Quantitative calculation method and device suitable for total resource quantity of trace elements in gas field water of water-driven gas reservoir

Abstract

The invention relates to the technical field of oil-gas field development, and discloses a quantitative calculation method and device suitable for the total trace element resource quantity of gas field water of a water-driven gas reservoir, and the method comprises the steps: firstly, quantitatively calculating the water body reserves of the gas field water according to the water body type of the gas reservoir; then calculating the average content of the trace elements in the gas field water by adopting a well point area weighing method, a mineralization degree constraint weighing method and an isoline area weighing method respectively, and determining the optimal value of the average content of the trace elements in the gas field water in the three calculation results; and finally, based on the water body reserves of the gas field water and the optimal average content of the trace elements, the total resource quantity of the trace elements in the gas field water is obtained through quantitative calculation. According to the method, the available value of the trace elements in the gas field water is quantitatively calculated, the total resource scale of the trace elements in the gas field water is quantitatively evaluated, and certain guiding significance is provided for new energy utilization of developed gas field gas reservoirs in the later period.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field development, and in particular to a quantitative calculation method and device for the total resource amount of water trace elements in a water-driven gas reservoir. Background Art

[0002] At present, there are two common methods for treating gas field water. One is to inject it back into the ground through reinjection wells, and the other is to treat it through ground treatment devices and then discharge it to meet the standards. With the rapid development of the domestic new energy industry in recent years, the demand for lithium-ion batteries and bromine has continued to increase. Therefore, extracting lithium and bromine resources from gas field water and salt lake brine has become a new technological development trend. The pilot test of lithium extraction from gas field water in the Longwangmiao Formation of the Southwest Oil and Gas Field has achieved a breakthrough, realizing the first extraction of lithium from gas field water. More importantly, it has confirmed the feasibility of the lithium extraction process from gas field water of "pretreatment + lithium extraction cabin", which points out the direction for the extraction of lithium resources from gas field water in the industry.

[0003] The article "Comprehensive Potential Analysis and Development Suggestions for the Late Development of Old Gas Fields in the Sichuan Basin" proposed by Hu Hao, Zhou Hong, Long Hui and others analyzes the feasibility of the utilization of new energy sources for gas field water from the perspective of comprehensive utilization of gas reservoirs, including helium extraction, lithium extraction and bromine extraction, and ultimately improves the comprehensive benefits of gas reservoirs. The article "Distribution Characteristics of Lithium in Different Geological Environments and Ecological, Environmental and Biological Health Effects" proposed by Yu Yang, Wang Denghong, Wang Wei and others analyzes the content of lithium resources in different environments and clarifies the differences in lithium content in gas field water and geothermal water. Furthermore, the article "Research on the Process Technology of Lithium Extraction from Underground Brine" proposed by Wang Huan mainly demonstrates the process measures for extracting lithium and bromine from a process perspective. However, there are few articles in the industry that quantitatively calculate trace elements such as lithium and bromine in gas field water. Summary of the invention

[0004] In order to solve the problems and shortcomings existing in the above-mentioned prior art, the present invention proposes a method and device for quantitatively calculating the total resource amount of trace elements in water of water-driven gas reservoirs and gas fields. The method is based on the idea of ​​comprehensive geological analysis and innovatively uses multiple methods to quantitatively calculate the scale of trace elements such as lithium and bromine in water of gas reservoirs and gas fields, thereby providing certain guiding significance for gas field water treatment and comprehensive utilization of resources in developed gas fields.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0006] A quantitative calculation method for the total amount of trace elements in water in a gas field of a water-driven gas reservoir, the method mainly comprising the following steps:

[0007] Determine the water body type and quantitatively calculate the water reserves of gas field water according to the water body type;

[0008] The average content of trace elements in gas field water is calculated by using the well point area trade-off method, the mineralization constraint trade-off method and the contour area trade-off method, and the optimal value of the average content of trace elements in gas field water is determined based on the calculation results.

[0009] Based on the quantitatively calculated gas field water volume and the optimal value of the average content of trace elements, the total resources of trace elements in the gas field water are finally obtained by quantitative calculation.

