Technology for mixing, dissolving and injecting carbon dioxide and water in deep saline water layer into tubular column

Abstract

The invention belongs to the technical field of deep saline water layer mixing, dissolving and injecting processes, and particularly relates to a deep saline water layer carbon dioxide and water mixing, dissolving and injecting tubular column process, which comprises the following steps: S1, fully mixing carbon dioxide and water pumped out in a water pumping test in mixing equipment according to a mass fraction of 2-5%, s2, injecting the mixed solution in the step S1 into a drilling well through a drill rod, and averagely and continuously injecting the mixed solution for a certain time at a certain flow according to numerical simulation conditions to complete injection of all the mixed solution, S3, monitoring the flow, temperature and pressure of water, the flow and pressure of carbon dioxide and the temperature of a wellhead in the injection process, the underground shallow and deep sensors need to monitor temperature and pressure in real time, carbon dioxide is mixed with water, solubility of carbon dioxide in water can be increased, sealing or recycling efficiency is improved, viscosity of crude oil can be reduced, the crude oil can flow more easily, fluidity of oil gas is improved, permeability is improved, and the oil gas can be recycled. And the oil gas extraction efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of deep saline layer mixed dissolution injection technology, in particular to a deep saline layer carbon dioxide and water mixed dissolution injection pipe column technology. Background Art

[0002] With the rapid development of the world economy, the global demand for primary energy has increased rapidly. With the massive consumption of primary energy, the emission of greenhouse gases in the atmosphere, mainly carbon dioxide, has also increased year by year.

[0003] The increase in the content of greenhouse gases such as carbon dioxide in the atmosphere is one of the important reasons for global warming and frequent climate disasters. It is necessary to promote the implementation of CCS technology, which uses deep underground space for gas storage, with a small footprint and long energy storage time. Compared with salt caverns, deep underground saline aquifers have been proven to be used for gas storage. Due to the wide distribution of saline aquifers, the energy storage space and potential are even greater, and it has become the focus of research on large-scale energy storage in the world. However, in the process of gas storage;

[0004] How to mix and dissolve carbon dioxide with water and inject it into saline layers is a major challenge. Therefore, there is an urgent need to provide a deep saline layer carbon dioxide and water mixed dissolution injection pipe column process to meet the needs of engineering construction. By mixing carbon dioxide with water, the solubility of carbon dioxide in water is increased, thereby improving the efficiency of sealing or enhancing recovery. In addition, through the process of mixed injection of water and carbon dioxide, the viscosity of crude oil can be reduced, making crude oil easier to flow, improving the fluidity of oil and gas, improving permeability, and enhancing the recovery efficiency of oil and gas. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] Therefore, the purpose of the present invention is to provide a process for dissolving and injecting carbon dioxide into a pipe column in a deep saline layer by mixing carbon dioxide and water. By mixing carbon dioxide and water in this method, the solubility of carbon dioxide in water can be increased, thereby improving the efficiency of sealing or enhancing recovery. In addition, by the process of mixed injection of water and carbon dioxide, the viscosity of crude oil can be reduced, making crude oil easier to flow, improving the fluidity of oil and gas, improving permeability, and enhancing the recovery efficiency of oil and gas.

[0007] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions:

[0008] A process for injecting a carbon dioxide and water mixed solution into a deep saline aquifer through a pipe string, which comprises the following steps:

[0009] S1. Mixing: Mix carbon dioxide and the water pumped out during the pumping test in a mixing device in a proportion of 2% to 5% by mass fraction for sufficient mixing;

[0010] S2. Injecting the mixed solution: Inject the mixed solution in step S1 into the well through the drill pipe, and inject it continuously at a certain flow rate for a certain time according to the numerical simulation situation to complete the injection of all the mixed solution;

[0011] S3. Monitoring and control: During the injection process, monitor the flow rate, temperature, pressure of the water, and the flow rate, pressure, and wellhead temperature of carbon dioxide. The downhole shallow and deep sensors should monitor the temperature and pressure in real time;

[0012] S4. Tracing: Add a tracer to the water to analyze the mixing effect of the injected water and the formation water;

[0013] S5. Subsequent monitoring and evaluation.

