Method for identifying late formation corrosion of carbonate rocks

Abstract

The invention provides an identification method for late formed rock corrosion of carbonate rocks. The method comprises the following steps: collecting a sampling sample from an underground rock core and a field outcrop sample; performing first observation treatment on the sampled sample to establish a sedimentary-diagenesis sequence, and preliminarily determining the type of the late diagenesis corrosion hole; performing second observation treatment on the sampled sample to identify the hydrocarbon inclusion state of the sampled sample; performing third observation treatment on the sampled sample to identify the uniform temperature and freezing point temperature of the gas-liquid two-phase fluid inclusion in the sampled sample; determining the content of main trace elements in the sampled sample; measuring the carbon and oxygen isotope value of the sampled sample; according to the sedimentary-diagenesis sequence, the type of the corrosion hole, the state of the hydrocarbon inclusion, the uniform temperature and freezing point temperature of the gas-liquid two-phase fluid inclusion, the content of main trace elements and the carbon and oxygen isotope value, the identification basis of late diagenesis corrosion of the carbonate rock is determined; the method is used for achieving the effect of improving the carbonate rock late formation rock corrosion identification efficiency.

Description

Technical Field

[0001] The present application relates to the technical field of oil and gas field exploration and development, and in particular to a method for identifying late diagenetic dissolution of carbonate rocks. Background Art

[0002] Carbonate rocks are rich in oil and gas resources. Deeply buried marine carbonate reservoirs have been a key area of exploration in recent years, and their reservoir genesis has been a research hotspot in the field of petroleum exploration. Classical models of carbonate porosity evolution suggest that porosity decreases with increasing burial depth due to destructive processes such as cementation and compaction. Whether marine carbonate rocks can undergo late diagenetic dissolution is a controversial issue for deep-buried reservoirs. Case studies suggest that carbonate rocks can undergo deep burial dissolution through rapid uplift, organic acid and hydrothermal activity, and thermochemical sulfate reduction. Therefore, methods for identifying late diagenetic dissolution in carbonate rocks have become a promising area of research.

[0003] In the existing technology, the identification method of late diagenetic dissolution of carbonate rocks mainly focuses on judging the diagenetic dissolution pores based on the macroscopic characteristics of hand specimens and microscopic characteristics under a microscope.

[0004] However, most research works consider the pore formation of deep-buried marine carbonate reservoirs to be in the sedimentary-early diagenetic stage, and there is no unified understanding of the dissolution mechanism and identification signs of late diagenetic dissolution pores. Moreover, due to the limitations of existing observation methods and environmental complexity, the accuracy of identifying late diagenetic dissolution of carbonate rocks is insufficient, resulting in a large waste of time and cost, and there is a technical problem of low efficiency in identifying late diagenetic dissolution of carbonate rocks. Summary of the Invention

[0005] The present application provides a method for identifying late diagenetic dissolution of carbonate rocks, so as to improve the efficiency of identifying late diagenetic dissolution of carbonate rocks.

[0006] In a first aspect, the present application provides a method for identifying late diagenetic dissolution of carbonate rocks, comprising:

[0007] Sampling samples were collected from downhole cores and field outcrop samples;

[0008] The first observation processing of the sampled samples was carried out to establish the sedimentary-diagenetic sequence and preliminarily determine the type of late diagenetic solution holes;

[0009] performing a second observation process on the sampled sample to identify the hydrocarbon inclusion state of the sampled sample;

[0010] performing a third observation process on the sampled sample to identify the homogenization temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions in the sampled sample;

[0011] Determine the content of main and trace elements in the sampled samples;

[0012] Determine the carbon and oxygen isotope values of the sampled samples;

[0013] The identification basis of late diagenetic dissolution of carbonate rocks is determined based on the sedimentary-diagenetic sequence, the type of dissolution pores, the state of hydrocarbon inclusions, the homogenization temperature and freezing point temperature of gas-liquid two-phase fluid inclusions, the content of major and trace elements, and the carbon and oxygen isotope values.

[0014] In one possible embodiment, a first observation process is performed on the sampled sample to establish a sedimentary-diagenetic sequence, including:

[0015] Grinding the sample to obtain a first observation sample;

[0016] The first observation sample is observed and processed using an optical microscope and a cathodoluminescence microscope to determine the period of the constituent rock minerals;

[0017] Based on the stages of the constituent rock minerals, a sedimentary-diagenetic sequence was established, and the types of late diagenetic dissolution pores were preliminarily determined.

[0018] In a possible embodiment, the types of dissolution holes include:

[0019] Late diagenetic minerals with obvious dissolution structures, accompanied by intracrystalline solution pores, intercrystalline solution pores and solution caves. Late diagenetic minerals refer to minerals formed in the late diagenetic stage, including medium-coarse-grained dolomite and saddle dolomite;

[0020] Dissolution pores developed around rock stylolites, which are jagged textures created by pressure solution in rocks;

[0021] Asphalt is distributed in the central dissolution pores, and the surrounding minerals show dissolution phenomena, forming intercrystalline dissolution pores, intracrystalline dissolution pores and caves.

