Method and device for determining organic carbon content of margarious hydrocarbon source rock

Abstract

The invention relates to a method and a device for determining the organic carbon content of marsh hydrocarbon source rock, and the method comprises the following steps: obtaining the organic carbon content and a plurality of mineral component parameters of a series of rock cores of a sea-land transition phase hydrocarbon source rock stratum section, and determining the correlation between the organic carbon content and each mineral component parameter; screening at least one target mineral component parameter related to the organic carbon content based on the correlation; fitting to obtain a function relation between the organic carbon content and the core logging response value and at least one target mineral component parameter; determining at least one target mineral component parameter of the to-be-measured rock core based on the logging curve; and determining the organic carbon content according to the target logging response value of the to-be-measured rock core, the at least one target mineral component parameter and the function relation. The organic carbon content of the margarious hydrocarbon source rock calculated by the method has the characteristics of high accuracy and reliable result, and effective technical support is provided for logging evaluation of the organic carbon content of the margarious hydrocarbon source rock in exploration and development of shale oil and gas and compact oil and gas.

Description

Technical Field

[0001] The invention relates to a method and a device for determining the organic carbon content of marl source rocks. Background Art

[0002] Organic carbon is the material basis for the production of oil and gas in unconventional oil and gas (shale oil and gas and tight oil and gas) reservoirs. Since the 1980s, scholars have done a lot of research on source rocks. By studying the relationship between geochemical parameters and logging response characteristics, they have proposed a variety of methods for evaluating organic carbon content using logging information. For example, the ΔlgR method and the method of calculating organic carbon content using uranium concentration in gamma spectroscopy logging information have been widely used in source rock formations dominated by mud, but there are often large errors in calculating organic carbon content in transitional phase marl source rocks. The methods in the prior art are not applicable to transitional phase marl source rocks. Therefore, it is necessary to establish a suitable method for calculating organic carbon content based on the characteristics of transitional phase marl source rocks. Summary of the invention

[0003] In order to enrich the existing methods for determining the organic carbon content of marly source rocks applicable to the marine-continental transition phase and improve the accuracy and reliability of the calculated organic carbon content of marly source rocks, the present invention proposes a method and device for determining the organic carbon content of marly source rocks. The technical solution proposed by the present invention is as follows:

[0004] In a first aspect, the present invention provides a method for determining the organic carbon content of a marl source rock, comprising:

[0005] Obtain the organic carbon content and multiple mineral component parameters measured in a series of cores of source rock layers in the marine-continental transition phase, and determine the correlation between the organic carbon content of the marl source rock and the parameters of each mineral component;

[0006] Based on the correlation, at least one target mineral component parameter related to the organic carbon content of the marl source rock is screened from the multiple mineral component parameters;

[0007] Acquire the core logging response value corresponding to the logging depth of the core series of the source rock layer section and the at least one target mineral component parameter;

[0008] According to the organic carbon content of the cores of the source rock layer series, the core logging response value and the at least one target mineral component parameter, fitting is performed to obtain a functional relationship between the organic carbon content and the core logging response value and the at least one target mineral component parameter;

[0009] Determine the at least one target mineral component parameter of the core to be tested based on the acquired well logging curve of the core to be tested in the source rock layer section;

[0010] A target logging response value of the core to be tested is obtained, and the organic carbon content of the core to be tested is determined according to the target logging response value of the core to be tested, the at least one target mineral component parameter and the functional relationship.

[0011] In one or some embodiments, the plurality of mineral component parameters include clay mineral content and carbonate mineral content;

[0012] The correlation between the organic carbon content of the marl source rock and the parameters of each mineral component is determined in the following way:

[0013] According to the organic carbon content, clay mineral content and carbonate mineral content of the core series of source rock layers in the marine-continental transition phase, the first correlation between the organic carbon content of the marl source rock and the clay mineral content, and the second correlation between the organic carbon content of the marl source rock and the carbonate mineral content were determined by the least squares method.

[0014] In one or some embodiments, the screening of at least one target mineral component parameter related to the organic carbon content of the marl source rock from the multiple mineral component parameters based on the correlation includes:

[0015] The mineral component parameters whose correlation is greater than a preset value are screened from the multiple mineral component parameters to obtain at least one target mineral component parameter related to the organic carbon content of the marl source rock.

[0016] In one or some embodiments, the core logging response value includes a compensated density logging value and a resistivity logging value, and the at least one target mineral component parameter includes clay mineral content;

[0017] The fitting of the functional relationship between the organic carbon content, the core logging response value and the at least one target mineral component parameter of the core of the source rock layer series includes:

[0018] According to the organic carbon content, compensated density logging value, resistivity logging value and clay mineral content of the core series of source rock layers, the functional relationship between organic carbon content and compensated density logging value, resistivity logging value and clay mineral content was fitted.

[0019] In one or some embodiments, the functional relationship between the organic carbon content and the compensated density logging value, the resistivity logging value and the clay mineral content is obtained by fitting according to the organic carbon content, the compensated density logging value, the resistivity logging value and the clay mineral content of the core series of the source rock layer, including:

[0020] Establish the corresponding relationship between the organic carbon content at each logging depth and the compensated density logging value, the common logarithm of the resistivity logging value and the clay mineral content;

[0021] According to the corresponding relationship of the source rock layer segments, a preset fitting method is used to determine the functional relationship between the organic carbon content of the source rock layer and the compensated density logging value, the common logarithm of the resistivity logging value and the clay mineral content.

