Shale gas potential prediction method and device

Abstract

The present invention discloses a method and device for predicting shale gas potential, wherein the method comprises: analyzing the composition of the obtained natural gas sample to determine the natural gas composition and the absolute content of the wet gas component; performing isotope analysis on each component of the natural gas to determine the carbon-hydrogen isotope inversion amplitude of methane and ethane; performing non-fractionation enrichment purification treatment and test analysis on the methane in the natural gas to determine the methane cluster isotope; and comprehensively judging the shale gas production area and potential according to the absolute content of the wet gas component, the carbon-hydrogen isotope inversion amplitude and the methane cluster isotope. The present invention is based on the comprehensive analysis and evaluation technology of natural gas, and the analysis object - natural gas is simple and easy to obtain. Through the combination of relatively mature natural gas composition analysis technology, conventional carbon isotope analysis technology, and methane cluster isotope analysis technology, the gas content of shale, the size of production, possible potential, and the judgment of shale gas sweet spot area are predicted with high accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of shale gas exploration and development, and in particular to a shale gas potential prediction method and device. Background Art

[0002] This section is intended to provide a background or context to the embodiments of the invention recited in the claims. No admission is made that the description herein is prior art by inclusion in this section.

[0003] Shale gas is a type of energy with great potential, cleanness and high efficiency, and has developed rapidly in recent years. The geological conditions for the formation of shale gas are complex. The strata that host shale gas range from old (Ordovician) to new (Tertiary), and may have undergone multiple stages of structural changes, resulting in complex and diverse structures and different gas production capacities. The production of shale gas wells in geographically adjacent locations may vary greatly, rapidly transitioning from high-yield wells to non-gas-producing wells. How to accurately predict the production of shale gas wells, gas production cycles, and shale gas sweet spots is of great significance to shale gas exploration and development.

[0004] At present, most research focuses on evaluating the gas content of shale, and there are many related research technologies and methods. For example:

[0005] 1) Formation pressure estimation: if the overpressure is abnormal, it may be a good gas-bearing layer; if the pressure is low, it may be a poor shale gas production area. However, there are many factors affecting the pressure anomaly, and the shale production cannot be directly calibrated, resulting in wells with similar pressure coefficients but significantly different gas production.

[0006] 2) Methods and techniques for directly determining shale gas content using experimental techniques, such as designing various experimental methods and equipment to determine the adsorbed gas content of shale. This method requires core samples, which is cumbersome to operate and limits its use when core samples are not available. In addition, the results obtained can well reflect the adsorbed gas in shale gas, but the free gas determines the shale gas production. This method will lose some free gas, so the evaluation of shale gas production will be distorted to a certain extent.

[0007] 3) By analyzing the geological characteristics of shale gas producing areas, the geological conditions of favorable shale gas sweet spots are summarized and predicted, including shale organic matter abundance, brittle mineral content, structural location, etc., so as to determine whether an area is a possible favorable accumulation area. This method cannot ensure the success rate of prediction, and more importantly, it cannot determine the scale and sustainability of shale gas well production, let alone the problems related to shale gas accumulation.

[0008] 4) There are relatively few studies on the technology for determining the timing and mechanism of shale gas accumulation. Since shale gas is produced from shale itself, it is generally believed to be self-generated and self-reserved. The methods previously used to study oil and gas accumulation in conventional reservoirs, such as fluid inclusions and K-Ar isotope dating of diagenetic minerals, have lost their due role in shale gas research. As a result, it is impossible to answer whether natural gas in this special field and resource type, 'shale gas', has migration. Summary of the invention

[0009] An embodiment of the present invention provides a shale gas potential prediction method, the method comprising:

[0010] Analyze the composition of the obtained natural gas samples to determine the composition of the natural gas and the absolute content of the wet gas component;

[0011] Conduct isotope analysis on each component of natural gas to determine the carbon and hydrogen isotope inversion amplitude of methane and ethane;

[0012] Carry out non-fractionation enrichment, purification, testing and analysis of methane in natural gas to determine methane cluster isotopes;

[0013] Based on the absolute content of wet gas components, the inversion amplitude of carbon and hydrogen isotopes and methane cluster isotopes, a comprehensive judgment is made on the shale gas production area and its potential.

