A water-based drilling mud pH adjusting device and method

Abstract

This invention belongs to the field of water-based rock cuttings treatment and resource utilization technology, specifically involving a device and method for adjusting the pH of water-based rock cuttings. It uses CO2 to replace traditional acidic agents such as hydrochloric acid and sulfuric acid, and uses dodecane as a volume displacement medium to achieve quantitative measurement of CO2 gas introduction and discharge, calculate the single-pass CO2 absorption rate, and stably adjust the pH of alkaline water-based rock cuttings to 7-7.5 after CO2 neutralization. The neutralization effect is long-lasting and stable with no pH rebound. The adjustment device has a simple structure, and the adjustment method significantly and stably reduces the pH of water-based rock cuttings without rebound. While completing the harmless pretreatment of water-based rock cuttings and avoiding secondary pollution from reagents, it can solve the dual environmental and economic problems caused by greenhouse gas emissions and alkaline water-based rock cuttings, realizing the resource utilization of CO2. This provides a low-carbon, precise, and pollution-free standardized laboratory control technology system for the green construction of "zero-waste oilfields," taking into account the economic benefits of resource utilization and contributing to the construction of "zero-waste oilfields."

Description

Technical Field

[0001] This invention belongs to the field of water-based rock debris treatment and resource utilization technology, specifically relating to a device and method for adjusting the pH of water-based rock debris, which can adjust the pH of water-based rock debris using CO2 in the laboratory. Background Technology

[0002] Water-based rock cuttings are solid wastes generated during shale gas development, consisting of a mixture of chemical treatment agents and formation rock cuttings. Their main components include suspended solids, clay, inorganic salts, and additives used during drilling. Water-based rock cuttings are generally alkaline, and their primary treatment method is solidification and landfilling. This not only occupies land but also easily pollutes water and soil with leachate, failing to completely eliminate environmental risks. Research on their resource utilization is still in its early stages. Currently, industrial resource-based treatment of water-based rock cuttings commonly uses hydrochloric acid, sulfuric acid, and humic acid to adjust the pH. However, this method has drawbacks such as poor pH control precision, equipment corrosion, damage to the mud's colloidal structure, introduction of harmful ions causing secondary pollution, difficulty in solid-liquid separation, and high reagent costs.

[0003] For example, Chinese Patent 202311761072.3 discloses a rapid digestion method for heavy metal detection in water-based drilling cuttings samples, which includes:

[0004] A. Freeze-dry the sample to be tested, and then grind the freeze-dried sample to be tested;

[0005] B. Take m grams of the sample to be tested after grinding in step A and mix it with V1 ml of hydrofluoric acid, and heat it at 120℃~125℃ for 30 min~90 min, preferably for 30 min;

[0006] C. Add 2 ml of hydrofluoric acid, 3 ml of nitric acid, and 4 ml of hydrochloric acid, and heat the acid system at 120℃~125℃ for 60min~120min.

[0007] D. Cool the sample to be tested after heating in step C, make up to V5 ml, mix well, centrifuge, and separate the solid and liquid to obtain the digested sample solution;

[0008] Wherein, m:V1:V2:V3:V4=0.1~0.2:0.5~1:0.5~1:1:3; preferably m:V1:V2:V3:V4=0.1:0.5~1:0.5~1:1:3, the sum of the total volumes of V1, V2, V3, and V4 is Vtotal in ml, Vtotal:m is less than 60, m:V5=0.1:10~50, the centrifugation speed is 3000~8000 rpm, preferably 3000~6000 rpm, and the centrifugation time is preferably 5min~10min;

[0009] The sample to be tested in step A is at least one of soil, clear water rock fragments, polymer rock, and polysulfonate rock fragments, preferably clear water rock fragments. The freeze-drying temperature is -60℃ to -50℃. The freeze-drying time in step A is preferably 12 to 24 hours.