[0022] In one possible embodiment, performing a second observation process on the sampled sample to identify the hydrocarbon inclusion state of the sampled sample includes:

[0023] The sampled samples are identified using a fluorescence microscope to determine the hydrocarbon inclusion state of the sampled samples, wherein the hydrocarbon inclusion state includes the state containing hydrocarbon inclusions and the state containing no hydrocarbon inclusions.

[0024] In one possible embodiment, a third observation process is performed on the sample to identify the homogenization temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions in the sample, including:

[0025] The sampled samples were measured using a hot and cold stage to identify the homogenization temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions in the sampled samples.

[0026] In one possible embodiment, determining the content of major and trace elements in a sample includes:

[0027] The main and trace element contents of the samples were determined by electron probe under the working conditions of accelerating voltage of 15 kV, beam current of 10 nA and beam spot size of 8 μm.

[0028] In one possible embodiment, determining the carbon and oxygen isotope values of the sample includes:

[0029] Based on the sedimentary-diagenetic sequence, a microdrill was used to obtain multiple 30 mg samples of carbonate mineral powder from different sedimentary-diagenetic stages.

[0030] The carbon and oxygen isotope values of carbonate mineral powder were determined using an isotope mass spectrometer.

[0031] In one possible embodiment, after determining the basis for identifying late diagenetic dissolution of carbonate rocks based on the sedimentary-diagenetic sequence, the type of dissolution pores, the state of hydrocarbon inclusions, the homogenization temperature and freezing point temperature of gas-liquid two-phase fluid inclusions, the content of major and trace elements, and carbon and oxygen isotope values, the following is further included:

[0032] Obtaining identification samples of the carbonate rock to be identified;

[0033] According to the identification basis, the identification samples of the carbonate rock to be identified are identified to determine the late diagenetic dissolution characteristics of the carbonate rock to be identified.

[0034] In a second aspect, the present application provides a device for identifying late diagenetic dissolution of carbonate rocks, comprising:

[0035] Acquisition module, used to collect sampling samples from downhole cores and field outcrop samples;

[0036] a first processing module for performing a first observation processing on the sampled samples to establish a sedimentary-diagenetic sequence and preliminarily determine the type of late diagenetic dissolution pores;

[0037] a second processing module, configured to perform a second observation process on the sampled sample to identify the hydrocarbon inclusion state of the sampled sample;

[0038] a third processing module, configured to perform a third observation process on the sampled sample to identify the uniform temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions in the sampled sample;

[0039] The first determination module is used to determine the content of major and trace elements in the sample;

[0040] The second determination module is used to determine the carbon and oxygen isotope values of the sample;

[0041] The identification module is used to determine the identification basis of late diagenetic dissolution of carbonate rocks based on the sedimentary-diagenetic sequence, the state of hydrocarbon inclusions, the homogenization temperature and freezing point temperature of gas-liquid two-phase fluid inclusions, the content of major and trace elements, and the carbon and oxygen isotope values.

[0042] In a possible implementation, the first processing module is further configured to:

[0043] Grinding the sample to obtain a first observation sample;

[0044] The first observation sample is observed and processed using an optical microscope and a cathodoluminescence microscope to determine the period of the constituent rock minerals;

[0045] A sedimentary-diagenetic sequence is established based on the stages of the constituent rock minerals.

[0046] In a possible implementation, the first processing module is further configured to:

[0047] Types of dissolution pores include:

[0048] Late diagenetic minerals with obvious dissolution structures, accompanied by intracrystalline solution pores, intercrystalline solution pores and solution caves. Late diagenetic minerals refer to minerals formed in the late diagenetic stage, including medium-coarse-grained dolomite and saddle dolomite;

[0049] Dissolution pores developed around rock stylolites, which are jagged textures created by pressure solution in rocks;

[0050] Asphalt is distributed in the central dissolution pores, and the surrounding minerals show dissolution phenomena, forming intercrystalline dissolution pores, intracrystalline dissolution pores and caves.

[0051] In a possible implementation, the second processing module is further configured to:

[0052] The sampled samples are identified using a fluorescence microscope to determine the hydrocarbon inclusion state of the sampled samples, wherein the hydrocarbon inclusion state includes the state containing hydrocarbon inclusions and the state containing no hydrocarbon inclusions.

[0053] In a possible implementation, the third processing module is further configured to:

[0054] The sampled samples were measured using a hot and cold stage to identify the homogenization temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions in the sampled samples.

[0055] In a possible implementation, the first determining module is further configured to:

[0056] The main and trace element contents of the samples were determined by electron probe under the working conditions of accelerating voltage of 15 kV, beam current of 10 nA and beam spot size of 8 μm.

[0057] In a possible implementation, the second determining module is further configured to:

[0058] Based on the sedimentary-diagenetic sequence, a microdrill was used to obtain multiple 30 mg samples of carbonate mineral powder from different sedimentary-diagenetic stages.

[0059] The carbon and oxygen isotope values of carbonate mineral powder were determined using an isotope mass spectrometer.

[0060] In a possible implementation, the identification module is further configured to:

[0061] Obtaining identification samples of the carbonate rock to be identified;

[0062] According to the identification basis, the identification samples of the carbonate rock to be identified are identified to determine the late diagenetic dissolution characteristics of the carbonate rock to be identified.

