Method, system and equipment for evaluating tight oil reservoir while drilling

Abstract

The invention belongs to the field of petroleum geological exploration, particularly relates to a method, a system and equipment for evaluating a tight oil reservoir while drilling, and aims to solve the problem that the fluid property of the tight oil reservoir cannot be accurately evaluated from multiple dimensions in the prior art. The method comprises the following steps: calculating a parameter set of compressibility indexes of an existing tight oil conclusion layer, and normalizing parameters in the parameter set to obtain normalized parameters corresponding to different layers; on the basis of each normalization parameter, calculating a correlation degree, and further obtaining a weight coefficient of each normalization parameter; calculating compressibility indexes of different layers based on the normalized parameters of the different layers and the corresponding weight coefficients; further combining a gas logging total hydrocarbon value, a methane relative value and a pyrolysis Pg value to construct an evaluation standard of the oil-water layer; and obtaining data of the reservoir to be evaluated, obtaining the compressibility index of the reservoir to be evaluated, and further obtaining the fluid property of the tight oil reservoir to be evaluated. According to the method, the fluid property of the tight oil reservoir can be accurately determined from multiple dimensions.

Description

Background Art

[0003] Tight oil is characterized by low porosity and low permeability, making it difficult to directly obtain natural production capacity. Usually, construction measures such as fracturing are required. Reservoirs with higher brittleness and better oil content often have better fracturing effects, which can then increase the production of tight reservoirs. Traditional brittleness evaluation methods based on Young's modulus and Poisson's ratio mainly rely on acoustic logging after drilling and cannot achieve evaluation of reservoir brittleness while drilling. Methods for calculating brittleness index based on mineral composition do not consider the mechanical properties of mineral components themselves. Therefore, current methods cannot accurately determine the fluid properties of tight oil reservoirs from multiple dimensions. Summary of the Invention

[0004] To solve the above problems in the prior art, that is, the current methods cannot accurately evaluate the fluid properties of tight oil reservoirs while drilling from multiple dimensions, the present invention provides a method for evaluating tight oil reservoirs while drilling. The method includes:

[0005] S100, obtaining the gas logging total hydrocarbon value, methane relative value, pyrolysis Pg value, pore structure characteristic parameters and mineral composition data of different layers with existing tight oil well testing conclusions; based on the pore structure characteristic parameters and the mineral composition data, calculating the parameter set of the compressibility index of the existing tight oil conclusion layers; the existing tight oil conclusion layers and the reservoir to be evaluated belong to the same oil and gas reservoir; the parameter set includes roundness coefficient, Young's toughness ratio, and mineral brittleness;

[0006] S200, respectively normalizing the three parameters of roundness coefficient, Young's toughness ratio, and mineral brittleness in the parameter set to obtain the normalized parameters corresponding to different layers; based on each normalized parameter, calculating the correlation degree by the grey correlation method, and combining each normalized parameter to further obtain the weight coefficient of each normalized parameter;

[0007] S300, calculating the compressibility index of different layers based on the normalized parameters of different layers and their corresponding weight coefficients;

[0008] S400, constructing an evaluation standard for oil and water layers based on the compressibility index of different layers and the gas logging total hydrocarbon value, methane relative value, and pyrolysis Pg value;

[0009] S500, obtaining the gas logging total hydrocarbon value, methane relative value, pyrolysis Pg value, pore structure characteristic parameters and mineral composition data of the reservoir to be evaluated, obtaining the compressibility index of the reservoir to be evaluated by the method of S100 - S300, and then combining the gas logging total hydrocarbon value, methane relative value, and pyrolysis Pg value of the reservoir to be evaluated, and obtaining the oil - water property of the reservoir to be evaluated according to the determination standard of the oil and water layers.

[0010] In a preferred embodiment, for each layer, the method for calculating the Young's toughness ratio is:

[0011] Among them, E is the comprehensive Young's modulus of the current layer, and K i is the Young's modulus of the i-th mineral in the mineral composition data of the current layer; W i is the percentage content of the i-th mineral in the mineral composition data of the current layer; D is the comprehensive fracture toughness of the current layer, and C i is the fracture toughness of the i-th mineral in the mineral composition data of the current layer; W i is the percentage content of the i-th mineral in the mineral composition data of the current layer; G is the Young's toughness ratio of the current layer.

[0012] For each layer, the method for calculating mineral brittleness is:

[0013] Among them, B is the mineral brittleness of the current layer; W 石英 、W 长石 、W 方解石 、W 白云石 and W 黏土 are respectively the mineral contents of quartz, feldspar, calcite, dolomite and clay in the mineral composition data of the current layer, %.

[0014] In a preferred embodiment, for each layer, the method for calculating the roundness coefficient is: Y = L / S;

[0015] Among them, Y is the roundness coefficient in the pore structure characteristic parameters of the current layer; L is the sum of the major axis lengths of the cuttings pores in the pore structure characteristic parameters of the current layer, mm; S is the sum of the minor axis lengths of the cuttings pores in the pore structure characteristic parameters of the current layer, mm.

[0016] In a preferred embodiment, for the three parameters of the roundness coefficient, Young's toughness ratio, and mineral brittleness of each layer, the specific method for calculating the normalized parameters is:

[0017] For each parameter, calculate the difference between the maximum value and the minimum value corresponding to each parameter as the range corresponding to each parameter;

[0018] The method for obtaining each normalized parameter for each layer is: H 归一 =(H - H min ) / H 极差 ;

[0019] Among them, H 归一is the parameter value after normalization of the current parameter of the current layer, H max is the maximum value of the current parameter, H min is the minimum value of the current parameter, H 极差 is the range of the current parameter, H is the current parameter of the current layer.

