Method and system for evaluating formation fluid properties using light hydrocarbon log envelope area

Abstract

This invention discloses a method and system for evaluating formation fluid properties using the envelope area of ​​light hydrocarbon logging, belonging to the field of oil and gas exploration and development technology. The method includes: collecting light hydrocarbon logging experimental data and light hydrocarbon sample data from the target formation in the study area; arranging the light hydrocarbon logging experimental data in an ordered manner to obtain reprocessed light hydrocarbon logging data; dividing the light hydrocarbon sample data into known fluid property sample data and unknown fluid property sample data, and plotting them as a two-dimensional scatter plot; summarizing representative formation fluid characteristic values ​​based on the plotted light hydrocarbon logging reprocessed data of known fluid property samples, calculating the envelope area ratio of the characteristic value segments of each known fluid property sample, and establishing a formation fluid property evaluation standard based on the envelope area ratio; and applying the formation fluid property evaluation standard to samples with unknown fluid properties to evaluate formation fluid properties. This invention can improve the accuracy of formation fluid evaluation.

Description

Technical Field

[0001] This application relates to the field of oil and gas exploration and development technology, and in particular to a method and system for evaluating formation fluid properties using the envelope area of ​​light hydrocarbon logging. Background Technology

[0002] Formation fluid property assessment is an essential production step in oil and gas exploration. The most intuitive and reliable technical means of formation fluid assessment is to conduct direct formation testing in the drilling or completed well sites. The test results are the most important reference standard for analyzing the fluid properties of the area. However, due to the high cost of formation testing operations, the number of actual formation test samples is limited. Secondly, the industry commonly uses combined analysis of multiple logging data to obtain comprehensive interpretation conclusions of formation fluids, which generally can only be output after well completion, making it difficult to meet the needs of real-time fluid identification during drilling. Therefore, developing drilling-while-drilling formation fluid identification and assessment technologies to improve the timeliness and reliability of fluid assessment is an important research direction in oil and gas exploration.

[0003] Light hydrocarbon logging technology is a field-based logging-while-drilling technique that allows for sampling and laboratory analysis of key target formations during drilling, offering advantages in data acquisition during drilling. Light hydrocarbon logging can obtain peak area information for hundreds of hydrocarbon components in reservoir fluids, reflecting their compositional characteristics. Traditional light hydrocarbon logging fluid identification methods mostly select single or a few hydrocarbon-sensitive parameters for fluid identification, relying only on local component information. This makes them highly susceptible to component anomalies and sample disturbances, resulting in insufficient parameter stability and a need to improve reservoir fluid identification success rates.

[0004] In addition, the hydrocarbon components in the existing light hydrocarbon logging raw output data are not strictly ordered according to the number of carbon atoms; isomers, cyclic hydrocarbons, and aromatic hydrocarbons are interspersed. Directly using the raw spectra for analysis easily leads to the loss of component evolution patterns, restricting the full exploitation and utilization of light hydrocarbon logging data. Current technology lacks a technical solution for fine-grained classification and evaluation of gas layers, gas-water co-layers, and gas-water-bearing layers based on the overall spectral characteristics of multiple components and relying on envelope area ratios. Summary of the Invention

[0005] Based on this, it is necessary to provide a method and system for evaluating formation fluid properties using the envelope area of ​​light hydrocarbon logging to address the above technical problems. This method involves the overall characteristics of a combination of multiple continuous hydrocarbon components, and its variation characteristics are more stable and reliable compared to single or a few sensitive parameters.

