Earth surface geochemical identification method and system for geothermal resource water supply fracture

Abstract

The invention provides an earth surface geochemical identification method and system for water supply fracture of geothermal resources. The method comprises the following steps: preferably selecting a plurality of inorganic salt chemical identification indexes according to water supply principles and water transmission characteristics of different geothermal systems; determining a matched sampling net degree to collect a sample according to a required exploratory area range; the sample is processed according to a set rule, and content values of different indexes in the sample are measured; on the basis, the water supply fracture and the water transmission direction are identified according to the types of the chemical identification indexes and the corresponding numerical value distribution condition; and calculating a temperature evaluation score of geothermal water supply fracture based on the chemical identification index, and carrying out heat storage grade division. By adopting the scheme, the problem that the water supply fracture cannot be identified by the existing geochemical exploration technology is solved, the water supply fracture, the water guide fracture, the water transmission channel and the water transmission direction are accurately identified by preferably setting the machine salt indexes and the combination distribution thereof, the operation is simple and clear, and the practicability is good.

Description

Technical Field

[0001] The present invention relates to the technical field of geothermal resource surface geochemical exploration, and in particular to a method and system for surface geochemical identification of geothermal resource water supply faults. Background Art

[0002] Geothermal resources are generally concentrated along the edges of tectonic plates, with heat sources mainly from deep earth conduction and heat generated by radioactive substances in the earth's crust. Geothermal resources consist of four elements: "source, connection, cover, and storage". "Source" refers to the heat source, "connection" refers to the channel connecting the heat source. For hydrothermal heat storage, "connection" also refers to the water supply channel, "cover" refers to the cover layer of the heat storage, and "storage" refers to the heat storage.

[0003] Among the existing geothermal resource surface geochemical exploration technologies, gas, element, and microbial geochemical exploration technologies are generally used. The main goal is to find "reservoir" elements and to explore and analyze the geothermal resources of existing strata. In terms of hydrochemical research, the main comparison is the content of geothermal water and surface water components, and the hydrogen and oxygen isotope composition to determine the source of geothermal water and estimate the temperature of the heat reservoir. The identification and evaluation of the "source, connection, and cover" elements mainly rely on the results of seismic data, geophysical exploration, and geological research. That is, surface geochemical exploration technology cannot identify and evaluate the water supply fractures, water conduction fractures, water transmission channels, and water transmission directions of geothermal resources.

[0004] The information disclosed in the background technology section of the present invention is only intended to deepen the understanding of the general background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art known to those skilled in the art. Summary of the invention

[0005] To solve the above problems, the present invention provides a surface geochemical identification method for geothermal resource water supply fractures, including an index optimization link, a sample collection link, a sample index determination link, a water supply fracture identification link, and a thermal reservoir temperature evaluation link. The present invention optimizes Na, K, Ca, etc. and their combined indicators to identify water supply fractures, water conduction fractures, water transmission channels, water transmission directions, and evaluate thermal reservoir temperatures. The operation is simple and reliable. Preferably, in one embodiment, the method includes:

[0006] Indicator optimization setting steps: According to the water supply principle and water transmission characteristics of different geothermal systems, multiple indicators that can identify geothermal water supply fractures and water transmission directions are selected as water supply fracture chemical identification indicators;

[0007] Sample collection steps: determine the matching sampling grid according to the required exploration area range, and then implement the collection operation to obtain samples;

[0008] Indicator determination steps: After processing the sample according to the set rules, the content values ​​of different chemical identification indicators in the sample are determined by using analytical instruments or chemical titration method;

[0009] The water supply break identification step includes identifying the water supply break and the water transmission direction according to the types of chemical identification indicators and the corresponding numerical distribution;

[0010] Thermal storage evaluation steps, calculating the temperature evaluation score of water supply breaks based on chemical identification indicators, and classifying thermal storage levels.

[0011] Preferably, in one embodiment, in the indicator optimization setting step, the soluble inorganic salt ion Na content, K content and Ca content are set as water supply break chemical identification indicators.

[0012] Furthermore, in one embodiment, in the sample collection step, the process of carrying out the collection operation to obtain the sample includes: collecting soil samples after drilling to a set depth range using a matching drilling tool.

[0013] Optionally, in one embodiment, in the indicator determination step, the process of determining the indicator content in the sample includes:

[0014] Take a set amount of soil sample, dry it at a first constant drying temperature, and then grind it;

[0015] After grinding to the set particle size, take out the sample that meets the test requirements and put it into a small paper bag for testing;

[0016] After being dried at a second constant temperature, the mixture is cooled and poured into a plastic tabletting ring, flattened and compacted, and pressed into a flat and smooth round tablet using a press;

[0017] Then, the content of the chemical identification index of the inorganic salt is determined by using an analytical instrument or a chemical titration method. The analytical instrument includes a spectral instrument and an ion chromatograph.

