Apparatus, method, model for determining content of glauconite and construction method and application thereof

Abstract

The application provides a device and method for determining glauconite content, a model and a construction method and application thereof, and the determining method comprises the following steps: determining and optimizing first basic parameters by using conventional logging data in combination with regional geological data, the first basic parameters comprising PE sh , rho sh and V sh ; obtaining second basic parameters based on common sedimentary rock mineral logging characteristic values, the second basic parameters comprising PE qz , PE gl , rho qz , rho gl and rho f ; obtaining third basic parameters based on lithology density logging data, the third basic parameters comprising PE and RHOB; and substituting the first basic parameters, the second basic parameters and the third basic parameters into a calculation model of the glauconite content in the sandstone to obtain V gl , V qz and the application has the advantages of economy, rapidness, rich information, high accuracy, convenience in operation and the like by quantitatively calculating the glauconite content in the sandstone through scientific theoretical methods.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil geological exploration, in particular to a device for determining the content of smectite in sandstone, a method for determining the content of smectite in sandstone, a calculation model of the content of smectite in sandstone, a method for constructing the calculation model of the content of smectite in sandstone, and a method for applying the calculation model of the content of smectite in sandstone. BACKGROUND

[0002] In shallow clastic rock oil and gas fields such as the South American Orinoco Basin, smectite minerals are commonly developed in sandstone. On the one hand, smectite is a clay mineral with high natural gamma ray and low resistivity, which is the logging response characteristics of clay minerals, so that the sandstone with high smectite content is often mistaken for sandy mudstone or argillaceous sandstone, and the reservoir is missed. On the other hand, due to the high maturity of smectite, the burial depth is relatively shallow, and it exists in the form of spherical or pellet-shaped particles with particle characteristics, which fills in the pores, reduces the porosity and permeability of sandstone, and increases the irreducible water saturation of sandstone, affecting the correct evaluation of sandstone reservoirs.

[0003] In the prior art, the characteristics of smectite clay are relatively clear, but the characteristics of its clastic particles are not clear, and only a small amount of literature qualitatively analyzes the particles from physical analysis data such as core slices. There is less data on quantitative analysis of smectite content. The existing small amount of literature indicates that the content of smectite in the core sample sandstone is mainly determined by test analysis, and the relationship between smectite content and neutron logging data or density logging data is regressed to fit the formula for quantitative calculation.

[0004] For example, the patent document with the invention name of a method and device for determining the content of glauconite in glauconite sandstone and the publication number of CN 105510986 A disclosed on April 20, 2016, discloses a method for determining the content of glauconite in glauconite sandstone. The method comprises the following steps: preparing an overlap curve of the volume density logging curve and the neutron porosity logging curve of the reference logging, and identifying the glauconite sandstone; performing multiple linear regression on the amplitude value of the glauconite content obtained from the core data and the corresponding volume density logging curve and neutron porosity logging curve, to obtain the linear relationship between the glauconite content identification factor and the volume density data and the neutron porosity data; calculating the glauconite content identification factor of the reference logging according to the linear relationship; performing nonlinear regression processing on the amplitude value of the glauconite content and the glauconite content identification factor, to obtain the nonlinear relationship between the glauconite content and the glauconite content identification factor; and determining the content of glauconite in the glauconite sandstone of the logging to be identified by using the nonlinear relationship. Although the content of glauconite in the glauconite sandstone can be accurately determined by using the method, the method needs to determine the content of glauconite in the sandstone, and is limited by factors such as the number of samples, the difficulty of operation, and economic benefits, so it is difficult to popularize and use, and the correlation coefficient of the glauconite content and the single neutron data or the density data is not high, and the accuracy is not high. SUMMARY

[0005] The present application aims to solve at least one of the above-mentioned deficiencies in the prior art. For example, one of the purposes of the present application is to provide a model and a method for quantitatively calculating the content of glauconite in sandstone.

[0006] To achieve the above-mentioned purposes, one aspect of the present application provides a method for determining the content of glauconite in sandstone, which comprises the following steps:

[0007] Based on conventional logging data and litho-density logging data, the content of glauconite is calculated by using a calculation model of the content of glauconite in sandstone, and the calculation model is shown in the following formula (1):

[0008]

[0009] In formula (1), PE is the logging value of the photoelectric absorption cross-section index, b / e; RHOB is the logging value of the rock volume density, g / cm 3 ; PE sh is the photoelectric absorption cross-section index of clay minerals other than glauconite, b / e; p sh is the rock volume density of clay minerals other than glauconite, g / cm 3 ; V sh is the volume content of clay minerals other than glauconite, v / v; PE qz is the photoelectric absorption cross-section index of quartz or other sandstone clastic components, b / e; p qzρ is the rock volume density of the quartz or other sandstone clastic component, g / cm3 3 ; V qz is the volume content of the quartz or other sandstone clastic component, v / v; PE gl is the photoelectric absorption cross section index of the glauconite, b / e; ρ gl is the rock volume density of the glauconite, g / cm3 3 ; V gl is the volume content of the glauconite, v / v; ρ f is the volume density of the fluid, g / cm3 3 ; is the formation porosity, v / v.