[0006] In a first aspect, embodiments of this application provide a method for evaluating formation fluid properties using the envelope area of ​​light hydrocarbon logging, the method comprising: Data acquisition steps: Collect light hydrocarbon logging test data and light hydrocarbon sample data of the target layer in the study area; Data processing steps: Arrange the light hydrocarbon logging test data in an orderly manner to obtain light hydrocarbon logging reprocessed data; Data partitioning steps: Based on whether there are test conclusions or well logging interpretation conclusions regarding the formation fluid properties of the light hydrocarbon sample data corresponding to the depth segment of the target layer, the light hydrocarbon sample data of the target layer is divided into sample data with known fluid properties and sample data with unknown fluid properties. Two-dimensional mapping steps: Based on the light hydrocarbon logging heavy processing data, two-dimensional scatter plots are generated on the known fluid property sample data and the unknown fluid property sample data to obtain light hydrocarbon logging heavy processing data maps of known fluid property samples and light hydrocarbon logging heavy processing data maps of unknown fluid property samples. The steps for establishing the evaluation criteria are as follows: Based on the light hydrocarbon logging data of the known fluid property samples, the characteristic values ​​representing the formation fluids are summarized and plotted. The envelope area ratio of the characteristic value segments of each known fluid property sample is calculated, and a formation fluid property evaluation criterion based on the envelope area ratio is established. Evaluation steps: Based on the light hydrocarbon logging data of the unknown fluid property sample, calculate the envelope area ratio of the characteristic value segment of the unknown fluid property sample, and obtain the formation fluid property evaluation of the unknown fluid property sample by referring to the formation fluid property evaluation standard.

[0007] In one embodiment, the data processing step is described as follows: hydrocarbons with different carbon numbers are arranged in ascending order of carbon number; hydrocarbons with the same carbon number are arranged in ascending order of structure, i.e., chain hydrocarbons first, then cyclic hydrocarbons, and finally aromatic hydrocarbons with benzene rings; chain hydrocarbons with the same carbon number are arranged first as normal hydrocarbons and then as isomers.

[0008] In one embodiment, in the two-dimensional mapping step, the light hydrocarbon logging data is processed in a format that is the effective data format required for mapping, including: hydrocarbon symbols, the sorting number corresponding to the hydrocarbon, and the peak area corresponding to the hydrocarbon.

[0009] In one embodiment, during the two-dimensional mapping step, the depth segment corresponding to the known fluid property sample data contains test conclusions or well logging interpretation conclusions regarding the formation fluid properties.

[0010] In one embodiment, during the two-dimensional mapping step, the depth segment corresponding to the unknown fluid property sample data does not contain test conclusions or well logging interpretation conclusions regarding the formation fluid properties.

[0011] In one embodiment, in the two-dimensional plotting step, the two-dimensional scatter plot uses the sorting number corresponding to different hydrocarbon substances and the peak area corresponding to the hydrocarbon substances as coordinates.

[0012] In one embodiment, the step of establishing the evaluation criteria includes establishing a formation fluid property evaluation criterion based on the envelope area ratio, which includes: Based on the well logging data of light hydrocarbons from the known fluid property samples, the characteristic values ​​of the light and heavy components of the formation fluids were analyzed and summarized. Calculate the areas of the eigenvalue segments of the lighter and heavier components between the upper and lower envelope boundaries to obtain the envelope area of ​​the eigenvalue segments of the lighter and heavier components. The ratio of the envelope area of ​​the characteristic value segment of the lighter component to the envelope area of ​​the characteristic value segment of the heavier component is calculated. Combined with the test results and well logging interpretation results of the formation fluid properties corresponding to the known fluid property samples, the range of envelope area ratios corresponding to different formation fluid properties is determined, and a formation fluid property evaluation standard based on the envelope area ratio is established.

[0013] In one embodiment, the characteristic values ​​of the lighter components include the maximum carbon value m and the minimum carbon value 1, and the characteristic values ​​of the heavier components include the minimum carbon value n and the maximum carbon value w. Where m, n, and w are integers greater than 1, and w > n > m.