[0018] In actual application, in one embodiment, in the water supply fracture identification step, if it is identified that there is a high-value band of soluble inorganic salt ion indicators that meets the set conditions between the fracture and the heat storage, the indicator distribution positions overlap, and the high-value band starts from the fracture and ends at the heat storage area, then the band is judged to be a water transmission channel, and the current fracture is a water supply fracture.

[0019] Specifically, in an optional embodiment, in the heat storage evaluation step, the temperature evaluation score of the water supply break water transmission channel is calculated according to the following formula:

[0020]

[0021] Where D 通 is the water transmission channel temperature evaluation score, C iare the content values ​​of different indicators of Na, K and Ca, is the regional mean.

[0022] Furthermore, in one embodiment, a comprehensive evaluation score is obtained by calculating and summing multiple indicators of an area that meets the set conditions, and then divided by the number of indicators used to calculate an average of the comprehensive evaluation score, which represents the percentage of enhancement of the ion heat exchange between geothermal hot water and surface water compared with the background area. The thermal reservoir temperature level of the current fault is determined based on this value and the set division rules.

[0023] On the other hand, in a preferred embodiment, the water supply break identification step further includes:

[0024] Based on the values ​​of each chemical identification index, contour maps are drawn for the corresponding areas. The distribution characteristics of the chemical identification indexes in the corresponding areas are identified according to the contour maps, and then the fracture type is determined.

[0025] Based on other aspects of the method described in any one or more of the above embodiments, the present invention further provides a storage medium storing program codes that can implement the method described in any one or more of the above embodiments.

[0026] Based on the application aspects of the method described in any one or more of the above embodiments, the present invention also provides a surface geochemical identification system for geothermal resource water supply fractures, which executes the method described in any one or more of the above embodiments.

[0027] Compared with the closest prior art, the present invention also has the following beneficial effects:

[0028] The present invention provides a surface geochemical identification method and system for geothermal resource water supply fractures. The method selects multiple chemical identification indicators according to the water supply principles and water transmission characteristics of different geothermal systems; comprehensively considers the water supply principles and water transmission characteristics of different geothermal systems to select multiple inorganic salt ion distribution values ​​that can effectively identify geothermal water supply fractures and water transmission directions as chemical identification indicators, thereby fundamentally ensuring the accuracy of fracture measurement and identification;

[0029] Determine the matching sampling grid according to the required exploration area range, and then implement the collection operation to obtain samples; adopt the grid dynamically matching the exploration area range to implement the sample collection operation, and improve the collection efficiency without affecting the accuracy of sample collection;

[0030] After processing the sample according to the set rules, the content values ​​of different chemical identification indicators in the sample are determined by analytical instruments (spectroscopic instruments, ion chromatographs, etc.) or chemical titration methods; before determining the indicator data value, the sample is first processed to a state that meets the measurement requirements, which helps to maintain the authenticity and reliability of the measurement data, provide accurate data support, and provide a reliable basis for subsequent judgment and calculation;

[0031] The steps of identifying water supply breaks are as follows: identifying water supply breaks and water transmission directions according to the types of chemical identification indicators and the corresponding numerical distributions; further calculating the temperature evaluation score of the water supply breaks based on the chemical identification indicators, and dividing the heat storage levels; adopting this scheme, inorganic salt ions such as Na, K, Ca and their combined indicators are optimized to identify water supply breaks, water conducting breaks, water transmission channels, water transmission directions, and evaluate the heat storage temperature, with higher identification efficiency and accuracy.

[0032] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0034] Figure 1 It is a schematic flow chart of a surface geochemical identification method of a geothermal resource water supply fault provided by an embodiment of the present invention;

[0035] Figure 2 This is an example of a contour map of chemical identification indicators in the exploration area of ​​Implementation Case 1 in the surface geochemical identification method for geothermal resource water supply fractures provided in an embodiment of the present invention;

[0036] Figure 3 This is an example of a contour map of chemical identification indicators in the exploration area of ​​Implementation Case 2 in the surface geochemical identification method for geothermal resource water supply fractures provided in an embodiment of the present invention;

[0037] Figure 4 It is a schematic structural diagram of a surface geochemical identification system for geothermal resource water supply fractures provided in another embodiment of the present invention. DETAILED DESCRIPTION

[0038] The following will describe the implementation methods of the present invention in detail in conjunction with the accompanying drawings and embodiments, so that the implementers of the present invention can fully understand how the present invention applies technical means to solve technical problems and achieve the implementation process of technical effects and implement the present invention specifically according to the above implementation process. It should be noted that as long as there is no conflict, the various embodiments and various features of the embodiments in the present invention can be combined with each other, and the technical solutions formed are all within the protection scope of the present invention.

[0039] Although the flowcharts describe the operations as sequential processes, many of the operations may be performed in parallel, concurrently, or simultaneously. The order of the operations may be rearranged. A process may be terminated when its operations are completed, but may also have additional steps not included in the accompanying drawings. A process may correspond to a method, function, procedure, subroutine, subprogram, etc.

