Dividing method for diagenetic facies based on hydrocarbon minerals

Abstract

The invention discloses a diagenetic facies division method based on hydrocarbon minerals. The diagenetic facies division method comprises the following steps: S1, collecting samples; s2, analyzing a casting body sheet; s3, analyzing a fluorescent slice; s4, calculation of diagenesis parameters; the method is suitable for the technical field of diagenesis phase division of clastic rock oil and gas reservoirs, the diagenesis phase division method based on hydrocarbon minerals is provided, diagenesis phase division standards comprise information of hydrocarbon fluid activities, information is analyzed and identified by means of casting body slices and fluorescent slices, operation is easy, and practicability is high.

Description

Technical Field

[0001] The present invention belongs to the technical field of diagenetic facies division of clastic rock oil and gas reservoirs, and specifically relates to a method for dividing diagenetic facies based on hydrocarbon-indicating minerals. Background Art

[0002] At the present stage, most continental oilfields in China have entered the oil and gas exploration stage with lithologic and stratigraphic subtle oil and gas reservoirs as the main targets. Research shows that the physical properties of reservoir bodies are mainly affected and controlled by the comprehensive effects of sedimentation, tectonism and diagenesis. Especially for the reservoir spaces of low-permeability reservoirs, their formation and distribution are mainly controlled by the type and intensity of diagenesis. It also controls the distribution of reservoir bodies and the heterogeneity within reservoir bodies. Under the conditions of similar sedimentary facies, tectonic background and hydrocarbon source rock conditions, finding favorable diagenetic facies related to oil and gas enrichment is the key and difficult point in the exploration of low-permeability sandstone reservoirs.

[0003] Diagenetic facies are the products of sediments in a specific sedimentary and physico-chemical environment, undergoing certain diagenetic processes and evolution stages under the action of diagenesis, tectonics, etc., and include comprehensive characteristics such as rock particles, cements, textures, pores and fractures.

[0004] Patent "Deep tight sandstone reservoir evaluation method for identifying reservoir diagenetic facies based on artificial intelligence" (Patent Publication No. CN113820754A). The invention discloses a favorable reservoir evaluation method for deep tight sandstone based on artificial intelligence for identifying reservoir diagenetic facies. This method divides the rock types of sandstones by modifying the end members of the QFL chart and establishing a new sandstone classification chart. By corresponding each rock type to the diagenetic facies, a method for dividing diagenetic facies based on rock types is established. Using the logging data of core wells in the study area, the logging response characteristics of each diagenetic facies are obtained. Using the logging data of the determined rock facies to train a BP neural network to identify the diagenetic facies types of each well in the study area, analyze the lateral distribution law of diagenetic facies in the deep tight sandstone reservoir, calculate the reservoir comprehensive evaluation index at each drilling well point in the reservoir and draw a plane distribution map of the reservoir comprehensive evaluation index, and predict the favorable areas of the deep tight sandstone reservoir. The present invention realizes the systematic evaluation of the entire well section of the deep tight sandstone reservoir, can accurately predict the favorable areas in the reservoir, and lays a foundation for the exploration and development of deep oil and gas. The purpose of this patent is the logging identification and application of diagenetic facies, and no specific description is made on the specific rock mineral characteristics of diagenetic facies.

[0005] Patent "Quantitative Identification Method for Diagenetic Facies of Rich Debris Tight Reservoirs" (Patent Publication No. CN114089437A). The present invention provides a quantitative identification method for diagenetic facies of rich debris tight reservoirs. The quantitative identification method for diagenetic facies of rich debris tight reservoirs includes: Step 1, determining the study area and selecting data points; Step 2, relocating the cores and performing standardization processing on logging data; Step 3, dividing diagenetic facies; Step 4, fitting the mathematical function relationship between the three factors and the logging curves; Step 5, identifying the diagenetic facies of non-core well sections. The quantitative identification method for diagenetic facies of rich debris tight reservoirs innovatively proposes a division scheme for diagenetic facies of rich debris tight reservoirs from the perspectives of pore genesis, tight genesis, and types of tight minerals; uses the three-factor method to identify different diagenetic facies, thereby enabling the determination of the diagenetic facies types of the entire well section. This patent also focuses on the identification and division of the logging characteristics of diagenetic facies, and the research object is rich debris tight sandstone.