[0010] The particle size of the sample to be tested after grinding in step B is less than 100 mesh. The sample to be tested after grinding is first moistened with water and then mixed with hydrofluoric acid. The preferred mass ratio of water to m is 0.1:1 g / mL.

[0011] The heating in steps B and C is carried out using a graphite digestion apparatus, preferably in a container made of polypropylene material, for a total time of less than 4 hours, preferably less than 2 hours.

[0012] Chinese Patent 202111545028.X discloses a method for treating polysulfonated drilling fluid cuttings waste liquid, comprising the following steps:

[0013] Rock cuttings were added to water and stirred evenly. Then, a non-ionic depolymerizing flocculant aqueous solution was added and stirred evenly. The mixture was then subjected to the first pressure filtration to obtain the first filtrate.

[0014] Adjust the pH of the first filtrate to 4-6, add an aqueous solution of cationic depolymerizing flocculant and stir well, then perform a second filtration to obtain the second filtrate.

[0015] Add a chelating agent to the second filtrate and stir well. Then perform a third filtration to obtain the third filtrate.

[0016] In the step of adjusting the pH of the first filtrate to 4-6, hydrochloric acid solution with a concentration of 10-15% is used to adjust the pH.

[0017] For every 100 m³ of rock cuttings, the remaining components are added as follows: 500–1000 kg of water, 100–200 kg of nonionic depolymerizing flocculant aqueous solution, 1000–2000 kg of cationic depolymerizing flocculant aqueous solution, and 100–200 kg of chelating agent.

[0018] The concentration of the nonionic depolymerizing flocculant aqueous solution is 0.3-0.5%, and the concentration of the cationic depolymerizing flocculant aqueous solution is 30-50%. The nonionic depolymerizing flocculant aqueous solution includes one or more of nonionic polyacrylamide aqueous solution, polyethylene oxide aqueous solution, and polyvinyl alcohol aqueous solution. The cationic depolymerizing flocculant aqueous solution includes one or more of polyethyleneimine aqueous solution, dimethyl diallyl ammonium chloride acrylamide copolymer aqueous solution, and dimethylamine ethyl acrylate chloromethane copolymer aqueous solution. The chelating agent includes one or more of polycarboxylates, polyepoxysuccinates, and inorganic phosphates.

[0019] The treatment method for polysulfonated drilling fluid cuttings waste also includes using a third-pressure filtration solution to prepare the drilling fluid. The steps for preparing the drilling fluid include: adding bentonite, potassium polyacrylamide, and polymer cellulose to water for hydration and dispersion; after the polymer molecular chains are fully extended, adding the third-pressure filtration solution and mixing to obtain the drilling fluid; and adding 5% bentonite, 1.0% to 2.0% potassium polyacrylamide, and 3.0% to 5.0% polymer cellulose by mass percentage of the mixture to a mixture of the third-pressure filtration solution and water in a volume ratio of 70:30 to 30:70.

[0020] CO2, one of the most significant greenhouse gases, primarily originates from fossil fuel combustion, industrial processes, and natural processes. Thermal power generation and fuel-related industries, such as the firing of building materials, generate large amounts of easily captured CO2. To address the issue of large-scale CO2 emissions and the shortcomings of water-based mud pH adjustment technologies, this study develops a more effective, environmentally friendly, and large-scale-suitable water-based rock cuttings pH adjustment device and method. This addresses the problems of traditional water-based rock cuttings acidity regulators, such as poor control precision, equipment corrosion, the introduction of harmful ions causing secondary pollution, difficulties in solid-liquid separation, and high reagent costs. Summary of the Invention

[0021] The purpose of this invention is to overcome the shortcomings of existing technologies and to develop and design a water-based rock debris pH adjustment device and method to realize the resource utilization of industrial CO2, reduce direct greenhouse gas emissions, and meet the dual needs of harmless pretreatment of water-based rock debris and low-carbon carbon sequestration.