[0010] Preferably, in the present invention, the determining of the water body type and the quantitative calculation of the water body reserve according to the water body type include:

[0011] If the water body type is bottom water, the bottom area, top area, bottom elevation and gas bottom elevation of the water body are obtained based on the contour plane formed by the single well structural data. At the same time, the water body porosity is obtained based on the logging interpretation data of the single well drilling water body, and the water body reserves are quantitatively calculated using formula (1):

[0012]

[0013] Among them, V1 is the water storage; S w is the bottom area of ​​the water body; S g is the top boundary area of ​​the water body; H wg is the water body altitude; H g is the air base altitude; Φ w is the porosity of the water body;

[0014] If the water body type is edge water, the gas layer radius, edge water distribution distance, gas cap altitude, gas bottom altitude and edge water bottom elevation are obtained based on the contour plane map formed by the single well structural data. At the same time, the water body porosity is obtained based on the logging interpretation data of the single well drilling water body. The edge water body reserves are quantitatively calculated using formula (2):

[0015] V2=(π×(R1+R2) 2 ×(H3-H g )-π×R1 2 ×(H g -H1))×Φ w Formula (2);

[0016] Among them, R1 is the radius of the gas layer; R2 is the edge water distribution distance; H1 is the gas cap altitude; H g is the air bottom altitude; H3 is the water bottom boundary altitude, Φ w is the porosity of the water body.

[0017] Preferably, in the present invention, if the water body type is bottom water and the inclination angle of the target layer is less than 5°, the water body reserve is calculated by formula (3) according to the bottom boundary area of ​​the water body, the thickness of the water layer and the porosity of the water body:

[0018] V1=Sw ×H w ×Φ w Formula (3);

[0019] Among them, H w is the thickness of the water layer.

[0020] Preferably, in the present invention, the sampling well point area trade-off method is used to calculate the average content of trace elements in gas field water, including: obtaining the content of trace elements in gas field water of a single gas well and the well control area of ​​a single well according to the gas well experimental analysis data, and calculating the average content of trace elements in gas field water by formula (4):

[0021]

[0022] in, is the average content of trace elements in the gas reservoir; P i is the trace element content corresponding to the i-th well; A i is the well-controlled area corresponding to the i-th well.

[0023] Preferably, in the present invention, the sampling mineralization constraint trade-off method is used to calculate the average content of trace elements in gas field water, including: obtaining the mineralization of gas field water in a single well according to the single well structure data, and calculating the average content of trace elements in gas field water according to formula (5) based on the calculation result of the well point area trade-off method.

[0024]

[0025] in, is the average content of trace elements in gas reservoirs; P i is the trace element content corresponding to the i-th well; Kd i is the mineralization corresponding to the i-th well; A i is the well-controlled area corresponding to the i-th well.

[0026] Preferably, in the present invention, the sampling contour area trade-off method is used to calculate the average content of trace elements in gas field water, including: based on the contour map of the gas reservoir trace element content distribution plane map, according to the area between different contour lines, the average content of trace elements in gas field water is calculated by formula (6):

[0027]

[0028] Where: is the average content of trace elements in gas reservoirs; P i is the trace element content corresponding to the i-th well; CP i is the trace element content corresponding to the ith contour line; CP i+1 is the trace element content corresponding to the i+1th contour line; A iis the well-controlled area corresponding to the i-th well.

[0029] Preferably, in the present invention, determining the optimal value of the average content of trace elements in gas field water based on the calculation results includes:

[0030] If the relative error of the average content of trace elements in gas field water calculated by the well point area trade-off method, the mineralization constraint trade-off method and the contour area trade-off method does not exceed 30%, the average value of the three methods shall be taken as the optimal value of the average content of trace elements;

[0031] If the relative error of the average content of trace elements in gas field water calculated by the well point area trade-off method, the mineralization constraint trade-off method and the contour area trade-off method exceeds 30%, the minimum value of the three calculation results is taken as the optimal value of the average content of trace elements.

[0032] Based on the same inventive concept, the present invention also proposes a device for quantitatively calculating the total amount of trace elements in water in a water-driven gas reservoir, the device comprising:

[0033] Gas field water body reserve acquisition module, used to determine the water body type and quantitatively calculate the water body reserve of gas field water according to the water body type;

[0034] The module for obtaining the average content of trace elements in gas field water uses the well point area trade-off method, the mineralization constraint trade-off method and the contour area trade-off method to calculate the average content of trace elements in gas field water, and determines the optimal value of the average content of trace elements in gas field water based on the calculation results;

[0035] The module for obtaining the total trace element resources in gas field water is based on the quantitatively calculated water reserves and the optimal value of the average content of trace elements, and finally quantitatively calculates the total trace element resources in gas field water.