[0006] Patent "Method for Restoring Diagenetic Facies Evolution during Burial Process" (Publication No. CN108376189B). The present invention provides a method for restoring diagenetic facies evolution during the burial process of clastic rock reservoirs. This method determines the spatial distribution of different types of diagenetic facies, quantitatively predicts the distribution area of favorable diagenetic facies, and further determines the distribution of favorable reservoir beds. Through the study of the sedimentary facies, original fabric, diagenetic environment, and burial history of the target layer in the study area, the diagenetic facies types and distributions at different stages during the burial process of clastic rock reservoirs are restored. This patent does not consider the relationship between diagenetic facies and hydrocarbon activities.

[0007] Patent "A Method for Dividing Diagenetic Facies of Tight Oil Reservoirs" (Publication No. CN108805158B). The present invention provides a method for dividing different diagenetic facies of tight oil reservoirs, belonging to the technical field of oil reservoir exploration. The present invention first obtains the characteristic parameters of the diagenetic facies of tight oil reservoirs, and then uses the clustering analysis and grey correlation degree method to optimize and analyze the characteristic parameters to obtain the diagenetic facies types of tight oil reservoirs and divide the diagenetic facies. This patent mainly relies on the static parameters of the current reservoir in the division of diagenetic facies and uses clustering analysis to refine the division of diagenetic facies.

[0008] Patent "A Quantitative Evaluation Method for Diagenetic Facies of Low-Permeability Sandstone" (Publication No. CN112580200A) The present invention discloses a quantitative evaluation method for diagenetic facies of low-permeability sandstone, including determining the target formation; obtaining the apparent compaction rate, apparent cementation rate, apparent dissolution rate, apparent porosity and apparent microporosity of the target formation; obtaining the diagenetic index; obtaining the porosity, permeability, pore type and main diagenetic processes of the target formation; determining the diagenetic facies of the target formation according to the apparent compaction rate, apparent cementation rate, apparent dissolution rate, apparent porosity, apparent microporosity, diagenetic index, porosity, permeability, pore type and main diagenetic processes of the target formation; and taking corresponding measures for exploration and development according to the diagenetic facies of the target formation. The two parameters of apparent cementation rate and apparent dissolution rate are optimized to make the influence of dissolution and cementation on the reservoir more accurately characterized. And the parameter of apparent porosity is added to characterize the influence of intergranular pores on the reservoir, and finally the diagenetic index is summarized by five parameters. The division of this patent is mainly based on the current reservoir rock and physical property parameters, without considering oil and gas activities and their influences.

[0009] "Method for Dividing Diagenetic Facies of Clastic Rock Reservoirs" (Publication No. CN108090278B) The present invention discloses a method for dividing diagenetic facies of clastic rock reservoirs. This method first combines the magnitudes of the compaction rate Com, cementation rate Cem and dissolution rate Dis to divide the diagenetic facies D-n of clastic rocks into 9 major types, calculates the total compaction rate of rock samples, the cementation rate of each cementing mineral and the dissolution rate of each dissolving mineral, and then calculates the total cementation rate and total dissolution rate of the rock samples; then compares the total compaction rate, total cementation rate and total dissolution rate of the obtained rock samples with the compaction rate, cementation rate and dissolution rate corresponding to the 9 major diagenetic facies types; and determines the diagenetic facies of this rock sample to be named: A-i+J-B-i+R-C-i. The method of the present invention has the advantages of simple operation, reliable theory and good quantification. This patent mainly divides diagenetic facies based on the compaction rate, cementation rate and dissolution rate, without considering different diagenetic minerals and oil and gas activity factors.

[0010] "A Quantitative Evaluation Method for Diagenetic Facies of Tight Sandstone Reservoirs" (Publication No. CN104360039A) The present invention relates to a quantitative evaluation method for diagenetic facies of tight sandstone reservoirs, belonging to the technical field of oil and gas reservoir evaluation. The present invention can, under the condition of less core data in the area to be evaluated, use the core data and logging data of the area to be evaluated to divide the diagenetic facies types of the tight sandstone reservoirs in the area to be evaluated, establish the relationship between the diagenetic facies types of the tight sandstone reservoirs in the area to be evaluated and the logging parameters of the core wells, determine the diagenetic facies types of the non-core well tight sandstone reservoirs in the area to be evaluated, realize the quantitative evaluation of the diagenetic facies of the tight sandstone reservoirs in the area to be evaluated, determine the distribution characteristics of the favorable diagenetic facies zones and favorable reservoirs of the tight sandstone reservoirs, provide a reliable basis for predicting favorable exploration and development areas, and guiding oil and gas exploration and development, and reduce the exploration and development costs. It mainly divides diagenetic facies by using logging data.