[0022] In one or some embodiments, the target logging response value includes a compensated density logging value and a resistivity logging value; the at least one target mineral component parameter includes a clay mineral content; and determining the organic carbon content of the core to be tested according to the target logging response value of the core to be tested, the at least one target mineral component parameter and the functional relationship includes:

[0023] According to the compensated density logging value, resistivity logging value and clay mineral content of the core to be tested, the organic carbon content of the core to be tested is determined by the following formula:

[0024] TOC=111.09-44.28×ρ b +2.8×log 10 (R LLD )+0.0715×V CLAY ;

[0025] Where TOC is the organic carbon content, ρ b is the compensated density logging value, R LLD is the resistivity logging value, V CLAY Clay mineral content.

[0026] In one or some embodiments, the logging curve of the core to be tested is obtained by:

[0027] The target well is cored by drilling the target layer section to obtain the core to be tested, and a logging curve corresponding to the depth of the core to be tested is obtained.

[0028] In one or some embodiments, the step of determining the at least one target mineral component parameter of the core to be tested based on the acquired logging curve of the core to be tested in the source rock layer segment includes:

[0029] Obtaining a well logging curve of the core to be tested, and calculating a formation lithology profile using an optimization method based on the well logging curve;

[0030] The at least one target mineral component parameter of the core to be measured is obtained from the formation lithology profile.

[0031] In one or some embodiments, the logging curve includes a compensated density logging curve and a resistivity logging curve; the step of obtaining the logging curve of the core to be tested and calculating the formation lithology profile using an optimization method based on the logging curve includes:

[0032] The compensated density logging curve and the resistivity logging curve of the core to be tested are obtained, and the formation lithology profile is calculated by using an optimization method based on the compensated density logging curve and the resistivity logging curve.

[0033] In a second aspect, the present invention provides a device for determining the organic carbon content of a marl source rock, comprising:

[0034] A correlation determination module is used to obtain the organic carbon content and multiple mineral component parameters obtained by measuring a series of cores of source rock layers in the marine-continental transition phase, and determine the correlation between the organic carbon content of the marl source rock and the parameters of each mineral component;

[0035] A screening module, for screening and obtaining at least one target mineral component parameter related to the organic carbon content of the marl source rock from the plurality of mineral component parameters based on the correlation;

[0036] A response value acquisition module, used to acquire the core logging response value corresponding to the logging depth of the core series of the source rock layer section and the at least one target mineral component parameter;

[0037] A fitting module, for fitting a functional relationship between the organic carbon content, the core logging response value and the at least one target mineral component parameter of a series of cores of a source rock layer, according to the organic carbon content, the core logging response value and the at least one target mineral component parameter;

[0038] A formation lithology calculation module, used for determining the at least one target mineral component parameter of the core to be tested based on the acquired logging curve of the core to be tested in the source rock layer section;

[0039] The calculation module is used to obtain the target logging response value of the core to be tested, and determine the organic carbon content of the core to be tested according to the target logging response value of the core to be tested, the at least one target mineral component parameter and the functional relationship.

[0040] In a third aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for determining the organic carbon content of marlite source rock as described in the first aspect.

[0041] In a fourth aspect, the present invention provides an electronic device, comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus;

[0042] Memory, used to store computer programs;

[0043] The processor is used to implement the method for determining the organic carbon content of the marl source rock as described in the first aspect when executing the program stored in the memory.

[0044] Based on the above technical solution, the beneficial effects of the present invention compared with the prior art are as follows:

[0045] The method for determining the organic carbon content of a marl source rock provided by the present invention determines the correlation between the organic carbon content of the marl source rock and each mineral component parameter by obtaining the core logging response value, the organic carbon content and multiple mineral component parameters of a series of cores of a source rock layer section; then, based on the correlation, at least one target mineral component parameter related to the organic carbon content of the marl source rock is screened from the multiple mineral component parameters; then, according to the organic carbon content, the core logging response value and the at least one target mineral component parameter of the series of cores of the source rock layer section, a functional relationship between the organic carbon content and the core logging response value and the at least one target mineral component parameter is fitted. The present invention is based on core logging data of a series of marl source rock layers in a certain geographical area, namely, core logging response values ​​and laboratory analysis data, namely, organic carbon content and multiple mineral component parameters, establishes a corresponding relationship between organic carbon content, core logging response values ​​and multiple mineral component parameters, analyzes the intrinsic relationship between organic carbon content, core logging response values ​​and multiple mineral component parameters, determines the functional relationship between organic carbon content of source rocks in marine-continental transition phase, core logging response values ​​and multiple mineral component parameters by a mathematical fitting method, and then determines the organic carbon content of the core to be tested according to the target logging response value of the core to be tested, the target mineral component parameter and the functional relationship obtained by the above fitting. The calculated organic carbon content of the marl source rock has the characteristics of high accuracy and reliable results, and provides effective technical support for logging evaluation of organic carbon content of marl source rocks in shale oil and gas and tight oil and gas exploration and development.