[0036] A computer device comprises a memory, a processor and a computer program stored in the memory and executable in the processor. When the processor executes the computer program, the steps of the quantitative calculation method for the total resources of water trace elements in a gas field of a water-driven gas reservoir are implemented.

[0037] A computer-readable storage medium stores a computer program, which, when executed in a computer processor, implements the steps of the above-mentioned method for quantitatively calculating the total resources of trace elements in water in a gas field of a water-driven gas reservoir.

[0038] Beneficial effects of the present invention:

[0039] The present invention adopts multiple methods to quantitatively calculate the overall scale of trace elements in gas field water, so as to obtain the extractable and usable industrial raw materials such as bromine, and realize quantitative evaluation of the usable value of trace elements in gas field water. This method can provide certain technical guidance for the utilization of new energy in developed gas fields and gas reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The foregoing and following detailed description of the present invention will become more apparent when read in conjunction with the following drawings, in which:

[0041] Figure 1 is a flow chart of the method of the present invention;

[0042] Figure 2 It is a structural diagram of the device of the present invention;

[0043] Figure 3 The bottom water distribution diagram of the Sinian gas reservoir in the W gas field in Example 2;

[0044] Figure 4 The well location map of the bromine element well point area weighing of the Sinian gas reservoir in the W gas field in Example 2;

[0045] Figure 5 This is the well location map weighed by the bromine element contour area of ​​the Sinian gas reservoir in the W gas field in Example 2. DETAILED DESCRIPTION

[0046] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions for achieving the purpose of the present invention will be further described below through several specific embodiments. It should be noted that the technical solutions claimed for protection in the present invention include but are not limited to the following embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work shall fall within the scope of protection of the present invention.

[0047] Example 1

[0048] At present, there are two common methods for treating gas field water. One is to inject it back into the ground through reinjection wells, and the other is to treat it through ground treatment devices and then discharge it to meet the standards. With the rapid development of the domestic new energy industry in recent years, the demand for lithium-ion batteries and bromine has continued to increase. Therefore, extracting lithium and bromine resources from gas field water and salt lake brine has become a new technological development trend. The pilot test of lithium extraction from gas field water in the Longwangmiao Formation of the Southwest Oil and Gas Field has achieved a breakthrough, realizing the first extraction of lithium from gas field water. More importantly, it has confirmed the feasibility of the lithium extraction process from gas field water of "pretreatment + lithium extraction cabin", which points out the direction for the extraction of lithium resources from gas field water in the industry.

[0049] The article “Comprehensive Potential Analysis and Development Suggestions for the Late Development of Old Gas Fields in the Sichuan Basin” proposed by Hu Hao, Zhou Hong, Long Hui and others analyzes the feasibility of the utilization of new energy sources for gas field water from the perspective of comprehensive utilization of gas reservoirs, including helium extraction, lithium extraction and bromine extraction, ultimately improving the comprehensive benefits of gas reservoirs. The article “Distribution Characteristics of Lithium in Different Geological Environments and Its Ecological, Environmental and Biological Health Effects” proposed by Yu Yang, Wang Denghong, Wang Wei and others analyzes the content of lithium resources in different environments and clarifies the differences in lithium content in gas field water and geothermal water. Furthermore, the article “Research on the Process Technology for Lithium Extraction from a Certain Underground Brine” proposed by Wang Huan mainly demonstrates the process measures for extracting lithium and bromine from a process perspective. However, there are currently few articles in the industry that conduct quantitative calculations of trace elements such as lithium and bromine in gas field water.

[0050] Based on this, the embodiments of the present invention specifically propose a method and device for quantitatively calculating the total resource amount of trace elements in gas field water suitable for water-driven gas reservoirs. This method is based on the idea of ​​comprehensive geological analysis and innovatively uses multiple methods to quantitatively calculate the scale of trace elements such as lithium and bromine in gas field water of gas reservoirs, thereby providing certain guiding significance for gas field water treatment and comprehensive resource utilization of developed gas fields.

[0051] In order to facilitate the understanding of the technical solution of the present invention, the present invention first introduces and illustrates a quantitative calculation method for the total resources of trace elements in gas field water.