[0014] As a preferred embodiment of the process for injecting a carbon dioxide and water mixed solution into a deep saline aquifer through a pipe string according to the present invention, in step S1, the following system is used to mix carbon dioxide and the water source in the pumping experiment:

[0015] Dissolution system: Under certain pressure and temperature conditions, use a mixing device to dissolve carbon dioxide and water. Carbon dioxide can form a supercritical fluid or a liquid state in water under high pressure;

[0016] Bubble column system: Carbon dioxide gas forms small bubbles through a certain device, and after a certain time, carbon dioxide gradually dissolves into the water.

[0017] As a preferred embodiment of the process for injecting a carbon dioxide and water mixed solution into a deep saline aquifer through a pipe string according to the present invention, in step S3, the following are further included:

[0018] Temperature, pressure and flow rate monitoring: Monitor the temperature and pressure of the underground injection environment to ensure that the carbon dioxide aqueous solution can be injected smoothly and maintain a good dissolution state;

[0019] Reservoir pressure and saturation monitoring: Real-time monitor the pressure of the underground reservoir and the saturation of carbon dioxide through pressure monitoring equipment to ensure the stable storage of carbon dioxide underground.

[0020] As a preferred embodiment of the process for injecting a carbon dioxide and water mixed solution into a deep saline aquifer through a pipe string according to the present invention, in step S4, two tracers are included as follows:

[0021] 1) Sodium bromide, prepared at 50 mg / L;

[0022] 2) Sodium fluorescein: the concentration should be configured based on the detection limit of the instrument.

[0023] As a preferred solution of the process of injecting a mixture of carbon dioxide and water into a pipe column in a deep saline layer described in the present invention, in the step S2, when the mixed carbon dioxide aqueous solution is transported to the underground reservoir through the pipe column, it is ensured that the injection pipeline has a strong pressure resistance to cope with the underground high-pressure environment.

[0024] As a preferred solution of the process of dissolving a mixture of carbon dioxide and water in a deep saline layer and injecting it into a pipe column according to the present invention, step S5 includes the following steps:

[0025] S5.1. Underground monitoring: the injected CO2 may gradually spread to other areas of the reservoir, ensuring that the distribution, pressure changes, and dissolution of CO2 in the reservoir are within a safe and effective range;

[0026] S5.2, Reservoir behavior analysis, through seismic monitoring and pressure sensor technology, to evaluate the underground carbon dioxide storage behavior and its possible leakage risk;

[0027] S5.3, water quality and environmental monitoring, monitoring the impact of carbon dioxide on groundwater quality to ensure that the water source is not polluted or altered;

[0028] S5.4. Environmental impact assessment: evaluate the long-term impact of carbon dioxide injection on the ground and surrounding environment to ensure that there will be no adverse impact on the ecological environment.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. Improve the dissolution efficiency of carbon dioxide: By mixing carbon dioxide with water, the solubility of carbon dioxide in water can be increased, thereby improving the efficiency of storage or enhanced recovery;

[0031] 2. Reduce greenhouse gas emissions: For carbon dioxide storage applications, this process helps to effectively store carbon dioxide underground, reducing its impact on the atmosphere;

[0032] 3. Improve oil and gas recovery rate. By mixing and injecting water and carbon dioxide, the viscosity of crude oil can be reduced, making it easier to flow, improving the fluidity of oil and gas, improving permeability, and enhancing the recovery efficiency of oil and gas;

[0033] 3. Multiple applications: This technology can not only be used for carbon dioxide storage and enhanced oil and gas recovery, but also improve groundwater quality, etc., and has a wide range of application prospects; BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below in combination with the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0035] Figure 1 This is a schematic diagram of the steps of the column injection process of the present invention;

[0036] Figure 2 This is a schematic diagram of the distribution steps of step S2 of the present invention;

