Oil shale identification and oil content calculation method and system, storage medium and equipment

Abstract

The invention belongs to the field of petroleum and natural gas exploration and development, and provides an oil shale identification and oil content calculation method and system, a storage medium and equipment, and the method comprises the steps: determining an oil shale stratum through a logging response curve; determining the oil shale stratum with high organic matter content according to the organic matter content in the oil shale stratum; based on the high-organic-matter-content oil shale stratum, an intersection chart of a logging response curve and core analysis total organic carbon content measured data is established, and sensitive parameters are determined; calculating the total organic carbon content according to the sensitive parameters; and calculating the oil content of the oil shale stratum according to the total organic carbon content. According to the method, the logging data and the core analysis data are comprehensively utilized, the relation between the total organic carbon content TOC and the oil content of the oil shale is established, the oil content of the oil shale stratum is calculated more accurately and efficiently, and the precision and efficiency of oil shale resource evaluation are improved.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas exploration and development, and particularly relates to methods, systems, storage media and equipment for oil shale identification and oil content calculation. Background Technology

[0002] With my country's rapid economic development, the demand for energy is constantly increasing, highlighting the contradiction between oil and gas supply and demand. This necessitates expanding the scope of oil and gas exploration and development to ensure national energy security. Unconventional oil and gas resources, as an important type of oil and gas resource, have attracted significant attention from many countries and oil companies in recent years, leading to increased exploration, development, and research efforts and yielding fruitful results, effectively supplementing conventional oil and gas resources. The world possesses extremely rich oil shale resources, and significant progress has been made in the development and comprehensive utilization technology of oil shale in recent years. Countries such as the United States, China, and Australia have formulated ambitious strategic plans for the development and utilization of oil shale, indicating that oil shale development is poised for rapid growth.

[0003] Oil shale is a high-ash, solid, combustible organic mineral. Low-temperature dry distillation yields shale oil with an oil content >3.5% and high organic matter content, primarily sapropelic, humic, or mixed types. Its calorific value is generally ≥4.18 MJ / g. Given the tight global oil and gas supply and demand, rising oil prices, and increasing the difficulty of increasing conventional oil and gas production, the urgent task is to intensify the exploration and development of oil shale resources. This includes clarifying the quality and distribution characteristics of oil shale in key basins in my country, improving resource exploration, striving to discover new large-scale, high-quality oil shale deposits, prioritizing favorable oil shale exploration and development targets, expanding resource potential, promoting the exploration and evaluation of oil shale resources in my country, and accelerating the development and comprehensive utilization of oil shale. This is of great significance for realizing the large-scale development and utilization of oil shale resources in my country and effectively alleviating the contradiction between crude oil supply and demand.

[0004] Existing technologies include methods for determining organic matter content using well logging curves, but the accuracy of the calculated oil shale oil content is low, resulting in the oil shale oil content calculated by existing technologies not meeting development requirements. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a method, system, storage medium, and device for identifying oil shale and calculating its oil content, thereby improving the accuracy of oil shale oil content calculation.

[0006] The present invention provides a method for identifying oil shale and calculating its oil content, the method comprising:

[0007] The oil shale formation was determined by well logging response curves;

[0008] Based on the organic matter content in the oil shale formations, oil shale formations with high organic matter content were identified;

[0009] Based on the oil shale formation with high organic matter content, a cross plot of well logging response curves and measured data of total organic carbon content from core analysis was established to determine sensitive parameters.

[0010] The total organic carbon content is calculated based on the aforementioned sensitive parameters;

[0011] Based on the total organic carbon content, the oil content of the oil shale formation was calculated.

[0012] Furthermore, the determination of oil shale formations through well logging response curves includes:

[0013] By utilizing the characteristics of high natural gamma, high neutron porosity, high sonic transit time, and high resistivity in the well logging response curve, the oil shale formation used for calculating organic matter content was identified.