[0010] In an exemplary embodiment of the method for determining the content of glauconite in sandstone of the present application, the method can specifically include the following steps:

[0011] The first basic parameters including PE sh , ρ sh and V sh are determined and optimized by using conventional logging data in combination with regional geological data;

[0012] The second basic parameters including PE qz , PE gl , ρ qz , ρ gl and ρ f are obtained based on common sedimentary rock mineral logging characteristic values;

[0013] The third basic parameters including PE and RHOB are obtained based on lithology density logging data;

[0014] The first basic parameters, the second basic parameters and the third basic parameters are substituted into the calculation model of the content of glauconite in sandstone to obtain V gl , V qz and .

[0015] In an exemplary embodiment of the method for determining the content of glauconite in sandstone of the present application, the conventional logging data can include rock volume density, compensated neutron and natural gamma; and the lithology density logging data can include photoelectric absorption cross section index and rock volume density.

[0016] In an exemplary embodiment of the method for determining the content of glauconite in sandstone of the present application, when having regional core X diffraction clay mineral analysis results, PE sh and ρ sh can be determined and optimized by using formula (2) and formula (3),

[0017] PE sh =∑V shi ×PE shi Equation (2)

[0018] ρ sh =∑V sji ×ρ shi Equation (3)

[0019] In Equation (2) and Equation (3), V shi is the volume content of the i th clay mineral except glauconite, v / v; PE shi is the photoelectric absorption cross-section index of the i th clay mineral except glauconite, b / e; ρ shi is the volume density of the i th clay mineral except glauconite, g / cm 3 .

[0020] When there is no regional core X-diffraction clay mineral analysis result, PE sh and ρ sh may be determined and optimized by calculating the photoelectric absorption cross-section index logging average value and the volume density logging average value of the mudstone section.

[0021] In one exemplary embodiment of the method for determining the glauconite content in the sandstone of the present application, V sh may be determined and optimized by using Equation (4) and Equation (5).

[0022]

[0023] In Equation (4) and Equation (5), LOG is the neutron logging value; LOG min is the neutron value of pure sandstone; LOG max is the neutron value of pure mudstone; and ΔSH is the shale index, dimensionless.

[0024] Another aspect of the present application provides a calculation model for the glauconite content in sandstone, which is shown in Equation (1) as follows:

[0025]

[0026] In Equation (1), PE is the photoelectric absorption cross-section index logging value, b / e; RHOB is the rock volume density logging value, g / cm 3 ; PE sh is the photoelectric absorption cross-section index of the clay mineral except glauconite, b / e; ρ sh is the rock volume density of the clay mineral except glauconite, g / cm 3 ; V sh is the volume content of the clay mineral except glauconite, v / v; PE qzphotoelectric absorption cross section index of quartz or other sandstone clastic components, b / e; p qz rock bulk density of quartz or other rock clastic components, g / cm 3 ; V qz volume content of quartz or other sandstone clastic components, v / v; PE gl photoelectric absorption cross section index of glauconite, b / e; p gl rock bulk density of glauconite, g / cm 3 ; V gl volume content of glauconite, v / v; p f volume density of pore fluid, g / cm 3 ; formation porosity, v / v.

[0027] Another aspect of the present application provides a method for constructing a calculation model of glauconite content in sandstone as described above, which comprises:

[0028] establishing a rock volume physical model composed of glauconite and quartz as framework minerals, clay minerals other than glauconite as interstitial material, and oil, gas and water as pore fluid;

[0029] combining litho-density logging data and the rock volume physical model to obtain a glauconite sandstone logging response equation set;

[0030] determining the glauconite sandstone logging response equation set as the calculation model of glauconite content in sandstone.

[0031] Another aspect of the present application provides a method for applying the calculation model of glauconite content in sandstone as described above in obtaining sandstone reservoir information.