[0014] Secondly, embodiments of this application provide a system for evaluating formation fluid properties using the envelope area of ​​light hydrocarbon logging, the system comprising: The data acquisition module collects light hydrocarbon logging experimental data and light hydrocarbon sample data of the target layer in the study area; The data processing module arranges the light hydrocarbon logging experiment data in an orderly manner to obtain light hydrocarbon logging reprocessed data; The data segmentation module divides the light hydrocarbon sample data of the target layer into sample data with known fluid properties and sample data with unknown fluid properties based on whether there are test conclusions or well logging interpretation conclusions for the formation fluid properties of the corresponding depth segment of the light hydrocarbon sample data of the target layer. The two-dimensional mapping module, based on the light hydrocarbon logging heavy processing data, performs two-dimensional scatter plots on the known fluid property sample data and the unknown fluid property sample data to obtain light hydrocarbon logging heavy processing data maps of known fluid property samples and light hydrocarbon logging heavy processing data maps of unknown fluid property samples. The evaluation criteria establishment module summarizes the characteristic values ​​of formation fluids based on the light hydrocarbon logging heavy processing data of the known fluid property samples, calculates the envelope area ratio of the characteristic value segments of each known fluid property sample, and establishes a formation fluid property evaluation criterion based on the envelope area ratio. The evaluation module generates a map based on the light hydrocarbon logging data of the unknown fluid property sample, calculates the envelope area ratio of the characteristic value segment of the unknown fluid property sample, and obtains the formation fluid property evaluation of the unknown fluid property sample by referring to the formation fluid property evaluation standard.

[0015] In one embodiment, the evaluation criterion establishment module includes: The eigenvalue analysis module generates maps based on the light hydrocarbon logging data of the known fluid property samples and analyzes and summarizes the eigenvalues ​​of the light and heavy components that represent the formation fluids. The envelope area calculation module calculates the area of ​​the eigenvalue segments of the lighter and heavier components between the upper and lower envelope boundary lines, thus obtaining the envelope area of ​​the eigenvalue segments of the lighter and heavier components. The standard establishment module calculates the ratio of the envelope area of ​​the characteristic value segment of the lighter component to the envelope area of ​​the characteristic value segment of the heavier component. Combining the test results and well logging interpretation results of the formation fluid properties corresponding to the known fluid property samples, it determines the range of envelope area ratios corresponding to different formation fluid properties and establishes a formation fluid property evaluation standard based on the envelope area ratio.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The aforementioned method and system for evaluating formation fluid properties using the envelope area of ​​light hydrocarbon logging summarizes representative formation fluid characteristic values ​​based on the reprocessed light hydrocarbon logging data of known fluid property samples. It calculates the envelope area ratio of the characteristic value segments for each known fluid property sample and establishes a formation fluid property evaluation standard based on the envelope area ratio. This involves the overall characteristics of a combination of multiple continuous hydrocarbon components. Compared to existing technologies that evaluate formation fluids based on the characteristics of a single or a few sensitive hydrocarbon parameters, this method offers more stable variation characteristics, higher reliability, and improved accuracy in formation fluid evaluation.

[0017] The above-mentioned method and system for evaluating formation fluid properties using the envelope area of ​​light hydrocarbon logging involves mapping the light hydrocarbon logging data of the unknown fluid property sample, calculating the envelope area ratio of the characteristic value segment of the unknown fluid property sample, and obtaining the formation fluid property evaluation of the unknown fluid property sample by referring to the formation fluid property evaluation standard. It is highly operable and has high practical value.

[0018] The above-mentioned method and system for evaluating formation fluid properties using the envelope area of ​​light hydrocarbon logging can be applied to evaluate the fluid properties in corresponding natural gas-bearing formations within the wellbore of both ongoing and completed wells. It provides a more detailed evaluation of formation fluid levels, accurate to the levels of gas layers, gas-water co-layers, and gas-water-bearing layers.