[0014] Furthermore, determining oil shale formations with high organic matter content based on the organic matter content in the oil shale formation includes:

[0015] By using a proportional overlay diagram of sonic transit time logging curves and deep induction resistivity logging curves, oil shale formations with high organic matter content can be identified.

[0016] Furthermore, based on the oil shale formation with high organic matter content, a cross-plot of well logging response curves and measured total organic carbon content data from core analysis is established to determine sensitive parameters, including:

[0017] Based on wells with core analysis data, cross plots were established with the gamma ray spectral logging uranium curve value, sonic transit time logging curve value, compensated density logging curve value, natural gamma curve value, compensated neutron curve value, and the overlap map area parameter calculated using the ΔlogR method, respectively, and the measured total organic carbon content data from the core analysis data to determine sensitive parameters.

[0018] Furthermore, the logging curve parameters include:

[0019] The sensitive parameters are: logging response curve parameters that have a high regression correlation coefficient with the measured data of total organic carbon content in core analysis.

[0020] Furthermore, the formula for calculating the total organic carbon content is as follows:

[0021] TOC = 3.408 × e 0.376×U +0.047×Δt+3.014

[0022] Where U is the uranium logging curve value of the gamma spectral logging and Δt is the sonic logging curve value.

[0023] Furthermore, the formula for calculating the oil content of the oil shale formation is as follows:

[0024] T = a × TOC + b

[0025] Where a and b are fitting coefficients.

[0026] This invention also provides an oil shale identification and oil content calculation system for implementing the aforementioned oil shale identification and oil content calculation method, comprising:

[0027] Oil shale formation identification module, used to identify oil shale formations;

[0028] A module for identifying oil shale formations with high organic matter content is used to identify oil shale formations with high organic matter content in the oil shale formations.

[0029] The sensitive parameter determination module is used to determine sensitive parameters with high correlation coefficients in the oil shale formation with high organic matter content.

[0030] The total organic carbon content calculation module is used to establish the relationship between the total organic carbon content and the sensitive parameter, and to calculate the total organic carbon content.

[0031] The oil content calculation module is used to establish the relationship between the total organic carbon content and the oil content of the oil shale formation, and to calculate the oil content of the oil shale formation.

[0032] The present invention also proposes a computer-readable storage medium storing a program or instructions that, when run on a computer, cause the computer to execute the aforementioned method for identifying oil shale and calculating its oil content.

[0033] The present invention also proposes a device including a processor coupled to a memory; the processor is used to read and execute a computer program stored in the memory to implement the aforementioned method for identifying oil shale and calculating its oil content.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] 1. Using well logging response curves to identify oil shale formations, multi-parameter comprehensive analysis helps to identify oil shale more accurately.

[0036] 2. By overlaying sonic transit time logging curves and deep induction resistivity logging curves, the changes in organic matter content in oil shale formations can be identified more precisely, thereby improving the resolution of formation evaluation.

[0037] 3. By establishing a cross-plot between the well logging response curve and the measured data of total organic carbon content from core analysis, it is helpful to identify the most sensitive parameters related to oil content, thereby improving the accuracy of oil content calculation.

[0038] 4. By improving the accuracy of oil content prediction, exploration and development investment can be optimized, and cost-effectiveness can be improved.

[0039] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A flowchart illustrating a method for identifying oil shale and calculating its oil content according to the present invention is shown.

[0042] Figure 2 A schematic diagram of well logging curves for an oil shale-rich section of a formation according to an embodiment of the present invention is shown;

[0043] Figure 3a This diagram illustrates a cross-plot of the measured total organic carbon content from core analysis and the area parameters of the overlay plot calculated using the ΔlogR method, according to an embodiment of the present invention.

[0044] Figure 3b This diagram shows a cross-plot of measured total organic carbon content data from core analysis and uranium logging curves from gamma ray spectroscopy, according to an embodiment of the present invention.