[0052] In this embodiment, it should be noted that the water in the gas reservoir mainly exists in the form of edge water, bottom water, condensate water, etc. The driving mode of the gas reservoir can be divided into two categories: gas drive and water drive. The gas reservoir whose power to flow to the gas well depends on the pressure energy of the gas itself is called gas drive gas reservoir; the gas reservoir whose power depends on the pressure head of edge water or bottom water is called water drive gas reservoir.

[0053] Bottom water is the water body that is retained at the bottom of the gas reservoir and cannot be completely discharged due to the constraints of lithology and structural factors during the gas accumulation process.

[0054] Edge water is groundwater that gathers in the lower part of the oil and gas layer (such as the wing of the anticline) and surrounds the oil and gas from the edge of the oil and gas layer. The oil-water (or gas-water) interface intersects with the top and bottom of the oil and gas layer.

[0055] In this embodiment, it should be noted that trace elements refer to lithium, bromine and other elements contained in the gas reservoir water. When calculating the total resource of elements in the gas reservoir water, the total amount of each trace element is calculated by referring to the following quantitative calculation method.

[0056] Therefore, this embodiment is particularly aimed at water-driven gas reservoirs, and a quantitative calculation method for the total amount of trace elements in water in gas fields suitable for water-driven gas reservoirs is particularly proposed. Figure 1 , this method mainly includes the following steps.

[0057] Step S101: Determine the water body type, and quantitatively calculate the water volume of the gas field water according to the water body type.

[0058] In this embodiment, the top depth of the gas-water interface and the bottom boundary of the water body are based on the single well logging interpretation results. The gas-water top boundary takes the highest value of the gas-water layer elevation of the single well, and the water body bottom boundary takes the lowest value of the gas-water layer elevation of the single well. The gas bottom elevation and the water body bottom elevation are both regarded as a unified interface, that is, the top interface of the water body is a horizontal plane, and the bottom interface is also a horizontal plane. In order to facilitate the quantitative calculation of the water volume and simplify the gas-water distribution model, the specific calculation method is as follows:

[0059] (1) If the water type of the gas reservoir is judged to be bottom water

[0060] ① Considering that the gas-water distribution model is a cone, the gas cap volume and gas-water volume are calculated separately. The difference between the two is the bottom water volume, which is then multiplied by the water porosity to obtain the total water reserves of the gas field water in the gas reservoir. The calculation expression is as follows:

[0061]

[0062] ② Considering special cases, for large-scale wide and gentle anticline bottom water gas reservoirs, when the target layer dip angle is less than 5°, the bottom water body can be regarded as a cylinder to calculate the reserves, then the calculation expression of the water body reserves is as follows:

[0063] V1=S w ×H w ×Φ w Formula (3);

[0064] Where V1 is the water reserve, unit is 10 8 m 3 ; S w is the bottom area of ​​the water body, in m 2 ; S g is the top area of ​​the water body, in m 2 ;H wg is the water body altitude, in m; H g is the altitude of the gas cap, in m; H w is the thickness of the water layer, in m, Φ w is the porosity of water body, in %.

[0065] In this embodiment, the bottom boundary area and bottom boundary elevation of the water body are obtained through the bottom boundary structural plan map of the water body; the top boundary area and gas bottom elevation of the water body are obtained based on the top boundary structural plan map of the water body; the porosity of the water body is obtained based on the logging interpretation data of a single well drilling into the water body.

[0066] In this embodiment, the well logging interpretation data identifies the single well water body, and then the distribution of the single well water body on the structural map is read on the structural map to obtain data such as the water layer thickness and water body area.

[0067] (2) If the water type of the gas reservoir is determined to be edge water

[0068]

[0069] Among them, R1 is the radius of the air layer; R2 is the distance of the edge water distribution; H1 is the altitude of the top boundary of the air layer; H2 is the altitude of the top boundary of the edge water; H3 is the altitude of the bottom boundary of the edge water, Φ w is the porosity of the water body.

[0070] In this embodiment, the gas layer radius, edge water distribution distance and gas bottom altitude are obtained based on the gas layer bottom boundary structural plan map; the gas top altitude is obtained based on the gas layer top boundary altitude structural plan map; the edge water bottom boundary altitude is obtained based on the bottom boundary altitude structural plan map with edge water distribution.