[0019] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic flowchart of a method for evaluating formation fluid properties using the logging envelope area of ​​light hydrocarbons, provided in the embodiments of this application. Figure 2 This is a schematic diagram of the graph of light hydrocarbon logging heavy processing data of gas reservoir samples and the corresponding envelope area ratio parameters provided in the embodiments of this application; Figure 3 This is a schematic diagram of the plot of light hydrocarbon logging heavy processing data of gas-water co-layer samples and the corresponding envelope area ratio parameters provided in the embodiments of this application. Figure 4 This is a schematic diagram of the plot of light hydrocarbon logging heavy processing data of gas-bearing water layer samples and the corresponding envelope area ratio parameters provided in the embodiments of this application; Figure 5 This is a schematic diagram of the steps for establishing evaluation criteria provided in the embodiments of this application; Figure 6 This is an application example of well envelope area fluid identification in Embodiment A of this application; Figure 7 This is a schematic diagram of a system architecture for evaluating formation fluid properties using the logging envelope area of ​​light hydrocarbons, provided in an embodiment of this application. Figure 8 This is a schematic diagram of the architecture of the evaluation criteria establishment module provided in the embodiments of this application. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0022] Obviously, the accompanying drawings described below are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0023] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0024] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms “a,” “an,” “an,” “the,” and similar words used in this application do not indicate quantity limitation and may indicate singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or devices. The terms “connected,” “linked,” “coupled,” and similar words used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Multiple” used in this application refers to two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following objects are in an "or" relationship. The terms "first," "second," and "third" used in this application are merely to distinguish similar objects and do not represent a specific ordering of the objects.

[0025] The first aspect of this invention provides a method for evaluating formation fluid properties using the envelope area of ​​light hydrocarbon logging, such as... Figure 1 As shown, it includes the following steps: Step S101: Collect light hydrocarbon logging test data and light hydrocarbon sample data of the target layer in the study area.

[0026] Specifically, the light hydrocarbon logging experiment data contains more than one hundred different types of hydrocarbon (hydrocarbon) material parameters, some of which are shown in Table 1.

[0027] Table 1

[0028] Based on the ranking of the top 11 hydrocarbons in the light hydrocarbon logging experiment data listed in Table 1, the hydrocarbon symbol 22DMC4 (2,2-dimethylbutane) has 6 carbons, the hydrocarbon symbol CYC5 (cyclopentane) has 5 carbons, 22DMC4 is ranked 9th, and CYC5 is ranked 10th. It can be seen that the ranking rule of the light hydrocarbon logging experiment data is not arranged according to the number of carbons in ascending order.

[0029] Step S102: Arrange the light hydrocarbon logging experimental data in an orderly manner to obtain light hydrocarbon logging reprocessing data.

[0030] Specifically, the light hydrocarbon logging experimental data are arranged according to an ordered sorting rule to obtain light hydrocarbon logging reprocessing data.

[0031] Specifically, the sorting rules for the ordered arrangement are as follows: hydrocarbons with different carbon numbers are arranged in ascending order of the number of carbons; hydrocarbons with the same carbon number are sorted in ascending order of structural complexity, i.e., chain hydrocarbons first, then cyclic hydrocarbons, and finally aromatic hydrocarbons with benzene rings; chain hydrocarbons with the same carbon number are sorted in ascending order of normal hydrocarbons and then isomers.

[0032] The reprocessed data format for light hydrocarbon logging is the valid data format required for mapping, including: hydrocarbon symbols, corresponding sequence numbers, and peak areas. Examples of some reprocessed light hydrocarbon logging data formats are shown in Table 2.

[0033] Table 2

[0034] Step S103: Based on whether there are test conclusions or well logging interpretation conclusions regarding the formation fluid properties of the light hydrocarbon sample data corresponding to the depth segment of the target layer, the light hydrocarbon sample data of the target layer is divided into sample data with known fluid properties and sample data with unknown fluid properties.

[0035] Specifically, for samples with known fluid properties, there are test or well logging interpretation conclusions for the corresponding depth range of formation fluid properties, which are used to analyze the characteristic values ​​of different formation fluids and summarize formation fluid evaluation standards; for samples with unknown fluid properties, there are no test or well logging interpretation conclusions for the corresponding depth range of formation fluid properties, so the samples with unknown fluid properties are applied to the formation fluid property evaluation standards to evaluate the formation fluid properties.

[0036] Step S104: Based on the light hydrocarbon logging reprocessing data, perform two-dimensional scatter plots on the known fluid property sample data and the unknown fluid property sample data to obtain light hydrocarbon logging reprocessing data plots for known fluid property samples and light hydrocarbon logging reprocessing data plots for unknown fluid property samples.

[0037] Specifically, the two-dimensional scatter plot uses the sequence number corresponding to different hydrocarbon substances and the peak area corresponding to the hydrocarbon substances as coordinates.