[0046] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0047] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 It is a schematic flow chart of a method for determining organic carbon content of marl source rocks provided by an embodiment of the present invention;

[0050] Figure 2 A comparison chart of the organic carbon content of the marl source rock provided by the embodiment of the present invention and the organic carbon content calculated by the well logging method;

[0051] Figure 3 Schematic diagram of the structure of a device for determining the organic carbon content of marly source rocks provided by an embodiment of the present invention;

[0052] Figure 4 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0053] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0054] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0055] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0056] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0057] Organic carbon is the material basis for the production of oil and gas in unconventional oil and gas (shale oil and gas and tight oil and gas) reservoirs. Since the 1980s, scholars have done a lot of research on source rocks. By studying the relationship between geochemical parameters and logging response characteristics, they have proposed a variety of methods for evaluating organic carbon content using logging information.

[0058] In 1990, Passey et al. proposed the classic ΔlgR method, which uses logging data to evaluate the organic carbon content of source rocks. This method is applicable to both carbonate source rocks and clastic source rocks. The method is as follows: by appropriately calibrating the resistivity curve and the porosity curve, the porosity curve is superimposed on the resistivity curve, so that the two curves overlap in the mudstone section of the non-source rock section, while there is a certain amplitude difference between the two curves in the source rock section (rich in organic matter). Since organic matter has logging response characteristics such as low density, high resistivity, high acoustic time difference, and high neutrons, the organic carbon content can be judged based on the amplitude difference between the two curves. The larger the amplitude difference, the higher the organic carbon content.

[0059] The ΔlgR method is a theoretical-empirical formula proposed in the early research of hydrocarbon generation in source rocks. It has certain limitations: when the kerogen maturity of source rocks is in the immature-high maturity stage, the ΔlgR method can obtain relatively accurate calculation results. However, when the kerogen maturity of source rocks is in the high-to-over-high maturity stage, the calculation results of the ΔlgR method have certain errors. This limitation of the ΔlgR method is verified in the process of calculating the organic carbon content of source rocks. Due to the hydrocarbon expulsion effect, the existing total organic carbon content measured in the laboratory is low, resulting in a deviation in the organic matter maturity index LOM determined by the cross-plot of TOC and ΔlgR obtained by experimental analysis, which makes the method inaccurate in calculating the organic carbon content.

[0060] Another shortcoming of the ΔlgR method is that organic matter in source rocks is often associated with high pyrite, which affects the formation resistivity and reduces the logging resistivity value, resulting in a large deviation in the organic carbon content calculated using the ΔlgR method. In addition, in layers with high organic carbon content in source rocks, source rocks have higher resistivity values. When induction logging is used for measurement, due to the limitation of the instrument's measurement range, the logging resistivity measurement value is low, which also leads to a large deviation in the organic carbon content calculated using the ΔlgR method.

[0061] In addition to the ΔlgR method, there are also articles in the existing literature that use the uranium concentration in gamma spectroscopy logging information to calculate the organic carbon content. Most of the calculation methods use the characteristic that the organic carbon content changes linearly with the uranium concentration, but studies have found that in higher uranium-containing layers, the organic matter content and uranium concentration do not change linearly, but nonlinearly. Therefore, the method of using uranium concentration to calculate the organic carbon content in the literature has certain errors in the results obtained in high uranium-containing layers. In some carbonaceous mudstone layers, there will also be higher uranium concentrations, and the carbon in carbonaceous mudstone does not belong to the organic carbon in kerogen. The organic carbon content calculated using the uranium curve in natural gamma spectroscopy logging will be significantly higher.

[0062] The inventors found that the above method has been widely used in source rock formations dominated by mud, but when the above common method is used to calculate the organic carbon content in marine-continental transitional strata, large errors often occur. The organic carbon content of marine-continental transitional source rocks is often positively correlated with the carbonate content within a certain range, and negatively correlated with the clay mineral content, which is exactly the opposite of the aforementioned ΔlgR method and uranium curve method. Therefore, the above method is no longer applicable to the marly source rocks of the marine-continental transitional phase and cannot meet the inventors' expectations.

[0063] In summary, when the organic carbon content of source rocks is calculated using the existing method for calculating the organic carbon content of source rocks in the transitional phase, there is often a large error. It is necessary to establish a suitable method for calculating the organic carbon content according to the characteristics of the transitional phase marl source rocks. The inventors made the present invention after further research and development.

[0064] Embodiment 1

[0065] The embodiment of the present invention provides a method for determining the organic carbon content of marl source rock, referring to Figure 1 As shown, including:

[0066] S101, obtaining the organic carbon content and multiple mineral component parameters obtained by measuring a series of cores of source rock layers in the marine-continental transition phase, and determining the correlation between the organic carbon content of the marl source rock and the parameters of each mineral component;

[0067] A series of cores of source rock layers are selected for measurement to obtain the organic carbon content and multiple mineral component parameters, and the above-mentioned multiple mineral component parameters may include clay mineral content and carbonate mineral content. Specifically, cores are drilled and cored in the target layer of the target well, and the core measurement contents include organic carbon content, clay mineral content, and carbonate mineral content. The organic carbon content, clay mineral content, and carbonate mineral content are obtained through chemical test analysis of the cores, which are chemical analysis values. The measurement process can refer to the description in the prior art. According to the organic carbon content and multiple mineral component parameters of the series of cores, i.e., multiple cores, the correlation between the organic carbon content of the marl source rock and each mineral component parameter is determined respectively. The correlation calculation method can refer to the description in the prior art and is not specifically limited here.