[0045] Figure 3c This diagram shows a cross-plot of measured total organic carbon content data from core analysis and sonic transit time logging curves according to an embodiment of the present invention.

[0046] Figure 3d This diagram shows a cross-plot of measured total organic carbon content data from core analysis and compensated density logging curves according to an embodiment of the present invention.

[0047] Figure 3e This diagram shows a cross-plot of measured total organic carbon content data from core analysis and natural gamma curve values ​​according to an embodiment of the present invention.

[0048] Figure 3f This diagram shows a cross-plot of measured total organic carbon content data from core analysis and compensated neutron curve values ​​according to an embodiment of the present invention.

[0049] Figure 4 This diagram illustrates the identification and oil content results of a certain oil shale formation according to an embodiment of the present invention.

[0050] Figure 5 A schematic diagram of the device structure of the present invention is shown;

[0051] In the diagram, 501 is the processor and 502 is the memory. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0053] Figure 1 The diagram illustrates a flowchart of a method for identifying oil shale and calculating its oil content according to an embodiment of the present invention, specifically including:

[0054] S1: Determine the oil shale formation by logging response curves.

[0055] Shales with higher organic matter content are more radioactive, exhibiting higher natural gamma values ​​than ordinary shale and limestone. Natural gamma spectroscopy shows that shale with high organic matter content has a higher uranium content than the surrounding mudstone. The correlation between natural gamma readings and organic matter content indicates that higher radioactivity strata are associated with the presence of organic matter. Since kerogen is enriched in uranium, thorium, and potassium, and these elements are present in lower concentrations in mudstone than in kerogen, an increase in kerogen content leads to an increase in uranium, thorium, and potassium content in oil shale. Therefore, there is a positive correlation between uranium, thorium, and potassium content in strata and the organic matter content in rocks.

[0056] Because oil shale has a higher organic matter content than mudstone, its natural gamma-ray logging (NGR) values ​​are higher than those of mudstone and shale. Therefore, oil shale can be identified using abnormally high NGR values. Furthermore, studies of the target formation have revealed that oil shale also possesses characteristics such as high neutron porosity, high sonic transit time, and high resistivity.

[0057] Specifically, this includes: using the characteristics of high natural gamma, high neutron porosity, high sonic transit time, and high resistivity in the well logging response curve to determine the oil shale formation used for calculating organic matter content, wherein the oil shale is a shale formation containing high organic matter content and having oil generation potential.

[0058] S2: Based on the organic matter content in the oil shale formation, identify oil shale formations with high organic matter content.

[0059] Specifically, this includes using a proportional overlap diagram of sonic transit time logging curves and deep inductive resistivity logging curves to identify oil shale formations with high organic matter content; a larger proportional overlap area indicates a higher organic matter content.

[0060] S3: Based on the oil shale formation with high organic matter content, establish a cross plot of well logging response curves and measured data of total organic carbon content from core analysis to determine sensitive parameters.

[0061] Specifically, this includes: based on wells with core analysis data, establishing cross-plots with the gamma spectral logging uranium curve value, sonic transit time logging curve value, compensated density logging curve value, natural gamma curve value, compensated neutron curve value, and the overlap plot area parameter calculated using the ΔlogR method, respectively, and identifying sensitive parameters.

[0062] Among them, the sensitive parameters are logging curve parameters that have a high regression correlation coefficient with the measured data of total organic carbon content in core analysis, and the correlation coefficient R is required to be ≥0.8.

[0063] S4: Calculate the total organic carbon content based on the aforementioned sensitive parameters.

[0064] Specifically, this includes: establishing a relationship between total organic carbon content and the sensitive parameter using a linear regression method based on the sensitive parameter, and calculating the total organic carbon content;

[0065] The formula for calculating total organic carbon (TOC) is:

[0066] TOC = 3.408 × e 0.376×U +0.047×Δt+3.014

[0067] Where U is the uranium logging curve value of the gamma spectral logging and Δt is the sonic logging curve value.