[0011] "Method for Identifying Diagenetic Facies" (Publication No. CN105651962B) The present invention provides a method for identifying diagenetic facies. The method for identifying diagenetic facies includes: obtaining diagenetic facies characterization parameters, including measuring the intensity of diagenesis or the intensity of diagenesis and the content of diagenetic minerals; obtaining a comprehensive diagenetic coefficient based on the obtained intensity of diagenesis; or, the method for identifying diagenetic facies includes: obtaining diagenetic facies characterization parameters, including measuring the content of diagenetic minerals. The present invention identifies the type of reservoir diagenetic facies through the obtained comprehensive diagenetic coefficient or the content of diagenetic minerals, solves the technical problems of time-consuming and costly existing core analysis processes, and simultaneously realizes the quantitative evaluation of reservoir diagenetic facies. This patent mainly calculates the content of mineral components using rock density, and then determines the diagenetic facies of the rock.

[0012] In summary, at present, the division of diagenetic facies is mostly based on the rock characteristic parameters of the current reservoir, such as apparent compaction rate, apparent cementation rate, apparent dissolution rate, apparent porosity, and apparent microporosity, etc., to divide diagenetic facies, or uses logging curves for the identification and division of diagenetic facies, without involving the division of reservoir diagenetic facies types based on hydrocarbon activities. Summary of the Invention

[0013] The purpose of the present invention is to overcome the defects of the prior art and provide a method for dividing diagenetic facies based on hydrocarbon-indicating minerals.

[0014] To achieve the above purpose, the present invention adopts the following technical solutions:

[0015] A method for dividing diagenetic facies based on hydrocarbon-indicating minerals includes the following steps:

[0016] S1 Sample collection;

[0017] S2 Cast thin section analysis;

[0018] S3 Fluorescent thin section analysis;

[0019] S4 Calculation of diagenetic parameters;

[0020] S5 Division of diagenetic facies.

[0021] Preferably, in the step S1, the sample collection specifically includes:

[0022] Collect rock samples from the target interval and prepare cast thin sections and fluorescent thin sections.

[0023] Preferably, in the step S1, the size of the collected rock samples is not less than 5 cm * 5 cm.

[0024] Preferably, in the step S1, the sample collection specifically includes: to ensure the consistency of the subsequent observation fields of the casting thin section and the fluorescence thin section, the rock samples collected are made into casting thin sections and fluorescence thin sections respectively from the two cut surfaces after being cut in the middle.

[0025] Preferably, in the step S2, for the analysis of the casting thin section, the analyzed parameters include: the content of detrital quartz minerals, the content of detrital feldspar minerals, and the content of rock fragments.

[0026] Preferably, in the step S2, the analysis of the casting thin section includes: analyzing and identifying the content of matrix in the interstitial matter; the mineral contents of cements such as calcite, dolomite, siderite, pyrite, authigenic quartz, iron-bearing calcite, iron-bearing dolomite, barite, anhydrite, etc., and the porosity.

[0027] Preferably, in the step S3, the analysis of the fluorescence thin section specifically includes:

[0028] The fluorescence thin section is observed under a fluorescence microscope to distinguish the authigenic minerals in the identification results of the casting thin section and classify them into groups.

[0029] Preferably, in the step S3, the sample collection is divided into two types of components: hydrocarbon-indicating minerals and non-hydrocarbon-indicating minerals.

[0030] Preferably, in the step S3, the non-hydrocarbon-indicating minerals include the authigenic minerals before hydrocarbon fluids enter the reservoir in the rock; the hydrocarbon-indicating minerals include the authigenic minerals related to hydrocarbon activities or formed after hydrocarbon fluids enter the reservoir.

[0031] Preferably, in the step S3, it also includes: calculating the percentage ratios of the hydrocarbon-indicating minerals and the non-hydrocarbon-indicating minerals respectively.

[0032] Preferably, in the step S4, the calculation of the diagenetic parameters specifically includes: counting the intergranular volume, matrix filling rate, non-hydrocarbon-indicating mineral cementation rate, hydrocarbon-indicating mineral cementation rate, non-hydrocarbon-indicating mineral cementation rate / matrix filling rate, and hydrocarbon-indicating mineral cementation rate / matrix filling rate.