[0063] In a third aspect, the present application provides a device for identifying late diagenetic dissolution of carbonate rocks, comprising: a memory, a processor;

[0064] Memory stores computer-executable instructions;

[0065] The processor executes the computer-executable instructions stored in the memory, so that the processor executes the above first aspect and / or various possible implementations of the first aspect.

[0066] In a fourth aspect, the present application provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are executed by a processor, they are used to implement the above first aspect and / or various possible implementation methods of the first aspect.

[0067] In a fifth aspect, the present application provides a computer program product, comprising a computer program, which, when executed by a processor, implements the above first aspect and / or various possible implementations of the first aspect.

[0068] The present application provides a method for identifying late diagenetic dissolution of carbonate rocks. The method ensures the representativeness and extensiveness of the research samples by collecting sampling samples from underground cores and field outcrop samples. In addition, the sampling samples are subjected to a first observation process to establish a sedimentary-diagenetic sequence and preliminarily determine the type of late diagenetic dissolution pores, which not only provides an important time frame and basis for identifying late diagenetic dissolution, but also improves the reliability of the identification results. At the same time, the sampling samples are subjected to a second observation process to identify the state of hydrocarbon inclusions in the sampling samples. The sampling samples are subjected to a third observation process to The method is to identify the homogenization temperature and freezing point temperature of gas-liquid two-phase fluid inclusions in the sampled samples; determine the content of major and trace elements in the sampled samples; determine the carbon and oxygen isotope values of the sampled samples, and determine the basis for identifying late diagenetic dissolution of carbonate rocks based on the sedimentary-diagenetic sequence, the state of hydrocarbon inclusions, the homogenization temperature and freezing point temperature of gas-liquid two-phase fluid inclusions, the content of major and trace elements and carbon and oxygen isotope values, thereby improving the accuracy of identification, removing the limitation of complex environment on the identification process, improving the accuracy of identification results, and achieving the effect of improving the efficiency of identifying late diagenetic dissolution of carbonate rocks. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0070] Figure 1 A schematic diagram of a method for identifying late diagenetic dissolution of carbonate rocks provided in an embodiment of the present application Figure 1 ;

[0071] Figure 2 A schematic diagram of a method for identifying late diagenetic dissolution of carbonate rocks provided in an embodiment of the present application Figure 2 ;

[0072] Figure 3 A microscopic schematic diagram of late-stage pores provided in an embodiment of the present application;

[0073] Figure 4 A schematic diagram of the uniform temperature and salinity of the sampled samples provided in the embodiments of the present application;

[0074] Figure 5 A schematic diagram of a method for identifying late diagenetic dissolution of carbonate rocks provided in an embodiment of the present application Figure 3 ;

[0075] Figure 6 A schematic diagram of the intersection of carbon and oxygen isotope values of the samples provided in the embodiments of the present application;

[0076] Figure 7 A schematic diagram of the structure of a device for identifying late diagenetic dissolution of carbonate rocks provided in an embodiment of the present application;

[0077] Figure 8 A schematic diagram of the structure of a device for identifying late diagenetic dissolution of carbonate rocks provided in an embodiment of the present application.

[0078] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0079] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0080] Since most research works assume that the pores of deep-buried marine carbonate reservoirs are formed in the sedimentation-early diagenesis stage, there is no unified understanding of the dissolution mechanism and identification signs of late diagenetic dissolution pores. In addition, due to the limitations of existing observation methods and environmental complexity, the accuracy of identifying late diagenetic dissolution of carbonate rocks is insufficient, resulting in a large waste of time and costs, and there is a technical problem of low efficiency in identifying late diagenetic dissolution of carbonate rocks.

[0081] A method for identifying late diagenetic dissolution of carbonate rocks provided in an embodiment of the present application ensures the representativeness and breadth of research samples by collecting sampling samples from underground cores and field outcrop samples; in addition, by establishing a sedimentary-diagenetic sequence and preliminarily determining the type of late diagenetic dissolution pores, it not only provides an important time frame and basis for identifying late diagenetic dissolution, but also improves the reliability of the identification results; at the same time, a second observation process is performed on the sampled samples to identify the state of hydrocarbon inclusions in the sampled samples; a third observation process is performed on the sampled samples to identify the homogenization temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions in the sampled samples; the content of major and trace elements in the sampled samples is determined; the carbon and oxygen isotope values of the sampled samples are determined, and based on the parameters obtained by the above identification and determination, the identification basis of late diagenetic dissolution of carbonate rocks is determined, thereby improving the accuracy of identification, removing the limitations of the complex environment on the identification process, improving the robustness of the identification results, and achieving the effect of improving the efficiency of identifying late diagenetic dissolution of carbonate rocks.

[0082] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0083] Figure 1 A schematic diagram of a method for identifying late diagenetic dissolution of carbonate rocks provided in an embodiment of the present application Figure 1 ,like Figure 1 As shown, the method includes:

[0084] S101. Collect samples from downhole cores and field outcrop samples;

[0085] The samples were collected from downhole cores and field outcrop samples within carbonate reservoirs containing carbonate late diagenetic dissolution.