[0068] S5: Calculate the oil content of the oil shale formation based on the total organic carbon content.

[0069] Specifically, this includes: establishing a relationship between the total organic carbon content and the oil content of the oil shale formation through a fitting method, and calculating the oil content of the oil shale formation;

[0070] The formula for calculating the oil content of oil shale formations is:

[0071] T = a × TOC + b

[0072] Where a and b are fitting coefficients.

[0073] Example 1

[0074] Based on the above process, the following detailed description will be provided using specific embodiments.

[0075] This embodiment identifies and calculates the oil content of an oil shale-rich section in a certain formation.

[0076] By utilizing the characteristics of high natural gamma, high neutron porosity, high sonic transit time, and high resistivity in the well logging response curve, the oil shale formation used for calculating organic matter content was identified.

[0077] like Figure 2 The diagram shows a schematic of well logging curves for an oil shale-rich section of a formation. GR represents the natural gamma ray logging curve, SP the spontaneous potential logging curve, CAL the caliper curve, AC the sonic transit time logging curve, DEN the compensated density logging curve, CNC the compensated neutron logging curve, RD the deep induction logging curve, and RS the spherical focused resistivity curve. In this oil shale formation, the characteristics of high natural gamma ray, high neutron porosity, high sonic transit time, and high resistivity logging response are clearly visible, thus identifying this oil shale-rich section, which can be used to identify and calculate oil cut.

[0078] By using a proportionally superimposed map of sonic transit time logging curves and deep induction resistivity logging curves, it can be determined whether the formation is an oil shale formation with high organic matter content. A larger proportionally superimposed area indicates a higher organic matter content.

[0079] Specifically, the scale of the sonic transit time logging curve is -10 to 140 μs / ft, and the scale of the resistivity logging curve is 1 to 1000 ohm / mm. The red area is the area where the sonic transit time logging curve and the deep induction resistivity logging curve overlap at a certain scale, which indicates that the oil shale in this formation is an oil shale with a high organic matter content.

[0080] Based on the core analysis data of the formation and well, a cross plot of the well logging response curve and the measured data of total organic carbon content in the core analysis was established to determine the sensitive parameters.

[0081] like Figures 3a to 3f As shown, cross plots were created between the gamma ray spectroscopy uranium logging curve values, sonic transit time logging curve values, compensated density logging curve values, natural gamma ray curve values, compensated neutron logging curve values, and the overlap plot area parameters calculated using the ΔlogR method, and the measured total organic carbon content data from core analysis. The correlation coefficients of the cross plots were sorted from largest to smallest, and the top two parameters were selected as sensitive parameters, namely, the gamma ray spectroscopy uranium logging curve values ​​and the sonic logging curve values.

[0082] Establish the relationship between total organic carbon content and sensitive parameters, and calculate the total organic carbon content.

[0083] A formula was established to establish the relationship between total organic carbon content and oil content in oil shale formations, and the oil content of oil shale formations was calculated.

[0084] In this embodiment, the fitting coefficients a and b are obtained by fitting the data, with a value of 0.6486 and a value of -0.8562.

[0085] like Figure 4 As shown in the figure, the calculation results of the total organic carbon (TOC) content and oil content of the oil shale formation in this embodiment are shown in the figure.

[0086] Based on the above method, this invention also provides an oil shale identification and oil content calculation system corresponding to the above method, the device comprising:

[0087] Oil shale formation identification module, used to identify oil shale formations;

[0088] The module for identifying oil shale formations with high organic matter content is used to identify oil shale formations with high organic matter content.

[0089] The sensitive parameter determination module is used to determine sensitive parameters with high correlation coefficients in oil shale formations with high organic matter content;

[0090] The total organic carbon content calculation module is used to establish the relationship between total organic carbon content and sensitive parameters, and to calculate the total organic carbon content.