[0033] Preferably, in the step S4, the intergranular volume = interstitial matter + porosity;

[0034] The matrix filling rate = matrix / intergranular volume;

[0035] The non-hydrocarbon-indicating mineral cementation rate = non-hydrocarbon-indicating minerals / intergranular volume;

[0036] The hydrocarbon-indicating mineral cementation rate = hydrocarbon-indicating minerals / intergranular volume.

[0037] Preferably, in the step S5, the division of diagenetic facies specifically includes: based on the intergranular volume, matrix filling rate, non-hydrocarbon-bearing mineral cementation rate / matrix filling rate, and hydrocarbon-bearing mineral cementation rate / matrix filling rate of the sample; referring to the diagenetic facies division table, determine the diagenetic facies type of the sample.

[0038] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are:

[0039] In the present invention, a method for dividing diagenetic facies based on hydrocarbon-bearing minerals is proposed. The diagenetic facies division standard includes information on hydrocarbon fluid activities. Relying on the analysis and identification information of casting thin sections and fluorescence thin sections, the operation is simple and the practicability is strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a flowchart of a method for dividing diagenetic facies based on hydrocarbon-bearing minerals according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] The following further describes the specific embodiments of a method for dividing diagenetic facies based on hydrocarbon-bearing minerals of the present invention in conjunction with the attached Figure 1 , and is not limited to the description of the following embodiments for a method for dividing diagenetic facies based on hydrocarbon-bearing minerals of the present invention.

[0042] Example 1:

[0043] A method for dividing diagenetic facies based on hydrocarbon-bearing minerals, as Figure 1 shown, includes the following steps:

[0044] S1 Sample collection;

[0045] S2 Casting thin section analysis;

[0046] S3 Fluorescence thin section analysis;

[0047] S4 Calculation of diagenetic parameters;

[0048] S5 Division of diagenetic facies.

[0049] Example 2:

[0050] A method for dividing diagenetic facies based on hydrocarbon-bearing minerals, other steps are similar to those in Example 1. Further, in step S1, the sample collection specifically includes:

[0051] Collect rock samples from the target interval and prepare casting thin sections and fluorescence thin sections.

[0052] Further, in step S1, the size of the collected rock samples is not less than 5 cm * 5 cm.

[0053] Further, in step S1, sample collection specifically includes: To ensure the consistency of the subsequent observation fields of the cast thin sections and fluorescence thin sections, the rock samples collected are used to prepare cast thin sections and fluorescence thin sections from the two cut surfaces after being sectioned in the middle.

[0054] Example 3:

[0055] A method for classifying diagenetic facies based on hydrocarbon-bearing minerals. Other steps are similar to those in Example 1. Further, in step S2, for the analysis of cast thin sections, the parameters to be analyzed include: the content of detrital quartz minerals, the content of detrital feldspar minerals, and the content of rock fragments.

[0056] Further, in step S2, the analysis of cast thin sections includes: analyzing and identifying the content of matrix in the interstitial material; the mineral contents of cements such as calcite, dolomite, siderite, pyrite, authigenic quartz, iron-bearing calcite, iron-bearing dolomite, barite, anhydrite, etc., and the porosity.

[0057] Example 4:

[0058] A method for classifying diagenetic facies based on hydrocarbon-bearing minerals. Other steps are similar to those in Example 1. Further, in step S3, the analysis of fluorescence thin sections specifically includes:

[0059] The fluorescence thin sections are observed under a fluorescence microscope to distinguish the authigenic minerals in the identification results of the cast thin sections and classify them into groups.

[0060] Further, in step S3, sample collection divides the components into two categories: hydrocarbon-bearing minerals and non-hydrocarbon-bearing minerals.

[0061] Further, in step S3, non-hydrocarbon-bearing minerals include the authigenic minerals before hydrocarbon fluids enter the reservoir in the rock; hydrocarbon-bearing minerals include the authigenic minerals related to hydrocarbon activities or formed after hydrocarbon fluids enter the reservoir.

[0062] Further, in step S3, it also includes: calculating the percentage ratios of hydrocarbon-bearing minerals and non-hydrocarbon-bearing minerals respectively.