[0014] The embodiment of the present invention further provides a shale gas potential prediction device, the device comprising:

[0015] The natural gas composition analysis module is used to analyze the composition of the acquired natural gas samples and determine the natural gas composition and the absolute content of the moisture component;

[0016] The carbon and hydrogen isotope inversion amplitude analysis module is used to perform isotope analysis on each component of natural gas and determine the carbon and hydrogen isotope inversion amplitude of methane and ethane;

[0017] Methane cluster isotope analysis module, used for non-fractionation enrichment, purification and testing of methane in natural gas to determine methane cluster isotopes;

[0018] The comprehensive judgment module is used to make a comprehensive judgment on the shale gas production area and potential based on the absolute content of wet gas components, the amplitude of carbon and hydrogen isotope inversion and the methane cluster isotope.

[0019] An embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned shale gas potential prediction method when executing the computer program.

[0020] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the above-mentioned shale gas potential prediction method are implemented.

[0021] In the embodiment of the present invention, the composition of the obtained natural gas sample is analyzed to determine the composition of the natural gas and the absolute content of the wet gas component; the isotope analysis of each component of the natural gas is performed to determine the carbon and hydrogen isotope inversion amplitude of methane and ethane; the methane in the natural gas is subjected to non-fractionation enrichment purification treatment and test analysis to determine the methane cluster isotope; based on the absolute content of the wet gas component, the carbon and hydrogen isotope inversion amplitude and the methane cluster isotope, the shale gas production area and potential are comprehensively judged. The present invention is based on the comprehensive analysis and evaluation technology of natural gas. The analysis object - natural gas is simple and easy to obtain. Through the combination of relatively mature natural gas composition analysis technology, conventional carbon isotope analysis technology, and methane cluster isotope analysis technology, the gas content of shale, production size, possible potential, and shale gas sweet spot area are predicted with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0023] Figure 1 This is a flow chart of a shale gas potential prediction method in an embodiment of the present invention;

[0024] Figure 2 This is a flow chart of a method for determining the carbon and hydrogen isotope inversion amplitude in an embodiment of the present invention;

[0025] Figure 3 This is a flow chart of a method for determining a methane cluster isotope value in an embodiment of the present invention;

[0026] Figure 4 Schematic diagram of the relationship between the stable carbon isotope of methane and the content of moisture components in an embodiment of the present invention;

[0027] Figure 5 Schematic diagram of the relationship between the methane-ethane inversion amplitude and the ethane stable isotope in an embodiment of the present invention;

[0028] Figure 6 Schematic diagram of the possible relationship between the apparent temperatures of two methane cluster isotopes and the gas production in an embodiment of the present invention;

[0029] Figure 7 1 is a structural block diagram of a shale gas potential prediction device in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0031] The present invention is a set of comprehensive technologies for predicting gas content and evaluating shale gas production capacity in adjacent areas, which is established by integrating conventional and unconventional shale gas geochemical characteristic analysis technologies. The core technology is optimized, simple to operate, practical, effective and efficient, and can quickly and accurately help geologists and oil and gas companies predict the distribution area of ​​shale gas sweet spots.

[0032] Figure 1 Flow chart of the shale gas potential prediction method in the embodiment of the present invention; Figure 1 As shown, the method includes:

[0033] Step 102: Analyze the composition of the obtained natural gas sample to determine the natural gas composition and the absolute content of the moisture component;

[0034] Step 104: performing isotope analysis on each component of the natural gas to determine the carbon and hydrogen isotope inversion amplitudes of methane and ethane;

[0035] Step 106: performing non-fractionation enrichment and purification treatment and testing and analysis on the methane in the natural gas to determine the methane cluster isotopes;

[0036] Step 108: Based on the absolute content of wet gas components, the amplitude of carbon and hydrogen isotope inversion, and methane cluster isotopes, a comprehensive determination is made on the shale gas production area and its potential.

[0037] In the embodiment of the present invention, step 102 analyzes the composition of the natural gas sample, including:

[0038] The composition of natural gas samples was analyzed using gas chromatography.

