Oil-gas phase state type identification method and system

Abstract

The invention belongs to the technical field of oil-gas geological exploration and development, and relates to an oil-gas phase state type identification method and system, and the method comprises the steps: obtaining logging data and logging data of a target layer of a research area; selecting a phase prediction index of a target layer of the research area based on the logging data, and selecting a plurality of sample points of known phase types in the research area based on the logging data; calculating the principal component of the target layer according to the phase state prediction index, and establishing a geography-survey-recording integrated phase state prediction chart according to the plurality of sample points and the calculated principal component plumbing point; according to the gas logging response value of the hydrocarbon component of the oil and gas sample, determining the division standard of the oil and gas phase state type, and superposing the division standard to the geography-logging integrated phase state prediction chart to form a phase state prediction chart containing the critical phase state type; and according to the phase state prediction chart containing the critical phase state type, identifying the oil-gas phase state type of the target layer in the research area. According to the invention, the oil-gas phase state type of the oil-gas reservoir can be accurately identified, and the subdivision of the critical state type is realized.

Description

Technical Field

[0001] This application belongs to the technical field of oil and gas geological exploration and development, and particularly relates to a method and system for identifying oil and gas phase types. Background Technique

[0002] In deep basin reservoirs, oil and gas can present as single oil phase, gas phase, or oil-gas mixed phase. After being extracted to the surface, due to the decrease in temperature and pressure, a series of phase changes will occur, presenting different phase types from those in deep reservoirs. According to hydrocarbon specific gravity, it can be divided into extra-heavy oil, heavy oil, medium oil, light oil (volatile oil), condensate gas, and natural gas. According to gas-oil ratio, it can be divided into black oil, light oil (volatile oil), condensate gas, wet gas, and dry gas. The complex and unclear oil and gas phase types bring great challenges to oil and gas exploration and development. Therefore, clarifying the phase types, sorting out the characteristics and causes of phase space distribution, is helpful for oil and gas exploration and development.

[0003] In current research on oil and gas phases, common experimental sample analysis methods include crude oil cracking experiment, column chromatography conventional method, and high-temperature and high-pressure simulation experiment. Previous studies have summarized three major types of oil and gas phase discrimination methods, namely empirical statistical discrimination method, phase diagram discrimination method, and prediction modeling method.

[0004] The empirical statistical method is to summarize the regularities of different types of oil and gas reservoirs based on the composition and characteristic parameters of a large number of known oil and gas reservoirs, so as to guide the discrimination method of oil and gas reservoir phase types. There are 14 known empirical statistical methods, namely block diagram method, C 2+ content method, φ 1-parameter method, formation fluid density and average molecular weight method, ternary composition triangular diagram method of reservoir fluid, relationship method between gas-oil ratio and oil tank oil output of unit reservoir fluid, relationship method between surface production gas-oil ratio and oil tank oil density, C 5+ value method of reservoir condensate gas, C1 / C 5+ value method of reservoir condensate gas, hierarchical classification method, Z-factor method, potential function method, iC4 / nC4 and iC5 / nC5 method, C 5+ and N2 relationship method. Among them, the ternary composition triangular diagram method of reservoir fluid, φ 1-parameter method, formation fluid density and average molecular weight method, and relationship method between gas-oil ratio and oil tank oil output of unit reservoir fluid are commonly used oil and gas phase discrimination methods because of their relatively accurate discrimination of oil and gas phases.

[0005] The phase diagram identification method includes the PVT phase diagram method, the discrimination method of the relationship curve between liquid volume and dimensionless pressure, the discrimination method of the relationship curve between condensate oil content and saturation pressure, and the discrimination method of the relationship curve between dimensionless shrinkage rate and dimensionless pressure. Among them, the PVT phase diagram method is to draw the PVT phase diagram using the PVTsim software according to the component characteristics of hydrocarbon fluids, and to identify different phase types based on the PVT phase diagram characteristics of various oil and gas reservoirs and the position of the isothermal pressure reduction line of the reservoir temperature. For condensate gas reservoirs, if the formation pressure is close to or equal to the dew point, it is often possible to predict whether there is an oil ring in the condensate gas reservoir. For condensate gas reservoirs or volatile oil reservoirs in the near-critical state, accurately determining the fluid critical point is the key. The discrimination method of the relationship curve between liquid volume and dimensionless pressure roughly discriminates the type of oil and gas reservoir according to the curve shape and position of the relationship curve between the liquid volume percentage (relative to the volume at the saturation pressure point) and the dimensionless pressure (relative to the saturation pressure) obtained from the specific oil and gas reservoir fluid phase experiment. The discrimination method of the relationship curve between condensate oil content and saturation pressure is to take the gas and condensate oil produced from the well, prepare samples with different gas-oil ratios in the laboratory, measure their respective saturation pressures separately, draw the relationship curve between condensate oil content and saturation pressure, and thus discriminate the type of oil and gas reservoir. The discrimination method of the relationship curve between dimensionless shrinkage rate and dimensionless pressure applies the PVT data of the specific reservoir crude oil sample, calculates the dimensionless shrinkage rate and dimensionless pressure, and then discriminates the reservoir fluid type of the crude oil producing layer according to the chart.