[0040] Computer devices include user devices and network devices. Among them, user devices or clients include but are not limited to computers, smart phones, PDAs, etc.; network devices include but are not limited to a single network server, a server group consisting of multiple network servers, or a cloud composed of a large number of computers or network servers based on cloud computing. Computer devices can be operated alone to implement the present invention, or they can be connected to the network and implement the present invention through interactive operations with other computer devices in the network. The network where the computer device is located includes but is not limited to the Internet, wide area network, metropolitan area network, local area network, VPN network, etc.

[0041] The terms "first", "second", etc. may be used herein to describe various units, but these units should not be limited by these terms, and these terms are used only to distinguish one unit from another unit. The term "and / or" used herein includes any and all combinations of one or more of the listed associated items. When a unit is referred to as being "connected" or "coupled" to another unit, it can be directly connected or coupled to the other unit, or there can be intermediate units.

[0042] The terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "one", "one" and "item" used herein are also intended to include plural numbers. It should also be understood that the terms "include" and / or "comprise" used herein specify the existence of stated features, integers, steps, operations, units and / or components, without excluding the existence or addition of one or more other features, integers, steps, operations, units, components and / or combinations thereof.

[0043] Geothermal resources are generally concentrated along the edges of tectonic plates, with heat sources mainly from deep earth conduction and heat generated by radioactive substances in the earth's crust. Geothermal resources consist of four elements: "source, connection, cover, and storage". "Source" refers to the heat source, "connection" refers to the channel connecting the heat source. For hydrothermal heat storage, "connection" also refers to the water supply channel, "cover" refers to the cover layer of the heat storage, and "storage" refers to the heat storage.

[0044] Among the existing geothermal resource surface geochemical exploration technologies, gas, element, and microbial geochemical exploration technologies are generally used. The main goal is to find "reservoir" elements and to explore and analyze the geothermal resources of existing strata. In terms of hydrochemical research, the main comparison is the content of geothermal water and surface water components, and the hydrogen and oxygen isotope composition to determine the source of geothermal water and estimate the temperature of the heat reservoir. The identification and evaluation of the "source, connection, and cover" elements mainly rely on the results of seismic data, geophysical exploration, and geological research. That is, surface geochemical exploration technology cannot identify and evaluate the water supply fractures, water conduction fractures, water transmission channels, and water transmission directions of geothermal resources.

[0045] In order to solve the above problems, the present invention provides a surface geochemical identification method and system for geothermal resource water supply fractures. The researchers of the present invention consider that the surface geochemical exploration technology mainly relies on earthquake, geophysical and geological results, and cannot identify and evaluate the water supply fractures, water conducting fractures, water transmission channels and water transmission directions of geothermal resources. Based on this, the present invention preferably selects soluble inorganic salt ions Na, K, Ca and their combined indicators to identify water supply fractures, water conducting fractures, water transmission channels, water transmission directions, and can evaluate the temperature level of thermal storage.

[0046] In engineering applications, hydrothermal geothermal systems and combined hydrothermal and hot dry rock geothermal systems need to be supplied with water through water-conducting fractures. The water transmission channel is the connecting channel between surface water and hydrothermal heat storage. Surface water supply is a slow process. The soluble inorganic salt ions (Na, K, Ca) in hot water will be exchanged with surface water through the water transmission channel and migrate to the surface, forming high-value anomalies. Based on this, the present invention establishes a reliable identification method for water supply fractures and water transmission directions.

[0047] Next, the detailed process of the method of the embodiment of the present invention is described in detail based on the accompanying drawings. The steps shown in the flowchart of the accompanying drawings can be executed in a computer system including a set of computer executable instructions. Although the logical order of each step is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0048] Embodiment 1

[0049] Figure 1 A schematic diagram showing a flow chart of a method for identifying a geothermal resource water supply fault according to a first embodiment of the present invention is shown. Figure 1It can be seen that the method includes the following steps.

[0050] Indicator optimization setting steps: According to the water supply principle and water transmission characteristics of different geothermal systems, multiple indicators that can identify geothermal water supply fractures and water transmission directions are selected as water supply fracture chemical identification indicators;

[0051] Sample collection steps: determine the matching sampling grid according to the required exploration area range, and then implement the collection operation to obtain samples;

[0052] Indicator determination steps: After processing the sample according to the set rules, the values ​​of different chemical identification indicators in the sample are determined by analytical instruments or chemical titration;

[0053] The water supply break identification step includes identifying the water supply break and the water transmission direction according to the types of chemical identification indicators and the corresponding numerical distribution;

[0054] Thermal storage evaluation steps, calculating the temperature evaluation score of water supply breaks based on chemical identification indicators, and classifying thermal storage levels.

[0055] The scheme of the above-mentioned embodiments of the present invention optimizes the Na, K, and Ca inorganic salt ion indicators, establishes a "high sodium, high potassium, and high calcium" water transmission channel identification mode, and then identifies water supply fractures, water conducting fractures, water transmission channels, and water transmission directions, and has achieved good application effects in different exploration areas.