[0086] Specifically, according to the research scope, the basic geological data in the study area were sorted out, including drilling and outcrop stratigraphic information, regional tectonic background and sedimentary environment, and burial history, and well-preserved downhole cores and field outcrop samples in carbonate reservoirs containing carbonate late diagenetic dissolution were selected for intensive sampling.

[0087] S102, performing a first observation process on the sampled samples to establish a sedimentary-diagenetic sequence and preliminarily determine the type of late diagenetic dissolution pores;

[0088] In this embodiment, the sedimentation-diagenesis sequence refers to the sequence of various stages and processes of rock from deposition to diagenesis.

[0089] The samples were observed and processed using an optical microscope and a cathodoluminescence microscope to determine the period of diagenetic minerals, establish a sedimentary-diagenetic sequence, and preliminarily determine the type of late diagenetic dissolution pores.

[0090] S103, performing a second observation process on the sampled sample to identify the state of hydrocarbon inclusions in the sampled sample;

[0091] Use fluorescence microscopy to identify the type of fluid inclusions in the sampled samples and whether they contain hydrocarbon inclusions.

[0092] S104, performing a third observation process on the sample to identify the uniform temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions in the sample;

[0093] The homogenization temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions in the sampled samples were measured using a hot and cold stage.

[0094] S105, determining the content of main and trace elements in the sampled sample;

[0095] The content of main and trace elements in the samples was determined by electron probe.

[0096] S106, determining carbon and oxygen isotope values of the sample;

[0097] Based on the sedimentary-diagenetic sequence and dissolution characteristics, powders of samples taken at different sedimentary-diagenetic stages were obtained by micro-drilling, and the carbon (δ 13 C) and oxygen (δ 18 O) isotope value.

[0098] S107. Determine the basis for identifying late diagenetic dissolution of carbonate rocks based on the sedimentary-diagenetic sequence, the type of dissolution pores, the state of hydrocarbon inclusions, the homogenization temperature and freezing point of gas-liquid two-phase fluid inclusions, the contents of major and trace elements, and the carbon and oxygen isotope values.

[0099] Based on the sedimentary-diagenetic sequence, hydrocarbon inclusion state, homogenization temperature and freezing point temperature of gas-liquid two-phase fluid inclusions, major and trace element contents, and carbon and oxygen isotope values obtained in the above steps, and combined with petrology, inclusion and geochemical signals, the identification basis of late diagenetic dissolution of carbonate rocks can be determined.

[0100] The embodiment of the present application provides a method for identifying late diagenetic dissolution of carbonate rocks. By collecting sampling samples from underground cores and field outcrop samples, the representativeness and extensiveness of the research samples are ensured. In addition, the sampling samples are subjected to a first observation process to establish a sedimentary-diagenetic sequence and preliminarily determine the type of late diagenetic dissolution pores, which not only provides an important time frame and basis for identifying late diagenetic dissolution, but also improves the reliability of the identification results. At the same time, the sampling samples are subjected to a second observation process to identify the state of hydrocarbon inclusions in the sampling samples. The sampling samples are subjected to a third observation process. , in order to identify the homogenization temperature and freezing point temperature of gas-liquid two-phase fluid inclusions in the sampled samples; determine the main and trace element contents of the sampled samples; determine the carbon and oxygen isotope values of the sampled samples, and determine the identification basis of late diagenetic dissolution of carbonate rocks based on the sedimentary-diagenetic sequence, hydrocarbon inclusion state, homogenization temperature and freezing point temperature of gas-liquid two-phase fluid inclusions, main and trace element contents and carbon and oxygen isotope values, thereby improving the accuracy of identification, removing the limitations of complex environment on the identification process, improving the robustness of the identification results, and achieving the effect of improving the efficiency of identifying late diagenetic dissolution of carbonate rocks.

[0101] Figure 2 A schematic diagram of a method for identifying late diagenetic dissolution of carbonate rocks provided in an embodiment of the present application Figure 2 ,like Figure 2 As shown, this embodiment, based on the above embodiment, describes in detail the observation and processing process of the sampled sample, and the method includes:

[0102] S201, grinding the sample to obtain a first observation sample;

[0103] Specifically, the sample was ground into a thin slice with a thickness of 30 μm, and the thin slice was determined as the first observation sample.

[0104] S202, observing and processing the first observation sample using an optical microscope and a cathodoluminescence microscope to determine the period of the constituent rock minerals;

[0105] In this embodiment, the rock mineral stage refers to the order in which different minerals in the rock are formed.

[0106] Specifically, taking the Ediacaran Dengying Formation dolomite in Site A as an example, an optical microscope was used to observe the overall structure and mineral composition of the sample in Site A, and a cathodoluminescence microscope was used to observe the luminescence characteristics of the minerals under cathode ray excitation, so as to determine the formation period of the minerals that make up the rock.

[0107] S203. Establish a sedimentary-diagenetic sequence based on the phases of the constituent rocks and minerals, and preliminarily determine the types of late diagenetic dissolution pores and vugs;

[0108] In this embodiment, the types of dissolution pores include late diagenetic minerals with obvious dissolution structures, accompanied by intracrystalline dissolution pores, intercrystalline dissolution pores and caves; dissolution pores developed around rock sutures; dissolution pores with asphalt distributed in the center, and surrounding minerals showing dissolution phenomena, forming intercrystalline dissolution pores, intracrystalline dissolution pores and caves. Among them, late diagenetic minerals refer to minerals formed in the late diagenetic stage, including medium-coarse-grained dolomite and saddle dolomite, and the sutures are jagged textures caused by pressure dissolution in the rock mass.