[0020] In a preferred embodiment, the method for calculating the weight coefficients of the three parameters respectively is as follows:

[0021] Taking the normalized parameters of mineral brittleness of different layers as the mother factors, and the normalized parameters of roundness coefficient and the normalized parameters of Young's toughness ratio of different layers as the sub-factors, through mathematical analysis software, the correlation degree F of the normalized parameters of roundness coefficient is obtained Y and the correlation degree F of the normalized parameters of Young's toughness ratio G , the correlation degree F of the normalized parameters of mineral brittleness B The correlation degree is 1;

[0022] The calculation method of the weight coefficient A of Young's toughness ratio G is as follows: A G = F G / (F G + F B + F Y );

[0023] The calculation method of the weight coefficient of mineral brittleness A B is as follows: A B = F B / (F G + F B + F Y );

[0024] The calculation method of the weight coefficient A of roundness coefficient Y is as follows: A Y = F Y / (F G + F B + F Y );

[0025] In a preferred embodiment, for each layer, the calculation method of the compressibility index is as follows: Z = A G * G 归一 + A B * B 归一 + A Y * Y 归一 ;

[0026] where, Z is the compressibility index of the current layer, A G , A B and A YThey are the weight coefficients of the Yang toughness ratio, the weight coefficient of mineral brittleness, and the weight coefficient of the roundness coefficient, respectively, Y 归一 is the normalization parameter of the roundness coefficient for the current layer, B 归一 is the normalization parameter of mineral brittleness for the current layer; G 归一 is the normalization parameter of the Yang toughness ratio for the current layer.

[0027] In a preferred embodiment, the determination criterion for the oil-water layer is as follows:

[0028] For each layer: the compressibility index greater than or equal to the first threshold is a Class I reservoir; the compressibility index greater than the second threshold and less than the first threshold is a Class II reservoir; the compressibility index less than or equal to the second threshold is a Class III reservoir;

[0029] For Class I reservoirs: when the total hydrocarbon value is greater than 10%, the relative methane value is between 65% and 80%, and the pyrolysis Pg value is greater than 15 mg / g, it is an oil layer; when the total hydrocarbon value is between 5% and 10%, the relative methane value is between 80% and 85%, and the pyrolysis Pg value is between 10 mg / g and 15 mg / g, it is an oil-water layer; when the total hydrocarbon value is less than 5%, the relative methane value is greater than 85%, and the pyrolysis Pg value is less than 10 mg / g, it is an oil-bearing water layer;

[0030] For Class II reservoirs: when the total hydrocarbon value is greater than 20%, the relative methane value is between 65% and 80%, and the pyrolysis Pg value is greater than 20 mg / g, it is an oil layer; when the total hydrocarbon value is between 15% and 20%, the relative methane value is between 65% and 80%, and the pyrolysis Pg value is between 15 mg / g and 20 mg / g, it is a poor oil layer; when the total hydrocarbon value is between 10% and 20%, the relative methane value is between 80% and 85%, and the pyrolysis Pg value is between 10 mg / g and 20 mg / g, it is an oil-water layer; when the total hydrocarbon value is less than 10%, the relative methane value is greater than 85%, and the pyrolysis Pg value is less than 10 mg / g, it is an oil-bearing water layer;

[0031] For Class III reservoirs: when the total hydrocarbon value is greater than 50%, the relative methane value is between 65% and 75%, and the pyrolysis Pg value is greater than 25 mg / g, it is an oil layer; when the total hydrocarbon value is between 25% and 50%, the relative methane value is between 65% and 75%, and the pyrolysis Pg value is between 15 mg / g and 25 mg / g, it is a poor oil layer; when the total hydrocarbon value is between 15% and 25%, the relative methane value is between 80% and 85%, and the pyrolysis Pg value is between 15 mg / g and 25 mg / g, it is an oil-water layer; when the total hydrocarbon value is less than 15%, the relative methane value is greater than or equal to 85%, and the pyrolysis Pg value is less than 15 mg / g, it is an oil-bearing water layer.

[0032] On the other hand, the present invention proposes a system for evaluating a tight oil reservoir while drilling, which is used to determine the water-oil property of the reservoir to be evaluated. The system includes:

[0033] A parameter set determination module obtains the gas chromatographic total hydrocarbon values, methane relative values, pyrolysis Pg values, pore structure characteristic parameters, and mineral composition data of different layers of the existing tight oil testing conclusion layers; based on the pore structure characteristic parameters and the mineral composition data, calculates the parameter set of the compressibility index of the existing tight oil testing conclusion layers; the existing tight oil testing conclusion layers and the reservoir to be evaluated belong to the same oil and gas reservoir; the parameter set includes roundness coefficient, Yang toughness ratio, and mineral brittleness;

[0034] A weight coefficient determination module normalizes the parameters in the parameter set respectively to obtain the normalized parameters corresponding to different layers; based on each normalized parameter, calculates the correlation degree by the grey correlation method, and combines each normalized parameter to further obtain the weight coefficient of each normalized parameter;

[0035] A compressibility index determination module calculates the compressibility index of different layers based on the normalized parameters of different layers and their corresponding weight coefficients;

[0036] An oil-water standard determination module constructs a determination standard for oil-water layers based on the compressibility index of different layers and the gas chromatographic total hydrocarbon value, methane relative value, and pyrolysis Pg value;

[0037] A result determination module obtains the gas chromatographic total hydrocarbon value, methane relative value, pyrolysis Pg value, pore structure characteristic parameters, and mineral composition data of the reservoir to be evaluated, and obtains the compressibility index of the reservoir to be evaluated by the method of S100 - S300, and then combines the gas chromatographic total hydrocarbon value, methane relative value, and pyrolysis Pg value of the reservoir to be evaluated, and obtains the oil-water property of the reservoir to be evaluated according to the determination standard of the oil-water layer.

[0038] In the third aspect of the present invention, an electronic device is proposed, including:

[0039] At least one processor; and

[0040] A memory communicatively connected to at least one of the processors; wherein,

[0041] The memory stores instructions executable by the processor, and the instructions are used to be executed by the processor to implement the above-mentioned method for evaluating tight oil reservoirs while drilling.

[0042] The beneficial effects of the present invention:

[0043] (1) The present invention performs high-precision scanning on cuttings to obtain pore structure characteristic parameters, applies X-ray diffraction whole-rock analysis technology to obtain mineral composition data, forms a compressibility index by processing the data to establish a reservoir quality grading standard, and then combines the existing gas chromatographic total hydrocarbon value, methane relative value, and pyrolysis Pg to establish an oil-water layer evaluation standard, and further determines the tight oil reservoir;

[0044] (2) The present invention can accurately determine the fluid properties of tight oil reservoirs from multiple dimensions, which is of great significance for oil and gas exploration and promotes the development of the industry.