[0056] Specifically, considering that hydrothermal and combined hydrothermal and hot dry rock geothermal systems require water supply, it is difficult to supply surface water directly without faults leading to underground strata. Water supply through water supply faults is required to form hydrothermal heat storage. The process of surface water supply through water transmission channels is a slow process. The soluble inorganic salt ions (Na, K, Ca) in hot water will exchange with surface water through water transmission channels and migrate to the surface, forming high value anomalies.

[0057] Therefore, in an optional embodiment, in the indicator optimization setting step, the soluble inorganic salt ion Na content, K content, and Ca content are set as water supply break chemical identification indicators.

[0058] In actual application, it is necessary to first collect soil samples from the stratum to be tested. In an optional embodiment, in the sample collection step, the process of implementing the collection operation to obtain samples includes: using a matching drill to drill to a set depth range and then collecting soil samples.

[0059] Specifically, the sampling grid can be determined according to the scope of the exploration area, and field sample collection can be implemented. Soil samples are collected after being drilled to a certain depth using tools such as twist drills, preferably at a depth of 0.5-2m.

[0060] Further, an index determination step is performed, and after the sample is processed according to the set rules, the values ​​of different chemical identification indicators in the sample are determined by using a fluorescence spectrometer;

[0061] In some embodiments of the present invention, in the indicator determination step, the soil collected in the field is dried indoors and then crushed to a particle size state that meets the set requirements, and then the content of indicators such as Na, K, and Ca is determined using an X-ray fluorescence spectrometer.

[0062] In practical applications, in an optional embodiment, the process of determining the content of an indicator in a sample in the indicator determination step includes:

[0063] Take a set amount of soil sample, dry it at a first constant drying temperature, and then grind it;

[0064] After grinding to the set particle size, take out the sample that meets the test requirements and put it into a small paper bag for testing;

[0065] After being dried at a second constant temperature, the mixture is cooled and poured into a plastic tabletting ring, flattened and compacted, and pressed into a flat and smooth round tablet using a press;

[0066] Then, the content of chemical identification index of inorganic salt is determined by using analytical instruments (spectrographic instruments, ion chromatograph, etc.) or chemical titration method.

[0067] Next, the water supply break identification step is initiated to identify the water transmission channel and the water supply break, i.e., the corresponding water transmission direction, based on the numerical distribution of chemical identification indicators between the thermal storage and the current break;

[0068] In engineering applications, thermal reservoir identification can be done by geochemical methods or by referring to geological and geophysical results. The geochemical identification method is: if there is a low-value zone of gas indicators such as ethane, propane, and hydrogen in a certain area, the identification standard of this zone is set to be the gas content less than or equal to the mean of the exploration area minus n times the standard deviation (n>0); at the same time, there is a high-value zone of high-content inorganic salt indicators in thermal storage water, and the identification standard of this zone is set to be the inorganic salt content greater than or equal to the mean of the exploration area plus n times the standard deviation (n>0); then it is determined that there is a thermal reservoir in the underlying strata in the overlapping area of ​​the two positions.

[0069] In engineering applications, fault identification can be done by geochemical methods or by referring to geological and geophysical results. The geochemical identification method is: if there is a high-value zone of elemental mercury, combined mercury and other indicators in a certain area, and the identification standard of this zone is set to the indicator content greater than or equal to the mean value of the exploration area plus n times the standard deviation (n>0), then it is determined that there is a fault in the underlying stratum of the high-value zone.

[0070] The geochemical identification method of water supply fracture is as follows: if there is a high-value zone of indicators such as elemental mercury and combined mercury in a certain area, the identification standard of this zone is set as the indicator content is greater than or equal to the mean of the exploration area plus n times the standard deviation (n>0); at the same time, there are high-value zones of indicators such as Na, K, and Ca, and the identification standard of this zone is set as the indicator content is greater than or equal to the mean of the exploration area plus n times the standard deviation (n>0); then the overlapping area of ​​the two positions is determined as the water supply fracture location.

[0071] In actual application, due to the existence of a water transmission channel between the water supply fault and the heat storage, the identification mode of the water transmission channel is "high sodium, high potassium, and high calcium"; the direction of water transmission is from the water supply fault to the heat storage.

[0072] Therefore, in an optional embodiment, if there is a high-value band between the fracture and the heat storage that satisfies the set conditions for the easily soluble inorganic salt ion index, and the high-value band starts from the fracture and ends at the heat storage area, then the band is identified as a water transmission channel, and the fracture can be identified as a water supply fracture. Wherein, the high-value band requires that all the easily soluble inorganic salt ion chemical identification indexes meet their corresponding high-value indexes.

[0073] Furthermore, the present invention can also achieve quantitative evaluation of the thermal energy fracture formation heat storage level, calculate the temperature evaluation score of the water supply fracture based on the chemical identification index through the thermal storage evaluation step, and perform heat storage level classification.

