Method for determining engineering storage capacity of CO2 dissolution and mineralization of basalt stratum horizontal well

Abstract

The invention discloses a method for determining the engineering storage capacity of CO2 dissolution and mineralization of a horizontal well in a basalt stratum. The method comprises the steps that a hole wall image of an observation well, a basalt pore feature image of a drilling rock core in the observation well, a scanning image of a rock core sample in the observation well and the vertical distance between a CO2 solution in the horizontal well and the horizontal well are obtained; based on the hole wall image of the observation well, determining the void ratio and the porosity of the observation well in the vertical direction; determining the porosity in the vertical direction based on the basalt pore feature image of the drilling rock core in the observation well; determining a mineralization carbon sequestration coefficient based on the scanning image of the rock core sample in the observation well; based on the vertical distance, the reservoir volume of the CO2 solution injection influence range of the horizontal well is obtained through calculation; and determining the actual storage capacity of the basalt shallow horizontal well based on the porosity ratio and porosity in the vertical direction of the observation well, the porosity in the vertical direction, the mineralization carbon sequestration coefficient and the reservoir volume.

Description

Technical Field

[0001] The present application relates to the technical field of carbon emission reduction, and in particular to a method for determining the engineering storage capacity of CO2 dissolution mineralization in horizontal wells in basalt formations. Background Art

[0002] The CO2 storage project chooses basalt as the storage medium, mainly due to the unique advantages of basalt as a basic mineral in dissolving and storing CO2. In particular, when CO2 aqueous solution is injected into basalt, it can effectively avoid the risk of CO2 leakage and promote the dissolution and mineralization of CO2 to form carbonate minerals, thereby permanently fixing it underground. This process not only realizes the conversion of CO2 from gas to solid, but also avoids the limitation of caprock closure, making basalt formation a new CO2 dissolution storage technology with broad application prospects.

[0003] The current methods for evaluating the storage potential of basalt formations include unit mineralization method, mineral replacement method and pore filling method. Although they provide estimates of the CO2 storage potential of basalt to a certain extent, these methods do have the problem of rough estimation. Specifically, the unit mineralization method usually estimates the CO2 storage potential based on the content of reactive minerals in basalt. However, it ignores the effects of key factors such as mineral reaction rate, pore structure, and permeability on the storage capacity. The mineral replacement method assumes that CO2 will undergo replacement reactions with certain minerals in basalt to generate carbonate minerals. However, the actual mineral reaction process may be more complicated and is subject to multiple factors, such as temperature, pressure, and fluid composition. The pore filling method focuses on the capacity of basalt pore space to accommodate CO2. However, it ignores the effects of the anisotropy of pore structure, fluid flow characteristics, and the interaction between CO2 and minerals on the storage capacity.

[0004] In other words, the existing evaluation methods often only consider single-dimensional data, lack multi-dimensional and multi-level data support, and cannot fully reflect the true conditions of the formation. Therefore, the current methods for evaluating the storage potential of basalt formations are difficult to accurately reflect the actual amount of CO2 that can be taken in and the storage capacity of basalt formations in engineering storage. Summary of the invention

[0005] Based on the above problems, the present application provides a method for determining the engineering storage capacity of CO2 dissolution mineralization in horizontal wells in basalt formations.

[0006] The embodiments of the present application disclose the following technical solutions:

[0007] The first aspect of the embodiment of the present application discloses a method for determining the engineering storage capacity of CO2 dissolution mineralization in a horizontal well of a basalt formation, which is characterized by comprising:

[0008] Obtain the borehole wall image of the observation well, the basalt pore characteristic image of the drill core in the observation well, the scanned image of the core sample in the observation well, and the vertical distance of the CO2 solution in the horizontal well from the horizontal well. The observation well is a well drilled vertically into the basalt formation, which is used to observe the dissolution process of the CO2 solution and the changes in the groundwater environment. The horizontal well is a well extending horizontally along the basalt formation, and the CO2 solution is uniformly injected into the basalt formation through the horizontal well.

[0009] Based on the borehole wall image of the observation well, determine the porosity and porosity in the vertical direction of the observation well; based on the basalt pore characteristic image of the drilling core in the observation well, determine the porosity in the vertical direction; based on the scanning image of the core sample in the observation well, determine the mineralization carbon fixation coefficient; based on the vertical distance, calculate the reservoir volume within the influence range of the CO2 solution injection in the horizontal well;

[0010] Based on the porosity and porosity in the vertical direction of the observation well, the porosity in the vertical direction, the mineralization carbon fixation coefficient and the reservoir volume, the actual storage capacity of the shallow basalt horizontal well is determined.

