 33 is used to heat the internal substances of the reaction vessel 30.

[0091] In some embodiments of the present invention, the lining 31 is made of polytetrafluoroethylene material.

[0092] In some embodiments of the present invention, the reactor 30 is provided with a stirring impeller 32 inside, which facilitates the stirring and mixing of gas, liquid and rock sample 130 inside the reactor 30.

[0093] In some embodiments of the present invention, a thermocouple 120 is also provided inside the reaction vessel 30, and the thermocouple 120 is provided to facilitate real-time monitoring of the temperature inside the reaction vessel 30.

[0094] In some embodiments of the present invention, the reactor 30 is also connected to a venting line 110, and a venting switch 111 is provided on the venting line 110. The venting line 110 and the venting switch 111 facilitate the depressurization of the reactor 30 after the gas, water and rock inside the reactor 30 have completely reacted under high temperature and high pressure, so as to facilitate the quick and safe opening of the reactor 30.

[0095] An in-situ measurement method for water-rock reaction mechanism according to an embodiment of the present invention includes:

[0096] The in-situ measurement device described in the above embodiment is connected to the formation water tank 10, gas tank 90, reaction vessel 30, vacuum pump 40, Raman probe 21, and sampler.

[0097] Formation water with known water quality characteristics is loaded into formation water tank 10;

[0098] A sample of the gas to be injected, with a known gas composition, is loaded into gas container 90;

[0099] A rock sample 130 with a known mineral composition was placed at the bottom of the reaction vessel 30.

[0100] Turn on vacuum pump 40 to evacuate the formation water pipeline, vacuum pipeline, gas pipeline, pipeline where Raman probe 21 is located, sampling pipeline and reaction vessel 30. After completion, turn off vacuum pump 40.

[0101] Open the gas tank 90 and inject the gas sample into the reaction vessel 30 until the target gas pressure is reached;

[0102] Turn on the liquid circulation pump 12 and the gas circulation pump 94 to perform internal circulation of liquid and gas;

[0103] Heat the reactor 30 to the target temperature;

[0104] The reaction of water and rock was carried out at the target temperature and target pressure, and the spectral data of the reaction process were recorded by Raman probe 21;

[0105] Remove the sampler from any sampling line and perform gas phase composition analysis on the gas in the sampler;

[0106] Turn off the liquid circulation pump 12 and the gas circulation pump 94, and stop heating the reactor 30. Take out the rock sample 130 after the reaction is completed, and perform whole rock and clay composition analysis on the rock sample 130 after the reaction is completed.

[0107] In some embodiments of the present invention, removing the sampler from any sampling pipeline and performing gas phase composition analysis on the gas in the sampler includes:

[0108] When the pressure in the gas pipeline no longer decreases (i.e., during the gas dissolution stage), a sampler from the sampling pipeline is taken, and the gas phase composition of the gas in the sampler is analyzed.

[0109] When the spectral data recorded by the Raman probe 21 no longer changes (i.e., the rock and mineral reaction stage), take the sampler from one of the remaining sampling lines and perform gas phase composition analysis on the gas in the sampler.

[0110] In this embodiment of the invention, the water-rock reaction mechanism during CO2 geological sequestration is studied through indoor simulation by analyzing the original mineral composition and post-reaction mineral composition of rock sample 130, the original water quality characteristics of formation water (including pH value and ionic composition of water), the water quality characteristics of water during the reaction process obtained by analyzing the spectral data recorded by the Raman probe 21, and the relationship between the original gas composition in the injected gas and the gas composition at the end of the dissolution stage and the end of the reaction stage.

[0111] The following specific example illustrates the in-situ measurement method for the water-rock reaction mechanism described in the above embodiments.

[0112] Example 1

[0113] In-situ measurement methods for water-rock reaction mechanisms include:

[0114] Step 1: Collect samples of rock cuttings, formation water, and the gas to be injected from the injection site.

[0115] Step 1.1: Conduct whole-rock and clay composition analysis to obtain parameters such as stratigraphic mineral composition. In this embodiment, a D / MAX-2600 X-ray powder diffractometer was used to analyze the rock and clay mineral components. The sample mineral composition was found to be: 61% quartz, 15% plagioclase, 10% siderite, 2% calcite, and 12% clay minerals (illite, kaolinite, chlorite, etc.).

[0116] Step 1.2: Conduct a comprehensive water quality analysis to obtain parameters such as formation water pH and ionic composition. In this embodiment, NaOH solution is used for the experiment.