[0045] (3) The present invention applies cuttings data for tight oil evaluation, realizing the logging-while-drilling and real-time evaluation of tight oil reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Other features, objects, and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0047] Figure 1 It is a flowchart of a method for logging-while-drilling evaluation of a tight oil reservoir according to an embodiment of the present invention;

[0048] Figure 2 It is a schematic diagram of parameter characteristics of Well 101 in the WY structural belt according to an embodiment of the present invention;

[0049] Figure 3 It is a schematic diagram of the partition of the total hydrocarbon value of gas logging in Class I reservoirs according to an embodiment of the present invention;

[0050] Figure 4 It is a schematic diagram of the partition of the relative methane value in Class I reservoirs according to an embodiment of the present invention;

[0051] Figure 5 It is a schematic diagram of the partition of the pyrolysis Pg value in Class I reservoirs according to an embodiment of the present invention;

[0052] Figure 6 It is a schematic diagram of the partition of the total hydrocarbon value of gas logging in Class II reservoirs according to an embodiment of the present invention;

[0053] Figure 7 It is a schematic diagram of the partition of the relative methane value in Class II reservoirs according to an embodiment of the present invention;

[0054] Figure 8 It is a schematic diagram of the partition of the pyrolysis Pg value in Class II reservoirs according to an embodiment of the present invention;

[0055] Figure 9 It is a schematic diagram of the partition of the total hydrocarbon value of gas logging in Class III reservoirs according to an embodiment of the present invention;

[0056] Figure 10 It is a schematic diagram of the partition of the relative methane value in Class III reservoirs according to an embodiment of the present invention;

[0057] Figure 11 It is a schematic diagram of the partition of the pyrolysis Pg value in Class III reservoirs according to an embodiment of the present invention;

[0058] Figure 12 It is a schematic diagram of the structure of a computer system of a server for implementing the method, system, and device embodiments of the present application; Specific Embodiments

[0059] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related invention, rather than limiting the invention. Additionally, it should be noted that for ease of description, only the parts related to the relevant invention are shown in the drawings.

[0060] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the drawings and embodiments.

[0061] The present invention provides a method for evaluating a tight oil reservoir while drilling, and the method includes:

[0062] S100. Obtain the gas chromatographic total hydrocarbon values, methane relative values, pyrolysis Pg values, pore structure characteristic parameters, and mineral composition data of different layers of the existing tight oil test oil conclusion layers; based on the pore structure characteristic parameters (roundness coefficient) and the mineral composition data, calculate the parameter set of the compressibility index of the existing tight oil conclusion layers; the existing tight oil conclusion layers and the reservoir to be evaluated belong to the same oil and gas reservoir; the parameter set includes the roundness coefficient, Young's toughness ratio, and mineral brittleness.

[0063] Among them, the roundness coefficient is obtained from electron microscope scanning data. Generally, the pores of the reservoir are circular or elliptical. The closer the pores of the reservoir are to circular, the more uniform the stress direction, and it is not easy for the reservoir to form fractures. While for elliptical pores, cracks are likely to occur along the weak stress surface at the pore edge in the long strip direction, forming fractures. Therefore, the larger the roundness coefficient, the easier it is for the formation to form fractures after fracturing.

[0064] For the Young's toughness ratio, Young's modulus is a commonly used parameter to evaluate the brittleness of the formation. The higher the Young's modulus, the better the brittleness of the formation. While the fracture toughness reflects the ability of the material to resist brittle fracture. The larger the fracture toughness, the poorer the brittleness of the formation, and it is not easy to form fractures after fracturing. Therefore, the compressibility of the formation can be further evaluated by the ratio of the two.

[0065] The mineral brittleness is calculated from the X-ray diffraction whole rock analysis data. The higher the content of brittle minerals such as quartz, feldspar, calcite, and dolomite, the higher the brittleness of the rock, the stronger the compressibility, and it is easier to form natural fractures and induced fractures under external forces.

[0066] S200. Normalize the parameters in the parameter set respectively to obtain the normalized parameters corresponding to different layers; based on each normalized parameter, calculate the correlation degree by the grey relational analysis method, and combine each normalized parameter to further obtain the weight coefficient of each normalized parameter.

[0067] S300. Calculate the compressibility index of different layers based on the normalized parameters of different layers and their corresponding weight coefficients.

[0068] S400. Based on the compressibility indices of different layers, as well as the total hydrocarbon value measured by gas logging, the relative methane value, and the pyrolysis Pg value, establish the determination criteria for oil and water layers;

[0069] S500. Obtain the total hydrocarbon value measured by gas logging, the relative methane value, the pyrolysis Pg value, the pore structure characteristic parameters, and the mineral composition data of the reservoir to be evaluated. Through the methods of S100 - S300, obtain the compressibility index of the reservoir to be evaluated, and then combine the total hydrocarbon value measured by gas logging, the relative methane value, and the pyrolysis Pg value of the reservoir to be evaluated. According to the determination criteria for oil and water layers, obtain the oil - water property of the reservoir to be evaluated.

[0070] To more clearly illustrate the evaluation method for tight oil reservoirs while drilling of the present invention, the following details each step in the embodiments of the present invention.

[0071] The evaluation method for tight oil reservoirs while drilling in the first embodiment of the present invention includes steps S100 - S500, and each step is described in detail as follows:

[0072] S100. Obtain the total hydrocarbon value measured by gas logging, the relative methane value, the pyrolysis Pg value, the pore structure characteristic parameters, and the mineral composition data of different layers of the existing tight oil conclusion layer; Based on the pore structure characteristic parameters and the mineral composition data, calculate the parameter set of the compressibility index of the existing tight oil conclusion layer; The existing tight oil conclusion layer and the reservoir to be evaluated belong to the same oil and gas reservoir; The parameter set includes roundness coefficient, Young's toughness ratio, and mineral brittleness.

[0073] In this embodiment, the total hydrocarbon value is the total concentration of hydrocarbon gases, and the pyrolysis Pg value is the hydrocarbon generation potential. These two parameters can be measured by a gas logging instrument and a pyrolysis analyzer. The calculation formula for the relative methane value content is as follows:

[0074] Relative methane value = Concentration of C1 component / (Concentration of C1 component + Concentration of C2 component + Concentration of C3 component + Concentration of iC4 component + Concentration of nC4 component + Concentration of iC5 component + Concentration of nC5 component) * 100%

[0075] In the formula: C1 is methane, C2 is ethane, C3 is propane, iC4 is isobutane, nC4 is normal butane, iC5 is isopentane, and nC5 is normal pentane.

[0076] In this implementation, the sum of the short axes and the sum of the long axes of the pores in the pore structure characteristic parameters are data obtained by analyzing through electron microscope scanning technology, and the mineral composition data is obtained by analyzing and calculating through X - ray whole - rock analysis technology. The samples for pore structure characteristics, mineral composition data, and pyrolysis Pg value analysis are cuttings.