[0011] In a possible implementation, the step of acquiring the borehole wall image of the observation well includes:

[0012] A panoramic image of the observation well is taken based on a panoramic borehole imager and a panoramic imaging probe to obtain a borehole wall image of the observation well.

[0013] In a possible implementation, determining the porosity ratio and porosity in the vertical direction of the observation well based on the borehole wall image of the observation well includes:

[0014] Performing image threshold segmentation on the pore wall image to obtain a pore threshold image and a matrix threshold image;

[0015] Determining the pore area and the basalt matrix area in the pore wall image based on the pore threshold image and the matrix threshold image;

[0016] Based on the pore area and the basalt matrix area in the hole wall image, the porosity ratio and porosity in the vertical direction of the observation well are determined.

[0017] In a possible implementation, a method of obtaining a basalt pore characteristic image of a drilling core in an observation well includes:

[0018] The drill core obtained by drilling is scanned by X-ray CT to obtain the basalt pore characteristic images of the longitudinal and transverse sections respectively.

[0019] In a possible implementation, the determining of the porosity in the vertical direction based on the basalt pore characteristic image of the drilling core in the observation well includes:

[0020] Determine the pore characteristic area based on the basalt pore characteristic image of the longitudinal slice and the basalt pore characteristic image of the transverse slice;

[0021] Based on the pore characteristic area and the pore characteristic image area of ​​the longitudinally sliced ​​basalt, the porosity in the vertical direction is calculated.

[0022] In a possible implementation, determining the actual storage capacity of the shallow basalt horizontal well based on the porosity and porosity in the vertical direction of the observation well, the porosity in the vertical direction, the mineralization carbon fixation coefficient and the reservoir volume includes:

[0023] The porosity in the vertical direction and the average porosity in the vertical direction are calculated to obtain the actual porosity of the basalt reservoir;

[0024] The actual storage capacity of the shallow basalt horizontal well is determined based on the actual porosity of the basalt reservoir, the porosity ratio in the vertical direction of the observation well, the mineralization carbon fixation coefficient and the reservoir volume.

[0025] In a possible implementation, the scanning image of the core sample in the observation well is obtained by:

[0026] The core samples drilled from the observation well are crushed to obtain core samples in powder particle size form;

[0027] Scan the core sample in powder particle form to obtain a microscopic scanning image of the core sample.

[0028] In a possible implementation, determining the mineralization carbon fixation coefficient based on the scanned image of the core sample in the observation well includes:

[0029] Identifying basalt matrix image features and quartz mineral image features in the scanned image, and determining basalt matrix image feature areas and quartz mineral image feature areas in the scanned image;

[0030] Based on the characteristic area of ​​basalt matrix image and quartz mineral image, the mineralization carbon fixation coefficient of basalt reservoir matrix was calculated.

[0031] In a possible implementation, the calculating of the reservoir volume within the impact range of the horizontal well CO2 solution injection based on the vertical distance includes:

[0032] Get the length of the horizontal well;

[0033] According to the length of the horizontal well, the vertical distance between the CO2 solution and the upper side of the horizontal well, and the vertical distance between the CO2 solution and the lower side of the horizontal well, the reservoir volume within the influence range of the CO2 solution injection in the horizontal well is calculated.

[0034] In a possible implementation, determining the actual storage capacity of the shallow basalt horizontal well based on the porosity and porosity in the vertical direction of the observation well, the porosity in the vertical direction, the mineralization carbon fixation coefficient and the reservoir volume includes:

[0035] Based on the porosity ratio and porosity in the vertical direction of the logging, the porosity in the vertical direction, the mineralization carbon fixation coefficient and the reservoir volume, the total storage capacity of the CO2 solution in the horizontal well is calculated;

[0036] The ratio of the total storage capacity of the CO2 solution in the horizontal well to the amount of water required to dissolve one ton of CO2 solution is calculated to obtain the actual storage capacity of the CO2 solution in the horizontal well.