[0006] The prediction modeling method is also a commonly used method for identifying phase types. Existing domestic and foreign phase prediction models are mostly established based on mud logging or logging data, such as Pickles chart, hydrocarbon gas logging component values or hydrocarbon component ratio charts, etc. The Pickles chart divides the oil and gas layers into non-producing layers, gas layers and oil layers according to the numerical ranges of C1 / C2, C1 / C3, C1 / C4, and C1 / C5 in hydrocarbon components. The hydrocarbon gas logging component values or hydrocarbon component ratio charts select single components from hydrocarbon gas components that can represent the characteristics of oil, gas, and water, use two or three component or ratio parameters that can clearly divide the boundaries of oil, gas, and water layers to form a coordinate system, and divide the oil, gas, and water intervals based on the oil test results, that is, compile the chart, and then conduct graphical interpretation in the chart to distinguish oil, gas, and water layers. The cross-plot of gas component values and the triangular component chart are two relatively commonly used methods among them.

[0007] The existing methods for identifying the types of oil and gas phases mainly have the following two problems: (1) Most methods need to rely on hydrocarbon fluid component data for identification. For well positions lacking hydrocarbon fluid component data, the application of these methods will be restricted, and thus the types of oil and gas phases cannot be identified. (2) Existing domestic and foreign phase prediction models are mostly based on mud logging or logging data, and there are differences in the accuracy of identifying phase types in different research areas, and the identification accuracy is low. Summary of the Invention

[0008] In view of the problems existing in the prior art, the present application provides a method and system for identifying the types of oil and gas phases. Considering the geological background and based on gas logging and logging responses, a geophysical-logging-lithology integrated phase prediction model is established to accurately identify the types of oil and gas phases in oil and gas reservoirs through the established model, realize the subdivision of critical phase types, and further clarify the spatial distribution characteristics and genetic mechanisms of different oil and gas phase types, and formulate corresponding oil and gas exploration and development strategies.

[0009] In the first aspect of the present application, a method for identifying the types of oil and gas phases is provided, and the steps are as follows: Obtain the logging data and mud logging data of the target layer in the study area; Based on the logging data, select the phase prediction indicators for the target layer in the study area, and based on the mud logging data, select multiple sample points with known phase types for the target layer in the study area; Calculate the principal components of the target formation according to the phase prediction indicators, and establish a geophysical-logging-lithology integrated phase prediction chart based on the multiple sample points and the principal component projection points; According to the discrimination criteria for the types of oil and gas phases based on the gas logging response values of hydrocarbon components in oil and gas samples, superimpose the discrimination criteria on the geophysical-logging-lithology integrated phase prediction chart to form a phase prediction chart including critical phase types; Identify the types of oil and gas phases of the target layer in the study area according to the phase prediction chart including critical phase types.

[0010] In some embodiments, the phase prediction indicators include acoustic time difference DT, gamma value GR, resistivity value R, gas logging value Tg, gas logging value C1, hydrocarbon humidity ratio Wh, and the difference between hydrocarbon humidity ratio Wh and hydrocarbon balance ratio Bh.

[0011] In some embodiments, the acoustic time difference DT, gamma value GR, resistivity value R, gas logging value Tg, and gas logging value C1 are directly read from the logging curves of the target layer in the study area; the hydrocarbon humidity ratio Wh and hydrocarbon balance ratio Bh are calculated according to the gas logging response values of hydrocarbon components in oil and gas samples;

[0012]

[0013] In the formula, C1, C2, C3, C4, C5, iC4, nC4, iC5, and nC5 are the gas logging response values of the corresponding hydrocarbon components respectively.