[0037] Figure 3 This is a schematic diagram of the distribution steps of step S5 of the present invention. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0040] Secondly, the present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0041] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0042] The present invention provides a process for dissolving a mixture of carbon dioxide and water in a deep saline layer and injecting it into a pipe column. The method can be used to evaluate soil stability and identify areas where unstable soil may exist in advance by measuring the dissolution coefficient, so that corresponding reinforcement or treatment measures can be taken to avoid structural damage caused by unstable soil. The test process is simple, the cycle is fast, and the operation is simple and convenient. Please refer to Figure 1-2 , including the following steps:

[0043] The steps are as follows:

[0044] S1. Mixing: fully mixing the carbon dioxide and the water pumped out in the water pumping test in a mixing device at a ratio of 2% to 5% by mass;

[0045] S2, mixed solution injection, injecting the mixed solution in step S1 into the well through the drill pipe, and continuously injecting at a certain flow rate for a certain time on average according to the numerical simulation to complete the injection of all the mixed solutions;

[0046] S3. Monitoring and control: monitor the flow rate, temperature, pressure of water and the flow rate, pressure, and wellhead temperature of carbon dioxide during the injection process. Shallow and deep sensors in the well should monitor the temperature and pressure in real time.

[0047] S4, tracing, adding tracers to the water to analyze the mixing effect of injected water and formation water;

[0048] S5. Subsequent monitoring and evaluation.

[0049] In step S1, the following system is used to mix carbon dioxide with the water source in the pumping experiment:

[0050] Dissolution system: Under certain pressure and temperature conditions, carbon dioxide is dissolved in water using a mixing device. Carbon dioxide can form a supercritical fluid or liquid state in water under high pressure;

[0051] Bubble tower system: Carbon dioxide gas passes through certain equipment to form small bubbles. After a certain period of time, the carbon dioxide gradually dissolves into the water.

[0052] Step S3 also includes the following:

[0053] Temperature, pressure and flow monitoring: monitoring the temperature and pressure of the underground injection environment to ensure that the carbon dioxide aqueous solution can be smoothly injected and maintain a good dissolved state;

[0054] Reservoir pressure and saturation monitoring: Use pressure monitoring equipment to monitor the pressure of underground reservoirs and the saturation of carbon dioxide in real time to ensure the stable storage of carbon dioxide underground.

[0055] In step S4, two tracers are included, as follows:

[0056] Sodium bromide, prepared at 50 mg / L;

[0057] Sodium fluorescein, the concentration is configured based on the detection limit of the instrument.

[0058] Step S2: Before injection, reservoir assessment and site selection are required, including the following operations:

[0059] S21. Reservoir characteristics assessment: Before CO2 injection, evaluate the geological characteristics, reservoir thickness, porosity, permeability, pressure, and temperature parameters of the underground saline layer to determine whether the reservoir is suitable for CO2 injection;

[0060] S22. Water quality analysis: Analyze the chemical composition of groundwater to ensure that the reaction between water quality and the dissolution of carbon dioxide will not cause groundwater contamination or precipitation problems.

[0061] In step S2, when the mixed carbon dioxide aqueous solution is transported to the underground reservoir through the pipe column, it is ensured that the injection pipeline has a strong pressure resistance to cope with the underground high pressure environment.

[0062] Step S5 includes the following steps:

[0063] S5.1. Underground monitoring: the injected CO2 may gradually spread to other areas of the reservoir, ensuring that the distribution, pressure changes, and dissolution of CO2 in the reservoir are within a safe and effective range;

[0064] S5.2, Reservoir behavior analysis, through seismic monitoring and pressure sensor technology, to evaluate the underground carbon dioxide storage behavior and its possible leakage risk;

[0065] S5.3, water quality and environmental monitoring, monitoring the impact of carbon dioxide on groundwater quality to ensure that the water source is not polluted or altered;

[0066] S5.4. Environmental impact assessment: evaluate the long-term impact of carbon dioxide injection on the ground and surrounding environment to ensure that there will be no adverse impact on the ecological environment.