[0074] The higher the heat reservoir temperature, the more inorganic salts are dissolved, the higher the mineralization of the water, the stronger the exchange of soluble inorganic salt ions in hot water with surface water through water transmission channels, and the greater the intensity of high-value anomalies formed after migration to the surface. For surface geochemical anomaly areas, the higher the "high sodium, high potassium, and high calcium", the higher the heat reservoir temperature. Based on this, the degree of high can be quantitatively rated, and the calculation formula is:

[0075]

[0076] Where: D 通 is the water transmission channel temperature evaluation score, C i They are the content values ​​of different indicators such as Na, K, and Ca. is the regional mean. 通 The larger the value, the higher the water transmission channel temperature and the higher the heat storage temperature.

[0077] In practical application, multiple indicators of "high sodium, high potassium, high calcium" can be calculated and summed, and then divided by the number of indicators used to calculate value, It indicates the percentage of the degree of enhancement of the ion heat exchange between geothermal hot water and surface water compared with the background area, and can be used to evaluate the heat reservoir temperature. If it is calibrated with the heat reservoir temperature of a known geothermal field, the heat reservoir temperature of the same geological conditions can be evaluated.

[0078] According to the geothermal resource temperature classification standard of "Geothermal Resource Geological Exploration Specification (GB / T 11615-2010)": high temperature geothermal resources (T≥150℃), medium temperature geothermal resources (90≤T<150℃), low temperature geothermal resources (25≤T<90℃). Thermal reservoir evaluation classification method: The value range of 15-25 is evaluated as a low-temperature geothermal field; The value range of 25-35 is evaluated as medium-temperature geothermal field; A value of 35 points or more is evaluated as a high-temperature geothermal field.

[0079] The present invention provides a surface geochemical identification method for geothermal resource water supply fractures. The method is based on the property that the higher the heat reservoir temperature, the more inorganic salts are dissolved, the higher the mineralization of water, the stronger the exchange effect between the soluble inorganic salt ions in hot water and surface water through water transmission channels, and the greater the intensity of high-value anomalies formed after migrating to the surface. The Na, K, and Ca indicators are optimized, and a "high sodium, high potassium, and high calcium" water transmission channel identification mode is established to further identify water supply fractures, water conducting fractures, water transmission channels, and water transmission directions, and good application effects have been achieved in two exploration areas.

[0080] Embodiment 2

[0081] The surface geochemical identification method of geothermal resource water supply faults provided in an embodiment of the present invention comprises the following steps.

[0082] Indicator optimization setting steps: According to the water supply principle and water transmission characteristics of different geothermal systems, multiple indicators that can identify geothermal water supply fractures and water transmission directions are selected as water supply fracture chemical identification indicators;

[0083] Sample collection steps: determine the matching sampling grid according to the required exploration area range, and then implement the collection operation to obtain samples;

[0084] Indicator determination steps, after processing the sample according to the set rules, the values ​​of different chemical identification indicators in the sample are determined by using a fluorescence spectrometer;

[0085] The water supply break identification step includes identifying the water supply break and the water transmission direction according to the types of chemical identification indicators and the corresponding numerical distribution;

[0086] Thermal storage evaluation steps, calculating the temperature evaluation score of water supply breaks based on chemical identification indicators, and classifying thermal storage levels.

[0087] The steps consistent with the above-mentioned embodiment are not described in detail. In this embodiment, in the water supply break identification step, in order to more intuitively and accurately analyze the distribution of each chemical identification index and obtain a reliable break type identification result, the following steps are also included:

[0088] Based on the values ​​of the chemical identification indicators of Na, K, and Ca, contour maps are drawn for the corresponding areas. The distribution characteristics of the chemical identification indicators in the corresponding areas are identified according to the contour maps, and then the fracture type is determined.

[0089] By adopting the technical means of this embodiment, it is possible to display the indicator values ​​in combination with the terrain layout, allowing technical personnel to more intuitively and concretely analyze the distribution characteristics of the indicators on the terrain, and further improve the practicality and operability of the technical means on the basis of ensuring the recognition accuracy.

[0090] The present invention is further described below in conjunction with examples of implementation. The scope of the present invention is not limited by the examples, but is set forth in the claims.

[0091] Implementation case 1: Taking the geothermal surface geochemical exploration project in the Huangshadong geothermal field exploration area in Huizhou City, Guangdong Province as an example, a geothermal surface geochemical exploration project with an area of ​​216km was implemented in the Huangshadong geothermal field in Huizhou City, Guangdong Province. 2 The sampling and analysis test of the chemical detection network. The coordinates of the four turning points in the work area are (23°14'39.70" North, 114°33'25.86" East), (23°19'20.20" North, 114°38'18.25" East), (23°7'18.17" North, 114°41'11.63" East), (23°11'58.42" North, 114°46'3.95" East), the sampling points are 2km×2km apart, 70 physical points are deployed, and 70 soil samples are collected.

[0092] Sampling method: Use a twist drill to collect soil samples from 1.0-1.5m deep for the determination of the distribution of Na, K, and Ca indicators.