[0109] After determining the period of the minerals that make up the rock, the sedimentation and diagenesis processes of the rock are further inferred, thereby establishing a sedimentary-diagenetic sequence and preliminarily determining the type of late diagenetic dissolution pores.

[0110] Specifically, Figure 3 The microscopic diagram of the late-stage pores provided in the examples of this application is as follows: Figure 3 As shown, Figure 3 A is a hole developed near the stylolite (red arrow), Gaoshi 32 well, with a depth of 5433.89 meters. Figure 3 B is the intercrystalline solution pores on both sides of the stylolite (red arrows), Gaoshi 7 well, depth 5348.2 m; Figure 3 C is the intercrystalline dissolution pore where asphalt is distributed in medium-coarse crystalline dolomite cement (red arrow), Gaoke 1 well, depth 5151.74 meters; Figure 3 D is barite with dissolution structure (red arrow) and the surrounding saddle dolomite, Gaoshi 103 well, depth 5176.41 meters. Figure 3E is an intracrystalline solution pore in saddle dolomite, and the red dashed line is the boundary of the pore, Gaoshi 7 well, depth 5333.3 meters; Figure 3 F is the intracrystalline solution pore of saddle dolomite, the red dotted line is the boundary of the pore, Gaoshi 103 well, depth 5305.43 meters; Figure 3 G is the dissolved saddle dolomite (red dotted line) and quartz. The homogenization temperature range of saddle dolomite is 165-171 ° C. Gaoke 1 well, depth 5028.16 meters, Figure 3 H is the asphalt in the center of the intercrystalline pores of the dissolved saddle dolomite (red dashed line). The homogenization temperature of dolomite is 174-202 ° C. Moxi 108 well, depth 5336.08 meters;

[0111] After determining the period of the rock minerals in the A site, the corresponding sedimentary-diagenetic sequence was established and the types of dissolution holes were summarized. Figure 3 As shown in the figure, it can be summarized as follows: (1) Late-diagenetic minerals such as sulfate minerals, medium-coarse dolomite, and saddle dolomite have obvious dissolution structures, forming intracrystalline dissolution pores, intercrystalline dissolution pores, and dissolution caves; (2) Dissolution pores and caves developed near the stylolite. (3) Asphalt is distributed in the center of the dissolution pores and caves, and the surrounding minerals can be seen to dissolve. The pore types of deep-buried dissolution include intercrystalline dissolution pores, intracrystalline dissolution pores, and dissolution caves.

[0112] It is understandable that Figure 3 It is only used as a reference to demonstrate the effect and is not a point of improvement and does not affect the scope of protection of the embodiments of this application.

[0113] S204, using a fluorescence microscope to identify the sampled sample to determine the state of hydrocarbon inclusions in the sampled sample;

[0114] In this embodiment, the hydrocarbon inclusion state includes containing hydrocarbon inclusions and not containing hydrocarbon inclusions.

[0115] Specifically, a Zeiss AxioscopeA1 A Pol fluorescence microscope was used to identify hydrocarbon inclusions within the saddle dolomite minerals in Site A.

[0116] S205. Use a hot and cold stage to measure the sampled sample to identify the uniform temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions in the sampled sample.

[0117] Optionally, the salinity of the gas-liquid two-phase fluid inclusions in the sampled sample is determined based on the freezing point temperature in combination with a salinity conversion formula, wherein the salinity conversion formula is obtained by the following formula:

[0118] Salinity = 0.00 + 1.78 x T m - 0.0442 x T m2 +0.000557 x T m 3

[0119] Among them, T m is the freezing point temperature of the gas-liquid two-phase fluid inclusions in the sample.

[0120] Specifically, Figure 4 A schematic diagram of the uniform temperature and salinity of the sample provided in the embodiment of the present application, as shown in FIG. Figure 4 As shown in the figure, the homogenization temperature and freezing point temperature of the samples taken from site A were measured in combination with a Linkam THM600 / TS90 hot and cold stage, and the salinity of the samples taken from site A was determined according to the salinity conversion formula. Among them, black represents fabric-broken sliding dolomite (Md3), gray represents horse-tooth dolomite cement (Cd2), blue represents medium-coarse-crystalline dolomite cement (Cd3), yellow and yellow with X marks represent saddle dolomite (Cd4-I) and saddle dolomite (Cd4-II), respectively, and pink represents calcite cement (Cal). The homogenization temperature of the coarse-crystalline dolomite cement in site A is between 120-150℃, and the salinity is between 8-16wt.%, while the homogenization temperature of the saddle dolomite and calcite cements is between 150-230℃, the salinity of the saddle dolomite is between 8-24 wt.%, and the salinity of the calcite cement is between 4-12 between wt.%.

[0121] It is understandable that Figure 4 The results are only presented for illustrative purposes and do not affect the scope of protection of the embodiments of the present application.