[0091] The oil content calculation module is used to establish the relationship between total organic carbon content and oil content of oil shale formations, and to calculate the oil content of oil shale formations.

[0092] The present invention also provides a computer-readable storage medium storing a program or instructions that, when run on a computer, cause the computer to execute the oil shale identification and oil content calculation method described in the above-described method embodiments.

[0093] like Figure 5 As shown, an embodiment of the present invention also provides a device, including: a processor 501, the processor 501 being coupled to a memory 502, the processor 501 being used to read and execute a computer program stored in the memory 502 to implement an oil shale identification and oil content calculation method as described in the above method embodiment.

[0094] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for identifying oil shale and calculating its oil content, characterized in that, The method includes: The oil shale formation was determined by well logging response curves; Based on the organic matter content in the oil shale formations, oil shale formations with high organic matter content were identified; Based on the oil shale formation with high organic matter content, a cross plot of well logging response curves and measured data of total organic carbon content from core analysis was established to determine sensitive parameters. The total organic carbon content is calculated based on the aforementioned sensitive parameters; Based on the total organic carbon content, the oil content of the oil shale formation was calculated.

2. The method according to claim 1, characterized in that, The determination of oil shale formations through well logging response curves includes: By utilizing the characteristics of high natural gamma, high neutron porosity, high sonic transit time, and high resistivity in the well logging response curve, the oil shale formation used for calculating organic matter content was identified.

3. The method according to claim 1, characterized in that, The step of determining oil shale formations with high organic matter content based on the organic matter content in the oil shale formation includes: By using a proportional overlay diagram of sonic transit time logging curves and deep induction resistivity logging curves, oil shale formations with high organic matter content can be identified.

4. The method according to claim 1, characterized in that, Based on the oil shale formation with high organic matter content, a cross-plot of well logging response curves and measured total organic carbon content data from core analysis is established to determine sensitive parameters, including: Based on wells with core analysis data, cross plots were established with the gamma ray spectral logging uranium curve value, sonic transit time logging curve value, compensated density logging curve value, natural gamma curve value, compensated neutron curve value, and the overlap map area parameter calculated using the ΔlogR method, respectively, and the measured total organic carbon content data from the core analysis data to determine sensitive parameters.

5. The method according to claim 4, characterized in that, The sensitive parameters are: logging response curve parameters that have a high regression correlation coefficient with the measured data of total organic carbon content in core analysis.

6. The method according to claim 1, characterized in that, The formula for calculating the total organic carbon content is as follows: TOC=3.408×e 0.376xU +0.047×△t+3.014 Where U is the uranium logging curve value of the gamma spectral logging and Δt is the sonic logging curve value.

7. The method according to claim 1, characterized in that, The formula for calculating the oil content of the oil shale formation is as follows: T = a × TOC + b Where a and b are fitting coefficients.

8. A system for identifying oil shale and calculating its oil content, characterized in that, include: Oil shale formation identification module, used to identify oil shale formations; A module for identifying oil shale formations with high organic matter content is used to identify oil shale formations with high organic matter content in the oil shale formations. The sensitive parameter determination module is used to determine sensitive parameters with high correlation coefficients in the oil shale formation with high organic matter content. The total organic carbon content calculation module is used to establish the relationship between the total organic carbon content and the sensitive parameter, and to calculate the total organic carbon content. The oil content calculation module is used to establish the relationship between the total organic carbon content and the oil content of the oil shale formation, and to calculate the oil content of the oil shale formation.

9. A computer-readable storage medium, characterized in that, The system stores a program or instructions that, when executed on a computer, cause the computer to perform a method for identifying oil shale and calculating its oil content as described in any one of claims 1-7.

10. A device, characterized in that, Includes a processor, which is coupled to a memory; The processor is used to read and execute the computer program stored in the memory to implement the oil shale identification and oil content calculation method as described in any one of claims 1-7.

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