[0022] To achieve the above objectives, the present invention relates to a water-based rock cutting pH adjustment device suitable for reactions between gas-viscous fluid and gas-low viscosity liquid. Its main structure includes a gas supply metering unit, a gas drying unit, a reaction unit and a tail gas metering unit connected in sequence. CO2 enters the gas drying unit from the gas supply metering unit, and after drying, it reaches the reaction unit. The tail gas after the reaction enters the tail gas metering unit.

[0023] The gas metering unit includes at least a CO2 cylinder with a valve and a pressure reducing valve, a flow meter, a three-way valve, a No. 1 oil storage cylinder and a gas storage cylinder. The CO2 in the cylinder is pressure-regulated by the pressure reducing valve and flow-controlled by the flow meter, and then enters the No. 1 oil storage cylinder through the three-way valve. The inert oil in the No. 1 oil storage cylinder is used as a volume replacement medium and is pressed into the gas storage cylinder. An equal volume of CO2 is discharged and sent to the gas drying unit.

[0024] The gas drying unit can remove water vapor carried in CO2 and prevent moisture from interfering with the reaction system. It includes at least a drying tube and the desiccant and degreased cotton placed inside it. The drying tube adopts a U-shaped structure and is filled with desiccant. The filling height of the desiccant is lower than the opening of the conduits on both sides of the drying tube. Degreased cotton is filled above the desiccant, and the opening of the drying tube is sealed with a rubber stopper.

[0025] The reaction unit includes at least a reaction tube with an inlet and an outlet. CO2 dried by the gas drying unit is introduced into the reaction tube through the inlet and neutralized with the water-based rock debris in the reaction tube. The unreacted CO2 is discharged from the outlet.

[0026] The exhaust gas metering unit includes at least a No. 2 oil storage bottle and a recovery container. The CO2 that does not participate in the neutralization reaction is discharged into the No. 2 oil storage bottle as exhaust gas through the outlet, and the inert oil medium in the No. 2 oil storage bottle is pressed into the recovery container.

[0027] The inert oil medium in the No. 1 and No. 2 oil storage bottles involved in this invention serves as a volume replacement medium and does not react with CO2. It includes dodecane, which is chemically stable, highly inert, and does not react with or absorb CO2 at room temperature.

[0028] The desiccant includes anhydrous calcium chloride, and the degreased cotton serves to buffer airflow, fix the desiccant, and prevent dust from entering.

[0029] The reaction tube adopts a spiral structure, which can extend the contact path between CO2 and water-based rock debris in a limited space, increase the gas-solid contact time, and improve the degree of acid-base neutralization.

[0030] This invention relates to a method for adjusting the pH of water-based rock cuttings, implemented using a water-based rock cuttings pH adjustment device. This method effectively improves the chemical properties of the water-based rock cuttings, enabling waste liquid separation and discharge, and solid waste separation and return to the field, thus achieving resource utilization of the waste. The specific process includes the following steps:

[0031] S1, Adding ingredients

[0032] Add water-based rock cuttings into the reaction tube, close the main gas path and open the branch gas path through the three-way valve;

[0033] S2, Gas Supply

[0034] After closing the pressure reducing valve and opening the flow meter and valve, slowly open the pressure reducing valve to start supplying gas. Adjust the gas flow rate through the flow meter. Once the reading stabilizes, quickly close the branch gas line and open the main gas line at the same time.

[0035] S3, reaction

[0036] The CO2 in the gas cylinder is depressurized and controlled by a pressure reducing valve and a flow meter, and then injected into the No. 1 oil storage cylinder. An equal amount of inert oil medium is injected into the gas storage cylinder. An equal volume of gas in the gas storage cylinder is pushed into the drying tube by the injected inert oil medium. After drying, it is introduced into the reaction tube to begin a neutralization reaction with the water-based rock debris.

[0037] S4, Gas outage

[0038] After introducing the set amount of CO2, stop the neutralization reaction between CO2 and water-based rock debris. At the same time, open the branch gas path through the three-way valve, close the main gas path, close the valve, and wait for the gas inside the pressure reducing valve and flow meter to be discharged before closing the pressure reducing valve and flow meter.