[0037] In a second aspect, the present application provides a system for determining the engineering storage capacity of CO2 dissolution mineralization in a horizontal well in a basalt formation, comprising:

[0038] An acquisition unit is used to acquire a borehole wall image of an observation well, a basalt pore characteristic image of a drill core in the observation well, a scanned image of a core sample in the observation well, and a vertical distance between a CO2 solution in a horizontal well and the horizontal well; an observation well is a well vertically drilled into a basalt formation, and is used to observe the dissolution process of a CO2 solution and changes in the groundwater environment; a horizontal well is a well extending horizontally along a basalt formation, and a CO2 solution is uniformly injected into the basalt formation through the horizontal well;

[0039] The first determination unit is used to determine the porosity and porosity in the vertical direction of the observation well based on the borehole wall image of the observation well; determine the porosity in the vertical direction based on the basalt pore characteristic image of the drilling core in the observation well; determine the mineralization carbon fixation coefficient based on the scanning image of the core sample in the observation well; and calculate the reservoir volume within the influence range of the CO2 solution injection in the horizontal well based on the vertical distance;

[0040] The second determination unit is used to determine the actual storage capacity of the shallow basalt horizontal well based on the porosity and porosity in the vertical direction of the observation well, the porosity in the vertical direction, the mineralization carbon fixation coefficient and the reservoir volume.

[0041] Compared with the prior art, this application has the following beneficial effects:

[0042] The borehole wall image of the observation well provides the pore structure and distribution information of the formation in the vertical direction, which is helpful to determine the porosity ratio and porosity. The basalt pore characteristic image of the drill core in the observation well further refines the porosity information of the formation in the vertical direction, providing more detailed data for evaluating the storage space. According to the scanning image of the core sample in the observation well, the mineralization carbon fixation coefficient is determined by analyzing the mineral composition and distribution, which reflects the ability of CO2 to react with formation minerals. The vertical distance of the CO2 solution in the horizontal well from the horizontal well provides a data basis for calculating the reservoir volume within the influence range of CO2 solution injection. By obtaining multi-dimensional data such as borehole wall images, pore characteristic images, scanning images and vertical distances, the real situation of the formation is fully reflected, and the accuracy of the calculation is improved. Comprehensive consideration of multiple factors such as pore structure, mineral composition, reaction ability and fluid flow characteristics provides more comprehensive information for determining the storage capacity. Compared with the current data that only considers a single dimension, this application obtains multi-dimensional and multi-level data support to comprehensively reflect the true conditions of the formation, thereby being able to more accurately evaluate the CO2 storage capacity of the basalt formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0044] Figure 1 A flow chart of a method for determining the engineering storage capacity of CO2 dissolution mineralization in a horizontal well in a basalt formation provided in an embodiment of the present application;

[0045] Figure 2 A schematic diagram of a CO2 mineralization storage mode for a shallow horizontal well in basalt provided in an embodiment of the present application;

[0046] Figure 3 A schematic diagram of the structure of a liquid transport pipeline 4 provided in an embodiment of the present application;

[0047] Figure 4 A schematic diagram of a test method provided in an embodiment of the present application;

[0048] Figure 5 The mineralization carbon fixation coefficient C of the basalt reservoir matrix provided in the embodiment of the present application is Fix Schematic diagram of the calculation process;

[0049] Figure 6 A schematic diagram of a horizontal well CO2 injection impact range test process provided in an embodiment of the present application;

[0050] Figure 7 A schematic diagram of calculating the CO2 storage capacity of a shallow horizontal well in basalt provided in an embodiment of the present application;

[0051] Figure 8 A structural diagram of a system for determining engineering storage capacity for CO2 dissolution mineralization in horizontal wells in basalt formations provided in an embodiment of the present application. DETAILED DESCRIPTION

[0052] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] To facilitate understanding of the technical solutions provided by the embodiments of the present application, the professional terms involved in the embodiments of the present application will be explained below.

[0054] Basalt is a widely distributed rock with the potential to store CO2. Its special physical and chemical properties make it an ideal CO2 storage medium. Specifically, basalt is rich in divalent metal cations such as Ca2+, Mg2+, and Fe2+, which can react chemically with CO2 dissolved in water to form stable carbonate minerals (such as calcite, magnesium carbonate, siderite, and carbonate solid solutions), thereby achieving permanent storage of CO2.

[0055] To facilitate understanding of the technical solutions provided by the embodiments of the present application, the background technology involved in the embodiments of the present application will be described below.

[0056] As mentioned above, storage potential evaluation and calculation are crucial for the development of CO2 geological storage technology, especially in the context of global climate change and emission reduction needs. Different geological structures and formation types provide a variety of potential solutions for CO2 storage, among which basalt formations have attracted much attention due to their special physical and chemical properties.

[0057] Globally, CO2 storage projects in Iceland and the United States have chosen basalt as the storage medium, mainly due to the unique advantages of basalt formations in storing CO2. In particular, when CO2 aqueous solution is injected into basalt, it can effectively avoid the risk of CO2 leakage and promote the dissolution and mineralization of CO2, thereby permanently fixing it underground. This process not only realizes the conversion of CO2 from gas to solid, but also avoids the limitation of caprock closure, making basalt formations a CO2 storage method with broad application prospects.