[0014] In some embodiments, the method for calculating the principal components of the target formation according to the phase prediction indicators is as follows: Standardize the phase prediction indicators to obtain the standardized phase prediction indicators; Calculate the principal component Ⅰ and the principal component Ⅱ respectively; Principal component Ⅰ = 0.27*A1 - 0.10*A2 - 0.22*A3 + 0.56*A4 + 0.56*A5 - 0.34*A6 - 0.34*A7 Principal component Ⅱ = -0.61*A1 + 0.25*A2 + 0.65*A3 + 0.18*A4 + 0.21*A5 - 0.19*A6 - 0.13*A7 Wherein, A1 is the sonic transit time DT after standardization, A2 is the gamma value GR after standardization, A3 is the resistivity value R after standardization, A4 is the gas logging value Tg after standardization, A5 is the gas logging value C1 after standardization, A6 is the hydrocarbon humidity ratio Wh after standardization, and A7 is the difference between the hydrocarbon humidity ratio Wh and the hydrocarbon balance ratio Bh after standardization.

[0015] In some embodiments, the method for determining the classification standard of the oil and gas phase type according to the gas logging response value of the hydrocarbon components in the oil and gas sample is as follows: Calculate according to the gas logging response value of the hydrocarbon components in the oil and gas sample φ 1 parameter;

[0016] Wherein, C1, C2, C3, C4, C5 + are respectively the gas logging response values of the corresponding hydrocarbon components; According to the calculated φ 1 parameter, obtain the classification standard of the oil and gas phase type.

[0017] In some embodiments, the method for obtaining the classification standard of the oil and gas phase type according to the calculated φ 1 parameter is as follows: When φ 1 ≤ 2.5, the oil and gas phase type is black oil. Among them, when φ 1 ≤ 1, the oil and gas phase type is high-viscosity heavy oil reservoir. When 1 < φ 1 ≤ 2.5, the oil and gas phase type is ordinary black oil reservoir; when 2.5 < φ 1 ≤ 15, the oil and gas phase type is volatile oil. Among them, when 2.5 < φ 1 ≤ 7, the oil and gas phase type is volatile oil reservoir. When 7 < φ 1 ≤ 15, the oil and gas phase type is condensate gas cap oil reservoir; when φ 1 > 15, the oil and gas phase type is condensate gas. Among them, when 15 < φ 1 ≤ 80, the oil and gas phase type is condensate gas reservoir with oil rim; when φ 1 > 80, the oil and gas phase type is condensate gas reservoir without oil rim.

[0018] In the second aspect of the present application, there is provided an oil and gas phase type identification system for implementing the oil and gas phase type identification method described in the first aspect of the present application, including: An acquisition module for acquiring logging data and mud logging data of the target layer in the study area; A selection module for selecting phase prediction indicators of the target layer in the study area based on logging data and multiple sample points of known phase types based on mud logging data; A calculation module for calculating the principal components of the target formation according to the phase prediction indicators; A chart construction module for establishing an integrated geological-logging-mud logging phase prediction chart by plotting points based on the acquired multiple sample points and the calculated principal components; A discrimination standard determination module for determining the discrimination standard of hydrocarbon phase types according to the gas logging response values of hydrocarbon components in oil and gas samples; An overlay module for overlaying the discrimination standard on the integrated geological-logging-mud logging phase prediction chart to form a phase prediction chart including critical phase types; A phase type identification module for identifying the hydrocarbon phase types of the target layer in the study area according to the phase prediction chart including critical phase types.

[0019] Compared with the prior art, the advantages and positive effects of this application are as follows: The hydrocarbon phase type identification method and system provided by this application establish an integrated geological-logging-mud logging hydrocarbon phase prediction model by integrating geological background, gas logging, and logging responses, and overlay the discrimination standard of hydrocarbon phase types determined according to the gas logging response values of hydrocarbon components in oil and gas samples on the integrated geological-logging-mud logging phase prediction chart to form a phase prediction chart including critical phase types, and identify the hydrocarbon phase types of the target layer in the study area according to the phase prediction chart including critical phase types. It can accurately identify the hydrocarbon phase types of deep reservoirs, realize the subdivision of critical state types, and then clarify the spatial distribution characteristics and genetic mechanisms of different phase types, formulate corresponding oil and gas exploration and development strategies, and have important guiding significance for the exploration and development of deep oil and gas reservoirs. Brief Description of the Drawings