[0039] S5, Calculation

[0040] When the inert oil medium in the No. 2 oil storage bottle no longer flows into the recovery container, measure the volume of the inert oil medium in the beaker, i.e. the volume of CO2 that did not participate in the reaction. Based on the amount of CO2 introduced and discharged, calculate the single CO2 absorption rate.

[0041] The present invention relates to a method for adjusting the pH of water-based rock cuttings. To verify whether the pH value of water-based rock cuttings adjusted with CO2 has long-term stability, the following steps are taken:

[0042] First, the water-based rock debris after the neutralization reaction was divided into several groups of equal volume and transferred to numbered beakers. One group was immediately dried at a constant temperature, while the other groups served as control groups under multiple time gradients. After being left to stand for different periods, they were dried at a constant temperature of 60°C for 48 hours.

[0043] Then, the dried samples from each group were prepared into suspensions according to a unified standard, and the pH value of the supernatant was tested using pH test paper.

[0044] Finally, the experimental results were analyzed and evaluated.

[0045] Compared with existing technologies, this invention uses CO2 instead of traditional acidic chemical agents such as hydrochloric acid and sulfuric acid to neutralize alkaline water-based rock cuttings. This not only recycles excess CO2 emitted from industrial and energy sectors to achieve carbon sequestration and emission reduction, solving the dual environmental challenges of greenhouse gas emissions and alkaline water-based rock cutting disposal, aligning with the requirements of a circular economy and zero-waste oilfield construction, but also lowers the pH value of the water-based rock cuttings. The single-pass CO2 absorption rate is measured without introducing harmful ions, eliminating the need for acid regulator procurement costs. The reaction tube in the regulating device adopts a spiral structure, which extends the contact path between CO2 and the water-based rock cuttings within a limited space, improving the degree of acid-base neutralization. Verification shows that the pH value of the treated water-based rock cuttings decreases significantly and does not rebound after long-term storage, demonstrating a long-lasting and reliable neutralization effect. The pH-lowered water-based rock cuttings are easy to subsequently undergo harmless treatment, return to the field, and be used as building materials, solving the problem of the difficulty in soil reuse of alkaline water-based rock cuttings. Simultaneously, it possesses significant environmental benefits, industrial application value, and low-carbon technology demonstration significance, and has the potential for large-scale promotion and application. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the main structure of the water-based rock debris pH adjustment device involved in this invention. Detailed Implementation

[0047] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0048] Example 1:

[0049] The main structure of a water-based rock debris pH adjustment device described in this embodiment is as follows: Figure 1 As shown, it includes gas cylinder 1, No. 1 oil storage cylinder 2, gas storage cylinder 3, drying tube 4, reaction tube 5, No. 2 oil storage cylinder 6, recovery container 7, conduit 8, flow meter 9, water stop clamp 10 and three-way valve 11.

[0050] Gas cylinder 1, No. 1 oil storage cylinder 2, gas storage cylinder 3, drying tube 4, reaction tube 5, No. 2 oil storage cylinder 6, and recovery container 7 are connected in sequence via conduit 8;

[0051] A flow meter 9 is installed between gas cylinder 1 and oil storage cylinder 2.

[0052] Water-stopping clamps 10 are installed on the conduit 8 between gas cylinder 1 and No. 1 oil storage cylinder 2, on the conduit 8 at both ends of reaction tube 5, and on the conduit 8 between No. 2 oil storage cylinder 6 and recovery container 7.

[0053] There are two water-stop clamps 10 between gas cylinder 1 and oil storage cylinder 2, and the two are connected to the flow meter 9 via a three-way valve 11 on the conduit 8.

[0054] The gas cylinder 1 involved in this embodiment has a valve 12 and a pressure reducing valve 13;

[0055] Oil cylinder 2 (No. 1), gas cylinder 3, and oil cylinder 6 (No. 2) are all marked with volume markings, and their volumes are all greater than 1L.