[0058] The existing basalt CO2 storage technology mainly relies on the docking well method, which is mainly used in basalt reservoirs for oil and gas extraction. The construction depth of the docking horizontal well is usually several thousand meters underground, which is particularly suitable for areas in southwest my country where the Upper Permian coal resources are rich and basalt is developed under the coal system. However, this docking horizontal well CO2 mineralization storage technology in deep basalt formations has the problem of high construction costs. In the absence of direct economic benefits, it is difficult to compete with the existing carbon trading market prices from the perspective of economic cost by relying solely on the underground storage method of industrial carbon sources.

[0059] In addition, existing basalt CO2 storage potential evaluation methods, such as unit mineralization method, mineral replacement method and pore filling method, all have the problem of rough estimation. These methods mainly evaluate the storage potential based on the thickness and quality of basalt formations, but in practical applications, it is difficult to accurately evaluate the actual injectable amount of CO2 in basalt formations and the engineering storage capacity.

[0060] In order to solve the above problems, the embodiment of the present application obtains data through various means, including observation well wall images, drilling core pore characteristic images, core sample scanning images and vertical distance of CO2 solution diffusion, to ensure the integrity and comprehensiveness of the data. The reliability of the evaluation results is ensured by analyzing data at multiple levels such as porosity, porosity, mineralization carbon fixation coefficient and reservoir volume.

[0061] By observing the borehole wall images and the pore characteristic images of the drilling core, the pore characteristics can be evaluated more accurately, thereby improving the calculation accuracy of the porosity ratio and porosity. By scanning the core sample images, the mineralization carbon fixation coefficient can be determined more accurately, further improving the accuracy of the calculation of the effective storage capacity of the project. By measuring the vertical distance of the CO2 solution diffusion, the reservoir volume can be calculated more accurately, thereby better reflecting the actual storage effect.

[0062] In summary, the embodiments of the present application comprehensively determine the actual engineering storage capacity of shallow basalt horizontal wells based on multi-dimensional and multi-level data, thereby improving the accuracy of the evaluation of CO2 engineering storage potential.

[0063] By combining micro-mineral testing, indoor experiments and field tests, and based on the test data results, a scientific evaluation method for the CO2 storage capacity of shallow horizontal wells in basalt is proposed. This evaluation method is more scientific and reliable.

[0064] Therefore, this application is applicable to areas where the basalt strata are relatively thin but widely distributed, as well as high-carbon industrial plants or parks with a high degree of source-sink matching. It solves the underground storage engineering design problems and storage capacity calculation problems of large-scale centralized industrial carbon sources under geological conditions where the basalt strata are relatively thin and widely distributed. By adopting horizontal well technology, the CO2 solution injection efficiency and storage capacity can be greatly improved when the basalt strata are relatively thin, while reducing the technical costs of industrial carbon sources in the transportation and storage links.

[0065] In addition, the present embodiment also takes into account factors such as the chemical reactivity and mineral composition of the basalt formation, and conducts in-depth research on the dissolution and mineralization process of the CO2 solution. This not only helps to more accurately assess the storage potential, but also provides a scientific basis for optimizing the storage plan and improving the storage efficiency.

[0066] It should be noted that the method for determining the total storage capacity provided in the present application can be applied to the field of computer technology. The above is only an example, and the application field of the method, system, device and medium for determining the total storage capacity provided in the present application is not limited. In addition, the embodiment of the present application may not limit the execution subject of the determination of the total storage capacity. For example, the method for determining the total storage capacity of the embodiment of the present application can be applied to data processing devices such as terminal devices or servers. Among them, the terminal device can be an electronic device such as a computer, a personal digital assistant (PDA). The server can be a stand-alone server, a cloud server, or a cluster server composed of multiple servers.

[0067] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0068] The following is an example to illustrate a method for determining storage capacity provided by the present application. Figure 1 ,Should Figure 1 A flow chart of a method for determining storage capacity provided in an embodiment of the present application, the method comprising:

[0069] S101, obtaining a borehole wall image of an observation well, a basalt pore characteristic image of a drill core in the observation well, a scanned image of a core sample in the observation well, and a vertical distance of a CO2 solution in a horizontal well from above and below the horizontal well.

[0070] The observation well is a well drilled vertically into the basalt formation, which is used to observe the dissolution process of the CO2 solution and the changes in the groundwater environment. The horizontal well is a well extending horizontally along the basalt formation, and the CO2 solution is evenly injected into the basalt formation through the horizontal well.