[0093] Determination method of Na, K and Ca indicators: Take 70g (20 mesh) of soil sample and dry it in a constant temperature drying oven below 60℃, then use an agate ball mill to grind the sample to -0.074mm (200 mesh), then take out 5.0g of the test sample, put it into a small paper bag, dry it in a constant temperature drying oven at 105℃ for 2 hours, and put it in a dryer to cool; pour the cooled test sample gently into a plastic tablet ring, flatten it with a sample spoon and slightly compact it, press it into a flat and smooth disc with a press at a pressure of 35 tons, write the sample number on the edge of the plastic ring with a signature pen, and directly determine the content of Na, K and Ca with an X-ray fluorescence spectrometer.

[0094] Select Na, K, Ca indicators to draw contour lines (see attached Figure 2As shown in the figure, it is found that there is a high-value abnormal zone between the SF1, SF2, and SF3 faults and the Huangshadong thermal rich area (in line with the "high sodium, high potassium, high calcium" model). The identification standard of this high-value zone adopts a standard deviation greater than or equal to the regional mean plus 0.25 times, and the position overlap is relatively high. Therefore, it can be judged that the SF1, SF2, and SF3 faults are water supply faults, and the high-value abnormal zone is a water transmission channel. The water transmission direction is from the SF1, SF2, and SF3 faults to the Huangshadong thermal rich area (marked with a blue hollow arrow in the figure). The application results of the present invention are consistent with the existing geothermal geological exploration results, which verifies the effect of the present invention.

[0095] Thermal reservoir evaluation method: The mean values ​​of the indicators in the Huangsha Cave exploration area and the mean values ​​in the hydrothermal transmission channel area were statistically analyzed and compared, and the results are shown in Table 1; the degree of "high sodium, high potassium, and high calcium" was calculated, and the results are shown in Table 2. Although the high value distribution ranges of Na, K, and Ca overlap to a large extent, the high value distribution range of K is larger (see Figure 2 b) If Na and Ca are used to determine the water transport channel area, D K The distortion will be reduced (see Table 2). This embodiment adopts D Na , D Ca To calculate the average value, we get The value is 36.9, which is identified as a medium-temperature geothermal resource. The water temperature of the outcropping Huilin Hot Spring is 93°C, and the bottom temperature of the Huire 1 well in the Huangshadong geothermal field is 128°C at a depth of 3009m. These data support the effectiveness of the method of the present invention.

[0096] Table 1 Comparison of the mean values ​​of indicators in the Huangsha Cave exploration area of ​​Huizhou City, Guangdong Province and the mean values ​​of the abnormal area

[0097] Mean Number of samples Na(%) K(％) Ca(%) Mean value of water transmission channel area 19 0.15 1.88 0.18 Average value of Huangsha Cave Exploration Area 70 0.11 1.82 0.14

[0098] Table 2. Thermal reservoir evaluation score table of Huangsha Cave Exploration Area in Huizhou City, Guangdong Province (%)

[0099]

[0100] Implementation Case 2: Taking the geothermal surface geochemical exploration project in the Shiba Basin exploration area of ​​Huizhou City, Guangdong Province as an example, a geothermal surface geochemical exploration project in the Shiba geothermal field with an area of ​​228km 2 The coordinates of the four turning points of the work area are (23°14'39.70" North, 114°26'55.25" East), (23°34'42.81" North, 114°31'48.49" East), (23°22'38.74" North, 114°34'39.46" East), (23°27'18.81" North, 114°39'32.63" East), the sampling points are 1km×1km apart, 260 profile physical points are deployed, and 260 soil samples are collected.

[0101] The sampling method and sample determination method are the same as those in the above-mentioned implementation case 1.

[0102] Select Na, K, Ca indicators to draw contour lines (see attached Figure 3 As shown in the figure, it was found that there was a high-value anomaly zone between the Heyuan Deep Fault and the Shiba No. 1 thermal-rich area, Shiba No. 2 thermal-rich area, and Shiba No. 3 thermal-rich area (in line with the "high sodium, high potassium, and high calcium" model), and the position overlap was very high. Therefore, it can be judged that the Heyuan Deep Fault is a water supply fault, and the high-value anomaly zone is a water transmission channel. The direction of water transmission is from the Heyuan Deep Fault to the Shiba No. 1 thermal-rich area, Shiba No. 2 thermal-rich area, and Shiba No. 3 thermal-rich area (marked with purple hollow arrows in the figure). There are also high-value anomaly zones between the Shiba No. 2 and Shiba No. 3 heat-rich areas of the Zijin-Boluo fault (in line with the "high sodium, high potassium, high calcium" mode). The high value satisfies the zone greater than or equal to the regional mean plus 0.25 times the standard deviation, and the position overlap is relatively high. It can be judged that the Zijin-Boluo fault is a water supply fault, and the high-value anomaly zone is a water transmission channel. The water transmission direction is from the Zijin-Boluo fault to the Shiba No. 2 and Shiba No. 3 heat-rich areas. The application results of the present invention are consistent with the existing geothermal geological exploration results, verifying the effect of the present invention.

