Helium resource quantity evaluation method

Abstract

The invention provides a helium resource quantity evaluation method, which comprises the following steps of: performing regional geological background analysis on a helium resource evaluation region, and determining a potential distribution region of helium source rocks; helium source rock calculation units of different types are identified and divided; collecting a radioactive element content test sample of the geologic body of each helium source rock calculation unit and measuring the content of radioactive elements in the radioactive element content test sample; calculating the average helium generation rate of each helium source rock calculation unit according to the radioactive element content; determining the total helium generation amount of each helium source rock calculation unit according to the volume scale, the average helium generation rate and the effective helium generation time of each helium source rock calculation unit; determining an exhaust coefficient and a migration and accumulation coefficient of helium; according to the total helium generation amount and the helium discharge coefficient of each helium source rock calculation unit, the total helium discharge amount is determined, and then the helium resource amount of the helium resource evaluation area is determined by combining the helium migration and accumulation coefficient. According to the helium resource quantity evaluation method, various geological factors are comprehensively considered, a scientific calculation model and a scientific analysis method are adopted, the helium resource quantity can be accurately and comprehensively evaluated, and reliable technical support is provided for exploration, development and utilization of helium resources.

Description

Technical Field

[0001] The invention belongs to the field of helium resource exploration and evaluation, and specifically relates to a helium resource quantity evaluation method. Background Art

[0002] As an important strategic resource, helium plays an irreplaceable role in aerospace, medical, scientific research and other fields. However, due to its unique physical and chemical properties, the natural aggregation and preservation conditions of helium are extremely harsh, resulting in uneven distribution of helium resources around the world, with most resources concentrated in a few countries. Therefore, accurately assessing the amount of helium resources is of great significance to ensuring national energy security and promoting the sustainable development of the helium industry.

[0003] Existing helium resource evaluation methods mostly focus on the analysis of a single factor or a local area, lacking systematicity and comprehensiveness, resulting in great uncertainty in the evaluation results. In response to this problem, the present invention proposes a helium resource evaluation method that comprehensively considers multiple factors such as geological structure, rock type, radioactive element content, helium generation rate, expulsion coefficient and migration coefficient. Summary of the invention

[0004] The present invention aims to provide a helium resource evaluation method, which fully considers the helium generation of all helium-generating rocks and the loss of helium in each link from source rock to gas reservoir, so that the helium resource calculation result is more scientific and accurate.

[0005] The technical solution of the present invention is as follows:

[0006] A method for evaluating helium resources comprises the following steps:

[0007] a. Conduct regional geological background analysis on the helium resource evaluation area and determine the potential distribution area of ​​helium source rocks;

[0008] b. Identify and divide different types of helium source rock calculation units;

[0009] c. Collect radioactive element content test samples of each helium source rock calculation unit geological body and determine the content of radioactive elements therein;

[0010] d. Calculate the average helium generation rate of each helium source rock calculation unit based on the radioactive element content;

[0011] e. Determine the total amount of helium generated by each helium source rock calculation unit based on the volume scale, average helium generation rate and effective helium generation time of each helium source rock calculation unit;

[0012] f. Determine the expulsion coefficient and transport coefficient of helium;

[0013] g. Determine the total helium discharge based on the total helium generation and helium discharge coefficient of each helium source rock calculation unit, and then determine the helium resource volume in the helium resource evaluation area in combination with the helium migration and accumulation coefficient.

[0014] Furthermore, the helium source rock calculation unit includes the lower crust, the middle crust and the upper crust.

[0015] Furthermore, different types of helium source rock calculation units are identified and divided into:

[0016] Collect geological data of the helium resource evaluation area and use geological analysis methods to divide different types of helium source rock calculation units.

[0017] Furthermore, the radioactive elements include uranium and thorium.

[0018] Furthermore, the average helium generation rate of each helium source rock calculation unit is calculated based on the radioactive element content:

[0019] According to the amount of helium produced by the decay of radioactive elements and combined with the geological time scale, a helium generation rate calculation model is established;

[0020] The helium generation rate calculation model is used to calculate the average helium generation rate of each helium source rock calculation unit.

[0021] Furthermore, the helium expulsion coefficient is obtained according to the burial depth, lithology and permeability of the helium source rock calculation unit.

[0022] Furthermore, the geological analogy method is used to obtain the helium migration and accumulation coefficient in combination with the geological characteristics of known helium fields.