[0063] Example 5:

[0064] A method for classifying diagenetic facies based on hydrocarbon-bearing minerals. Other steps are similar to those in Example 1. Further, in step S4, the calculation of diagenetic parameters specifically includes: counting the intergranular volume, matrix filling rate, non-hydrocarbon-bearing mineral cementation rate, hydrocarbon-bearing mineral cementation rate, non-hydrocarbon-bearing mineral cementation rate / matrix filling rate, and hydrocarbon-bearing mineral cementation rate / matrix filling rate.

[0065] Further, in step S4, the intergranular volume = interstitial material + porosity;

[0066] The matrix filling rate = matrix / intergranular volume;

[0067] Non-hydrocarbon-indicating mineral cementation rate = non-hydrocarbon-indicating mineral / intergranular volume;

[0068] Hydrocarbon mineral cementation rate = hydrocarbon mineral / intergranular volume.

[0069] Example 6:

[0070] A diagenetic phase division method based on hydrocarbon-indicating minerals, the other steps are similar to those of Example 1. Further, in step S5, the division of diagenetic phases specifically includes: based on the intergranular volume, matrix filling rate, non-hydrocarbon-indicating mineral cementation rate / matrix filling rate, hydrocarbon-indicating mineral cementation rate / matrix filling rate of the sample; referring to the diagenetic phase division table, the diagenetic phase type of the sample is determined.

[0071] Example 7:

[0072] A diagenetic phase division method based on hydrocarbon-indicating minerals comprises the following steps:

[0073] S1: Sample collection, collect rock samples from the target layer, and make cast thin sections and fluorescent thin sections.

[0074] The size of the rock sample collected is 5cm*6cm;

[0075] In order to ensure the consistency of the subsequent observation field of cast thin sections and fluorescent thin sections, the collected rock samples were cut from the middle and distributed to produce cast thin sections and fluorescent thin sections.

[0076] S2: Casting thin section analysis

[0077] The casting thin section analysis mainly analyzes and identifies the following parameters, including the content of detrital quartz minerals, the content of detrital feldspar minerals and the content of rock fragments. Analysis results: The content of detrital quartz in this sample is 42.53%, the content of feldspar detrital is 25.34%, and the content of rock fragments is 23.53%.

[0078] Analyze and identify the content of impurities in the filling material; the content of minerals such as calcite, dolomite, siderite, pyrite, authigenic quartz, ferruginous calcite, ferruginous dolomite, barite, anhydrite, etc. in the cement; and the surface porosity. Analysis results: The sample has an impurity content of 6.00%, ferrocalcite cement 1.00%, dolomite cement 1.00%, kaolinite content 0.50%, and surface porosity 2%.

[0079] The analysis and identification of cast thin sections adopts the petroleum industry standard "SY / T 5368 Rock Thin Section Identification", which does not fall within the scope of protection of this patent.

[0080] S3: Fluorescence thin section analysis

[0081] ​The fluorescence thin sections are observed under a fluorescence microscope to distinguish the authigenic minerals in the identification results of the cast thin sections, and two types of components are divided. One is the authigenic minerals before hydrocarbon fluids enter the reservoir in the rock (abbreviated as non-hydrocarbon indicating minerals); the other is the authigenic minerals related to hydrocarbon activities or formed after hydrocarbon fluids enter the reservoir (abbreviated as hydrocarbon indicating minerals).

[0082] After the analysis of the sample fluorescence thin sections, ferrocalcite and kaolinite are hydrocarbon indicating minerals, and dolomite is a non-hydrocarbon indicating mineral.

[0083] Calculate the percentage of hydrocarbon indicating minerals and non-hydrocarbon indicating minerals respectively. The content of hydrocarbon indicating minerals in this sample is 1.5%, and the content of non-hydrocarbon indicating minerals is 1.00%.

[0084] S4: Calculation of diagenetic parameters

[0085] Statistical parameters such as intergranular volume, matrix filling rate, non-hydrocarbon indicating mineral cementation rate, hydrocarbon indicating mineral cementation rate, non-hydrocarbon indicating mineral cementation rate / matrix filling rate, and hydrocarbon indicating mineral cementation rate / matrix filling rate are counted.