[0071] See also Figure 2 , Figure 2 A schematic diagram of a CO2 mineralization storage mode in a shallow horizontal well of basalt provided in an embodiment of the present application, which includes a carbon source, recovery, liquefaction, a liquid transport pipeline, a pressure well, an observation well, a horizontal well and a basalt formation.

[0072] The carbon source, number 1, refers to a large-scale, centralized industrial carbon source, usually from a factory or other large emission source. The recovery, number 2, refers to the process by which the carbon source is collected and prepared for further processing. The liquefaction stage, number 3, is where carbon dioxide is converted into a liquid state for easy storage and transportation.

[0073] The liquid transport pipeline with reference number 4 is a pipeline system for transporting liquid carbon dioxide. This pipeline system ensures that the CO2 solution can be transported to the injection well stably and continuously.

[0074] The injection well denoted by number 5 is a wellhead drilled into the ground for injecting liquid carbon dioxide into the ground.

[0075] The observation well marked 6 is a well drilled vertically into the ground, which is mainly used to monitor the CO2 injection process and changes in the underground environment.

[0076] The horizontal well numbered 7 is a well that extends along the formation. Through the horizontal well, the CO2 solution can be more evenly distributed in the basalt formation, thereby improving the mineralization efficiency and storage capacity.

[0077] The basalt formation numbered 8 refers to a type of rock underground, usually formed by volcanic activity, with a certain porosity and permeability, which is suitable for use as a CO2 storage site. Its physical and chemical properties determine the CO2 storage capacity and mineralization efficiency. Therefore, before the actual engineering construction, it is necessary to conduct on-site surveys of the basalt formation to determine the appropriate well depth and injection parameters.

[0078] Carbon sources mainly come from CO2 emissions generated during industrial production. These emissions are usually large in scale and require centralized treatment. After a compression and recovery process, the CO2 in the industrial carbon source is compressed and recovered to form a water-soluble CO2 solution. This step is the key to ensuring that CO2 can be efficiently and safely transported and stored. After a compression and recovery process, the CO2 in the industrial carbon source is compressed and recovered to form a water-soluble CO2 solution. This step is the key to ensuring that CO2 can be efficiently and safely transported and stored. The compressed CO2 solution is transported through a liquid transport pipeline to the injection well 5. The observation well 6 is constructed as a vertical well. The bottom depth of the well is the pressure influence boundary of the CO2 solution injected into the horizontal well 7. The actual engineering construction should be determined according to the on-site survey of the basalt formation 8. In this way, the concentration of greenhouse gases in the atmosphere is reduced, and the effective treatment and storage of large-scale centralized industrial carbon sources are achieved by capturing and safely storing industrially generated carbon dioxide underground, especially in basalt formations with high porosity and permeability.

[0079] See also Figure 3 , Figure 3 A schematic structural diagram of a liquid transport pipeline 4 provided in an embodiment of the present application, comprising a fiber textile outer layer 4-1, a steel pipe layer 4-2 and a polytetrafluoroethylene (PTEE) tube 4-3.

[0080] The fiber textile outer layer (4-1) may have a thickness of 1 mm. As the outer protective layer of the steel pipe 4-2, the fiber textile outer layer provides additional physical protection and wear resistance. It may have certain anti-corrosion properties, which can further extend the service life of the pipeline.

[0081] The wall thickness of the steel pipe layer (4-2) can be 10 mm. The steel pipe is the main load-bearing part of the pipeline structure, and its wall thickness ensures sufficient strength and rigidity to withstand the pressure of the CO2 solution inside the pipeline and possible external loads.

[0082] The inner wall is nested with a 10mm thick polytetrafluoroethylene (PTFE) tube with an inner diameter of 120mm. Polytetrafluoroethylene (PTFE) is a material with excellent corrosion resistance and can resist the erosion of a variety of chemicals, including acidic CO2 solutions. Therefore, this double-layer structure is designed to prevent acidic corrosion of the pipeline caused by CO2 solutions during transportation.

[0083] Therefore, the structure of the liquid transport pipeline 4 provided in the embodiment of the present application comprehensively considers the strength, corrosion resistance and service life of the pipeline. The fiber textile outer layer provides additional physical protection and wear resistance, the steel pipe layer ensures the strength and rigidity of the pipeline, and the PTFE lining layer effectively prevents acid corrosion of the CO2 solution. This multi-layer structural design enables the liquid transport pipeline 4 to maintain long-term stable operation in a harsh transport environment, ensuring the safety and durability of the pipeline.