[0039] Specifically, the composition of natural gas samples is analyzed by gas chromatography to obtain the volume or molar ratio of methane, ethane and other hydrocarbon components (i.e., natural gas composition). The absolute content of moisture components in natural gas can be used as a preferred factor. Generally, gas with a higher absolute content of moisture components (C 2+ / C 1+>0.5%), the greater the possibility that the corresponding gas well is a high-yield well; the lower the wet gas component content, the higher the possibility of low or extremely low production. Even if the gas production is very high occasionally, the gas production cycle will not last for a long time and the overall gas production is low. However, there are exceptions, that is, due to the migration of shale gas, the wet gas component content is relatively low, but its production and surrounding areas are extremely favorable exploration areas.

[0040] According to the content of components above ethane (also called heavy hydrocarbons) in natural gas, it is divided into dry gas and wet gas. Wet gas is heavy hydrocarbon content ≥5%; dry gas is heavy hydrocarbon content <5%.

[0041] Hydrocarbon gas (hydrocarbon gas) is mainly C1 ~ C5 alkane, that is, methane to pentane. Among them, CH4 is methane, C 2+ It is heavy hydrocarbon gas (hydrocarbon gas with 2 carbon numbers or more), C 1+ Represents all hydrocarbon gases.

[0042] In the embodiment of the present invention, step 104 performs isotope analysis on each component of natural gas to determine the carbon and hydrogen isotope inversion amplitude of methane and ethane, such as Figure 2 As shown, including:

[0043] Step 202: performing isotope analysis on each component of natural gas using isotope mass spectrometry to determine the carbon and hydrogen isotope composition of methane and ethane;

[0044] Step 204: Determine the methane and ethane carbon isotope inversion amplitude according to the carbon and hydrogen isotope compositions of methane and ethane.

[0045] Specifically, the stable carbon and hydrogen isotope composition of methane and ethane is analyzed by isotope mass spectrometry. The inversion amplitude of carbon isotopes of methane and ethane [αC CH4-C2H6 =(δ 13 C CH4 +1000) / (δ 13 C C2H6 +1000)], the inversion amplitude is a necessary condition for judging a high-yield gas zone, but not a sufficient condition. That is, if the inversion amplitude is large, it may be a high-yield zone, but there are exceptions, where the yield is not high or even a non-yield zone; if the inversion amplitude is small or even no inversion, it is a low-yield, extremely low-yield or even non-yield gas zone.

[0046] Among them, αC CH4-C2H6 represents the inversion amplitude of carbon isotopes of methane and ethane, δ 13 C CH4 represents the methane isotope value, δ 13 C C2H6 Represents the ethane isotope value.

[0047] In the embodiment of the present invention, Figure 3As shown, step 106 performs non-fractionation enrichment, purification, and testing analysis on the methane in the natural gas to determine the methane cluster isotope value, including:

[0048] Step 302: performing non-fractionation enrichment and purification treatment on the methane in the natural gas to obtain methane with a purity that meets the requirements;

[0049] Step 304: Perform methane cluster isotope test and analysis on the methane with purity meeting the requirements by high-resolution isotope mass spectrometry to obtain two methane cluster isotopes.

[0050] Specifically, in step 302, methane with a purity that meets the requirements refers to a purity of >99.99%, and then a methane cluster isotope test and analysis is performed by high-resolution isotope mass spectrometry to obtain two methane cluster isotope values ​​(Δ 13 CH3D and Δ 12 CH2D2);

[0051] Purification is the process of removing other substances from a mixture of multiple substances through physical, chemical or biological methods to obtain one type or one substance.

[0052] No fractionation emphasizes that the processing has no effect on methane isotopes.

[0053] High-resolution isotope mass spectrometry is a new mass spectrometry technology that uses the principle that charged particles can be deflected in an electromagnetic field to separate and detect the composition of substances according to the mass differences of molecules or molecular fragments. This technology has completely changed the determination of special sites and the analysis of molecular coupling isotope ratios.

[0054] Clusters are a new means to measure the formation temperature of compounds, calibrate reaction mechanisms / processes and conditions, etc. Cluster isotope molecules refer to molecules containing two or more rare heavy isotopes in a certain type of substance, where the heavy isotopes can be one element or two different elements, such as methane. 13 CD( 13 CH3D, 13 CH2D2, 13 CHD3, 13 CD4). The abundance of cluster isotope molecules containing two heavy isotopes is basically ×10 -6 The level is even lower. In equilibrium, the relative abundance of molecules containing cluster isotopes is determined by the thermal equilibrium constant of the reaction, which is a monotonic function of temperature. As the temperature increases, the equilibrium constant approaches the random distribution frequency of the isotopes.