[0117] Step 1.3: Perform gas chromatography analysis to obtain the composition of the gas sample. In this embodiment, pure CO2 gas is used for the experiment;

[0118] Step 2: Place rock sample 130 into the device.

[0119] Step 2.1: Cut the rock fragments into regularly shaped rock samples 130 and place them at the bottom of the reactor 30. In this embodiment, the rock fragments are cut into 1cm×1cm×1cm cube rock samples 130. The rock samples 130 are weighed to obtain a weight of 2.73g. Then, the rock samples 130 are placed at the bottom of the reactor 30, ensuring that the placed rock samples 130 do not affect the operation of the stirring impeller 32.

[0120] Step 2.2: Connect the in-situ measuring device and ensure its airtightness.

[0121] Step 3: The device pumps in formation water.

[0122] Step 3.1: Turn on the gas-liquid circulation switch group 80, the sampling switch group (first sampling switch group 60, second sampling switch group 70), the vacuum switch 41, and the second gas injection switch 93, turn on the vacuum pump 40, evacuate the device, and then turn off the vacuum switch 41.

[0123] Step 3.2: Open the formation water switch 11 and pump the formation water in the formation water tank 10 into the device by vacuuming. After pumping is complete, close the formation water switch 11. In this embodiment, NaOH solution is used instead of formation water.

[0124] Step 4: Pump CO2 or a CO2-rich mixture into the apparatus. This embodiment uses pure CO2 gas for the experiment.

[0125] Step 4.1: Heating the fluid inside the reactor 30 using the heating jacket 33. In this embodiment, the NaOH solution inside the reactor 30 is heated to 25°C using the heating jacket 33.

[0126] Step 4.2: Observe the reading of thermocouple 120. When the temperature reaches the required level (80℃ in this embodiment), close the gas-liquid circulation switch group 80, turn on the gas injection pump 91, and turn on the second gas injection switch 93, the first sampling switch group 60, the second sampling switch group 70, and the first gas injection switch 92 in sequence to pump the gas into the reaction vessel 30 until the experimental pressure is reached. In this embodiment, the experimental pressure is 1 atm.

[0127] Step 5: Turn on the gas-liquid internal circulation.

[0128] Step 5.1: Close the first gas injection switch 92 and open the gas-liquid circulation switch group 80.

[0129] Step 5.2: Turn on the liquid circulation pump 12 and the gas circulation pump 94 to start the internal circulation of liquid and gas.

[0130] Step 6: Begin experimental measurement.

[0131] Step 6.1: Turn on the stirring impeller 32 to accelerate the dissolution of pure CO2 gas in the NaOH solution.

[0132] Step 6.2: Observe the pressure sensor 95. When the reading of the pressure sensor 95 no longer decreases, turn off the first sampling switch group 60, remove the first sampler 50, and perform chromatographic analysis on the gas in the first sampler 50 to obtain the gas phase composition. This composition is used to analyze the mass exchange between the liquid and gas phases during the dissolution process. In this embodiment, since pure CO2 gas is used, the gas composition does not change. When using a CO2-rich gas mixture for the experiment, due to the different partial pressures and solubilities of different gases in formation water, this step shows that the composition of the remaining gas changes after the CO2-rich gas mixture partially dissolves in the formation water.

[0133] Step 6.3: The Raman spectral signal is received at the connector 22 via the Raman probe 21 and transmitted to the Raman host 20. Raman spectral analysis is performed at regular intervals until the spectral data obtained by the Raman probe 21 no longer changes, completing the Raman spectral measurement. This measurement is used to analyze changes in the liquid phase composition caused by CO2 dissolution and rock chemical reactions. In this embodiment, the analysis focuses on changes in the liquid phase composition caused by CO2 dissolution, within a Raman shift range of 900–1450 cm⁻¹. -1 Within the displacement range, the highest peak displacement was 1384 cm. -1 Secondly, 1020cm -1 And the displacement is 1276cm -1 and 1370cm -1 The two weaker peaks, 1384 cm⁻¹, increase with time from second 0 to second 300. -1 and 1276cm -1 The two peaks gradually increase. Given CO2 (dissolved) and HCO3. - The characteristic peaks appeared at 1384 cm⁻¹. -1 and 1276cm -1 1020cm -1 and 1370cm -1 Therefore, it can be concluded that CO2 completely dissolves and reaches saturation after 300 seconds of reaction. The reactions that occur after CO2 dissolves in water include equations (1) and (2):

[0134] CO2 (gas phase) → CO2 (dissolved) (1)

[0135] CO2 + NaOH → HCO3 - + Na + (2)