[0023] Furthermore, the total helium discharge volume is determined based on the total helium generation volume and helium discharge coefficient of each helium source rock calculation unit, and then the helium resource volume of the helium resource evaluation area is determined in combination with the helium migration and accumulation coefficient as follows:

[0024] The total amount of helium generated in each helium source rock calculation unit is multiplied by the corresponding expulsion coefficient and migration coefficient to obtain the potential helium resource of each unit. The potential resource of all units is accumulated to obtain the total helium resource of the entire helium resource evaluation area.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] Improved evaluation accuracy: By dividing the helium source rock calculation units in detail and accurately collecting and testing the radioactive element content, the present invention can more accurately calculate the helium generation rate and the total amount of helium generation, thereby improving the accuracy of helium resource evaluation.

[0027] Comprehensive consideration of multiple factors: The present invention not only considers the helium generation capacity of the helium source rock, but also comprehensively analyzes the helium discharge conditions, migration and accumulation process, and the influence of geological structure on helium accumulation and preservation, making the evaluation results more comprehensive and reliable.

[0028] Improve resource utilization: By identifying favorable helium accumulation areas and possible escape channels, the present invention helps to guide subsequent exploration and development work and improve the utilization and mining efficiency of helium resources.

[0029] Wide applicability: The present invention is applicable to different types of helium source rocks and geological conditions, has strong versatility and applicability, and can provide strong support for helium resource evaluation worldwide. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings generally illustrate various embodiments by way of example and not limitation, and together with the description and claims, serve to illustrate the embodiments of the invention. Where appropriate, the same reference numerals are used throughout the drawings to refer to the same or similar parts. Such embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the present apparatus or method.

[0031] Figure 1 A schematic diagram of the method steps of the present invention is shown. DETAILED DESCRIPTION

[0032] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0033] The embodiment of the present invention provides a method for evaluating helium resources, comprising the following steps:

[0034] Step 1: Detailed division of helium source rock calculation units

[0035] First, we collect extensive geological data of the evaluation area, including but not limited to high-precision geological structure maps, detailed lithology profiles, accurate stratigraphic thickness data, and information on rock physical properties. We use geological analysis software and professional geological modeling technology to conduct a comprehensive analysis of these data.

[0036] According to the geological structure characteristics, different structural units are identified, such as fault zones, fold zones, etc. At the same time, the differences in lithology are considered, such as granite, basalt, sedimentary rock and other rock types. For the thickness of the formation, it is necessary not only to pay attention to the overall thickness change, but also to analyze the thickness distribution in different stratigraphic units.

[0037] Based on these factors, cluster analysis or regional division algorithms are used to divide regions with similar geological characteristics into a helium source rock calculation unit. Specifically, in a certain area, the geological structure is relatively stable, the lithology is mainly a specific type of sedimentary rock, and the thickness of the strata fluctuates little within a certain range, then the area can be divided into a calculation unit. In addition, ensure that each calculation unit contains representative parts of the lower crust, middle crust and upper crust as completely as possible. This can be determined through in-depth research on the crust structure and detailed analysis of geological profiles. For example, according to parameters such as the propagation speed of seismic waves and rock density, the boundaries of different crustal layers are divided and taken into account when dividing the calculation units.

[0038] Step 2: Accurate collection and testing

[0039] In each divided helium source rock calculation unit, a systematic sampling plan is formulated. The selection of sampling points needs to comprehensively consider the geological diversity and representativeness within the unit. The selection can be made based on factors such as topography, stratigraphic outcrops, and borehole distribution within the unit. In mountainous areas with large terrain fluctuations, sampling is selected on stratigraphic outcrops at different altitudes; in areas with boreholes, samples are collected in strata at different depths based on the borehole data.

[0040] For each sampling point, professional geological sampling tools, such as core drills, soil samplers, etc., are used to collect a sufficient number of samples for testing the content of radioactive elements. The collected samples must ensure their integrity and representativeness to avoid external contamination.

[0041] After the sample is collected, it is quickly sent to a professional high-precision laboratory. The laboratory is equipped with advanced analytical equipment, such as high-resolution mass spectrometers, inductively coupled plasma mass spectrometers (ICP-MS), etc. Using these equipment, the content of uranium (U) and thorium (Th) in the sample is accurately determined.