[0038] For example, based on the light hydrocarbon logging reprocessing data format shown in Table 2, using the sorted number corresponding to the hydrocarbon as the x-axis coordinate and the peak area corresponding to the hydrocarbon as the y-axis coordinate, a two-dimensional scatter plot of known fluid properties is generated for the sample, resulting in the light hydrocarbon logging reprocessing data plot of the gas reservoir sample as shown below. Figure 2 As shown, the plotted data of light hydrocarbon logging from the gas-water co-layer sample after heavy processing is as follows. Figure 3 As shown, the plotted data of light hydrocarbon logging from the gas-bearing water layer sample after heavy processing is as follows. Figure 4 As shown.

[0039] Step S105: Based on the light hydrocarbon logging data of known fluid property samples, summarize the characteristic values ​​of formation fluids, calculate the envelope area ratio of the characteristic value segments of each known fluid property sample, and establish a formation fluid property evaluation standard based on the envelope area ratio.

[0040] In this embodiment, Figure 2 , Figure 3 , Figure 4 The three samples were all samples with known fluid properties and had actual formation test results at the corresponding depths. They were respectively identified as gas layers, gas-water co-layers, and gas-water-bearing layers, and were used to establish evaluation standards. They were not unknown fluid samples to be evaluated.

[0041] Step S106: Based on the light hydrocarbon logging heavy processing data of the unknown fluid property sample, calculate the envelope area ratio of the characteristic value segment of the unknown fluid property sample, and obtain the formation fluid property evaluation of the unknown fluid property sample by referring to the established formation fluid property evaluation standard.

[0042] Based on the above embodiments, this application provides a detailed explanation of embodiment S105. Specifically, this application involves steps for establishing evaluation criteria, such as... Figure 5 As shown, it includes the following steps: Step S201: Based on the light hydrocarbon logging heavy processing data of the known fluid property sample, the characteristic values ​​of the light and heavy components representing the formation fluid are analyzed and summarized.

[0043] Specifically, the characteristic values ​​of the lighter components include the maximum carbon value m and the minimum carbon value 1; the characteristic values ​​of the heavier components include the minimum carbon value n and the maximum carbon value w.

[0044] Where m, n, and w are integers greater than 1, and w > n > m.

[0045] The method for determining the parameters m, n, and w is as follows: A batch of samples from known gas layers, gas-water co-layers, and gas-water-bearing layers in the study area, which have been confirmed by stratigraphic testing, were collected, and hydrocarbon orderly rearrangement and two-dimensional broken line mapping were completed for all of them; Observe the peak area distribution pattern of hydrocarbons in all spectra. Carbon number 1 (methane) is the starting point of the light end that exists in all samples. Statistically analyze the gas layer samples and record the maximum carbon number of the concentrated distribution of light components as m. Observe the spectra and record the minimum carbon number corresponding to the point where the peak area of ​​heavy components begins to rise significantly as n. Take the maximum carbon number of the component that can be stably detected by the light hydrocarbon logging in this area as w. The condition w>n>m must be met. The correspondence between the carbon numbers m, n, and w and the sorting numbers is directly mapped by rearranging the table in the data processing steps.

[0046] For example, within the study area, statistical analysis of known sample spectra from multiple wells revealed that the maximum carbon value (m) for the lighter components was 4, corresponding to the sequence number 5, and the corresponding hydrocarbon iC4H. 10 (Isobutane); The lightest component has a minimum carbon number of 1, corresponding to methane CH4 (methane); The heaviest component has a minimum carbon number of n=6, corresponding to the sequence number 10, and the corresponding hydrocarbon is 22DMC4 (2,2-dimethylbutane); The heaviest component has a maximum carbon number of w=7, corresponding to the sequence number 31, and the corresponding to TOL (toluene).

[0047] Step S202: Calculate the areas of the eigenvalue segments of the lighter and heavier components between the upper and lower envelope boundary lines to obtain the envelope area of ​​the eigenvalue segments of the lighter and heavier components.