[0071] In this embodiment, the structural map described above is a contour plane map formed by structural data of each single well.

[0072] In this embodiment, it should be noted that water body storage=water body volume×water body porosity.

[0073] In this embodiment, it should also be noted that if two types of water bodies, edge water and bottom water, exist in the gas reservoir at the same time, the water body reserves are the sum of the reserves of the two types of water bodies.

[0074] Step S102. Quantitatively calculate the average content of trace elements in gas reservoir water

[0075] In this embodiment, the average content of trace elements in gas field water is first calculated by the well point area trade-off method, the mineralization constraint trade-off method and the contour area trade-off method, and three calculation results are obtained. Finally, the optimal value of the average content of trace elements in gas field water is determined based on the calculation results of the three algorithms. The specific calculation method is as follows.

[0076] ① Well point area trade-off method

[0077] In order to solve the problem that some wells did not obtain gas field water samples, the well point area trade-off method can better evaluate the uniformity of sample spatial distribution. The average content is calculated by the following calculation expression:

[0078]

[0079] in, is the average content of trace elements in the gas reservoir, in g / L; P i is the trace element content corresponding to the i-th well, in g / L; A i is the well control area corresponding to the ith well, in km 2 .

[0080] In this embodiment, P i It can be obtained through experimental analysis data of a single well; the well control area can be obtained by manual reading and measurement, or the well control area can be automatically generated by existing software, thereby automatically reading the well control area.

[0081] ② Mineralization Constraint Trade-off Method

[0082] Mineralization refers to the total amount of various ions, molecules and compounds contained in groundwater, and is used to characterize the relative content of trace elements such as lithium and bromine in gas field water. In order to further balance the numerical distribution of sample points and accurately evaluate the planar distribution of elements such as lithium and bromine, this calculation process incorporates the mineralization of gas field water in a single well into the formula on the basis of the well point area trade-off, adds a constraint variable, and calculates the average content of lithium, bromine and other elements in the gas reservoir according to formula (5):

[0083]

[0084] in, is the average content of trace elements in gas reservoirs, in g / L; P i is the trace element content corresponding to the i-th well, in g / L; Kd i is the mineralization corresponding to the i-th well, in g / L; A i is the well control area corresponding to the ith well, in km 2 .

[0085] In this embodiment, the mineralization can be obtained through experimental analysis data of a single well.

[0086] ③Contour line area trade-off method

[0087] The contour area trade-off method is based on the contour map of the distribution plane of trace elements such as lithium and bromine. The area between different contour lines is used as the main reference factor for calculating the average content of trace elements. The following formula (6) is used to calculate the average content of trace elements in the entire gas reservoir:

[0088]

[0089] Where: is the average content of trace elements in gas reservoirs, in g / L; P i is the trace element content corresponding to the i-th well, in g / L; CP i is the content of trace elements corresponding to the ith contour line, in g / L; CP i+1 is the trace element content corresponding to the i+1th isoline, in g / L; A i is the well control area corresponding to the ith well, in km 2 .

[0090] ④ Optimization of three methods and determination of results

[0091] According to the calculation results obtained by the above three methods, if the relative error does not exceed 30%, the arithmetic mean of the three is taken as the optimal value of the average content of trace elements; if the relative error exceeds 30%, the minimum value of the three calculation results is taken as the optimal value of the average content of trace elements.

[0092] Step S103: Based on the quantitatively calculated gas field water volume and the optimal value of the average content of trace elements, the total resources of trace elements in the gas field water are finally quantitatively calculated.

[0093] In this embodiment, based on the water reserves calculated in step S101 and the average content of trace elements calculated in step S102, the total content of trace elements in the entire gas reservoir (i.e., the total resources) is obtained, and the calculation expression is as follows:

[0094]

[0095] Where: TP is the total content of trace elements in the gas reservoir, in units of 10,000 tons; V1 is the water reserves, in units of 10 8 m 3 ; is the average content of trace elements in gas reservoirs, in g / L.

[0096] Further, based on the same inventive concept, an embodiment of the present invention also provides a device for quantitatively calculating the total amount of trace elements in water in a water-driven gas reservoir, and the device is used to implement the above-mentioned method for quantitatively calculating the total amount of trace elements, as described in the following embodiments. As used below, the term "unit" or "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable. Refer to the attached manual. Figure 2 Specifically, the device may include: a water reserve acquisition module 201, a gas field water trace element average content meter acquisition module 202 and a gas field water trace element total resource acquisition module 203.