[0055] In the embodiment of the present invention, the shale gas production area and potential are comprehensively determined based on the absolute content of wet gas components, the amplitude of carbon and hydrogen isotope inversion, and the methane cluster isotope, including:

[0056] Determine the absolute content of the moisture component. If the absolute content of the moisture component is higher than a first preset threshold, the corresponding shale gas production area is a high-yield shale gas production area; if the absolute content of the moisture component is lower than a second preset threshold, the corresponding shale gas production area is a non-high-yield shale gas production area;

[0057] Determine the carbon and hydrogen isotope reversal amplitude. If the carbon and hydrogen isotope reversal amplitude is greater than the third preset threshold, the corresponding shale gas production area is a shale gas high-yield area; if the carbon and hydrogen isotope reversal amplitude is less than the fourth preset threshold, the corresponding shale gas production area is a shale gas non-high-yield area;

[0058] If the absolute content of the wet gas component is higher than the first preset threshold, the amplitude of the carbon and hydrogen isotope inversion is greater than the third preset threshold, the methane cluster isotopes are internally balanced, and the apparent temperature displayed by the methane cluster isotopes is lower than the maximum burial paleo-geothermal temperature, then the corresponding shale gas production area is a high-yield shale gas production area;

[0059] If the absolute content of the wet gas component is lower than the second preset threshold, the methane cluster isotopes are internally unbalanced, the apparent temperature displayed by the first methane cluster isotope is basically consistent with the maximum burial paleotemperature, and the apparent temperature displayed by the second methane cluster isotope is consistent with the current burial temperature, then the corresponding shale gas production area is a non-high-yield shale gas area;

[0060] If the absolute content of the wet gas component is lower than the second preset threshold, the carbon and hydrogen isotope inversion amplitude is greater than the third preset threshold, the methane cluster isotopes are internally balanced, and the apparent temperature displayed by the methane cluster isotopes is lower than the maximum burial paleotemperature, then the shale gas in the corresponding shale gas production area is shale gas migrated from other regions, and the area surrounding the corresponding shale gas production area is a favorable shale gas exploration area.

[0061] Specifically, make a comprehensive judgment based on the above analysis.

[0062] First, according to the cluster isotope value plate ( Figure 4 ) to determine whether the methane cluster isotopes have reached equilibrium; for samples that have reached equilibrium, the temperature at equilibrium is compared with the maximum burial paleotemperature and the current burial temperature of the area; generally, under the same conditions, the lower the apparent temperature of the cluster isotopes, the greater the gas production potential of the natural gas well.

[0063] Paleotemperature, generally speaking, in geology, "paleo" refers to the period 10,000 years ago. Paleotemperature refers to the temperature of a certain stratum at a certain point in geological history.

[0064] In the prior art, two methane cluster isotope values ​​(Δ 13 CH3D and Δ 12 CH2D2) to determine the corresponding apparent temperature.

[0065] like Figures 4 to 6For gas samples with high moisture content and large carbon and hydrogen isotope inversion, if the methane cluster isotopes reach internal equilibrium and the cluster isotopes (the two methane cluster isotope values ​​Δ 13 CH3D and Δ 12 If the apparent temperature displayed by CH2D2) is lower than the maximum burial paleotemperature experienced, it can be judged as a shale gas well and gas zone with high yield and good gas production sustainability.

[0066] If the methane cluster isotopes are not balanced, the moisture content is very low, especially one cluster isotope of methane (Δ 13 The apparent temperature of CH3D is basically consistent with the maximum burial paleotemperature experienced in the area, while another cluster isotope of methane (Δ 12 If the apparent temperature shown by CH2D2) is consistent with the current burial temperature, this area can be judged as a low-yield area regardless of whether the methane and ethane carbon isotopes have reversed.

[0067] There is another situation where the wet gas component content is low, the methane and ethane carbon isotope inversion amplitude is large, and the methane in the shale gas reaches the equilibrium of its own cluster isotopes, and the apparent temperature displayed is lower than the maximum burial paleotemperature, indicating that the gas is mainly shale gas from other regions rather than self-generated and self-stored sources. The total production of this shale gas well is medium to high, but there are definitely high-yield clusters around it, which can be designated as favorable shale gas exploration areas.