[0068] S102, screening out at least one target mineral component parameter related to the organic carbon content of the marl source rock from the multiple mineral component parameters based on the correlation;

[0069] After determining the correlation between the organic carbon content of the marl source rock and each mineral component parameter, the mineral components with a higher correlation with the organic carbon content of the marl source rock are screened out from multiple mineral component parameters to obtain the target mineral component parameters.

[0070] S103, obtaining core logging response values ​​corresponding to the logging depths of the core series of the source rock layer section and the at least one target mineral component parameter;

[0071] S104, fitting a functional relationship between the organic carbon content, the core logging response value and the at least one target mineral component parameter of the source rock layer series cores to obtain the organic carbon content, the core logging response value and the at least one target mineral component parameter;

[0072] A corresponding relationship between the organic carbon content of the core at each logging depth and the core logging response value and the target mineral component parameters is established, that is, the organic carbon content, the core logging response value and the target mineral component parameters are corresponded according to the logging depth, and the organic carbon content, the core logging response value and the target mineral component parameters at the same logging depth are grouped together. According to the corresponding relationship of the source rock layer section, a mathematical fitting method is used to determine the functional relationship between the organic carbon content of the source rock layer and the core logging response value and the target mineral component parameters.

[0073] S105, determining at least one target mineral component parameter of the core to be tested based on the acquired logging curve of the core to be tested in the source rock layer;

[0074] The logging curve of the core to be tested is obtained in the following manner: drilling and coring the target layer section of the target well to obtain the core to be tested, and obtaining the logging curve of the depth corresponding to the core to be tested.

[0075] The formation lithology of the core to be tested is calculated to obtain the mineral component parameters of the formation, namely the type and content of the mineral components, and obtain the at least one target mineral component parameter of the core to be tested.

[0076] S106, obtaining a target logging response value of the core to be tested, and determining the organic carbon content of the core to be tested according to the target logging response value of the core to be tested, the at least one target mineral component parameter and the functional relationship.

[0077] The present invention relates to the technical field of shale oil and gas and tight oil and gas logging evaluation in petroleum exploration and development, and the main purpose is to provide a method and device for determining the organic carbon content of marl source rocks, so as to solve the defect that the existing logging calculation method for the organic carbon content of source rocks has low precision when calculating the organic carbon content of marine-continental transitional phase source rocks. The method for determining the organic carbon content of marl source rocks provided by the present invention determines the correlation between the organic carbon content of the marl source rocks and the parameters of each mineral component by obtaining the core logging response value, organic carbon content and multiple mineral component parameters of a series of cores of source rock layers; then, based on the correlation, at least one target mineral component parameter related to the organic carbon content of the marl source rocks is screened from the multiple mineral component parameters; then, according to the organic carbon content of the series of cores of the source rock layers, the core logging response value and the at least one target mineral component parameter, a functional relationship between the organic carbon content and the core logging response value and the at least one target mineral component parameter is fitted. The present invention is based on core logging data of a series of marl source rock layers in a certain geographical area, namely, core logging response values ​​and laboratory analysis data, namely, organic carbon content and multiple mineral component parameters, establishes a corresponding relationship between organic carbon content, core logging response values ​​and multiple mineral component parameters, analyzes the intrinsic relationship between organic carbon content, core logging response values ​​and multiple mineral component parameters, determines the functional relationship between organic carbon content of source rocks in marine-continental transition phase, core logging response values ​​and multiple mineral component parameters by a mathematical fitting method, and then determines the organic carbon content of the core to be tested according to the target logging response value of the core to be tested, the target mineral component parameter and the functional relationship obtained by the above fitting. The calculated organic carbon content of the marl source rock has the characteristics of high accuracy and reliable results, and provides effective technical support for logging evaluation of organic carbon content of marl source rocks in shale oil and gas and tight oil and gas exploration and development.

[0078] In one embodiment, the multiple mineral component parameters in the above step S101 include clay mineral content and carbonate rock mineral content; the selected source rock layer series cores are measured to obtain the clay mineral content and carbonate rock mineral content; the correlation between the organic carbon content of the marl source rock and each mineral component parameter can be obtained by least squares analysis;

[0079] The correlation between the organic carbon content of the marl source rock and the parameters of each mineral component is determined in the following way:

[0080] According to the organic carbon content, clay mineral content and carbonate mineral content of the core series of source rock layers in the marine-continental transition phase, the first correlation between the organic carbon content of the marl source rock and the clay mineral content, and the second correlation between the organic carbon content of the marl source rock and the carbonate mineral content were determined by the least squares method.

[0081] In one embodiment, the above step S102, based on the correlation, screens out at least one target mineral component parameter related to the organic carbon content of the marl source rock from the multiple mineral component parameters, including:

[0082] The mineral component parameters whose correlation is greater than a preset value are screened from the multiple mineral component parameters to obtain at least one target mineral component parameter related to the organic carbon content of the marl source rock.

[0083] The above preset value can be set according to actual needs, such as 0.3.