[0042] During the measurement process, the laboratory's quality control standards were strictly followed and repeated measurements were performed to reduce errors. The measurement results of multiple sampling points were statistically analyzed, such as calculating the mean value, standard deviation, confidence interval, etc. Through these statistical analyses, the average abundance of uranium (U) and thorium (Th) in each calculation unit was determined.

[0043] Step 3: Calculate the helium production rate

[0044] Based on the basic principle of helium production from radioactive elements decay and combined with the geological time scale, a scientific and reasonable helium production rate calculation model is established. This model fully considers the decay constants and decay modes of uranium (U) and thorium (Th) as well as the changes in geological history.

[0045] For example, based on the known decay equations of uranium (U) and thorium (Th), the amount of helium produced by the decay of radioactive elements in different geological periods is calculated. At the same time, the influence of geological time scales, such as the sedimentation rate of strata and the time of tectonic movements, is considered. These factors are incorporated into the helium generation rate calculation model by establishing complex mathematical formulas or using numerical simulation methods.

[0046] Substitute the average abundance of uranium (U) and thorium (Th) in each helium source rock calculation unit into the model and use computer programs or professional mathematical calculation software to calculate. Through a large amount of data calculation and simulation, the average helium generation rate of each calculation unit is obtained. During the calculation process, the accuracy and reliability of the model are constantly verified, such as by comparing with known geological data or experimental results.

[0047] Step 4: Determine the total amount of helium produced

[0048] The volume, density, porosity and other detailed parameter data of the helium source rock calculated by geological exploration are used. For the calculation of volume, it is necessary to comprehensively consider the geometric shape of the calculation unit and the stratum fluctuation. The three-dimensional geological model can be constructed by geological modeling software to accurately calculate the volume of each unit.

[0049] Density can be determined by testing the physical properties of rock samples in the laboratory, or by referring to existing geological literature and databases. Porosity can be determined by a variety of methods, such as core analysis, logging data interpretation, etc.

[0050] Combined with the average helium generation rate and effective helium generation time calculated above, the total amount of helium generation in each unit can be calculated using physical and mathematical formulas. For example, the formula can be used: total amount of helium generation = volume × density × porosity × average helium generation rate × effective helium generation time. In the calculation process, attention should be paid to the uniformity of units and the accuracy of data.

[0051] Step 5: Analyze helium exhaust conditions

[0052] Study the geological parameters such as burial depth, lithology, and permeability of each helium source rock calculation unit in detail. The burial depth can be measured through seismic exploration data, drilling data, etc. The analysis of lithology requires the combination of rock thin section identification, mineral composition analysis, etc. The permeability can be determined by laboratory core permeability testing or field logging interpretation.

[0053] Through comprehensive analysis of these parameters, the possibility of helium being discharged from the source rock can be determined. For example, in shallow burial areas, due to the low pressure of the overlying rocks, the pores and cracks in the rocks are relatively well developed, which is conducive to the discharge of helium; loose sedimentary rocks usually have high porosity and permeability, which also provides favorable conditions for the discharge of helium; in rocks with high permeability, helium can more easily migrate to other strata through the pore and crack systems.

[0054] The helium expulsion coefficient of each unit is determined based on a large amount of experimental data, simulation calculation results or empirical formulas. This coefficient reflects the migration efficiency of helium from source rock to potential reservoir. For example, a physical model can be established to simulate the migration process of helium under different geological conditions, thereby determining the range of the expulsion coefficient.

[0055] Step 6: Evaluate the helium transport process

[0056] Using the geological analogy method, we extensively collect geological characteristic data of known helium fields, including information on stratigraphic structure, reservoir characteristics, migration pathways, caprock conditions, and accumulation patterns. We then organize and analyze these data in detail to extract key geological parameters and characteristics.

[0057] The geological characteristics of the evaluation area are comprehensively compared and analyzed with those of known helium fields. For example, the similarity of the stratigraphic structure, reservoir rock type and porosity, and the degree of development of migration channels between the evaluation area and known gas fields are compared. Through this comparison, the loss of helium during migration and accumulation in the evaluation area is evaluated.

[0058] Based on the evaluation results, the helium migration and accumulation coefficient is determined. This coefficient is used to correct the conversion of the total amount of helium generated to the final recoverable resource amount. The specific value of the migration and accumulation coefficient can be determined by establishing a mathematical model to simulate the loss of helium during the migration and accumulation process.