[0048] Specifically, the area of ​​the envelope is calculated using the principle of integration.

[0049] For example, such as Figure 2 , Figure 3 , Figure 4As shown, sort numbers 1-5 correspond to the feature segments of the lighter component; sort number 10 31 corresponds to the heavy component characteristic segment; the blue area is the envelope area of ​​the light component segment, and the red area is the envelope area of ​​the heavy component segment. The areas of the two regions are obtained by integration.

[0050] Step S203: Calculate the ratio of the envelope area of ​​the characteristic value segment of the lighter component to the envelope area of ​​the characteristic value segment of the heavier component. Combine the test results and well logging interpretation results of the formation fluid properties corresponding to the known fluid property samples to determine the range of envelope area ratios corresponding to different formation fluid properties, and establish a formation fluid property evaluation standard based on the envelope area ratio.

[0051] For example, known samples from the study area that have been confirmed by stratigraphic testing (including...) Figure 2 Gas layer samples, Figure 3 Gas-water co-layer samples Figure 4 Multiple standard samples, including those containing gas-water layers, were used to calculate the envelope area ratio for each sample. Statistical analysis showed that the ratio of all measured gas layer samples was generally high, the ratio of all measured gas-water layer samples was generally low, and the ratio of gas-water co-layer samples was in between. The statistical boundary value of different fluid sample clusters was used as the critical threshold.

[0052] Based on the statistical results of known samples in the study area, the following results were obtained: the ratio of envelope area of ​​samples in the gas-water layer is concentrated ≤1.25; the ratio of gas-water layer samples is concentrated in the range of 1.25-1.7; and the ratio of gas layer samples is ≥1.7. Therefore, the critical threshold in the evaluation criteria in Table 3 was determined.

[0053] Table 3. Evaluation Criteria for Formation Fluid Properties Based on Envelope Area Ratio

[0054] After establishing the evaluation criteria shown in Table 3 above, three reservoirs from Well A without direct formation testing results were selected as samples for evaluation of unknown fluid properties. Figure 6 As shown: (1) Layer 1A, well section 4140 4142m: The calculated envelope area ratio of the light component to the heavy component is 1.81, which is ≥1.7 according to the evaluation criteria in Table 3, and is therefore determined to be a gas layer; (2) Layer 2B, well section 4174 4176m: The calculated ratio of the envelope area of ​​the lighter / heavier component characteristic segment is 1.39, falling within 1.25. The 1.7 interval is determined to be a gas-water co-layer; (3) Layer 3C, well section 4178 4180m: The calculated envelope area ratio of the light component to the heavy component is 1.25. ≤1.25, so it is determined to be a gas-bearing water layer.

[0055] Subsequent well testing results were consistent with the results determined by this method, verifying the reliability of this method.

[0056] A second aspect of this invention provides a system for evaluating formation fluid properties using the logging envelope area of ​​light hydrocarbons. For example... Figure 7 As shown, the system 1 for evaluating formation fluid properties using the envelope area of ​​light hydrocarbon logging includes: Data acquisition module 10 collects light hydrocarbon logging experimental data and light hydrocarbon sample data of the target layer in the study area; Data processing module 20 arranges the light hydrocarbon logging test data in an orderly manner to obtain light hydrocarbon logging reprocessed data; The data segmentation module 30 divides the light hydrocarbon sample data of the target layer into sample data with known fluid properties and sample data with unknown fluid properties based on whether there are test conclusions or well logging interpretation conclusions for the formation fluid properties in the corresponding depth segment of the light hydrocarbon sample data of the target layer. The two-dimensional mapping module 40, based on the light hydrocarbon logging heavy processing data, performs two-dimensional scatter plots on the known fluid property sample data and the unknown fluid property sample data to obtain light hydrocarbon logging heavy processing data maps of known fluid property samples and light hydrocarbon logging heavy processing data maps of unknown fluid property samples. The evaluation criteria establishment module 50 summarizes the characteristic values ​​of formation fluids based on the light hydrocarbon logging heavy processing data of the known fluid property samples, calculates the envelope area ratio of the characteristic value segments of each known fluid property sample, and establishes a formation fluid property evaluation criterion based on the envelope area ratio. Evaluation module 60, based on the light hydrocarbon logging heavy processing data of the unknown fluid property sample, calculates the envelope area ratio of the characteristic value segment of the unknown fluid property sample, and obtains the formation fluid property evaluation of the unknown fluid property sample by referring to the formation fluid property evaluation standard.