[0122] A method for identifying late diagenetic dissolution of carbonate rocks provided in an embodiment of the present application establishes a sedimentary-diagenetic sequence by observing and processing sampled samples, providing an important time frame and basis for identifying late diagenetic dissolution, thereby improving the reliability of the identification results. At the same time, by identifying the state of hydrocarbon inclusions in the sampled samples, identifying the homogenization temperature and freezing point temperature of gas-liquid two-phase fluid inclusions in the sampled samples, and measuring the major and trace element contents and carbon and oxygen isotope values of the sampled samples, and based on the parameters obtained from the above identification and measurement, the basis for identifying late diagenetic dissolution of carbonate rocks is determined, thereby improving the accuracy of identification, removing the limitations of the complex environment on the identification process, reducing the complexity of the identification process, alleviating the burden of material and time costs, and achieving the effect of improving the efficiency of identifying late diagenetic dissolution of carbonate rocks.

[0123] Figure 5 A schematic diagram of a method for identifying late diagenetic dissolution of carbonate rocks provided in an embodiment of the present application Figure 3 ,like Figure 5 As shown, this embodiment, based on the above embodiment, describes in detail the measurement and identification process of the sample, and the method includes:

[0124] S501. Under the working conditions of accelerating voltage of 15 kV, beam current of 10 nA and beam spot size of 8 μm, the content of main and trace elements in the sample was determined by electron probe;

[0125] The working state of the electron probe was set to 15 kV acceleration voltage, 10 nA beam current and 8 μm beam spot size. Under this working state, the content of main and trace elements in the sampled samples was determined.

[0126] S502. Based on the sedimentation-diagenesis sequence, use a microdrill to obtain multiple 30 mg carbonate mineral powder samples from different sedimentation-diagenesis stages;

[0127] Based on the sedimentary-diagenetic sequence and dissolution characteristics, a micro-drill was used to obtain multiple 30 mg pieces of carbonate mineral powder from different sedimentary-diagenetic stages.

[0128] S503, using an isotope mass spectrometer to measure carbon and oxygen isotope values of carbonate mineral powder;

[0129] Specifically, Figure 6 The intersection diagram of the carbon and oxygen isotope values of the samples provided in the embodiment of the present application is measured by Finnigan MAT 253 isotope mass spectrometer. Figure 6 The carbon content of the carbonate mineral powder shown (δ 13 C) and oxygen (δ 18 O) Isotope values, where circles represent carbon and oxygen isotope values of the micrite dolomite (Md1) from site A, triangles represent carbon and oxygen isotope values of the fabric-preserved dolomite (Md2) from site A, and squares represent carbon and oxygen isotope values of the fabric-destroyed dolomite (Md3) from site A.

[0130] It is understandable that Figure 6 The results are only presented for illustrative purposes and do not affect the scope of protection of the embodiments of the present application.

[0131] S504. Determine the identification basis for late diagenetic dissolution of carbonate rocks based on the sedimentary-diagenetic sequence, the type of dissolution pores, the state of hydrocarbon inclusions, the homogenization temperature and freezing point of gas-liquid two-phase fluid inclusions, the contents of major and trace elements, and carbon and oxygen isotope values;

[0132] Based on the sedimentary-diagenetic sequence, hydrocarbon inclusion state, homogenization temperature and freezing point temperature of gas-liquid two-phase fluid inclusions, major and trace element contents, and carbon and oxygen isotope values obtained in the above steps, the identification basis of late diagenetic dissolution of carbonate rocks is determined, the mechanism of late diagenetic dissolution is explained, and then the development characteristics and identification marks of late dissolution of deep carbonate rocks are summarized and characterized.

[0133] S505, obtaining an identification sample of the carbonate rock to be identified;

[0134] After the identification basis of late diagenetic dissolution of carbonate rocks is determined, identification samples of the carbonate rocks to be identified are obtained.

[0135] S506. Identify the identification sample of the carbonate rock to be identified based on the identification basis to determine the late diagenetic dissolution characteristics of the carbonate rock to be identified.

[0136] In this embodiment, the late diagenetic dissolution characteristics of the carbonate rock to be identified include developmental features and identification marks.

[0137] Based on the identification basis of late diagenetic dissolution of carbonate rocks, the mechanism of late diagenetic dissolution is explained, and then the development characteristics and identification marks of late diagenetic dissolution of deep carbonate rocks to be identified are summarized and characterized.

[0138] The embodiment of the present application provides a method for identifying late diagenetic dissolution of carbonate rocks. By setting a specific acceleration voltage, beam current and beam spot size, an electron probe can accurately determine the content of major and trace elements in the sampled sample, which provides an accurate data basis for subsequent analysis. By drilling carbonate mineral powders in multiple different sedimentary-diagenetic stages through micro-drilling, the changes in mineral composition in different stages can be carefully analyzed, which helps to gain a deeper understanding of the diagenetic process of carbonate rocks. In addition, an isotope mass spectrometer is used to determine the carbon and oxygen isotope values of the carbonate mineral powder, and combined with the Based on information on sedimentary-diagenetic sequences, types of dissolution pores, the state of hydrocarbon inclusions, the homogenization temperature and freezing point temperature of gas-liquid two-phase fluid inclusions, the contents of major and trace elements, and carbon and oxygen isotope values, a basis for identifying late diagenetic dissolution of carbonate rocks was established, further enhancing the accuracy and reliability of identification. Finally, by obtaining carbonate rock samples to be identified and identifying them according to the previously established identification basis, the effectiveness and convenience of the identification method were ensured based on the late diagenetic dissolution characteristics of carbonate rocks, thereby achieving the effect of improving the efficiency of identifying late diagenetic dissolution of carbonate rocks.