[0032] In an exemplary embodiment of the method for applying the calculation model of glauconite content in sandstone, the method can comprise: calculating the volume content of glauconite by using the calculation model of glauconite content in sandstone;

[0033] According to the relationship between the volume content of glauconite and permeability obtained by core analysis, the influence of glauconite on sandstone permeability is corrected to obtain the permeability parameter of each depth point of the formation.

[0034] In an exemplary embodiment of the method for applying the calculation model of glauconite content in sandstone, the method can further comprise: according to the volume content of glauconite and ordinary sandstone components, the influence of glauconite on resistivity is corrected to obtain the water saturation parameter of each depth point of the formation.

[0035] Another aspect of the present application provides a method for applying the calculation model of glauconite content in sandstone as described above in optimizing oil and gas well production schemes.

[0036] Still another aspect of the present application provides a device for determining the content of glauconite in sandstone, which comprises a first data acquisition module, a second data acquisition module, a third data acquisition module and a calculation module, wherein,

[0037] The first data acquisition module is configured to determine and optimize the first basic parameters including PE sh , ρ sh and V sh in combination with conventional logging data and regional geological data.

[0038] The second data acquisition module is configured to acquire the second basic parameters including PE qz , PE gl , ρ qz , ρ gl and ρ f based on the characteristic values of sedimentary rock mineral logging.

[0039] The third data acquisition module is configured to acquire the third basic parameters including PE and RHOB based on lithology density logging data.

[0040] The calculation module is connected with the first data acquisition module, the second data acquisition module and the third data acquisition module respectively, and is configured to calculate the content of glauconite by the calculation model as described above.

[0041] Compared with the prior art, the present application has the following beneficial effects at least one of which is included:

[0042] (1) The present application can quantitatively calculate the content of glauconite in sandstone, and further accurately calculate the parameters of sandstone reservoir, which greatly improves the accuracy of reservoir porosity, permeability and water saturation parameters, for example, the interpretation accuracy of reservoir parameters is improved from 85% to 95%, and the coincidence rate of fluid discrimination is improved from 70% to more than 90%;

[0043] (2) The interpretation results of single well sand body type obtained by the present application can be combined with seismic data to determine the distribution of high-quality sand bodies on the plane, and the reservoir porosity, permeability and water saturation parameters obtained by the present application can be used to determine the reservoir productivity, correct production allocation and optimize the production scheme;

[0044] (3) The determination method of the present application uses a large amount of conventional logging data which is easy to obtain and has low recording cost, and calculates the content of glauconite in sandstone by scientific theoretical method, which has the advantages of economy, rapidness, rich information, high accuracy and easy operation;

[0045] (4) The present invention can generate significant economic and social benefits in terms of cost reduction and efficiency improvement, and has a significant impact on the field of strategic advance reserve technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of a calculation flow in an exemplary embodiment of a method for determining glauconite content in sandstone according to the present invention is shown.

[0047] Figure 2 A schematic diagram of a rock physics volume model in an exemplary embodiment of a method for determining glauconite content in sandstone according to the present invention is shown. DETAILED DESCRIPTION

[0048] Hereinafter, the device, method, model for determining the glauconite content, and the construction method and application thereof of the present invention will be described in detail with reference to the accompanying drawings and exemplary embodiments.

[0049] It should be noted that “first”, “second”, “third”, etc. are only for the convenience of description and distinction, and cannot be understood as indicating or implying relative importance.

[0050] Conventional logging techniques treat glauconite as a common clay mineral, ignoring its clastic particle characteristics. This fails to accurately reflect its impact on reservoirs, resulting in significant errors in the resulting reservoir parameters. To address technical issues such as inaccurate calculation of physical properties of glauconite-bearing sandstones, difficulty in classifying sandbody types, and low fluid identification accuracy, this paper proposes a method for determining the glauconite content in sandstones. The key technology is to establish a rock physics volume model and logging response equations for glauconite-bearing sandstones based on research into the rock physics characteristics of glauconite and its sensitive logging parameters. This allows for quantitative calculation of the glauconite content in the sandstone, thereby accurately calculating sandstone reservoir parameters, correctly evaluating sandbody types, and accurately identifying low-resistivity oil and gas layers.

[0051] In order to achieve the above objectives, the present invention provides a method for determining the glauconite content in sandstone.