[0084] In one embodiment, the core logging response value in the above step S104 includes a compensated density logging value and a resistivity logging value, and the logging curve corresponding to the logging depth can be obtained through the logging depth of the core to be tested, thereby obtaining the compensated density logging value and the resistivity logging value; the at least one target mineral component parameter includes clay mineral content;

[0085] The step S104 described above, according to the organic carbon content of the cores of the source rock layer series, the core logging response value and the at least one target mineral component parameter, fitting a functional relationship between the organic carbon content and the core logging response value and the at least one target mineral component parameter, comprises:

[0086] S1041. Based on the organic carbon content, compensated density logging value, resistivity logging value and clay mineral content of the core series of source rock layers, a functional relationship between the organic carbon content and the compensated density logging value, resistivity logging value and clay mineral content is obtained by fitting.

[0087] In one embodiment, the functional relationship between the organic carbon content and the compensated density logging value, the resistivity logging value and the clay mineral content is obtained by fitting according to the organic carbon content, the compensated density logging value, the resistivity logging value and the clay mineral content of the core of the source rock layer series described in step S1041, including:

[0088] S10411. Establish the corresponding relationship between the organic carbon content at each logging depth and the compensated density logging value, the common logarithm of the resistivity logging value and the clay mineral content;

[0089] S10412. Based on the corresponding relationship of the source rock layer segments, a preset fitting method is used to determine the functional relationship between the organic carbon content of the source rock layer and the compensated density logging value, the common logarithm of the resistivity logging value and the clay mineral content.

[0090] The present invention selects a series of cores of source rock layers to measure and obtain organic carbon content, and simultaneously measures clay mineral content and carbonate mineral content; analyzes the correlation between organic carbon content and mineral components, namely clay mineral content and carbonate mineral content, and obtains mineral components with high correlation with organic carbon content, and the mineral components with high correlation with organic carbon content obtained by the present invention are clay mineral content; uses logging curves to calculate formation lithology profiles using an optimization method to obtain clay mineral content and carbonate mineral content; then obtains logging response values, specifically, obtains resistivity logging values ​​corresponding to the logging depth of the core analysis corresponding to the organic carbon content, compensated density logging values, and clay mineral content calculated by the optimization method; establishes a corresponding relationship between the organic carbon content at each logging depth and the compensated density logging value, the common logarithm of the resistivity logging value, and the clay mineral content logging calculation value. The common logarithm of resistivity logging values, compensated density logging values ​​and clay mineral content calculated by logging are used as parameters to determine the organic carbon content. The organic carbon content calculated by logging data is applied. According to the corresponding relationship of the source rock layer, a mathematical fitting method is used to determine the functional relationship between the organic carbon content of the source rock layer and the compensated density logging value, the common logarithm of resistivity logging values ​​and the clay mineral content logging calculated value. The organic carbon content of the source rock layer is calculated using the determined functional relationship. The present invention has the characteristics of high accuracy and reliable results in calculating the organic carbon content of source rocks, and provides effective technical support for the exploration and development of tight oil and gas. The established relationship is:

[0091] TOC=111.09-44.28×ρ b +2.8×log 10 (R LLD )+0.0715×V CLAY ;

[0092] Where TOC is the organic carbon content, ρ b is the compensated density logging value, g / cm 3 ; R LLD is the resistivity logging value, Ω·m; V CLAY is the clay mineral content, %. In the functional relationship determined by the mathematical fitting method of the present invention, the organic carbon content has a linear relationship with the supplementary density logging value, the common logarithm of the resistivity logging value, and the clay mineral content logging calculated value.

[0093] The present invention considers the influence of mineral components on organic carbon content and calculates organic carbon content by using conventional well logging curves combined with formation lithology profiles. The above step S105, based on the well logging curve of the core to be tested obtained from the source rock layer, determines the at least one target mineral component parameter of the core to be tested, including:

[0094] S1051, obtaining a well logging curve of the core to be tested, and calculating a formation lithology profile using an optimization method based on the well logging curve;

[0095] The clay mineral content and carbonate mineral content can be directly measured from the core. Due to the limited number of cores, the logging curve is used downhole to calculate the continuous distribution of the mineral content of the target layer using the optimization method. The optimization method for calculating the mineral composition of shale oil reservoirs is a common method for calculating the lithological profile of the formation by logging. Those skilled in the art can refer to the detailed description of the prior art, such as the paper "Optimization Inversion Method for Mineral Composition of Shale Oil Reservoirs in Jiyang Depression" published in Volume 29, Issue 2 of "Special Oil and Gas Reservoirs". This method is described in detail. The examples listed in the paper obtained the contents of clay minerals, quartz minerals and carbonate minerals through logging calculations.

[0096] S1052. Obtain at least one target mineral component parameter of the core to be tested from the formation lithology profile.

[0097] The organic carbon content of the present invention is highly correlated with the clay mineral content, and the target mineral component parameter is the clay mineral content. The formation lithology profile includes the well logging calculation result of the clay mineral content, and the clay mineral content, that is, the target mineral component parameter, can be obtained from the formation lithology profile.

[0098] In one embodiment, the logging curve includes a compensated density logging curve and a resistivity logging curve; the step S1051 of obtaining the logging curve of the core to be tested, and calculating the formation lithology profile based on the logging curve by using an optimization method, includes:

[0099] The compensated density logging curve and the resistivity logging curve of the core to be tested are obtained, and the formation lithology profile is calculated by using an optimization method based on the compensated density logging curve and the resistivity logging curve.