[0077] In this embodiment, for each layer, the method for calculating the Young's toughness ratio is:

[0078] Among them, E is the comprehensive Young's modulus of the current layer, and K i is the Young's modulus of the i-th mineral in the mineral composition data of the current layer; W i is the percentage content of the i-th mineral in the mineral composition data of the current layer; D is the comprehensive fracture toughness of the current layer, and C i is the fracture toughness of the i-th mineral in the mineral composition data of the current layer; W i is the percentage content of the i-th mineral in the mineral composition data of the current layer; G is the Young's toughness ratio of the current layer.

[0079] In this embodiment, for each layer, the method for calculating mineral brittleness is as follows:

[0080] Among them, B is the mineral brittleness of the current layer; W 石英 , W 长石 , W 方解石 , W 白云石 and W 黏土 are the mineral contents of quartz, feldspar, calcite, dolomite, and clay in the mineral composition data of the current layer, respectively, %.

[0081] In this embodiment, for each layer, the method for calculating the roundness coefficient is as follows: Y = L / S;

[0082] Among them, Y is the roundness coefficient in the pore structure characteristic parameters of the current layer; L is the sum of the major axes of the cuttings pores in the pore structure characteristic parameters of the current layer; mm, and S is the sum of the minor axes of the cuttings pores in the pore structure characteristic parameters of the current layer; mm.

[0083] The formation in the WY structural belt is dense and highly heterogeneous. The formation porosity in the area ranges from 0.82% to 10.5%, with an average of about 5.32%. The permeability is mainly distributed between 0.01 and 143.92×10 -3 μm 2 and the average is 3.31×10 -3 μm 2 , belonging to a tight oil reservoir; in this embodiment, taking the WY structural belt as an example, the fracture toughness and Young's modulus of common minerals in the WY structural belt are shown in Table 1. The types and component contents of minerals in the layers with oil testing conclusions in the WY structural belt are shown in Table 2 for clay minerals, quartz, feldspar, calcite, and dolomite. The comprehensive Young's modulus, comprehensive fracture toughness, and Young's toughness ratio in Table 2 are parameters calculated based on the mineral contents, and the roundness coefficient is a parameter obtained by electron microscopy scanning; Table 1 Table of Fracture Toughness and Young's Modulus of Common Minerals in the WY Structural Zone For the convenience of calculation, Tables 2, 3, 4, and 5 summarize the data of the existing oil testing conclusion layers and the layers to be evaluated. Table 2 Table of Mineral Types and Composition Contents in the WY Structural Zone (Partial Data) The gas chromatogram total hydrocarbon value, methane relative value, pyrolysis Pg value, and oil testing conclusion of the existing oil testing conclusion layers and the layers to be evaluated are shown in Table 3. Table 3 Statistical Table of Oil Testing Data in the WY Structural Zone (Partial Data)

[0084] S200, normalize the parameters in the parameter set respectively to obtain the normalized parameters corresponding to different layers; based on each normalized parameter, calculate the correlation degree by the grey correlation method, and combine each normalized parameter to further obtain the weight coefficient of each normalized parameter;

[0085] In this embodiment, for the three parameters of each layer, the specific method for calculating the normalized parameters is as follows:

[0086] For each parameter, calculate the difference between the maximum value and the minimum value corresponding to each parameter as the range corresponding to each parameter;

[0087] The method for obtaining each normalized parameter of each layer is as follows:

[0088] H 归一 =(H - H min ) / H 极差 ;

[0089] where, where, H 归一 is the parameter value after normalization of the current parameter of the current layer, H max is the maximum value of the current parameter, H min is the minimum value of the current parameter, H 极差 is the range of the current parameter, and H is the current parameter of the current layer.

[0090] In this embodiment, the specific method for calculating the range of each parameter is as follows: Y 极差 =Y max -Y min ;

[0091] Y 极差 is the range of the roundness coefficient, Ymax is the maximum value of the roundness coefficient, Y min is the minimum value of the roundness coefficient G 极差 = G max - G min ;

[0092] In the formula, G 极差 is the range of the Young's toughness ratio, G max is the maximum value of the Young's toughness ratio, G min is the minimum value of the Young's toughness ratio; B 极差 = B max - B min ;

[0093] In the formula, B 极差 is the range of the mineral brittleness, B max is the maximum value of the mineral brittleness, B min is the minimum value of the mineral brittleness;

[0094] The method for obtaining each normalized parameter of each layer is as follows:

[0095] H 归一 = (H - H min ) / H 极差 ;

[0096] Among them, H 归一 is the normalized parameter value of the current parameter of the current layer, H max is the maximum value of the current parameter, H min is the minimum value of the current parameter, H 极差 is the range of the current parameter, and H is the current parameter of the current layer.

[0097] In this embodiment, the existing oil testing conclusion tight oil reservoirs belonging to the same oil and gas reservoir as the layer to be evaluated are respectively marked as layers 1 to N, and p represents any layer from 1 to N, that is, p = 1, 2, 3... N. The method for obtaining the normalized parameter of each layer is as follows: Y p归一 = (Y p - Y min ) / Y 极差 ;

[0098] In the formula, Y P归一 is the normalized roundness coefficient of the p-th layer, Y p is the roundness coefficient of the p-th layer; G p归一 = (G p - G min ) / G 极差 ;

[0099] In the formula, G P归一is the normalized Yang toughness ratio of the p-th layer, G p is the Yang toughness ratio of the p-th layer; B p归一 =(B p -B min ) / Y 极差 ;

[0100] In the formula, B P归一 is the normalized mineral brittleness of the p-th layer, B p is the mineral brittleness of the p-th layer.