[0057] Specifically, the data processing module 20 executes the following ordered sorting rules: hydrocarbons with different carbon numbers are arranged in ascending order of carbon number; hydrocarbons with the same carbon number are sorted in the order of first chain hydrocarbons, then cyclic hydrocarbons, and finally aromatic hydrocarbons; and chain hydrocarbons with the same carbon number are arranged in the order of first normal hydrocarbons and then isomers.

[0058] In one embodiment, such as Figure 8 As shown, the evaluation criterion establishment module 50 includes: The eigenvalue analysis module 51, based on the light hydrocarbon logging heavy processing data of the known fluid property sample, analyzes and summarizes the characteristic values ​​of the light and heavy components representing the formation fluid. The envelope area calculation module 52 calculates the area of ​​the eigenvalue segments of the lighter and heavier components between the upper and lower envelope boundary lines, and obtains the envelope area of ​​the eigenvalue segments of the lighter and heavier components. The standard establishment module 53 calculates the ratio of the envelope area of ​​the characteristic value segment of the lighter component to the envelope area of ​​the characteristic value segment of the heavier component. Combining the test results and well logging interpretation results of the formation fluid properties corresponding to the known fluid property samples, it determines the range of envelope area ratios corresponding to different formation fluid properties and establishes a formation fluid property evaluation standard based on the envelope area ratio.

[0059] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0060] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0061] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for evaluating formation fluid properties using light hydrocarbon log envelope area, characterized in that, The method includes: Data acquisition steps: Collect light hydrocarbon logging test data and light hydrocarbon sample data of the target layer in the study area; Data processing steps: The light hydrocarbon logging experimental data are arranged in an ordered manner to obtain light hydrocarbon logging reprocessed data; the sorting rules for the ordered arrangement are as follows: hydrocarbons with different carbon numbers are arranged in ascending order of carbon number; hydrocarbons with the same carbon number are sorted in ascending order of structure, i.e., first chain hydrocarbons, then cyclic hydrocarbons, and finally benzene ring aromatic hydrocarbons; chain hydrocarbons with the same carbon number are sorted first normal hydrocarbons and then isomers. Data partitioning steps: Based on whether there are test conclusions or well logging interpretation conclusions regarding the formation fluid properties of the light hydrocarbon sample data corresponding to the depth segment of the target layer, the light hydrocarbon sample data of the target layer is divided into sample data with known fluid properties and sample data with unknown fluid properties. Two-dimensional mapping steps: Based on the light hydrocarbon logging heavy processing data, two-dimensional scatter plots are generated for the known fluid property sample data and the unknown fluid property sample data to obtain light hydrocarbon logging heavy processing data maps for known fluid property samples and light hydrocarbon logging heavy processing data maps for unknown fluid property samples; the two-dimensional scatter plots use the sort number corresponding to different hydrocarbon substances and the peak area corresponding to the hydrocarbon substances as coordinates. The steps for establishing the evaluation criteria are as follows: Based on the light hydrocarbon logging data of the known fluid property samples, the characteristic values ​​representing the formation fluids are summarized and plotted. The envelope area ratio of the characteristic value segments of each known fluid property sample is calculated, and a formation fluid property evaluation criterion based on the envelope area ratio is established. Evaluation steps: Based on the light hydrocarbon logging data of the unknown fluid property sample, calculate the envelope area ratio of the characteristic value segment of the unknown fluid property sample, and obtain the formation fluid property evaluation of the unknown fluid property sample by referring to the formation fluid property evaluation standard.

2. The method of claim 1, wherein, In the two-dimensional mapping step, the light hydrocarbon logging data is processed in a format that is the valid data format required for mapping, including: hydrocarbon symbols, the corresponding sequence number of hydrocarbons, and the peak area of ​​hydrocarbons.