[0052] In an exemplary embodiment of the present invention, a method for determining the glauconite content in sandstone includes:

[0053] Based on conventional logging data and lithologic density logging data, the glauconite content in sandstone is calculated using the calculation model, which is shown in the following formula (1):

[0054]

[0055] In formula (1), PE is the log value of the photoelectric absorption cross-section index, b / e;

[0056] RHOB is the well logging value of rock bulk density, g / cm3 ;

[0057] PE sh photoelectric absorption cross-section index of clay minerals other than glauconite, b / e

[0058] ρ sh rock volume density of clay minerals other than glauconite, g / cm 3 ;

[0059] V sh volume content of clay minerals other than glauconite, v / v

[0060] PE qz photoelectric absorption cross-section index of quartz or other sandstone detrital component, b / e

[0061] ρ qz rock volume density of quartz or other detrital component, g / cm 3 ;

[0062] V qz volume content of quartz or other sandstone detrital component, v / v

[0063] PE gl photoelectric absorption cross-section index of glauconite, b / e

[0064] ρ gl rock volume density of glauconite, g / cm 3 ;

[0065] V gl volume content of glauconite, v / v

[0066] ρ f volume density of fluid, g / cm 3 ;

[0067] formation porosity, v / v

[0068] In particular, a method for determining the content of glauconite in sandstone can specifically include the following steps:

[0069] (1) using conventional logging data, combined with regional geological data to determine and optimize the first basic parameters, the first basic parameters including the photoelectric absorption cross-section index PE of clay minerals other than glauconite sh , the rock volume density ρ of clay minerals other than glauconite sh and the volume content V of clay minerals other than glauconite sh .

[0070] wherein the conventional logging data can include bulk density, compensated neutron, and natural gamma ray. When the conventional logging data and the regional geological data have regional core X-diffraction clay mineral analysis results, PE and p can be determined and optimized by using equations (2) and (3) sh and p sh , equations (2) and (3) are as follows:

[0071] PE sh =∑V shi ×PE shi Equation (2)

[0072] p sh =∑V shi ×p shi Equation (3)

[0073] In equations (2) and (3), V shi is the volume content of the i-th clay mineral other than glauconite, v / v; PE shi is the photoelectric absorption cross-section index of the i-th clay mineral other than glauconite, b / e; p shi is the bulk density of the i-th clay mineral other than glauconite, g / cm 3 .

[0074] When the conventional logging data and the regional geological data do not have regional core X-diffraction clay mineral analysis results, PE and p can be determined and optimized by calculating the photoelectric absorption cross-section index logging average value and the bulk density logging average value of the shale section sh and p sh .

[0075] In addition, V sh can be determined and optimized by using equations (4) and (5), equations (4) and (5) are as follows:

[0076]

[0077] In equations (4) and (5), LOG is the neutron logging value; LOG min is the neutron value of pure sandstone; LOG max is the neutron value of pure shale; and ΔSH is the shale index, dimensionless.

[0078] (2) obtaining a second basic parameter based on the common sedimentary rock mineral logging characteristic value, the second basic parameter including the photoelectric absorption cross-section index PE qz of quartz or other sandstone clastic components, the photoelectric absorption cross-section index PE gl of glauconite, the bulk density p qz of quartz or other rock clastic components, the bulk density p gl of glauconite, and the fluid bulk density pf For example, the second basic parameter can be obtained by referring to the mineral logging characteristic value commonly used in the industry.

[0079] (3) Obtain a third basic parameter based on litho-density logging data, the third basic parameter including a logging value of photoelectric absorption cross section index PE and a logging value of rock bulk density RHOB.

[0080] The litho-density logging data can include the photoelectric absorption cross section index and the rock bulk density.

[0081] (4) Substitute the first basic parameter, the second basic parameter and the third basic parameter into a calculation model of the content of glauconite in sandstone, to obtain the volume content of glauconite V gl , the volume content of quartz or other sandstone clastic components V qz and the formation porosity .

[0082] It should be noted that if the photoelectric absorption cross section index logging data sensitive to glauconite is absent, acoustic travel time logging data can be used instead, but the error of the calculated glauconite content is relatively large. That is, the calculation model of the content of glauconite in sandstone can also be as follows:

[0083]

[0084] In the formula, DT is the acoustic travel time logging value, b / e; RHOB is the rock bulk density logging value, g / cm 3 ; DT sh is the acoustic travel time value of clay minerals other than glauconite, b / e; p sh is the rock bulk density of clay minerals other than glauconite, g / cm 3 ; V sh is the volume content of clay minerals other than glauconite, v / v; DT qz is the acoustic travel time value of quartz or other sandstone clastic components, b / e; p qz is the rock bulk density of quartz or other sandstone clastic components, g / cm 3 ; V qz is the volume content of quartz or other sandstone clastic components, v / v; DT gl is the acoustic travel time value of glauconite, b / e; p gl is the rock bulk density of glauconite, g / cm 3 ; V gl is the volume content of glauconite, v / v; p f is the volume density of pore fluid, g / cm 3 ; is the formation porosity, v / v.