[0101] In this embodiment, the normalized parameter table of each layer of the WY structural belt calculated by the above method is shown in Table 4, Table 4 Normalized data table of the WY structural belt

[0102] In this embodiment, the method for calculating the weight coefficients of the three parameters is as follows:

[0103] Taking the normalized parameters of mineral brittleness of different layers as the parent factors, and the normalized parameters of roundness coefficient of different layers and the normalized parameters of Yang toughness ratio of different layers as the sub-factors, through mathematical analysis software, the correlation degree F Y of the normalized parameters of the roundness coefficient and the correlation degree F G of the normalized parameters of the Yang toughness ratio are obtained. The correlation degree F B of the normalized parameters of mineral brittleness is 1. In this embodiment, the correlation degree between the roundness coefficient and mineral brittleness is 0.6739, and the correlation degree between the Yang toughness ratio and mineral brittleness is 0.6152; The calculation method of the weight coefficient A G of the Yang toughness ratio is: A G =F G / (F G +F B +F Y ); The calculation method of the weight coefficient A B of mineral brittleness is: A B =F B / (F G +F B +F Y ); The calculation method of the weight coefficient A Y of the roundness coefficient is: A Y =F Y / (F G +F B +F Y ). In this embodiment, the weight coefficient of mineral brittleness is obtained as 0.4369, the weight coefficient of the roundness coefficient is 0.2944, and the weight coefficient of the Yang toughness ratio is 0.2688;

[0104] In this embodiment, the mathematical analysis software may be the grey modeling software provided by the Grey System Research Institute.

[0105] S300. Calculate the compressibility index of different layers based on the normalization parameters of different layers and their corresponding weight coefficients.

[0106] For each layer, the calculation method of the compressibility index is as follows: Z = A G *G 归一 + A B *B 归一 + A Y *Y 归一 ;

[0107] Wherein, Z is the compressibility index of the current layer, A G , A B and A Y are respectively the weight coefficient of the Yang toughness ratio, the weight coefficient of the mineral brittleness, the weight coefficient of the roundness coefficient, Y 归一 is the normalization parameter of the roundness coefficient of the current layer, B 归一 is the normalization parameter of the mineral brittleness of the current layer; G 归一 is the normalization parameter of the Yang toughness ratio of the current layer.

[0108] In this embodiment, when the roundness coefficient cannot be calculated due to other force majeure factors, the compressibility index can be calculated only through the weight coefficient of the Yang toughness ratio, the weight coefficient of the mineral brittleness, the normalization parameter of the Yang toughness ratio, and the normalization parameter of the mineral brittleness.

[0109] In this embodiment, the compressibility index and reservoir classification table of the WY structural belt are shown in Table 5, Table 5 Compressibility Index and Reservoir Classification Table

[0110] S400. Construct the determination criteria for oil and water layers based on the compressibility index of different layers, the total hydrocarbon value of gas logging, the relative methane value, and the pyrolysis Pg value.

[0111] The determination criteria for oil and water layers are as follows:

[0112] For each layer: a compressibility index greater than or equal to the first threshold is a Class I reservoir; a compressibility index greater than the second threshold and less than the first threshold is a Class II reservoir; a compressibility index less than or equal to the second threshold is a Class III reservoir; in this embodiment, preferably, the first threshold is 0.7 and the second threshold is 0.3.

[0113] A classification standard for oil and water layers is derived by combining the total hydrocarbon value, relative methane value, and pyrolysis Pg value. The parameter zoning for various types of reservoirs is shown in Figures 3 - 11 , and the classification table is shown in Table 6: Table 6 Classification Table for Oil and Water Layers of Different Reservoir Types

[0114] For Class I reservoirs: Those with a total hydrocarbon value greater than 10%, a relative methane value between 65% and 80%, and a pyrolysis Pg value greater than 15 mg / g are oil layers; those with a total hydrocarbon value between 5% and 10%, a relative methane value between 80% and 85%, and a pyrolysis Pg value between 10 mg / g and 15 mg / g are oil-water layers; those with a total hydrocarbon value less than 5%, a relative methane value greater than 85%, and a pyrolysis Pg value less than 10 mg / g are water-bearing oil layers;

[0115] For Class II reservoirs: Those with a total hydrocarbon value greater than 20%, a relative methane value between 65% and 80%, and a pyrolysis Pg value greater than 20 mg / g are oil layers; those with a total hydrocarbon value between 15% and 20%, a relative methane value between 65% and 80%, and a pyrolysis Pg value between 15 mg / g and 20 mg / g are poor oil layers; those with a total hydrocarbon value between 10% and 20%, a relative methane value between 80% and 85%, and a pyrolysis Pg value between 10 mg / g and 20 mg / g are oil-water layers; those with a total hydrocarbon value less than 10%, a relative methane value greater than 85%, and a pyrolysis Pg value less than 10 mg / g are water-bearing oil layers;

[0116] For Class III reservoirs: Those with a total hydrocarbon value greater than 50%, a relative methane value between 65% and 75%, and a pyrolysis Pg value greater than 25 mg / g are oil layers; those with a total hydrocarbon value between 25% and 50%, a relative methane value between 65% and 75%, and a pyrolysis Pg value between 15 mg / g and 25 mg / g are poor oil layers; those with a total hydrocarbon value between 15% and 25%, a relative methane value between 80% and 85%, and a pyrolysis Pg value between 15 mg / g and 25 mg / g are oil-water layers; those with a total hydrocarbon value less than 15%, a relative methane value greater than or equal to 85%, and a pyrolysis Pg value less than 15 mg / g are water-bearing oil layers. In the present invention, between a - b represents a closed interval. For example, between 80% and 85% means greater than or equal to 80% and less than or equal to 85%; and so on, without further elaboration.

[0117] S500: Obtain the gas chromatographic total hydrocarbon value, methane relative value, pyrolysis Pg value (Table 3), pore structure characteristic parameters, and mineral composition data (Table 2) of the reservoir to be evaluated. Through the methods of S100 - S300, and perform normalization processing, multiply by the weight coefficients of each normalization parameter to obtain the compressibility index of the reservoir to be evaluated (Table 5). Furthermore, combine the gas chromatographic total hydrocarbon value, methane relative value, and pyrolysis Pg value of the reservoir to be evaluated, and according to the determination criteria of the oil - water layer, obtain the oil - water property of the reservoir to be evaluated.