[0136] Taking the siderite reaction as an example, this study analyzes the changes in liquid phase composition caused by rock chemical reactions. The highest peak displacement was 1100 cm⁻¹ at 330 seconds of reaction. -1 This corresponds to the characteristic peak of amorphous ferrous carbonate. At 2100 seconds into the reaction, the peak position shift of the highest peak was 1083 cm⁻¹. -1 The corresponding characteristic peaks of siderite indicate that the chemical reactions that occur after CO2 dissolves in NaOH solution include those shown in equation (3):

[0137] HCO3 - + Fe 2+ → FeCO3 + H + (3)

[0138] Step 6.4: Close the second sampling switch group 70, remove the second sampler 51, and perform chromatographic analysis on the gas in the second sampler 51 to obtain the gas phase composition. This composition is used to analyze the mass exchange between the liquid and gas phases during the rock chemical reaction process. In this embodiment, since pure CO2 gas is used, the gas composition does not change. When using a CO2-rich gas mixture for the experiment, different gases undergo different chemical reactions with rock minerals after dissolving in formation water. Changes in ions in the liquid phase may cause some gases to precipitate or more gases to dissolve, resulting in changes in the composition of the remaining gas.

[0139] Step 6.5: Turn off the liquid circulation pump 12 and the gas circulation pump 94, turn off the heating jacket 33, turn on the vent switch 111, and depressurize the device through the vent line 110.

[0140] Step 6.6: Remove rock sample 130 from reaction vessel 30, weigh it, and perform whole-rock and clay composition analysis to obtain the weight change and mineral composition change caused by the chemical reaction. In this embodiment, the weight of rock sample 130 after the reaction was measured to be 2.78g, with a total of 0.05g of mineral precipitate formed. The rock and clay mineral components of rock sample 130 after the reaction were analyzed using a D / MAX-2600 X-ray powder diffractometer, and the mineral composition of the sample was found to be: 59% quartz, 15.5% plagioclase, 10% siderite, 4% calcite, and 11.5% clay minerals (illite, kaolinite, chlorite, etc.). By comprehensively analyzing the experimental data obtained in steps 6.2 to 6.6, the composition of the 0.05g mineral precipitate can be determined.

[0141] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An in-situ measurement device for water-rock reaction mechanism, characterized in that, It includes a formation water tank (10), a Raman probe (21), a reaction vessel (30), a vacuum pump (40), and a gas tank (90); The formation water tank (10) and the reaction vessel (30) are connected by a formation water pipeline, and a liquid circulation pump (12) is provided on the formation water pipeline; The reactor (30) and the vacuum pump (40) are connected by a vacuum pipeline; The reaction vessel (30) is connected to the gas tank (90) through a gas pipeline, and a gas circulation pump (94) is provided on the gas pipeline; The Raman probe (21) is connected to the formation water tank (10) and the reaction vessel (30) respectively via a connector (22). One end of the connector (22) is connected to the formation water tank (10), and the other end is connected to the reaction vessel (30). The two ends of the connector (22) are connected in parallel with gas-liquid circulation pipelines. One end of the gas-liquid circulation pipeline is connected to the connection point between the connector (22) and the formation water tank (10), and the other end is connected to the connection point between the connector (22) and the reactor (30). Several sampling lines are provided between the vacuum line and the gas line. One end of each sampling line is connected to the vacuum line, and the other end is connected to the gas line. Each sampling line is equipped with a sampler.

2. The in-situ measurement device for water-rock reaction mechanism according to claim 1, characterized in that, The formation water pipeline is also equipped with a formation water switch (11), which is located near the formation water tank (10).

3. The in-situ measurement device for water-rock reaction mechanism according to claim 2, characterized in that, The connection point between the connector (22) and the formation water tank (10) is located between the formation water switch (11) and the liquid circulation pump (12), and a gas-liquid circulation first switch (81) is provided between the connection point between the connector (22) and the formation water tank (10) and the liquid circulation pump (12). One end of the connector (22) is connected to the gas-liquid circulation pipeline through a gas-liquid circulation third switch (83), and the other end is connected to the gas-liquid circulation pipeline through a gas-liquid circulation fourth switch (84). A gas-liquid circulation second switch (82) is provided on the gas-liquid circulation pipeline.

4. The in-situ measurement device for water-rock reaction mechanism according to claim 1, characterized in that, A vacuum switch (41) is provided on the vacuum pipeline; The connection point between the sampling line and the vacuum line is located between the vacuum switch (41) and the reactor (30).