[0068] The present invention also provides a shale gas potential prediction device, as described in the following embodiments. Since the principle of the device to solve the problem is similar to that of the shale gas potential prediction method, the implementation of the device can refer to the implementation of the shale gas potential prediction method, and the repeated parts will not be repeated.

[0069] Figure 7 FIG. 1 is a structural block diagram of a shale gas potential prediction device according to an embodiment of the present invention. Figure 7 As shown, the shale gas potential prediction device includes:

[0070] The natural gas composition analysis module 02 is used to analyze the composition of the acquired natural gas sample and determine the natural gas composition and the absolute content of the moisture component;

[0071] The carbon and hydrogen isotope reversal amplitude analysis module 04 is used to perform isotope analysis on each component of natural gas and determine the carbon and hydrogen isotope reversal amplitude of methane and ethane;

[0072] Methane cluster isotope analysis module 06, used for non-fractionation enrichment and purification of methane in natural gas and test analysis to determine methane cluster isotopes;

[0073] The comprehensive determination module 08 is used to make a comprehensive determination of the shale gas production area and potential based on the absolute content of the wet gas component, the amplitude of the carbon and hydrogen isotope inversion and the methane cluster isotope.

[0074] In the embodiment of the present invention, the natural gas composition analysis module is specifically used for:

[0075] The composition of natural gas samples was analyzed using gas chromatography.

[0076] In the embodiment of the present invention, the carbon and hydrogen isotope inversion amplitude analysis module is specifically used for:

[0077] Use isotope mass spectrometry to perform isotope analysis on each component of natural gas to determine the carbon and hydrogen isotope composition of methane and ethane;

[0078] The inversion amplitude of methane and ethane carbon isotopes is determined based on the carbon and hydrogen isotope composition of methane and ethane.

[0079] In the embodiment of the present invention, the methane cluster isotope analysis module is specifically used for:

[0080] Carry out non-fractionation enrichment and purification treatment on methane in natural gas to obtain methane with purity that meets the requirements;

[0081] The methane cluster isotope test and analysis was performed on the methane with purity meeting the requirements by high-resolution isotope mass spectrometry to obtain two methane cluster isotopes.

[0082] In the embodiment of the present invention, the comprehensive determination module is specifically used for:

[0083] Determine the absolute content of the moisture component. If the absolute content of the moisture component is higher than a first preset threshold, the corresponding shale gas production area is a high-yield shale gas production area; if the absolute content of the moisture component is lower than a second preset threshold, the corresponding shale gas production area is a non-high-yield shale gas production area;

[0084] Determine the carbon and hydrogen isotope reversal amplitude. If the carbon and hydrogen isotope reversal amplitude is greater than the third preset threshold, the corresponding shale gas production area is a shale gas high-yield area; if the carbon and hydrogen isotope reversal amplitude is less than the fourth preset threshold, the corresponding shale gas production area is a shale gas non-high-yield area;

[0085] If the absolute content of the wet gas component is higher than the first preset threshold, the amplitude of the carbon and hydrogen isotope inversion is greater than the third preset threshold, the methane cluster isotopes are internally balanced, and the apparent temperature displayed by the methane cluster isotopes is lower than the maximum burial paleo-geothermal temperature, then the corresponding shale gas production area is a high-yield shale gas production area;

[0086] If the absolute content of the wet gas component is lower than the second preset threshold, the methane cluster isotopes are internally unbalanced, the apparent temperature displayed by the first methane cluster isotope is basically consistent with the maximum burial paleotemperature, and the apparent temperature displayed by the second methane cluster isotope is consistent with the current burial temperature, then the corresponding shale gas production area is a non-high-yield shale gas area;

[0087] If the absolute content of the wet gas component is lower than the second preset threshold, the carbon and hydrogen isotope inversion amplitude is greater than the third preset threshold, the methane cluster isotopes are internally balanced, and the apparent temperature displayed by the methane cluster isotopes is lower than the maximum burial paleotemperature, then the shale gas in the corresponding shale gas production area is shale gas migrated from other regions, and the area surrounding the corresponding shale gas production area is a favorable shale gas exploration area.

[0088] An embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned shale gas potential prediction method when executing the computer program.

[0089] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps of the above-mentioned shale gas potential prediction method are implemented.