[0118] In this embodiment, taking Well 101 in the WY structural belt as an example for verification. First, based on the gas chromatographic total hydrocarbon value display, oil stain and oil spot displays seen in logging cuttings, a total of three evaluation layers are divided. Collect the X - ray diffraction whole - rock analysis data of the cuttings of this well, obtain the pore structure characteristic parameters from the scanning electron microscopy of the cuttings, calculate the roundness coefficient data, and calculate the compressibility index of Well 101 in the WY structural belt. The data of Well 101 in the WY structural belt are shown in Table 7: Table 7 Data Table of Well 101 in the WY Structural Belt

[0119] After determining the reservoir classification, then combine the total hydrocarbon value, methane relative value, and pyrolysis Pg value, and classify the oil - water layer according to the evaluation criteria for different types of reservoirs. The data of the three layers are shown in Table 8: Table 8 Data Table of the Drilling - while - logging Display of Well 101 in the WY Structural Belt

[0120] Among them, for Evaluation Layer 1, the well section is 1718 - 1724m, the lithology is oil - stained siltstone ( Figure 2 Medium 4), the thickness is 6m, the compressibility index is 0.82 ( Figure 2 Medium 16), it is a Class I reservoir, the total hydrocarbon display value is 17.58% ( Figure 2 Medium 7), the methane relative value is 76.8% ( Figure 2 Medium 10), the Pg value is 17.2mg / g ( Figure 2 Medium 13), and it is evaluated as an oil layer according to the standard.

[0121] For Evaluation Layer 2, the well section is 1729 - 1734m, the lithology is oil - stained siltstone ( Figure 2 Medium 5), the thickness is 5m, the compressibility index is 0.54 ( Figure 2 Medium 17), it is a Class II reservoir, the total hydrocarbon display value is 16.62% ( Figure 2 Medium 8), the methane relative value is 83.1% ( Figure 2 Medium 11), the Pg value is 16.52mg / g ( Figure 2 Medium 14), and it is evaluated as an oil - water layer according to the standard.

[0122] Evaluation layer 3, well section 1737 - 1742m, lithology is oil-stained siltstone( Figure 2 No. 6 in the middle), thickness is 5m, compressibility index is 0.22( Figure 2 No. 18 in the middle), it is a Class III reservoir, total hydrocarbon display value is 26.73%( Figure 2 No. 9 in the middle), relative methane value is 73.1%( Figure 2 No. 12 in the middle), Pg value is 22.5mg / g( Figure 2 No. 15 in the middle), evaluated as a poor oil layer according to the standard.

[0123] Verification of the evaluation layer:

[0124] Evaluation layer 1, well section 1718 - 1724m, evaluated as an oil layer, the well section for oil testing after fracturing is 1718.2 - 1724.2m, pumping, daily oil production is 12.5m 3 , the oil production is higher than 1m of the industrial oil flow standard for well depth of 1000 - 2000m 3 and is consistent with the evaluation conclusion.

[0125] Evaluation layer 2, well section 1729 - 1734m, evaluated as an oil-water layer, the well section for oil testing after fracturing is 1728.8 - 1734.2m, pumping, daily oil production is 5.5m 3 , water is 2.5m 3 , the oil production is higher than 1m of the industrial oil flow standard for well depth of 1000 - 2000m 3 and the water cut is 31.25%, meeting the oil-water layer standard, and is consistent with the evaluation conclusion.

[0126] Evaluation layer 3, well section 1737 - 1742m, evaluated as a poor oil layer according to the standard, the well section for oil testing after fracturing is 1737.4 - 1742.2m, jet pump drainage, daily oil production is 0.75m 3 , the oil production is lower than 1m of the industrial oil flow standard for well depth of 1000 - 2000m 3 and it is a poor oil layer, which is consistent with the evaluation conclusion.

[0127] Although each step is described in the above order in the above embodiments, those skilled in the art can understand that in order to achieve the effects of this embodiment, different steps do not have to be executed in such an order, and they can be executed simultaneously (in parallel) or in a reversed order, and these simple changes are within the protection scope of the present invention.

[0128] The tight oil reservoir evaluation system according to the second embodiment of the present invention is used to determine the oil-water properties of the reservoir to be evaluated, and is characterized in that the system includes:

[0129] A parameter set determination module that obtains the gas chromatogram total hydrocarbon values, methane relative values, pyrolysis Pg values, pore structure characteristic parameters, and mineral composition data of different layers of existing tight oil well testing conclusion layers; based on the pore structure characteristic parameters and the mineral composition data, calculates the parameter set of the compressibility index of the existing tight oil well testing conclusion layers; the existing tight oil conclusion layers and the reservoir to be evaluated belong to the same oil and gas reservoir; the parameter set includes roundness coefficient, Young's toughness ratio, and mineral brittleness;

[0130] A weight coefficient determination module that respectively normalizes the parameters in the parameter set to obtain the normalized parameters corresponding to different layers; based on each normalized parameter, calculates the correlation degree by the grey correlation method, and combines each normalized parameter to further obtain the weight coefficient of each normalized parameter;

[0131] A compressibility index determination module that calculates the compressibility index of different layers based on the normalized parameters of different layers and their corresponding weight coefficients;

[0132] An oil-water standard determination module that constructs the determination standard of oil-water layers based on the compressibility index of different layers and the gas chromatogram total hydrocarbon values, methane relative values, and pyrolysis Pg values;

[0133] A result determination module that obtains the gas chromatogram total hydrocarbon values, methane relative values, pyrolysis Pg values, pore structure characteristic parameters, and mineral composition data of the reservoir to be evaluated, and obtains the compressibility index of the reservoir to be evaluated by the method of S100 - S300, and then combines the gas chromatogram total hydrocarbon values, methane relative values, and pyrolysis Pg values of the reservoir to be evaluated, and obtains the oil-water property of the reservoir to be evaluated according to the determination standard of the oil-water layers.

[0134] Those skilled in the art of the present technology can clearly understand that for the convenience and conciseness of description, the specific working process and related explanations of the above-described system can refer to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0135] It should be noted that the above-described tight oil reservoir evaluation system during drilling provided in the above embodiments is only illustrated by the division of the above functional modules. In actual applications, the above functions can be allocated to different functional modules according to needs, that is, the modules or steps in the embodiments of the present invention can be further decomposed or combined. For example, the modules in the above embodiments can be combined into one module, or further split into multiple sub-modules to complete all or part of the functions described above. For the names of the modules and steps involved in the embodiments of the present invention, they are only used to distinguish each module or step and are not regarded as an improper limitation of the present invention.

[0136] An electronic device according to the third embodiment of the present invention includes:

[0137] At least one processor; and

[0138] A memory communicatively connected to at least one of the processors; wherein,

[0139] The memory stores instructions executable by the processor, and the instructions are used to be executed by the processor to implement the above-mentioned evaluation method for tight oil reservoirs while drilling.

[0140] A computer-readable storage medium according to a fourth embodiment of the present invention, the computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above-mentioned evaluation method for tight oil reservoirs while drilling.