[0097] The structure is described in detail below.

[0098] The gas field water body reserve acquisition module 201 is used to determine the water body type and quantitatively calculate the water body reserve of the gas field water according to the water body type.

[0099] The gas field water trace element average content meter acquisition module 202 uses the well point area trade-off method, the mineralization constraint trade-off method and the contour area trade-off method to calculate the average content of trace elements in the gas field water, and determines the optimal value of the average content of trace elements in the gas field water based on the calculation results of the above three methods.

[0100] The gas field water trace element total resource acquisition module 203 finally quantitatively calculates and obtains the total resource of trace elements in the gas field water based on the quantitatively calculated gas field water body reserves and the optimal value of the average content of trace elements.

[0101] It should be noted that the systems, devices, models or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. For the convenience of description, in this specification, the above devices are described in various units according to their functions. Of course, when implementing the present invention, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0102] Furthermore, in the present specification, adjectives such as first and second may be used merely to distinguish one element or action from another, without necessarily or implying any actual such relationship or order.

[0103] Furthermore, an embodiment of the present invention also provides a computer device, which includes a memory, a processor, and a computer program stored in the memory and executable in the processor. When the processor executes the computer program, the steps of the above-mentioned method for quantitatively calculating the total resources of trace elements in gas field water are implemented.

[0104] Furthermore, an embodiment of the present invention also provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed in a computer processor, the steps of the above-mentioned method for quantitatively calculating the total resources of trace elements in gas field water are implemented.

[0105] Example 2

[0106] This example uses the method of the present invention to demonstrate the entire calculation process of quantitatively calculating the total bromine resources in gas field water.

[0107] The Sinian gas reservoir in the W gas field is a large-scale wide and gentle structural anticline gas reservoir, and the faults in the area are not developed. It is mainly composed of dolomite deposits in the intertidal and subtidal zones of the restricted platform, with a stratum thickness of 500-600m, and the main layer is the second member of the Sinian Dengying Formation. The reservoir lithology is mainly algal dolomite and granular dolomite, with an average porosity of 3.01% and a permeability of 0.03mD, which is a low-porosity and ultra-low permeability reservoir. The gas reservoir is a bottom water gas reservoir with a unified gas-water interface (-2434m). The water properties of the gas field are relatively stable, and the water properties are basically the same. The water body is rich in a variety of associated resources such as lithium, bromine, potassium, and iodine. The content of lithium and bromine resources is high, among which the lithium content is 2-3 times the industrial mining value, and the bromine content is 2-4 times the industrial mining value. The lithium content of a single well is 144.8mg / L, and the bromine content is 48-319mg / L.

[0108] (1) Quantitative calculation of total water reserves in gas reservoirs

[0109] The top boundary of the gas reservoir is calculated based on the structural development characteristics of the water layer, and the water layer formation dip angle is 2.3°, which meets the calculation conditions of formula (3) in the above embodiment 1. Therefore, the above formula (3) is used to calculate the water reserves of the gas reservoir. The top boundary depth of the water body is the gas-water interface interpreted by the well logging of each well in the gas reservoir. The gas-water interface has a uniform altitude of -2434m. The bottom boundary of the water body is controlled by three dry wells outside the gas reservoir. The well logging interpretations of W101, W102 and W103 are all dry wells with altitude values ​​of -2650m. Therefore, the bottom boundary altitude of the water body is determined to be -2650m. The water body thickness is the difference between the bottom boundary of the water body and the top boundary of the water body. The water body reserves refer to the porosity of the gas layer of 3%, and the water body area is the closed area formed by the bottom boundary of the water body (refer to the attached manual). Figure 3 ), the specific calculation result is:

[0110] Water body thickness Hw = -2434-(-2650) = 216m.

[0111] Area formed by the bottom boundary of the water body = 461.76km 2 .

[0112] Water volume V1 = 216 × 461.76 × 1,000,000 × 0.03 = 29.92 × 10 8 m 3 .