[0139] Figure 7 This is a schematic diagram of the structure of a device for identifying carbonate late diagenetic dissolution provided in an embodiment of the present application. The device of this embodiment can be in the form of software and / or hardware. Figure 7 As shown, the device 700 for identifying late diagenetic dissolution of carbonate rocks provided in an embodiment of the present application includes: a collection module 701, a first processing module 702, a second processing module 703, a third processing module 704, a first determination module 705, a second determination module 706, and an identification module 707:

[0140] The collection module 701 is used to collect samples from downhole cores and field outcrop samples;

[0141] The first processing module 702 is used to perform a first observation process on the sampled samples to establish a sedimentary-diagenetic sequence and preliminarily determine the type of late diagenetic dissolution pores;

[0142] The second processing module 703 is used to perform a second observation process on the sample to identify the state of hydrocarbon inclusions in the sample;

[0143] The third processing module 704 is used to perform a third observation process on the sample to identify the uniform temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions in the sample;

[0144] The first determination module 705 is used to determine the content of major and trace elements in the sample;

[0145] The second determination module 706 is used to determine the carbon and oxygen isotope values of the sample;

[0146] Identification module 707 is used to determine the identification basis of late diagenetic dissolution of carbonate rocks based on the sedimentary-diagenetic sequence, the type of dissolution pores, the state of hydrocarbon inclusions, the homogenization temperature and freezing point temperature of gas-liquid two-phase fluid inclusions, the content of major and trace elements, and the carbon and oxygen isotope values.

[0147] In a possible implementation, the first processing module 702 is further configured to:

[0148] Grinding the sample to obtain a first observation sample;

[0149] The first observation sample is observed and processed using an optical microscope and a cathodoluminescence microscope to determine the period of the constituent rock minerals;

[0150] Based on the stages of the constituent rock minerals, a sedimentary-diagenetic sequence was established, and the types of late diagenetic dissolution pores were preliminarily determined.

[0151] In a possible implementation, the first processing module 702 is further configured to:

[0152] Types of dissolution pores include:

[0153] Late diagenetic minerals with obvious dissolution structures, accompanied by intracrystalline solution pores, intercrystalline solution pores and solution caves. Late diagenetic minerals refer to minerals formed in the late diagenetic stage, including medium-coarse-grained dolomite and saddle dolomite;

[0154] Dissolution pores developed around rock stylolites, which are jagged textures created by pressure solution in rocks;

[0155] Asphalt is distributed in the central dissolution pores, and the surrounding minerals show dissolution phenomena, forming intercrystalline dissolution pores, intracrystalline dissolution pores and caves.

[0156] In a possible implementation, the second processing module 703 is further configured to:

[0157] The sampled samples are identified using a fluorescence microscope to determine the hydrocarbon inclusion state of the sampled samples, wherein the hydrocarbon inclusion state includes the state containing hydrocarbon inclusions and the state containing no hydrocarbon inclusions.

[0158] In a possible implementation, the third processing module 704 is further configured to:

[0159] The sampled samples were measured using a hot and cold stage to identify the homogenization temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions in the sampled samples.

[0160] In a possible implementation, the first determining module 705 is further configured to:

[0161] The main and trace element contents of the samples were determined by electron probe under the working conditions of accelerating voltage of 15 kV, beam current of 10 nA and beam spot size of 8 μm.

[0162] In a possible implementation, the second determining module 706 is further configured to:

[0163] Based on the sedimentary-diagenetic sequence, a microdrill was used to obtain multiple 30 mg samples of carbonate mineral powder from different sedimentary-diagenetic stages.

[0164] The carbon and oxygen isotope values of carbonate mineral powder were determined using an isotope mass spectrometer.

[0165] In a possible implementation, the identification module 707 is further configured to:

[0166] Obtaining identification samples of the carbonate rock to be identified;

[0167] According to the identification basis, the identification samples of the carbonate rock to be identified are identified to determine the late diagenetic dissolution characteristics of the carbonate rock to be identified.

[0168] The device for identifying late diagenetic dissolution of carbonate rocks provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effects are similar, and are not described in detail in this embodiment.

[0169] Figure 8 This is a schematic diagram of the structure of a device for identifying late diagenetic dissolution of carbonate rocks provided in an embodiment of the present application. Figure 8 As shown, the electronic device 800 provided in this embodiment includes: at least one processor 801 and a memory 802. Optionally, the device 800 also includes a communication component 803. The processor 801, the memory 802 and the communication component 803 are connected via a bus.

[0170] During the specific implementation process, at least one processor 801 executes the computer-executable instructions stored in the memory 802, so that the at least one processor 801 performs the above method.

[0171] The specific implementation process of the processor 801 can be found in the above method embodiment. Its implementation principle and technical effects are similar and will not be repeated here in this embodiment.