[0086] Intergranular volume = interstitial matter (%) + pore face rate (%);

[0087] Matrix filling rate = matrix (%) / intergranular volume;

[0088] Non-hydrocarbon indicating mineral cementation rate = non-hydrocarbon indicating mineral (%) / intergranular volume;

[0089] Hydrocarbon indicating mineral cementation rate = hydrocarbon indicating mineral (%) / intergranular volume;

[0090] The intergranular volume of this sample is 10.50%, the matrix filling rate is 0.57, the non-hydrocarbon indicating mineral cementation rate is 0.17, and the hydrocarbon indicating mineral cementation rate is 0.25.

[0091] S5: Division of diagenetic facies

[0092] The division criteria of diagenetic facies (see the following table).

[0093]

[0094] Referring to the diagenetic facies division table, the diagenetic facies type of the sample is determined to be medium compaction early filling type.

[0095] Example 8:

[0096] A diagenetic facies division method based on hydrocarbon indicating minerals includes the following steps:

[0097] S1: Sample collection, collect rock samples from the target interval and make cast thin sections and fluorescence thin sections.

[0098] The size of the collected rock sample is 6.5 cm * 4.8 cm;

[0099] To ensure the consistency of the subsequent observation fields of the casting thin sections and fluorescence thin sections, the rock samples collected are made into casting thin sections and fluorescence thin sections respectively from the two cut surfaces after being sectioned in the middle.

[0100] S2: Analysis of casting thin sections

[0101] The analysis of casting thin sections mainly analyzes and identifies the following parameters, including the content of detrital quartz minerals, the content of detrital feldspar minerals and the content of rock fragments. Analysis results: The content of detrital quartz in this sample is 44.36%, the content of feldspar fragments is 19.44%, and the content of rock fragments is 21.97%.

[0102] Analyze and identify the content of matrix in the interstitial material; the content of minerals such as calcite, dolomite, siderite, pyrite, authigenic quartz, iron-bearing calcite, iron-bearing dolomite, barite, anhydrite, etc. in the cement; the porosity. Analysis results: The content of matrix in this sample is 0.50%, the content of iron-bearing calcite cement is 14.00%, the content of kaolinite is 0.50%, and the porosity is 0.50%.

[0103] The analysis and identification of casting thin sections adopts the petroleum industry standard "SY / T 5368 Rock Thin Section Identification", which does not fall within the protection scope of this invention patent.

[0104] S3: Analysis of fluorescence thin sections

[0105] The fluorescence thin sections are observed under a fluorescence microscope to distinguish the authigenic minerals in the identification results of the casting thin sections, and two types of components are divided. One is the authigenic minerals before the hydrocarbon fluids in the rock enter the reservoir (abbreviation: non-hydrocarbon indicating minerals); the other is the authigenic minerals related to hydrocarbon activities or formed after the hydrocarbon fluids enter the reservoir (abbreviation: hydrocarbon indicating minerals).

[0106] After the analysis of the fluorescence thin sections of the sample, iron-bearing calcite and kaolinite are hydrocarbon indicating minerals, and dolomite is a non-hydrocarbon indicating mineral.

[0107] Calculate the percentage ratios of the hydrocarbon indicating minerals and non-hydrocarbon indicating minerals respectively. The content of hydrocarbon indicating minerals in this sample is 14.5%, and the content of non-hydrocarbon indicating minerals is 0%.

[0108] S4: Calculation of diagenetic parameters

[0109] Statistical parameters such as intergranular volume, matrix filling rate, non-hydrocarbon indicating mineral cementation rate, hydrocarbon indicating mineral cementation rate, non-hydrocarbon indicating mineral cementation rate / matrix filling rate, hydrocarbon indicating mineral cementation rate / matrix filling rate, etc.

[0110] Intergranular volume = interstitial material (%) + porosity (%);

[0111] Matrix filling rate = matrix (%) / intergranular volume;

[0112] Non-hydrocarbon indicating mineral cementation rate = non-hydrocarbon indicating mineral (%) / intergranular volume;

[0113] The hydrocarbon-bearing mineral cementation rate = hydrocarbon-bearing minerals (%) / intergranular volume;

[0114] The intergranular volume of this sample is 15.50%, the matrix filling rate is 0.03, the non-hydrocarbon-bearing mineral cementation rate is 0, and the hydrocarbon-bearing mineral cementation rate is 0.94.

[0115] S5: Division of diagenetic facies

[0116] Referring to the diagenetic facies division table, it is determined that the diagenetic facies type of the sample is medium compaction and strong late cementation type.