[0067] Although the present invention has been described above with reference to the embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the various features in the embodiments disclosed in the present invention may be used in combination with each other in any manner, and the fact that these combinations are not exhaustively described in this specification is only for the sake of omitting space and saving resources. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A process for dissolving a mixture of carbon dioxide and water in a deep saline layer and injecting it into a pipe column, characterized in that: The steps are as follows: S1. Mixing: fully mixing the carbon dioxide and the water pumped out in the water pumping test in a mixing device at a ratio of 2% to 5% by mass; S2, mixed solution injection, injecting the mixed solution in step S1 into the well through the drill pipe, and continuously injecting at a certain flow rate for a certain time on average according to the numerical simulation to complete the injection of all the mixed solutions; S3. Monitoring and control: monitor the flow rate, temperature, pressure of water and the flow rate, pressure, and wellhead temperature of carbon dioxide during the injection process. Shallow and deep sensors in the well should monitor the temperature and pressure in real time. S4, tracing, adding tracers to the water to analyze the mixing effect of injected water and formation water; S5. Subsequent monitoring and evaluation.

2. A process for dissolving a mixture of carbon dioxide and water in a deep saline layer and injecting it into a pipe column according to claim 1, characterized in that: In step S1, the carbon dioxide is mixed with the water source in the pumping experiment using the following system: Dissolution system: Under certain pressure and temperature conditions, carbon dioxide is dissolved in water using a mixing device. Carbon dioxide can form a supercritical fluid or liquid state in water under high pressure; Bubble tower system: Carbon dioxide gas passes through certain equipment to form small bubbles. After a certain period of time, the carbon dioxide gradually dissolves into the water.

3. A process for dissolving a mixture of carbon dioxide and water in a deep saline layer and injecting it into a pipe column according to claim 2, characterized in that: The step S3 further includes the following: Temperature, pressure and flow monitoring: monitoring the temperature and pressure of the underground injection environment to ensure that the carbon dioxide aqueous solution can be smoothly injected and maintain a good dissolved state; Reservoir pressure and saturation monitoring: Use pressure monitoring equipment to monitor the pressure of underground reservoirs and the saturation of carbon dioxide in real time to ensure the stable storage of carbon dioxide underground.

4. A process for dissolving a mixture of carbon dioxide and water in a deep saline layer and injecting it into a pipe column according to claim 3, characterized in that: In step S4, two tracers are included, as follows: 1) Sodium bromide, prepared at 50 mg / L; 2) Sodium fluorescein: the concentration should be configured based on the detection limit of the instrument.

5. A process for dissolving a mixture of carbon dioxide and water in a deep saline layer and injecting it into a pipe column according to claim 4, characterized in that: The S2, before injection, requires reservoir assessment and site selection, including the following operations: S21. Reservoir characteristics assessment: Before CO2 injection, evaluate the geological characteristics, reservoir thickness, porosity, permeability, pressure, and temperature parameters of the underground saline layer to determine whether the reservoir is suitable for CO2 injection; S22. Water quality analysis: Analyze the chemical composition of groundwater to ensure that the reaction between water quality and the dissolution of carbon dioxide will not cause groundwater contamination or precipitation problems.

6. A process for dissolving a mixture of carbon dioxide and water in a deep saline layer and injecting it into a pipe column according to claim 5, characterized in that: In step S2, when the mixed carbon dioxide aqueous solution is transported to the underground reservoir through the pipe column, it is ensured that the injection pipeline has a strong pressure resistance to cope with the underground high pressure environment.

7. A process for dissolving a mixture of carbon dioxide and water in a deep saline layer and injecting it into a pipe column according to claim 6, characterized in that: The step S5 includes the following steps: S5.

1. Underground monitoring: the injected CO2 may gradually spread to other areas of the reservoir, ensuring that the distribution, pressure changes, and dissolution of CO2 in the reservoir are within a safe and effective range; S5.2, Reservoir behavior analysis, through seismic monitoring and pressure sensor technology, to evaluate the underground carbon dioxide storage behavior and its possible leakage risk; S5.3, water quality and environmental monitoring, monitoring the impact of carbon dioxide on groundwater quality to ensure that the water source is not polluted or altered; S5.

4. Environmental impact assessment: evaluate the long-term impact of carbon dioxide injection on the ground and surrounding environment to ensure that there will be no adverse impact on the ecological environment.

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