[0085] Another aspect of the present application provides a model for calculating the content of glauconite in sandstone.

[0086] In another exemplary embodiment of the present application, a model for calculating the content of glauconite in sandstone is shown in the following equation (1):

[0087]

[0088] In equation (1), PE is the log value of photoelectric absorption cross section index of b / e;

[0089] RHOB is the log value of rock bulk density, g / cm 3 ;

[0090] PE sh is the photoelectric absorption cross section index of clay minerals other than glauconite, b / e;

[0091] ρ sh is the rock bulk density of clay minerals other than glauconite, g / cm 3 ;

[0092] V sh is the volume content of clay minerals other than glauconite, v / v;

[0093] PE qz is the photoelectric absorption cross section index of quartz or other sandstone clastic components, b / e;

[0094] ρ qz is the rock bulk density of quartz or other sandstone clastic components, g / cm 3 ;

[0095] V qz is the volume content of quartz or other sandstone clastic components, v / v;

[0096] PE gl is the photoelectric absorption cross section index of glauconite, b / e;

[0097] ρ gl is the rock bulk density of glauconite, g / cm 3 ;

[0098] V gl is the volume content of glauconite, v / v;

[0099] ρ f is the volume density of pore fluid, g / cm 3 ;

[0100] is the formation porosity, v / v.

[0101] The application further provides a method for constructing the calculation model of the glauconite content in the sandstone.

[0102] In another exemplary embodiment of the application, the method for constructing the calculation model of the glauconite content in the sandstone comprises the following steps:

[0103] (1) establishing a rock volume physical model composed of glauconite and quartz as the framework minerals, clay minerals other than glauconite as the interstitial material, and oil, gas and water as the pore fluid.

[0104] (2) combining the lithology density logging data and the rock volume physical model to obtain a glauconite sandstone logging response equation set.

[0105] (3) determining the glauconite sandstone logging response equation set as the calculation model of the glauconite content in the sandstone. gl The continuous glauconite content V qz and the formation porosity can be obtained through the glauconite sandstone logging response equation set.

[0106] The application further provides a method for applying the calculation model of the glauconite content in the sandstone to obtain the information of the sandstone reservoir.

[0107] In another exemplary embodiment of the application, the method for applying the calculation model of the glauconite content in the sandstone can comprise:

[0108] calculating the volume content of the glauconite by using the calculation model of the glauconite content in the sandstone;

[0109] correcting the influence of the glauconite on the permeability of the sandstone according to the relationship between the volume content of the glauconite and the permeability obtained through core analysis, to obtain more accurate permeability parameters of each depth point of the formation;

[0110] and correcting the influence of the glauconite on the resistivity according to the volume content of the glauconite and the ordinary sandstone composition, to obtain more accurate water saturation parameters of each depth point of the formation.

[0111] The application further provides a method for applying the calculation model of the glauconite content in the sandstone as described above to optimize the production scheme of the oil and gas well.

[0112] The application further provides a device for determining the glauconite content in the sandstone.

[0113] In another exemplary embodiment of the application, the device for determining the glauconite content in the sandstone comprises a first data acquisition module, a second data acquisition module, a third data acquisition module and a calculation module.

[0114] The first data acquisition module is configured to determine and optimize the first basic parameters by combining conventional well logging data and regional geological data. The first basic parameters include PE sh , ρ sh and V sh .

[0115] The second data acquisition module is configured to acquire second basic parameters based on the sedimentary rock mineral logging characteristic value, and the second basic parameters include PE qz PE gl , ρ qz , ρ gl and ρ f .

[0116] The third data acquisition module is configured to acquire third basic parameters based on lithologic density logging data, where the third basic parameters include PE and RHOB.

[0117] The calculation module is connected to the first data acquisition module, the second data acquisition module and the third data acquisition module respectively, and is configured to calculate and obtain the glauconite content according to the calculation model described above.

[0118] In order to better understand the present invention, the content of the present invention is further explained below with reference to the accompanying drawings and examples, but the content of the present invention is not limited to the following embodiments.

[0119] Example 1

[0120] like Figure 1 As shown, a method for determining the glauconite content in sandstone can be achieved by adopting the following technical solutions:

[0121] Step S1: Based on the clarification of the dual rock physical characteristics of glauconite, namely, clay properties and clastic particle properties, a rock volume physical model is established, which includes glauconite and quartz as framework minerals, clay minerals other than glauconite as interstitial materials, and oil, gas, and water as pore fluids.