[0113] (2) Quantitative calculation of average bromide ion content in gas reservoir water

[0114] ① Well point area trade-off method

[0115] This time, 40 bromine gas wells were sampled, and the samples were mainly concentrated within the gas-water interface. Therefore, the area within the top boundary of the water body was used as the boundary to determine the well point area division area (refer to the attached manual Figure 4 ), the average bromide ion content is calculated according to formula (4) in Example 1, specifically:

[0116]

[0117] Therefore, the average bromine content in the water of the gas reservoir and gas field was calculated by the well point area trade-off method to be 180.78 mg / L.

[0118] ② Mineralization Constraint Trade-off Method

[0119] The mineralization constraint trade-off method is based on the well point area trade-off, and further uses the mineralization of each well as a constraint factor. In the process of bromide ion distribution characteristics, the distribution characteristics are determined according to the trend of ion mineralization distribution as a constraint condition. The average bromide ion content is calculated according to formula (5) in Example 1. The specific calculation process is as follows:

[0120]

[0121] Therefore, the average bromine content in the gas field water was calculated to be 181.36 mg / L using the mineralization constraint trade-off method.

[0122] ③Contour line area trade-off method

[0123] Based on the bromine element data of a single well in the gas reservoir, combined with the structural and reservoir distribution characteristics of the gas reservoir, a bromine element contour map was drawn. Figure 5 It can be seen that the single-well bromine content of the gas field water in the entire gas reservoir is 100-306 mg / L, and the distribution characteristics are relatively stable, generally distributed in 100-180 mg / L, and the value at some well points is above 200 mg / L, which is mainly distributed in the W46 and W108 well areas on the south side and the W24 well area on the north side. Referring to formula (6) in Example 1, the average bromide ion content of the entire gas reservoir is obtained, and the specific calculation results are as follows:

[0124]

[0125] Therefore, the average bromine content in the water of the gas reservoir and gas field was calculated to be 183.05 mg / L using the contour area trade-off method.

[0126] According to the three calculation methods, the average bromine content calculated by the well point area trade-off method is 180.78 mg / L, the average bromine content calculated by the mineralization constraint trade-off method is 181.36 mg / L, and the average bromine content calculated by the contour area trade-off method is 183.05 mg / L. The bromine sampling wells in this gas reservoir are distributed relatively evenly, and the distribution of bromide ions in the gas field water is relatively evenly distributed. The values ​​calculated by the three methods are not much different, and the relative error is less than 30%. Therefore, the arithmetic mean of the three methods is used as the final average bromine content in the water of the Sinian gas reservoir in the W gas field, which is 181.73 mg / L.

[0127] (3) Quantitative calculation of the total bromine resources in gas reservoir water

[0128] Based on the calculated water reserves and the average content of bromine in the gas field water, the total content of bromine in the gas field water of the entire gas reservoir is estimated to be 543,700 tons according to formula (7) in Example 1. The specific calculation process is as follows:

[0129]

[0130] The above description is only a preferred embodiment of the present invention and does not constitute any form of hindrance to the present invention. Any simple modification or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A quantitative calculation method for the total resources of trace elements in water in a water-driven gas reservoir, characterized in that: The following steps are involved: Determine the water body type and quantitatively calculate the water reserves of gas field water according to the water body type; The average content of trace elements in gas field water is calculated by using the well point area trade-off method, the mineralization constraint trade-off method and the contour area trade-off method, and the optimal value of the average content of trace elements in gas field water is determined based on the calculation results. Based on the quantitatively calculated gas field water volume and the optimal value of the average content of trace elements, the total resources of trace elements in the gas field water are finally obtained by quantitative calculation.

2. The quantitative calculation method for the total amount of trace elements in water in a water-driven gas reservoir according to claim 1 is characterized in that: The determining of the water body type and the quantitative calculation of the water body reserves according to the water body type include: If the water body type is bottom water, the bottom area, top area, bottom elevation and gas bottom elevation of the water body are obtained based on the contour plane formed by the single well structural data. At the same time, the water body porosity is obtained based on the logging interpretation data of the single well drilling water body, and the water body reserves are quantitatively calculated using formula (1): Among them, V1 is the water storage; S w is the bottom area of ​​the water body; S g is the top boundary area of ​​the water body; H wg is the water body altitude; H g is the air base altitude; Φ w is the porosity of the water body; If the water body type is edge water, the gas layer radius, edge water distribution distance, gas cap altitude, gas bottom altitude and edge water bottom elevation are obtained based on the contour plane map formed by the single well structural data. At the same time, the water body porosity is obtained based on the logging interpretation data of the single well drilling water body. The edge water body reserves are quantitatively calculated using formula (2): V2=(π×(R1+R2) 2 ×(H3-H g )-π×R1 2 ×(H g -H1))×Φ w Formula (2); Among them, R1 is the radius of the gas layer; R2 is the edge water distribution distance; H1 is the gas cap altitude; H g is the air bottom altitude; H3 is the water bottom boundary altitude, Φ w is the porosity of the water body.