[0103] Thermal reservoir evaluation method: The mean values ​​of the indicators in the Shiba Basin exploration area were statistically analyzed and compared with the mean values ​​in the heat transfer channel area. The results are shown in Table 3. The degree of "high sodium, high potassium and high calcium" was calculated, and the results are shown in Table 4. The value is 36.6, which is identified as a high-temperature geothermal resource. Using the Huire 1 well (depth 3009m, bottom temperature 128°C) in Huangshadong as a calibration, it is predicted that the heat storage temperatures at 3009m in the Shiba No. 1 anomaly area, the Shiba No. 2 anomaly area, and the Shiba No. 3 anomaly area are 156°C respectively, all of which are high-temperature geothermal resources. The application results of the present invention are consistent with the existing geothermal geological exploration results, which verifies the effect of the present invention.

[0104] Table 3 Comparison of the mean values ​​of the exploration area indicators in Shiba Basin, Huizhou City, Guangdong Province and the mean values ​​of the abnormal area

[0105] Mean Number of samples Na(%) K(％) Ca(%) Mean value of water transmission channel area 90 0.15 1.97 0.16 Average value of Shiba Basin exploration area 260 0.10 1.47 0.12

[0106] Table 4 Thermal reservoir evaluation score table of Shiba Basin exploration area in Huizhou City, Guangdong Province (%)

[0107]

[0108] For the above-mentioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the order of the actions described, because according to the present invention, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0109] It should be pointed out that in other embodiments of the present invention, the method can also obtain a new geothermal resource fracture identification method by combining one or several of the above embodiments to achieve accurate identification and research of geothermal resource fracture strata.

[0110] It should be noted that, based on the method in any one or more of the above-mentioned embodiments of the present invention, the present invention also provides a storage medium, on which is stored a program code that can implement the method as described in any one or more of the above-mentioned embodiments, and when the code is executed by the operating system, it can implement the surface geochemical identification method of geothermal resource water supply fracture as described above.

[0111] The above embodiments disclosed in the present invention describe the method in detail. The method of the present invention can be implemented by various devices or systems. Therefore, based on other aspects of the method described in any one or more embodiments, the present invention also provides a surface geochemical identification system for geothermal resource water supply fractures. The system is used to perform the surface geochemical identification method for geothermal resource water supply fractures described in any one or more embodiments. Specific embodiments are given below for detailed description.

[0112] Embodiment 3

[0113] Figure 4 FIG. 4 is a schematic diagram showing the structure of a surface geochemical identification system for geothermal resource water supply faults provided in an embodiment of the present invention. Figure 4 As shown, the system includes:

[0114] An index optimization setting module, which is configured to select multiple indicators capable of identifying geothermal water supply fractures and water transmission directions according to water supply principles and water transmission characteristics of different geothermal systems as water supply fracture chemical identification indicators;

[0115] The sample collection module is configured to determine the matching sampling grid according to the required exploration area range, and then implement the collection operation to obtain samples;

[0116] The index determination module is configured to process the sample according to the set rules and then use an analytical instrument or chemical titration method to determine the content values ​​of different chemical identification indicators in the sample;

[0117] a water supply break identification module configured to identify water supply breaks and water transmission directions based on the types of chemical identification indicators and corresponding numerical distributions;

[0118] The heat storage evaluation module is configured to calculate the temperature evaluation score of the water supply break based on the chemical identification index and to classify the heat storage level.

[0119] Preferably, in one embodiment, the indicator optimization setting module is configured to set the soluble inorganic salt ion Na content, K content, and Ca content as water supply break chemical identification indicators.

[0120] Furthermore, in one embodiment, the sample collection module performs a collection operation to obtain samples according to the following operations: using a matching drilling tool to drill to a set depth range and then collecting soil samples.

[0121] In an optional embodiment, the indicator determination module determines the indicator content value in the sample through the following steps:

[0122] Take a set amount of soil sample, dry it at a first constant drying temperature, and then grind it;

[0123] After grinding to the set particle size, take out the sample that meets the test requirements and put it into a small paper bag for testing;

[0124] After being dried at a second constant temperature, the mixture is cooled and poured into a plastic tabletting ring, flattened and compacted, and pressed into a flat and smooth round tablet using a press;

[0125] Then, the content of chemical identification index of inorganic salt is determined by using analytical instruments (spectrographic instruments, ion chromatograph, etc.) or chemical titration method.

[0126] In actual application, in one embodiment, the water supply fracture identification module is configured as follows: if it is identified that there is a high-value band of soluble inorganic salt ion indicators that meets the set conditions between the fracture and the heat storage, the indicator distribution positions overlap, and the high-value band starts from the fracture and ends at the heat storage area, then the band is judged to be a water transmission channel, and the current fracture is a water supply fracture.

[0127] Furthermore, in a preferred embodiment, the water supply break identification module is further configured as follows:

[0128] Based on the values ​​of each chemical identification index, contour maps are drawn for the corresponding areas. The distribution characteristics of the chemical identification indexes in the corresponding areas are identified according to the contour maps, and then the fracture type is determined.