[0122] The established rock volume physical model is as follows Figure 2 shown. Figure 2 The V in V represents the volume of rock. ma Represents the rock skeleton volume, V sh represents the volume of clay minerals excluding glauconite, V qz Indicates the volume of quartz, V gl represents the volume of glauconite, and φ represents the porosity of the formation. Figure 2It can be seen that the rock volume is equal to the sum of the volumes of the rock framework, clay interstitial material and pores, wherein the rock framework volume is the sum of the volumes of quartz and chlorite, and the pore volume is the volume of oil (gas) or water filled therein. The rock volume model is the basis for establishing correct and rigorous petrophysical equations.

[0123] Step S2, combine the lithology density logging data and the established rock volume physical model, and use the photoelectric absorption cross section index sensitive to the characteristics of chlorite detrital particles, rock volume density, and natural gamma and compensated neutron logging data sensitive to the characteristics of chlorite clay to establish a chlorite sandstone logging response equation set. The chlorite sandstone logging response equation set is shown as follows:

[0124]

[0125] In the formula, PE is the logging value of the photoelectric absorption cross section index, b / e; RHOB is the logging value of the rock volume density, g / cm 3 ; PE sh is the photoelectric absorption cross section index of clay minerals other than chlorite, b / e; ρ sh is the rock volume density of clay minerals other than chlorite, g / cm 3 ; V sh is the volume content of clay minerals other than chlorite, v / v; PE qz is the photoelectric absorption cross section index of quartz or other sandstone detrital components, b / e; ρ qz is the rock volume density of quartz or other rock detrital components, g / cm 3 ; V qz is the volume content of quartz or other sandstone detrital components, v / v; PE gl is the photoelectric absorption cross section index of chlorite, b / e; ρ gl is the rock volume density of chlorite, g / cm 3 ; V gl is the volume content of chlorite, v / v; ρ f is the volume density of pore fluid, g / cm 3 ; is the formation porosity, v / v.

[0126] Step S3, use conventional logging data to determine and optimize the basic parameters of the equation set: PE sh , ρ sh and V sh ; the conventional logging data includes rock volume density, compensated neutron and natural gamma.

[0127] When there are regional core X-ray diffraction clay mineral analysis results, the basic parameters PE sh and ρsh Specifically,

[0128] PE sh =∑V shi ×PE shi

[0129] ρ sh =∑V shi ×ρ shi

[0130] In the formula, V shi is the volume content of the i-th clay mineral except glauconite, v / v; PE shi is the photoelectric absorption cross-section index of the i-th clay mineral except glauconite, b / e; ρ shi is the volume density of the i-th clay mineral except glauconite, g / cm 3 .

[0131] When there is no regional core X diffraction clay mineral analysis result, the basic parameters PE sh and ρ sh of the equation set are determined and optimized. Specifically, the photoelectric absorption cross-section index logging average value and the volume density logging average value of the mudstone section are determined.

[0132] The basic parameter V sh of the equation set is determined and optimized. Specifically,

[0133]

[0134] In the formula, LOG is the neutron logging value; LOG min is the neutron value of pure sandstone; LOG max is the neutron value of pure mudstone; ΔSH is the shale index, dimensionless.

[0135] In step S4, the PE sh , ρ sh and V sh obtained by optimization and the known PE qz , PE gl , ρ qz , ρ gl and ρ f theoretical values are substituted into the glauconite sandstone logging response equation set to calculate V gl , V qz and .

[0136] Compared with the prior art, the key improvement points of the present application mainly include the following three aspects:

[0137] (1) Conventional logging technology treats glauconite as an ordinary clay mineral, ignoring the characteristics of glauconite's clastic particles, and cannot correctly reflect the impact of glauconite on the reservoir, resulting in large errors in the obtained reservoir parameter results. The present invention, based on the study of the clay characteristics and clastic particle characteristics of glauconite, optimizes glauconite-sensitive logging data, establishes a rigorous logging response equation group and processing and interpretation technology, and performs fine processing and interpretation of glauconite-containing complex clastic rock reservoirs, greatly improving the accuracy of reservoir porosity, permeability and water saturation parameters.

[0138] (2) A small number of comprehensive technologies use experimental means to test and analyze the glauconite content in the sandstone of the core sample, and quantitatively calculate it by fitting the formula by regressing the relationship between the glauconite content and neutron logging data or density logging data. However, since this method requires the determination of the glauconite content in the sandstone, it is limited by factors such as the number of samples, operational difficulty, and economic benefits. The accuracy is not high and it is difficult to promote and use it. The technology of the present invention uses a large amount of conventional logging data that is easy to obtain and has low acquisition cost, and calculates the glauconite content in the sandstone through a scientific theoretical method. It has the advantages of being economical, fast, rich in information, high in accuracy, and easy to operate.