[0084] S102. Based on the borehole wall image of the observation well, determine the porosity and porosity in the vertical direction of the observation well; based on the basalt pore characteristic image of the drill core in the observation well, determine the porosity in the vertical direction; based on the scanned image of the core sample in the observation well, determine the mineralization carbon fixation coefficient; based on the vertical distance, calculate the reservoir volume within the influence range of the CO2 solution injection in the horizontal well.

[0085] S103. Determine the actual storage capacity of the shallow basalt horizontal well based on the porosity and porosity in the vertical direction of the observation well, the porosity in the vertical direction, the mineralization carbon fixation coefficient and the reservoir volume.

[0086] Figure 4 The test method schematic diagram provided for the embodiment of the present application shows the indoor experiment and field test method of the porosity and porosity ratio of basalt formation. This process involves using a panoramic borehole imager and a panoramic imaging probe to take images of the borehole wall of the observation well, and then calculating the porosity ratio and porosity through image analysis.

[0087] A panoramic borehole imager 6-1 and a panoramic imaging probe 6-2 are used to take a panoramic image of the observation well 6 to obtain a borehole wall image 6-3 of the observation well. The acquired borehole wall image is subjected to image threshold segmentation to separate a pore threshold image and a matrix threshold image. The pore area and the basalt matrix area in the panoramic borehole wall image are counted. Based on the counted pore area and matrix area, the porosity ratio e0 and porosity n0 in the vertical direction of the observation well are calculated. Among them, the porosity ratio e0 is the ratio of the area of ​​the pores in the panoramic image to the area of ​​the rock matrix in the panoramic image, and the porosity n0 is the area of ​​the pores in the panoramic image to the area of ​​the panoramic image. The panoramic image area can be expressed as the product of the circumference of the observation well borehole and the depth of the observation well borehole.

[0088] That is, the calculation formula of the void ratio can be expressed as:

[0089] The calculation formula of porosity can be expressed as:

[0090] Among them, S p is the area of ​​the pores in the panoramic image (unit: mm 2 );S mis the area of ​​the rock matrix in the panoramic image (unit: mm 2 ); S is the panoramic image area (unit: mm 2 ); C is the circumference of the observation well borehole (unit: mm); L0 is the depth of the observation well borehole (unit: mm).

[0091] The drill core obtained by drilling is scanned by X-ray CT, and the longitudinal and transverse sections are sliced ​​to obtain the basalt pore characteristic images. The pore characteristic area in the X-ray image is counted, and the horizontal porosity n is calculated. h and vertical porosity n v Finally, the actual porosity of the basalt reservoir is the average value of the core data and the pore wall image data (n0+n v ) / 2.

[0092] Figure 5 A schematic diagram of the calculation process of the mineralization carbon fixation coefficient CFix of the basalt reservoir matrix provided in the embodiment of the present application, first, a core sample is drilled from the observation well 6. Then, the collected core is crushed to a suitable size and shape for subsequent SEM scanning. The crushed sample is scanned using SEM to obtain a high-resolution image thereof.

[0093] In the SEM image, the acquired SEM image is carefully analyzed to identify the image features of the basalt matrix and the image features of the quartz mineral. This step can be done with the help of professional image analysis software or manual annotation to distinguish different types of mineral components.

[0094] Statistical analysis of the characteristic area of ​​basalt matrix image per unit area of ​​SEM image S matrix and the characteristic area S of the quartz mineral image carb , using the statistically obtained area data of basalt matrix and quartz minerals, the mineralization carbon fixation coefficient of the basalt reservoir matrix is ​​calculated, that is, C Fix It reflects the ability of the basalt matrix to fix carbon dioxide under certain conditions and is one of the important indicators for evaluating the storage potential of the reservoir.

[0095] The following is an explanation of the process of testing the impact range of CO2 injection in horizontal wells. Figure 6Schematic diagram of the testing process of the impact range of CO2 injection in horizontal wells provided in the embodiment of the present application. A polytetrafluoroethylene coated casing 7-1 is embedded in the horizontal well 7, and the hole wall opening and row spacing design can be 100mm. When the CO2 solution is injected into the horizontal well, seepage and diffusion will occur, thereby affecting the surrounding reservoir area. The vertical distances above and below the horizontal well are the upper boundary R1 and the lower boundary R2, respectively. By measuring the different vertical distances above and below the horizontal well (i.e., the upper boundary R1 and the lower boundary R2), the reservoir volume within the impact range of CO2 solution injection can be estimated. Finally, the reservoir volume within the impact range of CO2 solution injection in the horizontal well is calculated to be Where L is the length of the horizontal well.