[0100] In one embodiment, the target logging response value in the above step S106 includes a compensated density logging value and a resistivity logging value; the at least one target mineral component parameter includes a clay mineral content; and the above step S106 of determining the organic carbon content of the core to be tested according to the target logging response value of the core to be tested, the at least one target mineral component parameter and the functional relationship includes:

[0101] According to the compensated density logging value, resistivity logging value and clay mineral content of the core to be tested, the organic carbon content of the core to be tested is determined by the following formula:

[0102] TOC=111.09-44.28×ρ b +2.8×log 10 (R LLD )+0.0715×V CLAY ;

[0103] Where TOC is the organic carbon content, ρ b is the compensated density logging value, g / cm 3 ; R LLD is the resistivity logging value, Ω·m; V CLAY is the clay mineral content, %.

[0104] The present invention is based on logging data (resistivity logging value, compensated density logging value, clay mineral content) and laboratory analysis data (i.e., organic carbon content) of marl source rock layers in a certain geographical area, establishes a corresponding relationship between the laboratory analysis value of organic carbon content and the resistivity logging value, compensated density logging value and clay mineral content of the formation calculated by the optimization method, analyzes the intrinsic relationship between the laboratory analysis value of organic carbon content and the common logarithm of resistivity logging value, compensated density logging value and clay mineral content calculated by logging, determines the functional relationship between the laboratory analysis value of organic carbon content of source rock and the common logarithm of resistivity logging value, compensated density logging value and clay mineral content calculated by logging by a mathematical fitting method, and has the characteristics of high accuracy and reliable results for the calculated organic carbon content of marl source rock, and provides effective technical support for the logging evaluation of organic carbon content of marl source rock in shale oil and gas and tight oil and gas exploration and development. When establishing the functional relationship, the present invention selects the mineral with the best correlation with the organic carbon content, namely the clay mineral content, thereby improving the calculation accuracy.

[0105] Referring to Table 1, there are TOC (Total Organic Carbon) values ​​of core analysis, corresponding logging response values, and TOC logging calculation results of the present invention:

[0106] The formula of the present invention has good practical application effect in the quantitative evaluation of TOC of marl source rocks. The TOC calculated by the method of the present invention has good consistency with the core analysis result, which improves the calculation accuracy.

[0107] Reference Figure 2As shown in the figure, it is a comparison chart of the TOC content of source rock calculated by the method of the present invention and the TOC content of source rock obtained by experimental measurement. In the figure, the first track (WIRE.GR) is natural gamma logging, the second track (DEPTHFEET) is depth, the third track (WIRE.LLD) is resistivity logging, the fourth track (WIRE.RHOB) is compensated density logging, the fifth track (MULTI.VOL_ILLITE) is the clay mineral content curve calculated by logging, and the sixth track is the comparison of TOC calculated by logging (WIRE.TOC_CAL) and TOC of core analysis (CORE.T). Figure 2 It can be seen that the TOC value calculated by the functional relationship of the present invention for logging data processing (the sixth track WIRE.TOC_CAL in the figure) and the TOC value obtained by the core experimental measurement of the source rock (the sixth bar graph CORE.TOC in the figure) have good consistency, high calculation accuracy and obvious application effect. This shows that the method has obvious practical application effect in the calculation of organic carbon content of marl source rocks in the transitional phase of marine and terrestrial phases, and can provide effective technical support for the logging evaluation of organic carbon content of marl source rocks in the exploration and development of shale oil and gas and tight oil and gas.

[0108]

[0109] Table 1

[0110] Embodiment 2

[0111] The embodiment of the present invention provides a device for determining the organic carbon content of marl source rock, referring to Figure 3 As shown, including:

[0112] The correlation determination module 201 is used to obtain the organic carbon content and multiple mineral component parameters obtained by measuring the core of the source rock layer series of the marine-continental transition phase, and determine the correlation between the organic carbon content of the marl source rock and the various mineral component parameters;

[0113] A screening module 202 is used to screen and obtain at least one target mineral component parameter related to the organic carbon content of the marl source rock from the multiple mineral component parameters based on the correlation;

[0114] The response value acquisition module 203 is used to obtain the core logging response value corresponding to the logging depth of the core series of the source rock layer section and the at least one target mineral component parameter.

[0115] A fitting module 204 is used to fit the organic carbon content, the core logging response value and the at least one target mineral component parameter of the core of the source rock layer series to obtain a functional relationship between the organic carbon content and the core logging response value and the at least one target mineral component parameter;

[0116] The formation lithology calculation module 205 is used to determine the at least one target mineral component parameter of the core to be tested based on the acquired logging curve of the core to be tested in the source rock layer section;

[0117] The calculation module 206 is used to obtain the target logging response value of the core to be tested, and determine the organic carbon content of the core to be tested according to the target logging response value of the core to be tested, the at least one target mineral component parameter and the functional relationship.

[0118] The above-mentioned correlation determination module 201 includes an analysis and testing module and a correlation analysis module. The analysis and testing module is used to select a series of core measurements of source rock layers and obtain the organic carbon content, and simultaneously measure the clay mineral content and the carbonate mineral content; the correlation analysis module is used to analyze the correlation between the organic carbon content and the mineral components, namely the clay mineral content and the carbonate mineral content, and obtain the mineral components with high correlation with the organic carbon content. The mineral components with high correlation with the organic carbon content obtained by the present invention are the clay mineral content.