[0139] (3) The present invention uses sensitive logging data of glauconite sandstone to establish a method for determining the glauconite content in complex sandstones. The method can simultaneously calculate parameters such as the glauconite content, ordinary sandstone content, porosity, permeability, and water saturation at each depth point in the formation, thereby obtaining a variety of reservoir information that is accurate in depth and correlated with each other. The method can analyze the impact of glauconite on reservoir physical properties, oil and gas content, and production from multiple aspects, and has guiding significance for the efficient exploration and development of oil and gas fields.

[0140] Therefore, compared with the prior art, the beneficial effects of the present invention are as follows:

[0141] (1) After obtaining accurate glauconite content using the determination method of the present invention, the influence of glauconite on sandstone permeability is corrected based on the relationship between glauconite content and permeability according to core analysis on the basis of conventional sandstone permeability determination methods, thereby obtaining more accurate permeability parameters. At the same time, the influence of glauconite on resistivity can be corrected based on the percentage content of glauconite and ordinary sandstone components, thereby obtaining more accurate water saturation parameters. The corrected resistivity data and water saturation data can be used to effectively identify low-resistivity oil layers and improve the production capacity of oil and gas wells.

[0142] After testing, the reservoir parameters were calculated based on the glauconite content obtained by the determination method of the present invention, and the reservoir parameter interpretation accuracy was improved from 85% to more than 95%, and the fluid discrimination compliance rate was improved from 70% to more than 90%.

[0143] (2) Using single well sand body type interpretation results combined with seismic data, the distribution of high-quality sand bodies in the plane can be determined; using reservoir porosity, permeability and water saturation parameters, reservoir productivity can be determined, correct production allocation can be determined, and production plan can be optimized.

[0144] For example, during the exploration and development of P oilfield in Ecuador from 2019 to 2020, the accuracy of evaluation of glauconite sandstone reservoir, identification and prediction accuracy of high-quality sand bodies were improved by using the method, the high-yield well was increased from about 20% to 82%, and the single well production was increased from less than 300 barrels per day to 800 barrels per day.

[0145] (3) The glauconite content and reservoir parameter interpretation results obtained based on the determination method of the application can produce significant economic and social benefits in terms of cost reduction and efficiency improvement, and have a significant impact on the strategic advanced reserve technology field, and are expected to be converted into benefits within 1-3 years.

[0146] Although the application has been described above in connection with exemplary embodiments and the accompanying drawings, it should be clear to those skilled in the art that various modifications can be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. A method for determining the content of smectite in sandstone, characterized in that, The determination method comprises: The content of the glauconite is calculated based on conventional logging data and litho-density logging data, and a calculation model of the content of the glauconite in the sandstone is used, and the calculation model is shown in the following formula (1): In formula (1), PE is the log value of photoelectric absorption cross section index, b / e; RHOB is the log value of rock bulk density, g / cm 3 PE sh is the photoelectric absorption cross-section index of clay minerals except glauconite, b / e; ρ sh is the rock bulk density of clay minerals other than glauconite, g / cm 3 ; V sh is the volume content of clay minerals excluding glauconite, v / v; PE qz is the photoelectric absorption cross-section index of quartz or other sandstone debris components, b / e; ρ qz is the bulk density of rock composed of quartz or other rock fragments, g / cm 3 ; V qz is the volume content of quartz or other sandstone debris, v / v; PE gl is the photoelectric absorption cross-section index of glauconite, b / e; ρ gl is the rock bulk density of glauconite, g / cm 3 ; V gl is the volume content of glauconite, v / v; ρ f is the bulk density of the pore fluid, g / cm 3 ; is the formation porosity, v / v.

2. The method for determining the smectite content in sandstone according to claim 1, characterized in that, The determination method specifically comprises the following steps: The first basic parameters including PE sh , p sh and V sh are determined and optimized by using conventional logging data in combination with regional geological data. Based on the sedimentary rock mineral logging characteristic value, a second basic parameter is obtained, and the second basic parameter includes PE qz , PE gl , p qz , p gl , and p f ; Based on the litho-density logging data, a third basic parameter is obtained, and the third basic parameter comprises PE and RHOB; substituting the first, second and third basic parameters into a calculation model of the content of glauconite in the sandstone, V gl , qz and .