[0172] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASICs), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly executed by a hardware processor or by a combination of hardware and software modules within the processor.

[0173] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage.

[0174] A bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be categorized as address buses, data buses, and control buses. For ease of illustration, the buses in the drawings of this application are not limited to just one bus or just one type of bus.

[0175] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0176] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above method is implemented.

[0177] The readable storage medium may be implemented by any type of volatile or non-volatile memory device, or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium may be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0178] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be an integral part of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist in the device as discrete components.

[0179] The division of units is merely a logical functional division; actual implementations may employ alternative divisions, such as combining or integrating multiple units or components into another system, or omitting or disabling certain features. Furthermore, any direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between devices or units, either through an interface, electrical, mechanical, or other means.

[0180] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0181] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0182] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the method of the present invention. The aforementioned storage medium includes various media that can store program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0183] Those skilled in the art will appreciate that all or part of the steps in the above-described method embodiments can be implemented using hardware associated with program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0184] Finally, it should be noted that those skilled in the art will readily identify other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The present invention is not limited to the precise structure described above and illustrated in the accompanying drawings, and various modifications and variations may be made without departing from the scope thereof. The scope of the present invention is limited solely by the appended claims.

Claims

1. A method for identifying late diagenetic dissolution of carbonate rocks, characterized in that: include: Sampling samples were collected from downhole cores and field outcrop samples; Performing a first observational process on the sampled samples to establish a sedimentary-diagenetic sequence and preliminarily determine the type of late diagenetic dissolution pores; performing a second observation process on the sampled sample to identify the hydrocarbon inclusion state of the sampled sample; performing a third observation process on the sampled sample to identify the uniform temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions in the sampled sample; Determining the content of main and trace elements in the sampled sample; Determining the carbon and oxygen isotope values of the sample; The identification basis of late diagenetic dissolution of carbonate rocks is determined based on the sedimentary-diagenetic sequence, the type of dissolution pores, the state of the hydrocarbon inclusions, the homogenization temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions, the content of major and trace elements, and the carbon and oxygen isotope values.

2. The method according to claim 1, characterized in that The first observation processing of the sampled samples to establish a sedimentary-diagenetic sequence and determine the type of corresponding dissolution holes includes: Grinding the sample to obtain a first observation sample; Observing and processing the first observation sample using an optical microscope and a cathodoluminescence microscope to determine the period of the constituent rock minerals; Based on the stages of the constituent rock minerals, the sedimentary-diagenetic sequence was established, and the types of late diagenetic dissolution pores were preliminarily determined.

3. The method according to claim 2, characterized in that The types of dissolution holes include: Late diagenetic minerals with obvious dissolution structures, accompanied by intracrystalline solution pores, intercrystalline solution pores and solution caves. Late diagenetic minerals refer to minerals formed in the late diagenetic stage, including medium-coarse-grained dolomite and saddle dolomite; Dissolution pores developed around rock stylolites, which are jagged textures created by pressure solution in rocks; Asphalt is distributed in the central dissolution pores, and the surrounding minerals show dissolution phenomena, forming intercrystalline dissolution pores, intracrystalline dissolution pores and caves.

4. The method according to claim 1, wherein The performing a second observation process on the sampled sample to identify the hydrocarbon inclusion state of the sampled sample includes: The sampled sample is identified using a fluorescence microscope to determine the hydrocarbon inclusion state of the sampled sample, wherein the hydrocarbon inclusion state includes containing hydrocarbon inclusions and not containing hydrocarbon inclusions.

5. The method according to claim 1, wherein The performing a third observation process on the sample to identify the uniform temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions in the sample, comprises: The sampled sample is measured using a hot and cold stage to identify the uniform temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions in the sampled sample.

6. The method according to claim 1, characterized in that Determining the content of main and trace elements in the sampled sample comprises: Under the working conditions of an accelerating voltage of 15 kV, a beam current of 10 nA, and a beam spot size of 8 μm, the contents of major and trace elements in the sampled samples were determined by an electron probe.

7. The method according to claim 1, characterized in that Determining the carbon and oxygen isotope values of the sampled sample comprises: Based on the sedimentary-diagenetic sequence, a microdrill is used to drill out a plurality of 30 mg of carbonate mineral powders from the sampling samples at different sedimentary-diagenetic stages; The carbon and oxygen isotope values of the carbonate mineral powder are determined by an isotope mass spectrometer.

8. The method according to any one of claims 1 to 7, characterized in that After determining the identification basis of late diagenetic dissolution of carbonate rocks based on the sedimentary-diagenetic sequence, the type of the dissolution pores, the state of the hydrocarbon inclusions, the homogenization temperature and freezing point temperature of the gas-liquid two-phase fluid inclusions, the major and trace element contents, and the carbon and oxygen isotope values, the method further includes: Obtaining identification samples of the carbonate rock to be identified; According to the identification basis, the identification sample of the carbonate rock to be identified is identified to determine the late diagenetic dissolution characteristics of the carbonate rock to be identified.

9. An identification device for late diagenetic dissolution of carbonate rocks, characterized by: include: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method for identifying late diagenetic dissolution of carbonate rocks according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method for identifying late diagenetic dissolution of carbonate rocks according to any one of claims 1 to 8.

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