[0119] The response value acquisition module 203 is specifically used to obtain the resistivity logging value, the compensated density logging value and the clay mineral content calculated by the optimization method corresponding to the logging depth of the core for analyzing the organic carbon content;

[0120] The above-mentioned formation lithology calculation module 205 is used to calculate the formation lithology profile by using the well logging curve using the optimization method to obtain the clay mineral content and the carbonate mineral content, and calculate the organic carbon content of the source rock layer section using the determined functional relationship.

[0121] The fitting module 204 includes a corresponding relationship establishment module and a function fitting module, wherein the corresponding relationship establishment module is used to establish the corresponding relationship between the organic carbon content of each logging depth and the compensated density logging value, the common logarithm of the resistivity logging value and the clay mineral content logging calculation value. The function fitting module is used to use the common logarithm of the resistivity logging value, the compensated density logging value and the clay mineral content calculated by logging as parameters for determining the organic carbon content, and to use the organic carbon content calculated by logging data, and to use a mathematical fitting method to determine the functional relationship between the organic carbon content of the source rock layer and the compensated density logging value, the common logarithm of the resistivity logging value and the clay mineral content logging calculation value according to the corresponding relationship of the source rock layer segment. The device for determining the organic carbon content of the marl source rock provided in the embodiment of the present invention has a realization principle and technical effect similar to any of the aforementioned method embodiments, which will not be repeated here.

[0122] Embodiment 3

[0123] An embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for determining the organic carbon content of marl source rock as described in any of the aforementioned method embodiments.

[0124] The computer-readable storage medium may be included in the device / apparatus described in the above embodiment; or it may exist independently without being assembled into the device / apparatus. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed, the method according to the embodiment of the present invention is implemented.

[0125] According to an embodiment of the present invention, the computer-readable storage medium may be a non-volatile computer-readable storage medium, for example, may include but is not limited to: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present invention, the computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, apparatus, or device.

[0126] Embodiment 4

[0127] An embodiment of the present invention provides an electronic device, referring to Figure 4 As shown, it includes a processor 111, a communication interface 112, a memory 113 and a communication bus 114, wherein the processor 111, the communication interface 112 and the memory 113 communicate with each other through the communication bus 114.

[0128] Memory 113, used for storing computer programs;

[0129] The processor 111 is used to implement the method for determining the organic carbon content of the marl source rock as described in any of the above method embodiments when executing the program stored in the memory 113.

[0130] The implementation principle and technical effect of the electronic device provided by the embodiment of the present invention are similar to those of any of the aforementioned method embodiments, and will not be repeated here.

[0131] The above-mentioned memory 113 can be an electronic memory such as a flash memory, an EEPROM (electrically erasable programmable read-only memory), an EPROM, a hard disk or a ROM. The memory 113 has a storage space for program codes for executing any method steps in the above-mentioned method. For example, the storage space for program codes may include various program codes for implementing various steps in the above method respectively. These program codes can be read from or written into one or more computer program products. These computer program products include program code carriers such as hard disks, compact disks (CDs), memory cards or floppy disks. Such computer program products are usually portable or fixed storage units. The storage unit may have a storage segment or storage space arranged similarly to the memory 113 in the above-mentioned electronic device. The program code can be compressed, for example, in an appropriate form. Generally, the storage unit includes a program for executing the method steps according to an embodiment of the present invention, that is, a code that can be read by, for example, a processor 111, and when these codes are run by an electronic device, the electronic device performs the various steps in the method described above.

[0132] In this document, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. The orientation or position relationship indicated by the terms "upper", "lower", etc. is based on the orientation or position relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0133] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict. The present invention is not limited to any single aspect, any single embodiment, or any combination and / or permutation of these aspects and / or embodiments. Each aspect and / or embodiment of the present invention can be used alone, or in combination with one or more other aspects and / or other embodiments.

[0134] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for determining the organic carbon content of marl source rocks, characterized in that: include: Obtain the organic carbon content and multiple mineral component parameters measured in a series of cores of source rock layers in the marine-continental transition phase, and determine the correlation between the organic carbon content of the marl source rock and the parameters of each mineral component; Based on the correlation, at least one target mineral component parameter related to the organic carbon content of the marl source rock is screened from the multiple mineral component parameters; Acquire the core logging response value corresponding to the logging depth of the core series of the source rock layer section and the at least one target mineral component parameter; According to the organic carbon content of the cores of the source rock layer series, the core logging response value and the at least one target mineral component parameter, fitting is performed to obtain a functional relationship between the organic carbon content and the core logging response value and the at least one target mineral component parameter; Determine the at least one target mineral component parameter of the core to be tested based on the acquired well logging curve of the core to be tested in the source rock layer section; A target logging response value of the core to be tested is obtained, and the organic carbon content of the core to be tested is determined according to the target logging response value of the core to be tested, the at least one target mineral component parameter and the functional relationship.