3. The quantitative calculation method for the total amount of trace elements in water in a water-driven gas reservoir according to claim 2 is characterized in that: If the water body type is bottom water and the target layer has an inclination angle of less than 5°, the water body reserves are calculated using formula (3) based on the bottom boundary area of ​​the water body, the thickness of the water layer and the porosity of the water body: V1=S w ×H w ×Φ w Formula (3); Among them, H w is the thickness of the water layer.

4. The quantitative calculation method for the total amount of trace elements in water in a water-driven gas reservoir according to claim 1 is characterized in that: The sampling well point area trade-off method is used to calculate the average content of trace elements in gas field water, including: obtaining the content of trace elements in gas field water of a single gas well and the well control area of ​​a single well according to gas well experimental analysis data, and calculating the average content of trace elements in gas field water by formula (4): in, is the average content of trace elements in the gas reservoir; P i is the trace element content corresponding to the i-th well; A i is the well-controlled area corresponding to the i-th well.

5. The quantitative calculation method for the total resources of water trace elements in a water-driven gas reservoir according to claim 1 is characterized in that: The sampling mineralization constraint trade-off method is used to calculate the average content of trace elements in gas field water, including: obtaining the mineralization of gas field water in a single well according to the single well structure data, and calculating the average content of trace elements in gas field water according to formula (5) based on the calculation result of the well point area trade-off method. in, is the average content of trace elements in gas reservoirs; P i is the trace element content corresponding to the i-th well; Kd i is the mineralization corresponding to the i-th well; A i is the well-controlled area corresponding to the i-th well.

6. The quantitative calculation method for the total amount of trace elements in water in a water-driven gas reservoir according to claim 1, characterized in that: The sampling contour area trade-off method for calculating the average content of trace elements in gas field water includes: based on the contour map of the gas reservoir trace element content distribution plane map, according to the area between different contour lines, the average content of trace elements in gas field water is calculated by formula (6): Where: is the average content of trace elements in gas reservoirs; P i is the trace element content corresponding to the i-th well; CP i is the trace element content corresponding to the ith contour line; CP i+1 is the content of trace elements corresponding to the i+1th contour line; A i is the well-controlled area corresponding to the i-th well.

7. The quantitative calculation method for the total resources of trace elements in water in a water-driven gas reservoir according to claim 1 is characterized in that: Based on the calculation results, the optimal value of the average content of trace elements in gas field water is determined, including: If the relative error of the average content of trace elements in gas field water calculated by the well point area trade-off method, the mineralization constraint trade-off method and the contour area trade-off method does not exceed 30%, the average value of the three methods shall be taken as the optimal value of the average content of trace elements; If the relative error of the average content of trace elements in gas field water calculated by the well point area trade-off method, the mineralization constraint trade-off method and the contour area trade-off method exceeds 30%, the minimum value of the three calculation results is taken as the optimal value of the average content of trace elements.

8. Applicable to the quantitative calculation device of the total resources of water trace elements in water-driven gas reservoirs and gas fields, characterized in that: include: Gas field water body reserve acquisition module, used to determine the water body type and quantitatively calculate the water body reserve of gas field water according to the water body type; The module for obtaining the average content of trace elements in gas field water uses the well point area trade-off method, the mineralization constraint trade-off method and the contour area trade-off method to calculate the average content of trace elements in gas field water, and determines the optimal value of the average content of trace elements in gas field water based on the calculation results; The module for obtaining the total trace element resources in gas field water is based on the quantitatively calculated water reserves and the optimal value of the average content of trace elements, and finally quantitatively calculates the total trace element resources in gas field water.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable in the processor, characterized in that: When the processor executes the computer program, the method steps described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed in a computer processor, the method according to any one of claims 1 to 7 is implemented.

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