[0096] See also Figure 7 , Figure 7 A schematic diagram of calculating the CO2 storage capacity of a shallow horizontal well in basalt provided in the embodiment of the present application is shown in FIG. 1 . Substituting the index parameters obtained by the above calculation into Figure 7 The three capacity formulas shown are:

[0097] The calculation formula of basalt pore storage capacity can be expressed as:

[0098] Q pore =π(R1 2 +R2 2 )·L·(n0+n v ) / 2

[0099] The calculation formula of basalt matrix storage capacity can be expressed as:

[0100] Q matrix =C Fix π(R1 2 +R2 2 )·L·(n0+n v ) / (4·e0)

[0101] The calculation formula for the storage capacity of basalt formation boreholes can be expressed as:

[0102] Q Well =πR 2 ·L

[0103] The total storage capacity of CO2 solution in shallow horizontal wells in basalt is ∑QCO2.

[0104] For example, the actual capacity of CO2 storage in shallow horizontal wells in basalt can be calculated based on the fact that 22 to 25 tons of fresh water are needed to dissolve 1 ton of CO2.

[0105] Therefore, the embodiment of the present application combines the comprehensive evaluation methods of micro-mineral testing, indoor experiments and field tests to ensure that the CO2 storage capacity of shallow horizontal wells in basalt can be quantitatively evaluated on the basis of fully mastering the test data. This precise evaluation and calculation process not only improves the storage efficiency, but also provides strong data support for the subsequent formulation of storage strategies. Through this method, the storage capacity of CO2 can be more accurately predicted and planned, thereby ensuring the long-term stability and safety of the storage project.

[0106] The above are some specific implementations of the method for determining the engineering storage capacity of CO2 dissolution mineralization in horizontal wells in basalt formations provided in the embodiments of the present application. Based on this, the present application also provides a corresponding system for determining the engineering storage capacity of CO2 dissolution mineralization in horizontal wells in basalt formations. The system provided in the embodiments of the present application will be introduced from the perspective of functional modularization. Figure 8 A structural diagram of a system for determining engineering storage capacity for CO2 dissolution mineralization in horizontal wells in basalt formations provided in an embodiment of the present application.

[0107] The system comprises:

[0108] An acquisition unit is used to acquire a borehole wall image of an observation well, a basalt pore characteristic image of a drill core in the observation well, a scanned image of a core sample in the observation well, and a vertical distance between a CO2 solution in a horizontal well and the horizontal well; an observation well is a well vertically drilled into a basalt formation, and is used to observe the dissolution process of a CO2 solution and changes in the groundwater environment; a horizontal well is a well extending horizontally along a basalt formation, and a CO2 solution is uniformly injected into the basalt formation through the horizontal well;

[0109] The first determination unit is used to determine the porosity and porosity in the vertical direction of the observation well based on the borehole wall image of the observation well; determine the porosity in the vertical direction based on the basalt pore characteristic image of the drilling core in the observation well; determine the mineralization carbon fixation coefficient based on the scanning image of the core sample in the observation well; and calculate the reservoir volume within the influence range of the CO2 solution injection in the horizontal well based on the vertical distance;

[0110] The second determination unit is used to determine the actual storage capacity of the shallow basalt horizontal well based on the porosity and porosity in the vertical direction of the observation well, the porosity in the vertical direction, the mineralization carbon fixation coefficient and the reservoir volume.

[0111] The embodiments of the present application also provide corresponding devices and computer storage media for implementing the solutions provided by the embodiments of the present application.

[0112] The device includes a memory and a processor, the memory is used to store instructions or codes, and the processor is used to execute the instructions or codes so that the device executes the method described in any embodiment of the present application.

[0113] The computer storage medium stores codes, and when the codes are executed, a device executing the codes implements the test method described in any embodiment of the present application.