[0141] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes and related descriptions of the above-described storage device and processing device can refer to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0142] Those skilled in the art should be able to realize that the modules and method steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. The programs corresponding to the software modules and method steps can be placed in a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium well-known in the art. To clearly illustrate the interchangeability of electronic hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in the form of electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0143] Next, refer to Figure 12 , which shows a schematic structural diagram of a computer system of a server for implementing the method, system, and device embodiments of the present application. Figure 12 The server shown is only an example and should not impose any limitation on the functions and usage scope of the embodiments of the present application.

[0144] As Figure 12As shown, the computer system includes a central processing unit (CPU), 601, which can perform various appropriate actions and processes according to a program stored in a read only memory (ROM) 602 or a program loaded from a storage section 608 into a random access memory (RAM) 603. In the RAM 603, various programs and data required for system operations are also stored. The CPU 601, the ROM 602, and the RAM 603 are connected to each other via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0145] The following components are connected to the I / O interface 605: an input section 606 including a keyboard, a mouse, etc.; an output section 607 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc. and a speaker, etc.; a storage section 608 including a hard disk, etc.; and a communication section 609 including a network interface card such as a LAN (local area network) card, a modem, etc. The communication section 609 performs communication processing via a network such as the Internet. A drive 610 is also connected to the I / O interface 605 as required. A removable medium 611, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 610 as required so that a computer program read from the same can be installed into the storage section 608 as required.

[0146] In particular, according to embodiments of the present disclosure, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present disclosure include a computer program product that includes a computer program carried on a computer-readable medium, and the computer program includes program code for performing the methods shown in the flowcharts. In such an embodiment, the computer program can be downloaded and installed from a network through the communication section 609 and / or installed from the removable medium 611. When the computer program is executed by the central processing unit (CPU) 601, the above-described functions defined in the methods of the present application are performed. It should be noted that the computer-readable medium described above in the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the two. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples of the computer-readable storage medium can include, but are not limited to: an electrical connection with one or more wires, 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), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In the present application, the computer-readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, which carries the computer-readable program code. Such a propagated data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer-readable signal medium can also be any computer-readable medium other than the computer-readable storage medium, which can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted by any appropriate medium, including but not limited to: wireless, wire, optical fiber, RF, etc., or any suitable combination of the above.

[0147] Computer program code for performing the operations of this application can be written in one or more programming languages or combinations thereof. The above programming languages include object-oriented programming languages such as Java, Smalltalk, C++, and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, executed as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any kind of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (e.g., by connecting through the Internet using an Internet service provider).

[0148] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in the flowchart or block diagram can represent a module, a program segment, or a part of code that contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks can occur in a different order than that marked in the accompanying drawings. For example, two consecutive blocks shown can actually be executed substantially in parallel, and they can sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0149] The terms "first", "second", etc. are used to distinguish similar objects, rather than to describe or represent a specific order or sequence.

[0150] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or device / equipment that comprises a series of elements includes not only those elements but also other elements not expressly listed, or also includes elements inherent to those processes, methods, articles, or devices / equipment.

[0151] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for evaluating a tight oil reservoir while drilling, which is used to determine the fluid properties of the reservoir to be evaluated, characterized in that, The method includes: S100. Obtain the gas chromatography total hydrocarbon value, methane relative value, pyrolysis Pg value, pore structure characteristic parameters, and mineral composition data of the existing tight oil conclusion layer; based on the pore structure characteristic parameters and the mineral composition data, calculate the parameter set of the compressibility index of the existing tight oil conclusion layer; the existing tight oil conclusion layer and the reservoir to be evaluated belong to the same oil and gas reservoir; the pore structure characteristic parameter is the sum of the major axes and the sum of the minor axes of the cuttings pores; the parameter set includes the roundness coefficient, Yang toughness ratio, and mineral brittleness. S200. Respectively perform normalization processing on the three parameters of mineral brittleness, roundness coefficient, and Yang toughness ratio in the parameter set to obtain the normalized parameters corresponding to different layers; based on each normalized parameter, calculate the correlation degree by the grey relational analysis method, and combine each normalized parameter to further obtain the weight coefficient of each normalized parameter. S300. Based on the normalized parameters of different layers and their corresponding weight coefficients, calculate the compressibility index of different layers. S400. Based on the compressibility index of the tested oil layer, as well as the gas chromatography total hydrocarbon value, methane relative value, and pyrolysis Pg value, construct the evaluation criteria for oil and water layers. S500. Obtain the gas chromatography total hydrocarbon value, methane relative value, pyrolysis Pg value, pore structure characteristic parameters, and mineral composition data of the reservoir to be evaluated. Through the methods of S100 - S300, obtain the compressibility index of the reservoir to be evaluated, and then combine the gas chromatography total hydrocarbon value, methane relative value, and pyrolysis Pg value of the reservoir to be evaluated. According to the determination criteria of the oil and water layers, obtain the oil and water properties of the layer to be evaluated.

2. The method for evaluating a tight oil reservoir while drilling according to claim 1, wherein For each layer, the method for calculating the Yang toughness ratio is: Among them, E is the comprehensive Young's modulus of the current layer, and K i is the Young's modulus of the i-th mineral in the mineral composition data of the current layer; W i is the percentage content of the i-th mineral in the mineral composition data of the current layer; D is the comprehensive fracture toughness of the current layer, and C i is the fracture toughness of the i-th mineral in the mineral composition data of the current layer; W i is the percentage content of the i-th mineral in the mineral composition data of the current layer; G is the Young's toughness ratio of the current layer.

3. The method for evaluating tight oil reservoirs while drilling according to claim 1, wherein For each layer, the method for calculating the mineral brittleness is: Among them, B is the mineral brittleness of the current layer; W 石英 , W 长石 , W 方解石 , W 白云石 and W 黏土 are the mineral contents of quartz, feldspar, calcite, dolomite, and clay in the mineral composition data of the current layer, respectively, %.

4. The method for evaluating a tight oil reservoir while drilling according to claim 1, wherein For each layer, the method for calculating the roundness coefficient is: Y = L / S; Where, Y is the roundness coefficient in the pore structure characteristic parameters of the current layer; L is the sum of the major axes of the cuttings pores in the pore structure characteristic parameters of the current layer, in mm; S is the sum of the minor axes of the cuttings pores in the pore structure characteristic parameters of the current layer, in mm.