3. The method of claim 1, wherein, In the two-dimensional mapping step, the depth segment corresponding to the known fluid property sample data has test conclusions or well logging interpretation conclusions regarding the formation fluid properties.

4. The method of claim 1, wherein, In the two-dimensional mapping step, there are no test conclusions or well logging interpretation conclusions for the formation fluid properties in the depth segment corresponding to the unknown fluid property sample data.

5. The method of claim 1, wherein, The steps for establishing evaluation criteria include: establishing formation fluid property evaluation criteria based on envelope area ratio. Based on the well logging data of light hydrocarbons from the known fluid property samples, the characteristic values ​​of the light and heavy components of the formation fluids were analyzed and summarized. Calculate the areas of the eigenvalue segments of the lighter and heavier components between the upper and lower envelope boundaries to obtain the envelope area of ​​the eigenvalue segments of the lighter and heavier components. The ratio of the envelope area of ​​the characteristic value segment of the lighter component to the envelope area of ​​the characteristic value segment of the heavier component is calculated. Combined with the test results and well logging interpretation results of the formation fluid properties corresponding to the known fluid property samples, the range of envelope area ratios corresponding to different formation fluid properties is determined, and a formation fluid property evaluation standard based on the envelope area ratio is established.

6. The method of claim 5, wherein, The characteristic values ​​of the lighter components include the maximum carbon value m and the minimum carbon value 1, and the characteristic values ​​of the heavier components include the minimum carbon value n and the maximum carbon value w; wherein m, n, and w are integers greater than 1, and w>n>m.

7. A system for evaluating properties of formation fluids using light hydrocarbon log envelope area, the system comprising: include: The data acquisition module collects light hydrocarbon logging experimental data and light hydrocarbon sample data of the target layer in the study area; The data processing module arranges the light hydrocarbon logging experiment data in an orderly manner to obtain light hydrocarbon logging reprocessed data; The data segmentation module divides the light hydrocarbon sample data of the target layer into sample data with known fluid properties and sample data with unknown fluid properties based on whether there are test conclusions or well logging interpretation conclusions for the formation fluid properties of the corresponding depth segment of the light hydrocarbon sample data of the target layer. The two-dimensional mapping module, based on the light hydrocarbon logging heavy processing data, performs two-dimensional scatter plots on the known fluid property sample data and the unknown fluid property sample data to obtain light hydrocarbon logging heavy processing data maps of known fluid property samples and light hydrocarbon logging heavy processing data maps of unknown fluid property samples. The evaluation criteria establishment module summarizes the characteristic values ​​of formation fluids based on the light hydrocarbon logging heavy processing data of the known fluid property samples, calculates the envelope area ratio of the characteristic value segments of each known fluid property sample, and establishes a formation fluid property evaluation criterion based on the envelope area ratio. The evaluation module generates a map based on the light hydrocarbon logging data of the unknown fluid property sample, calculates the envelope area ratio of the characteristic value segment of the unknown fluid property sample, and obtains the formation fluid property evaluation of the unknown fluid property sample by referring to the formation fluid property evaluation standard.

8. The system of claim 7, wherein, The evaluation criteria establishment module includes: The eigenvalue analysis module generates maps based on the light hydrocarbon logging data of the known fluid property samples and analyzes and summarizes the eigenvalues ​​of the light and heavy components that represent the formation fluids. The envelope area calculation module calculates the area of ​​the eigenvalue segments of the lighter and heavier components between the upper and lower envelope boundary lines, thus obtaining the envelope area of ​​the eigenvalue segments of the lighter and heavier components. The standard establishment module calculates the ratio of the envelope area of ​​the characteristic value segment of the lighter component to the envelope area of ​​the characteristic value segment of the heavier component. Combining the test results and well logging interpretation results of the formation fluid properties corresponding to the known fluid property samples, it determines the range of envelope area ratios corresponding to different formation fluid properties and establishes a formation fluid property evaluation standard based on the envelope area ratio.

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