[0090] In the embodiment of the present invention, the composition of the obtained natural gas sample is analyzed to determine the composition of the natural gas and the absolute content of the wet gas component; the isotope analysis of each component of the natural gas is performed to determine the carbon and hydrogen isotope inversion amplitude of methane and ethane; the methane in the natural gas is subjected to non-fractionation enrichment and purification treatment to determine the methane cluster isotope; based on the absolute content of the wet gas component, the carbon and hydrogen isotope inversion amplitude and the methane cluster isotope, the shale gas production area and potential are comprehensively judged. The present invention is based on the comprehensive analysis and evaluation technology of natural gas. The analysis object - natural gas is simple and easy to obtain. Through the combination of relatively mature natural gas composition analysis technology, conventional carbon isotope analysis technology, and methane cluster isotope analysis technology, the gas content of shale, production size, possible potential, and shale gas sweet spot area are predicted with high accuracy.

[0091] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0092] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0093] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0094] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0095] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A shale gas potential prediction method, characterized in that: include: Analyze the composition of the obtained natural gas samples to determine the composition of the natural gas and the absolute content of the wet gas component; Conduct isotope analysis on each component of natural gas to determine the carbon and hydrogen isotope inversion amplitude of methane and ethane; Carry out non-fractionation enrichment, purification, testing and analysis of methane in natural gas to determine methane cluster isotopes; Based on the absolute content of wet gas components, the amplitude of carbon and hydrogen isotope inversion and methane cluster isotopes, a comprehensive prediction of shale gas production areas and potential is made; The methane in natural gas is enriched, purified and tested without fractionation to determine the methane cluster isotopes, including: Carry out non-fractionation enrichment and purification treatment on methane in natural gas to obtain methane with purity that meets the requirements; Performing methane cluster isotope testing and analysis on methane with purity meeting the requirements by high-resolution isotope mass spectrometry to obtain two methane cluster isotopes; the two methane cluster isotopes include a first methane cluster isotope and a second methane cluster isotope; Based on the absolute content of wet gas components, the amplitude of carbon and hydrogen isotope inversion and methane cluster isotopes, a comprehensive prediction of shale gas production areas and potential is made, including: Determine the absolute content of the moisture component. If the absolute content of the moisture component is higher than a first preset threshold, the corresponding shale gas production area is a high-yield shale gas production area; if the absolute content of the moisture component is lower than a second preset threshold, the corresponding shale gas production area is a non-high-yield shale gas production area; Determine the carbon and hydrogen isotope reversal amplitude. If the carbon and hydrogen isotope reversal amplitude is greater than the third preset threshold, the corresponding shale gas production area is a shale gas high-yield area; if the carbon and hydrogen isotope reversal amplitude is less than the fourth preset threshold, the corresponding shale gas production area is a shale gas non-high-yield area; If the absolute content of the wet gas component is higher than the first preset threshold, the amplitude of the carbon and hydrogen isotope inversion is greater than the third preset threshold, the methane cluster isotopes are internally balanced, and the apparent temperature displayed by the methane cluster isotopes is lower than the maximum burial paleo-geothermal temperature, then the corresponding shale gas production area is a high-yield shale gas production area; If the absolute content of the wet gas component is lower than the second preset threshold, the methane cluster isotopes are internally unbalanced, the apparent temperature displayed by the first methane cluster isotope is basically consistent with the maximum burial paleotemperature, and the apparent temperature displayed by the second methane cluster isotope is consistent with the current burial temperature, then the corresponding shale gas production area is a non-high-yield shale gas area; If the absolute content of the wet gas component is lower than the second preset threshold, the inversion amplitude of the carbon and hydrogen isotopes is greater than the third preset threshold, the methane cluster isotopes are internally balanced, and the apparent temperature displayed by the methane cluster isotopes is lower than the maximum burial paleotemperature, then the shale gas in the corresponding shale gas production area is shale gas from other regions, and the area surrounding the corresponding shale gas production area is a favorable shale gas exploration area; The first methane cluster isotope is Δ 13 CH3D; the second methane cluster isotope is Δ 12 CH2D2.

2. The shale gas potential prediction method according to claim 1, characterized in that: The composition of the natural gas sample is analyzed, including: The composition of natural gas samples was analyzed using gas chromatography.