[0059] Step 7: Consider the impact of geological structures

[0060] In-depth analysis of the geological structure in the evaluation area, including the impact of faults, folds, stratum tilt and other factors on helium accumulation and preservation. Detailed information on the geological structure is obtained through geological surveys such as seismic exploration and geological profile measurement.

[0061] For faults, analyze their properties (normal faults, reverse faults, etc.), scale, strike, dip and other parameters. Normal faults may become channels for helium to escape, while reverse faults may play a certain role in blocking helium. The shape and amplitude of the fold structure will also affect the accumulation and distribution of helium. Anticline structures are usually conducive to the accumulation of helium, while syncline structures may not be conducive to the preservation of helium.

[0062] Using geological analysis software and numerical simulation technology, quantitative analysis is performed on the relationship between geological structure and helium accumulation and preservation. Favorable helium accumulation areas are identified, which usually have good trap conditions, such as anticline structures of strata, sealing effects of faults, high-quality caprocks, etc. At the same time, attention should also be paid to possible helium escape channels, such as large normal faults or fracture zones. In resource evaluation, the influence of these factors is fully considered, and reasonable evaluation of helium resources in different regions is carried out.

[0063] Step 8: Comprehensive calculation of helium resources

[0064] The total amount of helium generated in each helium source rock calculation unit is multiplied by the corresponding expulsion coefficient and migration coefficient to obtain the potential helium resource amount of each unit.

[0065] Finally, the potential resource amounts of all calculation units are accumulated. During the accumulation process, attention should be paid to the consistency and accuracy of the data to avoid repeated calculations or omissions. The total amount of helium resources in the entire evaluation area is obtained through accumulation.

[0066] The helium resource evaluation method of the present invention can accurately and comprehensively evaluate the helium resource quantity by comprehensively considering various geological factors and adopting scientific calculation models and analysis methods, thereby providing reliable technical support for the exploration, development and utilization of helium resources.

[0067] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for evaluating helium resources, characterized in that: The following steps are involved: a. Conduct regional geological background analysis on the helium resource evaluation area and determine the potential distribution area of ​​helium source rocks; b. Identify and divide different types of helium source rock calculation units; c. Collect radioactive element content test samples of each helium source rock calculation unit geological body and determine the content of radioactive elements therein; d. Calculate the average helium generation rate of each helium source rock calculation unit based on the radioactive element content; e. Determine the total amount of helium generated by each helium source rock calculation unit based on the volume scale, average helium generation rate and effective helium generation time of each helium source rock calculation unit; f. Determine the expulsion coefficient and transport coefficient of helium; g. Determine the total helium discharge based on the total helium generation and helium discharge coefficient of each helium source rock calculation unit, and then determine the helium resource volume in the helium resource evaluation area in combination with the helium migration and accumulation coefficient.

2. The helium resource evaluation method according to claim 1, characterized in that: The helium source rock calculation unit includes the lower crust, the middle crust and the upper crust.

3. The helium resource evaluation method according to claim 1, characterized in that: Identify and classify different types of helium source rock calculation units as follows: Collect geological data of the helium resource evaluation area and use geological analysis methods to divide different types of helium source rock calculation units.

4. The helium resource evaluation method according to claim 1, characterized in that: The radioactive elements include uranium and thorium.

5. The helium resource evaluation method according to claim 1, characterized in that: The average helium generation rate of each helium source rock calculation unit is calculated based on the radioactive element content: According to the amount of helium produced by the decay of radioactive elements and combined with the geological time scale, a helium generation rate calculation model is established; The helium generation rate calculation model is used to calculate the average helium generation rate of each helium source rock calculation unit.

6. The helium resource evaluation method according to claim 1, characterized in that: The helium expulsion coefficient is obtained based on the burial depth, lithology and permeability of the helium source rock calculation unit.

7. The helium resource evaluation method according to claim 1, characterized in that: The helium migration and accumulation coefficient is obtained by using the geological analogy method combined with the geological characteristics of known helium fields.

8. The helium resource evaluation method according to claim 1, characterized in that: According to the total amount of helium generated by each helium source rock calculation unit and the helium expulsion coefficient, the total helium expulsion is determined, and then the helium resource volume in the helium resource evaluation area is determined in combination with the helium migration and accumulation coefficient as follows: The total amount of helium generated in each helium source rock calculation unit is multiplied by the corresponding expulsion coefficient and migration coefficient to obtain the potential helium resource of each unit. The potential resource of all units is accumulated to obtain the total helium resource of the entire helium resource evaluation area.

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