[0114] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the system or device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0115] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0116] It should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0117] It should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0118] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0119] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0120] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for determining the engineering storage capacity of CO2 dissolution mineralization in horizontal wells in basalt formations, characterized in that: include: Obtain the borehole wall image of the observation well, the basalt pore characteristic image of the drill core in the observation well, the scanned image of the core sample in the observation well, and the vertical distance of the CO2 solution in the horizontal well from the horizontal well. The observation well is a well drilled vertically into the basalt formation, which is used to observe the dissolution process of the CO2 solution and the changes in the groundwater environment. The horizontal well is a well extending horizontally along the basalt formation, and the CO2 solution is uniformly injected into the basalt formation through the horizontal well. Based on the pore wall image of the observation well, determine the porosity and porosity in the vertical direction of the observation well; based on the basalt pore characteristic image of the drilling core in the observation well, determine the porosity in the vertical direction; Based on the scanned image of the core sample in the observation well, the mineralization carbon fixation coefficient is determined; based on the vertical distance, the reservoir volume within the impact range of the CO2 solution injection in the horizontal well is calculated; Based on the porosity and porosity in the vertical direction of the observation well, the porosity in the vertical direction, the mineralization carbon fixation coefficient and the reservoir volume, the actual storage capacity of the shallow basalt horizontal well is determined.

2. The method according to claim 1, characterized in that The step of obtaining the borehole wall image of the observation well comprises: A panoramic image of the observation well is taken based on a panoramic borehole imager and a panoramic imaging probe to obtain a borehole wall image of the observation well.

3. The method according to claim 1, characterized in that The method of determining the porosity ratio and porosity in the vertical direction of the observation well based on the borehole wall image of the observation well comprises: Performing image threshold segmentation on the pore wall image to obtain a pore threshold image and a matrix threshold image; Determining the pore area and the basalt matrix area in the pore wall image based on the pore threshold image and the matrix threshold image; Based on the pore area and the basalt matrix area in the hole wall image, the porosity ratio and porosity in the vertical direction of the observation well are determined.

4. The method according to claim 1, characterized in that: Methods for obtaining images of basalt pore characteristics from drill cores in observation wells include: The drill core obtained by drilling is scanned by X-ray CT to obtain the basalt pore characteristic images of the longitudinal and transverse sections respectively.

5. The method according to claim 1, characterized in that The method of determining the porosity in the vertical direction based on the basalt pore characteristic image of the drilling core in the observation well includes: Determine the pore characteristic area based on the basalt pore characteristic image of the longitudinal slice and the basalt pore characteristic image of the transverse slice; Based on the pore characteristic area and the pore characteristic image area of ​​the longitudinally sliced ​​basalt, the porosity in the vertical direction is calculated.

6. The method according to claim 5, characterized in that The actual storage capacity of the shallow basalt horizontal well is determined based on the porosity ratio and porosity in the vertical direction of the observation well, the porosity in the vertical direction, the mineralization carbon fixation coefficient and the reservoir volume, including: The porosity in the vertical direction and the average porosity in the vertical direction are calculated to obtain the actual porosity of the basalt reservoir; The actual storage capacity of the shallow basalt horizontal well is determined based on the actual porosity of the basalt reservoir, the porosity ratio in the vertical direction of the observation well, the mineralization carbon fixation coefficient and the reservoir volume.

7. The method according to claim 1, characterized in that The scanning image of the core sample in the observation well is obtained by: The core samples drilled from the observation well are crushed to obtain core samples in powder particle size form; Scan the core sample in powder particle form to obtain a microscopic scanning image of the core sample.

8. The method according to claim 1, characterized in that The method of determining the mineralization carbon fixation coefficient based on the scanning image of the core sample in the observation well includes: Identifying basalt matrix image features and quartz mineral image features in the scanned image, and determining basalt matrix image feature areas and quartz mineral image feature areas in the scanned image; Based on the characteristic area of ​​basalt matrix image and quartz mineral image, the mineralization carbon fixation coefficient of basalt reservoir matrix was calculated.

9. The method according to claim 1, characterized in that: The reservoir volume of the horizontal well CO2 solution injection impact range calculated based on the vertical distance includes: Get the length of the horizontal well; According to the length of the horizontal well, the vertical distance between the CO2 solution and the upper side of the horizontal well, and the vertical distance between the CO2 solution and the lower side of the horizontal well, the reservoir volume within the influence range of the CO2 solution injection in the horizontal well is calculated.

10. The method according to claim 1, characterized in that The actual storage capacity of the shallow basalt horizontal well is determined based on the porosity and porosity in the vertical direction of the observation well, the porosity in the vertical direction, the mineralization carbon fixation coefficient and the reservoir volume, including: Based on the porosity ratio and porosity in the vertical direction of the logging, the porosity in the vertical direction, the mineralization carbon fixation coefficient and the reservoir volume, the total storage capacity of the CO2 solution in the horizontal well is calculated; The ratio of the total storage capacity of the CO2 solution in the horizontal well to the amount of water required to dissolve one ton of CO2 solution is calculated to obtain the actual storage capacity of the CO2 solution in the horizontal well.

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