[0056] The drying tube 4 has a U-shaped structure and is filled with desiccant 14 and degreased cotton 15.

[0057] The reaction tube 5 has a spiral structure and has an air inlet 16 and an air outlet 17;

[0058] Flow meter 9 is a rotor gas flow meter with flow control function;

[0059] Pressure reducing valve 13 has a pressure reducing function.

[0060] The process of using a water-based rock debris pH adjustment device according to this embodiment includes the following steps:

[0061] S1. Detection and Characterization

[0062] Several water-based rock cuttings were collected from a drilling site in Chongqing. The physicochemical properties of the water-based rock cuttings (including water content and initial pH) were tested to characterize the mineral composition of the water-based rock cuttings.

[0063] The moisture content is calculated by drying water-based rock fragments in a 60℃ constant temperature oven for 48 hours, based on the mass difference before and after drying, and is 50-60%.

[0064] The initial pH was measured using the pH potential method and test strips, and was between 8.5 and 9.5.

[0065] The mineral composition was determined by XRD analysis, and the results are as follows:

[0066] Mineral components quartz Potassium feldspar Sodium feldspar calcite barite Pyrite clay minerals content 40.8% 3.3% 10.6% 9.6% 6.1% 1.1% 28.5%

[0067] S2. Assembly and Inspection

[0068] First, gas cylinder 1, oil storage cylinder 2, gas storage cylinder 3, drying tube 4, reaction tube 5, oil storage cylinder 6 and recovery container 7 are connected in sequence through conduit 8;

[0069] Then, CO2 gas is introduced, and the airtightness is checked using a foaming leak detection agent;

[0070] Finally, dodecane was filled into oil storage cylinder 2 and oil storage cylinder 6, and CO2 was filled into gas storage cylinder 3.

[0071] The gas path that connects to oil storage bottle 2 through three-way valve 11 to oil storage bottle 6 is the main gas path, and the gas path leading to the outside is the branch gas path.

[0072] S3, Filling and Adjustment

[0073] 280mL of water-based rock cuttings are loaded into the reaction tube 5 through the air inlet 16. The water stop clamp 10 between the drying tube 4 and the air inlet 16 is closed. The water stop clamp 10 of the three-way valve 11 on the main air line is closed. The branch air line is opened. The remaining water stop clamps 10 are kept open.

[0074] S4, Debugging and Switching

[0075] Close the pressure reducing valve 13, open the flow meter 9 and valve 12 in sequence, and then slowly open the pressure reducing valve 13 to start supplying gas. When the reading of the flow meter 9 stabilizes in the range of 8-15 mL / min, quickly close the branch gas line, open the main gas line, and open the water stop clamp 10 between the drying tube 4 and the air inlet 16.

[0076] S5, Reaction

[0077] CO2 in cylinder 1 is depressurized and controlled by pressure reducing valve 13 and flow meter 9, and injected into oil storage cylinder 2. Dodecane is injected into gas storage cylinder 3 in an equal amount. An equal volume of CO2 is pressed into drying tube 4. After being dried by desiccant 14, it is introduced into reaction tube 5 through air inlet 16 and begins to neutralize with the built-in water-based rock debris.

[0078] During the reaction, the water-stop clamp 10 of the branch gas path is in the closed state, while the water-stop clamp 10 of the main gas path remains in the open state.

[0079] The CO2 flow rate was kept stable within the range of 8-15 mL / min throughout the process. If the CO2 flow rate suddenly decreased, the water-based rock debris in the reaction tube 5 would flow back into the drying tube 4. Therefore, it is necessary to pay attention to the reading of the flow meter 9 at all times to keep the CO2 flow rate stable.

[0080] S6. Terminate reaction, stop gas supply.