3. The shale gas potential prediction method according to claim 1, characterized in that: Conduct isotope analysis on each component of natural gas to determine the carbon and hydrogen isotope inversion amplitude of methane and ethane, including: Use isotope mass spectrometry to perform isotope analysis on each component of natural gas to determine the carbon and hydrogen isotope composition of methane and ethane; The inversion amplitude of methane and ethane carbon isotopes is determined based on the carbon and hydrogen isotope composition of methane and ethane.

4. A shale gas potential prediction device, characterized in that: include: The natural gas composition analysis module is used to analyze the composition of the acquired natural gas samples and determine the natural gas composition and the absolute content of the moisture component; The carbon and hydrogen isotope inversion amplitude analysis module is used to perform isotope analysis on each component of natural gas and determine the carbon and hydrogen isotope inversion amplitude of methane and ethane; Methane cluster isotope analysis module, used to carry out non-fractionation enrichment, purification and test analysis of methane in natural gas to determine methane cluster isotopes; Comprehensive judgment module, used to make comprehensive judgment on shale gas production area and potential based on the absolute content of wet gas components, carbon and hydrogen isotope inversion amplitude and methane cluster isotope; Methane cluster isotope analysis module, specifically used for: Carry out non-fractionation enrichment and purification treatment on methane in natural gas to obtain methane with purity that meets the requirements; Performing methane cluster isotope testing and analysis on methane with purity meeting the requirements by high-resolution isotope mass spectrometry to obtain two methane cluster isotopes; the two methane cluster isotopes include a first methane cluster isotope and a second methane cluster isotope; The comprehensive judgment module is specifically used for: Determine the absolute content of the moisture component. If the absolute content of the moisture component is higher than a first preset threshold, the corresponding shale gas production area is a high-yield shale gas production area; if the absolute content of the moisture component is lower than a second preset threshold, the corresponding shale gas production area is a non-high-yield shale gas production area; Determine the carbon and hydrogen isotope reversal amplitude. If the carbon and hydrogen isotope reversal amplitude is greater than the third preset threshold, the corresponding shale gas production area is a shale gas high-yield area; if the carbon and hydrogen isotope reversal amplitude is less than the fourth preset threshold, the corresponding shale gas production area is a shale gas non-high-yield area; If the absolute content of the wet gas component is higher than the first preset threshold, the amplitude of the carbon and hydrogen isotope inversion is greater than the third preset threshold, the methane cluster isotopes are internally balanced, and the apparent temperature displayed by the methane cluster isotopes is lower than the maximum burial paleo-geothermal temperature, then the corresponding shale gas production area is a high-yield shale gas production area; If the absolute content of the wet gas component is lower than the second preset threshold, the methane cluster isotopes are internally unbalanced, the apparent temperature displayed by the first methane cluster isotope is basically consistent with the maximum burial paleotemperature, and the apparent temperature displayed by the second methane cluster isotope is consistent with the current burial temperature, then the corresponding shale gas production area is a non-high-yield shale gas area; If the absolute content of the wet gas component is lower than the second preset threshold, the inversion amplitude of the carbon and hydrogen isotopes is greater than the third preset threshold, the methane cluster isotopes are internally balanced, and the apparent temperature displayed by the methane cluster isotopes is lower than the maximum burial paleotemperature, then the shale gas in the corresponding shale gas production area is shale gas from other regions, and the area surrounding the corresponding shale gas production area is a favorable shale gas exploration area; The first methane cluster isotope is Δ 13 CH3D; the second methane cluster isotope is Δ 12 CH2D2.

5. The shale gas potential prediction device according to claim 4, characterized in that: The natural gas composition analysis module is specifically used for: The composition of natural gas samples was analyzed using gas chromatography.

6. The shale gas potential prediction device according to claim 4, characterized in that: The carbon and hydrogen isotope reversal amplitude analysis module is specifically used for: Use isotope mass spectrometry to perform isotope analysis on each component of natural gas to determine the carbon and hydrogen isotope composition of methane and ethane; The inversion amplitude of methane and ethane carbon isotopes is determined based on the carbon and hydrogen isotope composition of methane and ethane.

7. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the shale gas potential prediction method according to any one of claims 1 to 3 is implemented.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the shale gas potential prediction method described in any one of claims 1 to 3 are implemented.

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