[0129] Specifically, in an optional embodiment, the thermal storage evaluation module calculates the temperature evaluation score of the water supply failure water transmission channel according to the following formula:

[0130]

[0131] Where D 通 is the water transmission channel temperature evaluation score, C i are the content values ​​of different indicators of Na, K and Ca, is the regional mean.

[0132] Furthermore, in an optional embodiment, the heat reservoir evaluation module is configured to calculate and sum multiple indicators of the area that meets the set conditions to obtain a comprehensive evaluation score, and then divide it by the number of indicators used to calculate a mean of the comprehensive evaluation score, which represents the percentage of the enhancement of the ion heat exchange effect between geothermal hot water and surface water compared to the background area, and determine the heat reservoir temperature level of the current fault based on this value and the set division rules.

[0133] In the surface geochemical identification system for geothermal resource water supply fractures provided by the embodiment of the present invention, each module or unit structure can operate independently or in combination according to actual indicator setting requirements and measurement calculation requirements to achieve corresponding technical effects.

[0134] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should be extended to equivalent substitutions of these features understood by ordinary technicians in the relevant field. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not meant to be limiting.

[0135] The "one embodiment" mentioned in the specification means that a particular feature, structure or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present invention. Therefore, the phrase "one embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0136] Although the embodiments disclosed in the present invention are as above, the above contents are only embodiments adopted for facilitating the understanding of the present invention and are not intended to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A surface geochemical identification method for geothermal resource water supply faults, characterized in that: The method comprises: Indicator optimization setting steps: According to the water supply principle and water transmission characteristics of different geothermal systems, multiple indicators that can identify geothermal water supply fractures and water transmission directions are selected as water supply fracture chemical identification indicators; Sample collection steps: determine the matching sampling grid according to the required exploration area range, and then implement the collection operation to obtain samples; Indicator determination steps: After processing the sample according to the set rules, the content values ​​of different chemical identification indicators in the sample are determined by using analytical instruments or chemical titration method; The water supply break identification step includes identifying the water supply break and the water transmission direction according to the types of chemical identification indicators and the corresponding numerical distribution; Thermal storage evaluation steps, calculating the temperature evaluation score of water supply breaks based on chemical identification indicators, and classifying thermal storage levels.

2. The method according to claim 1, characterized in that In the indicator optimization setting step, the soluble inorganic salt ion Na content, K content, and Ca content are set as water supply break chemical identification indicators.

3. The method according to claim 1, characterized in that: In the sample collection step, the process of implementing the collection operation to obtain samples includes: using a matching drilling tool to drill to a set depth range and then collecting soil samples.

4. The method according to claim 1, characterized in that In the indicator determination step, the process of determining the indicator content in the sample includes: Take a set amount of soil sample, dry it at a first constant drying temperature, and then grind it; After grinding to the set particle size, take out the sample that meets the test requirements and put it into a small paper bag for testing; After being dried at a second constant temperature, the mixture is cooled and poured into a plastic tabletting ring, flattened and compacted, and pressed into a flat and smooth round tablet using a press; Then, the content of the chemical identification index of the inorganic salt is determined by using an analytical instrument or a chemical titration method. The analytical instrument includes a spectral instrument and an ion chromatograph.

5. The method according to claim 1, characterized in that In the water supply fracture identification step, if it is determined that there is a high-value band that meets the set conditions for the soluble inorganic salt ion index between the fracture and the heat reservoir, and there is a high-value band that meets the set conditions between the fracture and the heat reservoir, the basis for the band identification is set to that the index content is greater than or equal to the mean of the exploration area plus n times the standard deviation (n>0), the distribution positions of the indicators overlap, and the high-value band starts from the fracture and ends at the heat storage area, then the band is judged to be a water transmission channel, and the current fracture is a water supply fracture.

6. The method according to claim 1, characterized in that In the thermal storage evaluation step, the temperature evaluation score of the water supply failure water transmission channel is calculated according to the following formula: Where D 通 is the water transmission channel temperature evaluation score, C i are the content values ​​of different indicators of Na, K and Ca, is the regional mean.

7. The method according to claim 1, characterized in that The comprehensive evaluation score is obtained by calculating and summing up multiple indicators in the area that meets the set conditions, and then divided by the number of indicators used to calculate the average comprehensive evaluation score, which represents the percentage of the enhancement of the ion heat exchange between geothermal hot water and surface water compared with the background area. Based on this value and the set division rules, the thermal reservoir temperature level of the current fault is determined.

8. The method according to claim 1, characterized in that The water supply break identification step also includes: Based on the values ​​of each chemical identification index, contour maps are drawn for the corresponding areas. The distribution characteristics of the chemical identification indexes in the corresponding areas are identified according to the contour maps, and then the fracture type is determined.

9. A storage medium, characterized in that: The storage medium stores program codes that can implement the method as claimed in any one of claims 1 to 8.

10. A surface geochemical identification system for geothermal resource water supply faults, characterized in that: The system executes the method according to any one of claims 1 to 8.

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