[0081] After the dodecane in the gas storage cylinder 3 reaches the 1L mark (indicating that 1L of CO2 has been introduced into the reaction tube 5), close the water stop clamp 10 between the gas inlet 16 and the drying tube 4 to stop the reaction between CO2 and water-based rock debris. At the same time, operate the three-way valve 11 to open the water stop clamp 10 of the branch gas path and close the water stop clamp 10 of the main gas path. Close the valve 12 in sequence. After the gas inside the pressure reducing valve 13 and the flow meter 9 is discharged, close the pressure reducing valve 13 and the flow meter 9.

[0082] S7. Single Absorption Rate Calculation

[0083] After the gas supply is stopped, when the dodecane in the No. 2 oil storage bottle 6 no longer flows into the recovery container 7, the volume of dodecane in the recovery container 7 is measured with a graduated cylinder, which is the volume of CO2 that did not participate in the reaction. Based on the known CO2 input and output, the single absorption rate is between 15-20%.

[0084] S8, grouping and drying

[0085] After the neutralization reaction, the water-based rock fragments were divided into several equal groups and transferred to labeled beakers. One group was immediately placed in a constant temperature oven at 60°C for 48 hours to dry. The other groups were left to stand for different periods and then dried at 60°C to obtain dried samples.

[0086] S9. Measure pH value

[0087] First, prepare the suspension according to the standard HJ962-2018 "Determination of Soil pH by Potentiometric Method", and pass each group of dried samples through a 2mm sieve.

[0088] Then, weigh 10g of each group and place them in 50mL beakers, and add 25mL of CO2-free pure water (the mass ratio of dried sample to pure water is 1:2.5).

[0089] Finally, seal the beaker with sealing film, stir vigorously with a magnetic stirrer for 2 minutes, let stand for 30 minutes, collect the supernatant and complete the pH measurement within 1 hour.

[0090] S10. Analysis and Evaluation

[0091] The pH test results of the immediate drying group and the drying group after standing for one week were compared and evaluated. The pH values ​​measured in the two groups are shown in the table below:

[0092] Group pH (test strips) Instant drying set 7-7.5 Drying group after standing for one week 7-7.5

[0093] It can be seen that the pH of the water-based rock debris after CO2 adjustment is stably maintained at 7-7.5, which is in the neutral range. After standing for a week, the pH does not rise, and the neutralization effect is long-lasting and stable. This eliminates the risk of strong alkaline pollution that originally existed in the water-based rock debris and meets the requirements for the harmless and resource-based disposal of water-based rock debris.

[0094] This embodiment relates to a water-based rock cuttings pH adjustment device that uses a volume displacement method. An inert oil medium that does not react with CO2 is used as the gas volume displacement medium. When a quantitative amount of inert oil medium is pressed into the gas storage bottle 3, it means that the same volume of CO2 enters the reaction tube 5. Thus, the volume of CO2 gas introduced can be read directly and the precise quantitative delivery of CO2 can be achieved. After the neutralization reaction is completed, the volume of dodecane in the recovery container 7 is the volume of unreacted CO2.

[0095] If negative pressure occurs in reaction tube 5, close the water stop clamp 10 between oil storage bottle 6 and recovery container 7 to prevent air from flowing back into oil storage bottle 6 from recovery container 7.

Claims

1. A water-based rock debris pH adjustment device, characterized in that, The main structure includes a gas supply metering unit, a gas drying unit, a reaction unit, and a tail gas metering unit connected in sequence. CO2 enters the gas drying unit from the gas supply metering unit, and after drying, it reaches the reaction unit. The tail gas after the reaction enters the tail gas metering unit. It is suitable for reactions between gas and viscous fluid and gas and low viscosity liquid.

2. The water-based rock debris pH adjustment device according to claim 1, characterized in that, The gas metering unit includes at least a CO2 cylinder with valves and pressure reducing valves, a flow meter, a three-way valve, a No. 1 oil storage cylinder, and a gas storage cylinder. The CO2 in the cylinder is pressure-regulated by the pressure reducing valve and flow-controlled by the flow meter before being introduced into the No. 1 oil storage cylinder through the three-way valve. The inert oil in the No. 1 oil storage cylinder is used as a volume replacement medium and is pressed into the gas storage cylinder. An equal volume of CO2 is discharged and sent to the gas drying unit.