3. The method for determining the smectite content in sandstone according to claim 2, characterized in that, The conventional logging data comprises rock bulk density, compensated neutron and natural gamma; and the litho-density logging data comprises photoelectric absorption cross-section index and rock bulk density.

4. The method for determining the smectite content in sandstone according to claim 3, characterized in that, When the regional core X-diffraction clay mineral analysis results are available, the PE is determined and preferred using Equations (2) and (3) sh and p sh , PE sh =∑V shi ×PE shi Equation (2) p sh =∑V shi ×ρ shi Equation (3) In formula (2) and formula (3), V shi volume content of the i-th clay mineral other than glauconite, v / v; PE shi photoelectric absorption cross-section index of the i-th clay mineral other than glauconite, b / e; p shi volume density of the i-th clay mineral other than glauconite, g / cm 3 ; When there is no regional core X-diffraction clay mineral analysis result, PE is determined and preferred by means of calculating the photoelectric absorption cross-section index logging average value and the bulk density logging average value of the mudstone section sh and p sh .

5. The method for determining the smectite content in sandstone according to claim 3, characterized in that, V is determined and preferred using formula (4) and formula (5) sh , In formula (4) and formula (5), LOG is a neutron logging value; LOG min is a neutron value for pure sandstone; LOG max is a neutron value for pure mudstone; ΔSH is a shale index, dimensionless.

6. A system for calculating the smectite content in sandstone, characterized by The calculation system can be calculated by using the formula shown in the following formula (1): In Equation (1), PE is the measured value of photoelectric absorption cross-section exponent, b / e; RHOB is the measured value of rock bulk density, g / cm 3 ; PE sh is the photoelectric absorption cross-section exponent of clay minerals other than glauconite, b / e; p sh is the rock bulk density of clay minerals other than glauconite, g / cm 3 ; V sh is the volume content of clay minerals other than glauconite, v / v; PE qz is the photoelectric absorption cross-section exponent of quartz or other sandstone detrital components, b / e; p qz is the rock bulk density of quartz or other sandstone detrital components, g / cm 3 ; V qz is the volume content of quartz or other sandstone detrital components, v / v; PE gl is the photoelectric absorption cross-section exponent of glauconite, b / e; p gl is the rock bulk density of glauconite, g / cm 3 ; V gl is the volume content of glauconite, v / v; p f is the volume density of pore fluid, g / cm 3 ; is the formation porosity, v / v.

7. A method of constructing a system for calculating the content of smectite in sandstone according to claim 6, characterized in that, The construction method comprises: A rock volume physical model is established, in which the glauconite and quartz are used as skeleton minerals, the clay minerals other than the glauconite are used as interstitial materials, and oil, gas and water are used as pore fluid; The litho-density logging data and the rock volume physical model are combined to obtain a glauconite sandstone logging response equation set; The glauconite sandstone logging response equation set is determined as the calculation system of the content of the glauconite in the sandstone.

8. An application method of the calculation system of the content of the glauconite in the sandstone in claim 6 in obtaining sandstone reservoir information.

9. The method of claim 8, wherein, The application method comprises: calculating the volume content of the glauconite by using the calculation system of the content of the glauconite in the sandstone; According to the relationship between the volume content of the glauconite and the permeability obtained by the core analysis, the influence of the glauconite on the permeability of the sandstone is corrected to obtain the permeability parameter of each depth point of the formation.

10. The use according to claim 8, characterized in that, The application method further comprises: according to the volume content of the glauconite and the ordinary sandstone composition, the influence of the glauconite on the resistivity is corrected to obtain the water saturation parameter of each depth point of the formation.

11. An application method of the calculation system of the content of the glauconite in the sandstone in claim 6 in optimizing the production scheme of the oil and gas well.

12. An apparatus for determining the smectite content of a sandstone, characterized by The determination device comprises a first data acquisition module, a second data acquisition module, a third data acquisition module and a calculation module, wherein, The first data acquisition module is configured to determine and optimize first basic parameters including PE sh , p sh , and V sh in combination with conventional logging data and regional geological data. The second data acquisition module is configured to be capable of acquiring second basic parameters including PE qz , PE gl , p qz , p gl , and p f based on the sedimentary rock mineral logging characteristic value. The third data acquisition module is configured to be capable of obtaining a third basic parameter based on the litho-density logging data, and the third basic parameter comprises PE and RHOB; The calculation module is connected with the first data acquisition module, the second data acquisition module and the third data acquisition module respectively, and is configured to be capable of calculating the content of the glauconite by using the calculation system in claim 6.

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