5. The in-situ measurement device for water-rock reaction mechanism according to claim 1, characterized in that, The gas pipeline is also equipped with an injection pump (91) and an injection first switch (92). In the direction of gas flow, the injection pump (91), the injection first switch (92) and the gas circulation pump (94) are arranged in sequence. The connection point between the sampling pipeline and the gas pipeline is located between the first gas injection switch (92) and the gas circulation pump (94).

6. The in-situ measurement device for water-rock reaction mechanism according to claim 5, characterized in that, The gas pipeline is also equipped with a pressure sensor (95). In the direction of gas flow, the gas injection pump (91), the first gas injection switch (92), the gas circulation pump (94) and the pressure sensor (95) are arranged in sequence.

7. The in-situ measurement device for water-rock reaction mechanism according to claim 6, characterized in that, The gas pipeline is also equipped with a second gas injection switch (93). In the direction of gas flow, the gas injection pump (91), the first gas injection switch (92), the second gas injection switch (93), the gas circulation pump (94), and the pressure sensor (95) are arranged in sequence. The connection point between the sampling pipeline and the gas pipeline is located between the first gas injection switch (92) and the second gas injection switch (93).

8. The in-situ measurement device for water-rock reaction mechanism according to claim 1, characterized in that, The sampling pipeline is also equipped with a sampling switch group, and the number of the sampling switch group is at least two, with at least two switches respectively located at both ends of the sampler.

9. The in-situ measurement device for water-rock reaction mechanism according to claim 8, characterized in that, The sampling pipelines include a first sampling pipeline and a second sampling pipeline. The first sampling pipeline is provided with a first sampler (50) and a first sampling switch group (60). The first sampling switch group (60) includes a first sampling first switch (61) and a first sampling second switch (62). The first sampling first switch (61) and the first sampling second switch (62) are respectively disposed at both ends of the first sampler (50). The second sampling pipeline is provided with a second sampler (51) and a second sampling switch group (70). The second sampling switch group (70) includes a second sampling first switch (71) and a second sampling second switch (72). The second sampling first switch (71) and the second sampling second switch (72) are respectively located at both ends of the second sampler (51).

10. The in-situ measurement device for water-rock reaction mechanism according to claim 1, characterized in that, The reactor (30) has a lining (31) inside its peripheral wall, and a heating jacket (33) is provided on the side wall of the lining (31) away from the reactor (30); an impeller (32) is provided inside the reactor (30); and a thermocouple (120) is also provided inside the reactor (30).

11. The in-situ measurement device for water-rock reaction mechanism according to any one of claims 1-10, characterized in that, The reactor (30) is also connected to a vent line (110), and a vent switch (111) is provided on the vent line (110).

12. A method for in-situ measurement of water-rock reaction mechanism, characterized in that, include: The in-situ measurement device according to any one of claims 1-11 is connected to a formation water tank (10), a gas tank (90), a reaction vessel (30), a vacuum pump (40), a Raman probe (21), and a sampler; Formation water with known water quality characteristics is loaded into formation water tank (10); A sample of the gas to be injected, with a known gas composition, is loaded into a gas container (90); A rock sample (130) with a known mineral composition is placed at the bottom of the reaction vessel (30); Turn on the vacuum pump (40) to evacuate the formation water pipeline, vacuum pipeline, gas pipeline, pipeline where the Raman probe (21) is located, sampling pipeline and reaction vessel (30). After completion, turn off the vacuum pump (40). Open the gas tank (90) and inject the gas sample into the reaction vessel (30) until the target gas pressure is reached; Turn on the liquid circulation pump (12) and the gas circulation pump (94) to perform internal circulation of liquid and gas; The reactor (30) is heated to the target temperature; The reaction of water and rock was carried out at the target temperature and target pressure, and the spectral data of the reaction process were recorded by Raman probe (21); Remove the sampler from any sampling line and perform gas phase composition analysis on the gas in the sampler; Turn off the liquid circulation pump (12) and the gas circulation pump (94), and stop heating the reactor (30). Take out the rock sample (130) after the reaction is completed, and perform whole rock and clay composition analysis on the rock sample (130) after the reaction is completed.

13. The in-situ measurement method for water-rock reaction mechanism according to claim 12, characterized in that, The step of removing the sampler from any sampling pipeline and performing gas phase composition analysis on the gas in the sampler includes: When the pressure in the gas pipeline no longer decreases, take a sampler from a sampling pipeline and perform gas phase composition analysis on the gas in the sampler. When the spectral data recorded by the Raman probe (21) no longer changes, take the sampler from one of the remaining sampling lines and perform gas phase composition analysis on the gas in the sampler.

Images