3. The water-based rock debris pH adjustment device according to claim 2, characterized in that, The gas drying unit can remove water vapor carried in CO2 to avoid moisture interfering with the reaction system. It includes at least a drying tube and a desiccant and degreased cotton placed inside it. The drying tube adopts a U-shaped structure and is filled with desiccant. The filling height of the desiccant is lower than the openings of the conduits on both sides of the drying tube. Degreased cotton is filled above the desiccant, and the opening of the drying tube is sealed with a rubber stopper.

4. The water-based rock debris pH adjustment device according to claim 3, characterized in that, The reaction unit includes at least a reaction tube with an inlet and an outlet. CO2 dried by the gas drying unit is introduced into the reaction tube through the inlet and neutralized with the water-based rock debris in the reaction tube. The unreacted CO2 is discharged from the outlet.

5. The water-based rock debris pH adjustment device according to claim 4, characterized in that, The exhaust gas metering unit includes at least a No. 2 oil storage bottle and a recovery container. The CO2 that does not participate in the neutralization reaction is discharged into the No. 2 oil storage bottle as exhaust gas through the outlet, and the inert oil medium in the No. 2 oil storage bottle is pressed into the recovery container.

6. The water-based rock debris pH adjustment device according to claim 5, characterized in that, The inert oil medium in oil storage bottles No. 1 and No. 2 serves as a volume replacement medium and does not react with CO2, including dodecane; the desiccant includes anhydrous calcium chloride, and the degreased cotton serves to buffer the airflow, fix the desiccant, and prevent dust from entering; the reaction tube adopts a spiral structure.

7. A water-based rock debris pH adjustment device according to claim 4 or 5, characterized in that, The specific process for adjusting the pH of water-based rock debris includes the following steps: S1, Adding ingredients Add water-based rock cuttings into the reaction tube, close the main gas path and open the branch gas path through the three-way valve; S2, Gas Supply After closing the pressure reducing valve and opening the flow meter and valve, slowly open the pressure reducing valve to start supplying gas. Adjust the gas flow rate through the flow meter. Once the reading stabilizes, quickly close the branch gas line and open the main gas line at the same time. S3, reaction The CO2 in the gas cylinder is depressurized and controlled by a pressure reducing valve and a flow meter, and then injected into the No. 1 oil storage cylinder. An equal amount of inert oil medium is injected into the gas storage cylinder. An equal volume of gas in the gas storage cylinder is pushed into the drying tube by the injected inert oil medium. After drying, it is introduced into the reaction tube to begin a neutralization reaction with the water-based rock debris. S4, Gas outage After introducing the set amount of CO2, stop the neutralization reaction between CO2 and water-based rock debris. At the same time, open the branch gas path through the three-way valve, close the main gas path, close the valve, and wait for the gas inside the pressure reducing valve and flow meter to be discharged before closing the pressure reducing valve and flow meter. S5, Calculation When the inert oil medium in the No. 2 oil storage bottle no longer flows into the recovery container, measure the volume of the inert oil medium in the beaker, i.e. the volume of CO2 that did not participate in the reaction. Based on the amount of CO2 introduced and discharged, calculate the single CO2 absorption rate.

8. The water-based rock debris pH adjustment device according to claim 7, characterized in that, The working principle is as follows: using the volume replacement method, an inert oil medium that does not react with CO2 is used as the gas volume replacement medium. A certain amount of inert oil medium is pressed into the gas storage bottle, which means that the same volume of CO2 enters the reaction tube. Thus, the volume of CO2 gas introduced can be read directly and the precise quantitative delivery of CO2 can be achieved. After the neutralization reaction is completed, the volume of dodecane in the recovery container is the volume of unreacted CO2.

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