2. The method for determining the organic carbon content of marl source rock according to claim 1, characterized in that: The plurality of mineral component parameters include clay mineral content and carbonate mineral content; The correlation between the organic carbon content of the marl source rock and the parameters of each mineral component is determined in the following way: According to the organic carbon content, clay mineral content and carbonate mineral content of the core series of source rock layers in the marine-continental transition phase, the first correlation between the organic carbon content of the marl source rock and the clay mineral content, and the second correlation between the organic carbon content of the marl source rock and the carbonate mineral content were determined by the least squares method.

3. The method for determining the organic carbon content of marly source rocks according to claim 1, characterized in that: The method of screening and obtaining at least one target mineral component parameter related to the organic carbon content of the marl source rock from the multiple mineral component parameters based on the correlation includes: The mineral component parameters whose correlation is greater than a preset value are screened from the multiple mineral component parameters to obtain at least one target mineral component parameter related to the organic carbon content of the marl source rock.

4. The method for determining the organic carbon content of marl source rock according to claim 1, characterized in that: The core logging response value includes a compensated density logging value and a resistivity logging value, and the at least one target mineral component parameter includes clay mineral content; The fitting of the functional relationship between the organic carbon content, the core logging response value and the at least one target mineral component parameter of the core of the source rock layer series includes: According to the organic carbon content, compensated density logging value, resistivity logging value and clay mineral content of the core series of source rock layers, the functional relationship between organic carbon content and compensated density logging value, resistivity logging value and clay mineral content was fitted.

5. The method for determining the organic carbon content of marl source rock according to claim 4, characterized in that: The functional relationship between the organic carbon content and the compensated density logging value, the resistivity logging value and the clay mineral content is obtained by fitting according to the organic carbon content, the compensated density logging value, the resistivity logging value and the clay mineral content of the core series of the source rock layer, including: Establish the corresponding relationship between the organic carbon content at each logging depth and the compensated density logging value, the common logarithm of the resistivity logging value and the clay mineral content; According to the corresponding relationship of the source rock layer segments, a preset fitting method is used to determine the functional relationship between the organic carbon content of the source rock layer and the compensated density logging value, the common logarithm of the resistivity logging value and the clay mineral content.

6. The method for determining the organic carbon content of marl source rock according to claim 1, characterized in that: The target logging response value includes a compensated density logging value and a resistivity logging value; the at least one target mineral component parameter includes a clay mineral content; and determining the organic carbon content of the core to be tested according to the target logging response value of the core to be tested, the at least one target mineral component parameter and the functional relationship includes: According to the compensated density logging value, resistivity logging value and clay mineral content of the core to be tested, the organic carbon content of the core to be tested is determined by the following formula: TOC=111.09-44.28×ρ b +2.8×log 10 (R LLD )+0.0715×V CLAY ; Where TOC is the organic carbon content, ρ b is the compensated density logging value, R LLD is the resistivity logging value, V CLAY Clay mineral content.

7. The method for determining the organic carbon content of marly source rocks according to claim 1, characterized in that: The logging curve of the core to be tested is obtained by the following method: The target well is cored by drilling the target layer section to obtain the core to be tested, and a logging curve corresponding to the depth of the core to be tested is obtained.

8. The method for determining the organic carbon content of marly source rocks according to claim 1, characterized in that: The step of determining the at least one target mineral component parameter of the core to be tested based on the acquired well logging curve of the core to be tested in the source rock layer segment comprises: Obtaining a well logging curve of the core to be tested, and calculating a formation lithology profile using an optimization method based on the well logging curve; The at least one target mineral component parameter of the core to be measured is obtained from the formation lithology profile.

9. The method for determining the organic carbon content of marly source rocks according to claim 8, characterized in that: The logging curves include compensated density logging curves and resistivity logging curves; the step of obtaining the logging curves of the core to be tested and calculating the formation lithology profile using an optimization method based on the logging curves includes: The compensated density logging curve and the resistivity logging curve of the core to be tested are obtained, and the formation lithology profile is calculated by using an optimization method based on the compensated density logging curve and the resistivity logging curve.

10. A device for determining the organic carbon content of marl source rock, characterized in that: include: A correlation determination module is used to obtain the organic carbon content and multiple mineral component parameters obtained by measuring a series of cores of source rock layers in the marine-continental transition phase, and determine the correlation between the organic carbon content of the marl source rock and the parameters of each mineral component; A screening module, for screening and obtaining at least one target mineral component parameter related to the organic carbon content of the marl source rock from the plurality of mineral component parameters based on the correlation; A response value acquisition module, used to acquire the core logging response value corresponding to the logging depth of the core series of the source rock layer section and the at least one target mineral component parameter; A fitting module, for fitting the organic carbon content of the cores of the source rock layer series, the core logging response value and the at least one target mineral component parameter to obtain a functional relationship between the organic carbon content and the core logging response value and the at least one target mineral component parameter; A formation lithology calculation module, used for determining the at least one target mineral component parameter of the core to be tested based on the acquired logging curve of the core to be tested in the source rock layer section; The calculation module is used to obtain the target logging response value of the core to be tested, and determine the organic carbon content of the core to be tested according to the target logging response value of the core to be tested, the at least one target mineral component parameter and the functional relationship.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method for determining the organic carbon content of marl source rock as described in any one of claims 1 to 9 is implemented.

12. An electronic device, characterized in that: It includes a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus; Memory, used to store computer programs; The processor is used to implement the method for determining the organic carbon content of the marl source rock as described in any one of claims 1 to 9 when executing the program stored in the memory.

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