[0117] The above content is a further detailed description of the present invention in combination with specific preferred implementation manners. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, and all should be regarded as belonging to the protection scope of the present invention.

Claims

1. A method for diagenetic phase division based on hydrocarbon-indicating minerals, characterized in that: The following steps are involved: S1 Sample collection; S2 casting thin section analysis; S3 fluorescence thin section analysis; S4 Calculation of diagenetic parameters; S5 Division of diagenetic phases.

2. A method for dividing diagenetic phases based on hydrocarbon-indicating minerals according to claim 1, characterized in that: In step S1, sample collection specifically includes: Collect rock samples from the target layer and make cast thin sections and fluorescent thin sections.

3. A method for dividing diagenetic phases based on hydrocarbon-indicating minerals according to claim 2, characterized in that: In step S1, the size of the collected rock sample is not less than 5cm*5cm.

4. A method for dividing diagenetic phases based on hydrocarbon-indicating minerals according to claim 2, characterized in that: In the step S1, sample collection specifically includes: in order to ensure the consistency of the casting thin section and the fluorescent thin section in the subsequent observation field, the collected rock sample is cut from two sections in the middle to produce the casting thin section and the fluorescent thin section.

5. A method for dividing diagenetic phases based on hydrocarbon-indicating minerals according to claim 1, characterized in that: In step S2, the casting thin section is analyzed, and the analysis parameters include: the content of detrital quartz minerals, the content of detrital feldspar minerals and the content of rock fragments.

6. A method for dividing diagenetic phases based on hydrocarbon-indicating minerals according to claim 1, characterized in that: In step S2, the casting thin section analysis includes: analyzing and identifying the content of impurities in the filling material; the content of minerals such as calcite, dolomite, siderite, pyrite, authigenic quartz, ferruginous calcite, ferruginous dolomite, barite, anhydrite, and the surface ratio of the cementing material.

7. A method for dividing diagenetic phases based on hydrocarbon-indicating minerals according to claim 1, characterized in that: In step S3, the fluorescent thin section analysis specifically includes: The fluorescent thin sections were observed under a fluorescence microscope to distinguish and group the authigenic minerals in the casting thin section identification results.

8. A method for dividing diagenetic phases based on hydrocarbon-indicating minerals according to claim 7, characterized in that: In step S3, samples are collected and divided into two types of components: hydrocarbon-indicating minerals and non-hydrocarbon-indicating minerals.

9. A method for dividing diagenetic phases based on hydrocarbon-indicating minerals according to claim 8, characterized in that: In step S3, non-hydrocarbon-indicating minerals include authigenic minerals before hydrocarbon fluids in rocks enter the reservoir; hydrocarbon-indicating minerals include authigenic minerals related to hydrocarbon activities or formed after hydrocarbon fluids enter the reservoir.

10. A method for dividing diagenetic phases based on hydrocarbon-indicating minerals according to claim 8, characterized in that: The step S3 further includes: calculating the percentages of hydrocarbon-indicating minerals and non-hydrocarbon-indicating minerals respectively.

11. A method for dividing diagenetic phases based on hydrocarbon-indicating minerals according to claim 1, characterized in that: In step S4, the calculation of diagenetic parameters specifically includes: statistics of intergranular volume, matrix filling rate, non-hydrocarbon-indicating mineral cementation rate, hydrocarbon-indicating mineral cementation rate, non-hydrocarbon-indicating mineral cementation rate / matrix filling rate, hydrocarbon-indicating mineral cementation rate / matrix filling rate.

12. A method for dividing diagenetic phases based on hydrocarbon-indicating minerals according to claim 11, characterized in that: In step S4, intergranular volume = interstitial material + surface ratio; Miscellaneous base filling rate = miscellaneous base / interparticle volume; Non-hydrocarbon-indicating mineral cementation rate = non-hydrocarbon-indicating mineral / intergranular volume; The cementation rate of hydrocarbon-indicating minerals = hydrocarbon-indicating minerals / intergranular volume.

13. A method for dividing diagenetic phases based on hydrocarbon-indicating minerals according to claim 1, characterized in that: In step S5, the division of diagenetic phases specifically includes: based on the intergranular volume, matrix filling rate, non-hydrocarbon-indicating mineral cementation rate / matrix filling rate, hydrocarbon-indicating mineral cementation rate / matrix filling rate of the sample; referring to the diagenetic phase division table to determine the diagenetic phase type of the sample.

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