5. The evaluation method for tight oil reservoirs while drilling according to claim 1, characterized in that, For the three parameters of each layer, the specific method for calculating the normalized parameter is: For each parameter, calculate the difference between the maximum value and the minimum value corresponding to each parameter as the range corresponding to each parameter. For the method of obtaining each normalized parameter of each layer: H 归一 = (H - H min ) / H 极差 ; Among them, H 归一 is the normalization parameter of the current layer, H max is the maximum value of the current parameter, H min is the minimum value of the current parameter, H 极差 is the range of the current parameter, and H is the current parameter value of the current layer.

6. The method for evaluating tight oil reservoirs while drilling according to claim 1, wherein The method for calculating the weight coefficients of the three parameters respectively is: Taking the normalized parameters of mineral brittleness in different layers as the mother factors, and the normalized parameters of roundness coefficient and the normalized parameters of Yang toughness ratio in different layers as the sub-factors, through mathematical analysis software, the correlation degree F of the normalized parameters of roundness coefficient is obtained Y and the correlation degree F of the normalized parameters of Yang toughness ratio G , the correlation degree F of the normalized parameters of mineral brittleness B is 1; Weight coefficient A of Yang Renbi G The calculation method is: A G = F G / (F G + F B + F Y ); Weight coefficient A of mineral brittleness B The calculation method is: A B = F B / (F G + F B + F Y ); Weight coefficient A of roundness coefficient Y The calculation method is: A Y = F Y / (F G + F B + F Y ).

7. The method for evaluating a tight oil reservoir while drilling according to claim 6, characterized in that, For each layer, the method for calculating the compressibility index is: Z = A G *G 归一 +A B *B 归一 +A Y *Y 归一 ; Among them, Z is the compressibility index of the current layer, A G , A B and A Y are the weight coefficients of the Young's toughness ratio, the weight coefficient of mineral brittleness, and the weight coefficient of roundness coefficient respectively. Y 归一 is the roundness coefficient normalization parameter of the current layer, B 归一 is the mineral brittleness normalization parameter of the current layer; G 归一 is the Young's toughness ratio normalization parameter of the current layer.

8. The method for evaluating a tight oil reservoir while drilling according to claim 7, wherein The determination criteria for oil and water layers are: For each layer: when the compressibility index is greater than or equal to the first threshold, it is a type I reservoir; when the compressibility index is greater than the second threshold and less than the first threshold, it is a type II reservoir; when the compressibility index is less than or equal to the second threshold, it is a type III reservoir. For type I reservoirs: when the total hydrocarbon value is greater than 10%, the methane relative value is between 65% and 80%, and the pyrolysis Pg value is greater than 15 mg / g, it is an oil layer; when the total hydrocarbon value is between 5% and 10%, the methane relative value is between 80% and 85%, and the pyrolysis Pg value is between 10 mg / g and 15 mg / g, it is an oil - water layer; when the total hydrocarbon value is less than 5%, the methane relative value is greater than 85%, and the pyrolysis Pg value is less than 10 mg / g, it is an oil - bearing water layer. For Class II reservoirs: When the total hydrocarbon value is greater than 20%, the relative methane value is between 65% and 80%, and the pyrolysis Pg value is greater than 20 mg / g, it is an oil layer; when the total hydrocarbon value is between 15% and 20%, the relative methane value is between 65% and 80%, and the pyrolysis Pg value is between 15 mg / g and 20 mg / g, it is a poor oil layer; when the total hydrocarbon value is between 10% and 20%, the relative methane value is between 80% and 85%, and the pyrolysis Pg value is between 10 mg / g and 20 mg / g, it is an oil-water layer; when the total hydrocarbon value is less than 10%, the relative methane value is greater than 85%, and the pyrolysis Pg value is less than 10 mg / g, it is an oil-bearing water layer; For Class III reservoirs: When the total hydrocarbon value is greater than 50%, the relative methane value is between 65% and 75%, and the pyrolysis Pg value is greater than 25 mg / g, it is an oil layer; when the total hydrocarbon value is between 25% and 50%, the relative methane value is between 65% and 75%, and the pyrolysis Pg value is between 15 mg / g and 25 mg / g, it is a poor oil layer; when the total hydrocarbon value is between 15% and 25%, the relative methane value is between 80% and 85%, and the pyrolysis Pg value is between 15 mg / g and 25 mg / g, it is an oil-water layer; when the total hydrocarbon value is less than 15%, the relative methane value is greater than or equal to 85%, and the pyrolysis Pg value is less than 15 mg / g, it is an oil-bearing water layer.

9. A logging-while-drilling evaluation system for tight oil reservoirs, which is used to determine the fluid properties of a reservoir to be evaluated, is characterized in that The system includes: A parameter set determination module, which obtains the gas logging total hydrocarbon value, relative methane value, pyrolysis Pg value, pore structure characteristic parameters, and mineral composition data of different layers of existing tight oil conclusion layers; based on the pore structure characteristic parameters and the mineral composition data, calculates the parameter set of the compressibility index of the existing tight oil conclusion layers; the existing tight oil conclusion layers and the reservoir to be evaluated belong to the same oil and gas reservoir; the parameter set includes roundness coefficient, Young's toughness ratio, and mineral brittleness; A weight coefficient determination module, which normalizes the parameters in the parameter set respectively to obtain the normalized parameters corresponding to different layers; based on each normalized parameter, calculates the correlation degree by the grey correlation method, and combines each normalized parameter to obtain the weight coefficient of each normalized parameter; A compressibility index determination module, which calculates the compressibility index of different layers based on the normalized parameters of different layers and their corresponding weight coefficients; An oil-water standard determination module, which constructs the determination standard of oil-water layers based on the compressibility index of different layers and the gas logging total hydrocarbon value, relative methane value, and pyrolysis Pg value; A result determination module, which obtains the gas logging total hydrocarbon value, relative methane value, pyrolysis Pg value, pore structure characteristic parameters, and mineral composition data of the reservoir to be evaluated, obtains the compressibility index of the reservoir to be evaluated by the method of S100-S300, and then combines the gas logging total hydrocarbon value, relative methane value, and pyrolysis Pg value of the reservoir to be evaluated, and obtains the oil-water property of the reservoir to be evaluated according to the determination standard of the oil-water layer.

10. An electronic device, characterized in that, It includes: At least one processor; And A memory communicatively connected to at least one of the processors; wherein, The memory stores instructions executable by the processor, and the instructions are used to be executed by the processor to implement the evaluation method while drilling for tight oil reservoirs according to any one of claims 1-8.

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