[0020] Figure 1 It is a schematic flow chart of the hydrocarbon phase type identification method described in the embodiment of this application; Figure 2 It is a schematic flow chart of the method for calculating the principal components of the target formation according to the phase prediction indicators in the embodiment of this application; Figure 3 It is a schematic flow chart of the method for determining the discrimination standard of hydrocarbon phase types according to the gas logging response values of hydrocarbon components in oil and gas samples in the embodiment of this application; Figure 4 It is a structural block diagram of the hydrocarbon phase type identification system described in the embodiment of this application; Figure 5 It is a schematic diagram of the phase prediction chart including critical phase types in the embodiment of this application; Figure 6Schematic diagram of the results of the oil and gas phase type identification of the C section of Well A by using the phase prediction chart including the critical phase type in the embodiment of the present application; Figure 7 Schematic diagram of the results of the oil and gas phase type identification of the D section of Well A by using the phase prediction chart including the critical phase type in the embodiment of the present application; Figure 8 Schematic diagram of the results of the oil and gas phase type identification of Well B by using the phase prediction chart including the critical phase type in the embodiment of the present application.

[0021] In the figure, 1. Acquisition module, 2. Selection module, 3. Calculation module, 4. Chart construction module, 5. Division standard discrimination module, 6. Superposition module, 7. Phase type identification module. Detailed implementation mode

[0022] Next, the present application will be specifically described through exemplary embodiments with reference to the accompanying drawings. However, it should be understood that, without further description, the elements, structures, and features in one embodiment can also be beneficially combined into other embodiments.

[0023] The present application provides a method and system for identifying the oil and gas phase type. By integrating logging data, mud logging data, and combining principal component analysis and gas logging response values, a ground-logging-mud logging integrated phase prediction chart is constructed, and the discrimination criteria for the oil and gas phase type are superimposed on the ground-logging-mud logging integrated phase prediction chart to obtain a phase prediction chart including the critical phase type. Through the phase prediction chart including the critical phase type, the oil and gas phase type of deep reservoirs can be comprehensively, systematically, and accurately identified. Compared with the method with a single data source, its accuracy is higher, and it can provide a more reliable basis for oil and gas exploration and development. The above method and system for identifying the oil and gas phase type will be described in detail below with reference to the accompanying drawings.

[0024] See Figure 1 , the first aspect embodiment of the present application provides a method for identifying the oil and gas phase type, and its steps are as follows: S1. Obtain the logging data and mud logging data of the target layer in the study area.

[0025] S2. Select the phase prediction indicators of the target layer in the study area based on the logging data, and select multiple sample points with known phase types of the target layer in the study area based on the mud logging data.

[0026] Specifically, in some embodiments of the application, the phase prediction indicators include acoustic travel time DT, gamma value GR, resistivity value R, gas logging value Tg, gas logging value C1, hydrocarbon humidity ratio Wh, and the difference between hydrocarbon humidity ratio Wh and hydrocarbon balance ratio Bh.

[0027] It should be noted that each logging parameter is controlled by different influencing factors, which leads to certain errors in the application of the phase prediction model established based on logging or well logging data. In the embodiments of the present application, considering the geological background comprehensively, seven phase prediction indicators are selected, namely acoustic travel time DT, gamma value GR, resistivity value R, gas logging value Tg, gas logging value C1, hydrocarbon humidity ratio Wh, and the difference between hydrocarbon humidity ratio Wh and hydrocarbon balance ratio Bh. These indicators cover the rock physical properties (acoustic travel time, gamma value, resistivity) and fluid properties (gas logging value, hydrocarbon humidity ratio, etc.). The comprehensive application of these indicators can more comprehensively reflect the geological characteristics and fluid properties of the oil and gas reservoir, thereby improving the accuracy of phase identification. Specifically, in some embodiments of the application, the acoustic travel time DT, gamma value GR, resistivity value R, gas logging value Tg, and gas logging value C1 are directly read from the well logging curves of the target layer in the study area. The hydrocarbon humidity ratio Wh and hydrocarbon balance ratio Bh are calculated according to the gas logging response values of the hydrocarbon components in the oil and gas samples.

[0028]

[0029]

[0030] In the formula, C1, C2, C3, C4, C5, iC4, nC4, iC5, and nC5 are the gas logging response values of the corresponding hydrocarbon components, and the numerical values can be derived from the well logging curves.

[0031] In the embodiments of the present application, by directly reading some indicators from the well logging curves and calculating the hydrocarbon humidity ratio and hydrocarbon balance ratio based on the gas logging response values, the efficient acquisition and processing of data are realized. This data processing method not only improves the work efficiency but also ensures the accuracy and consistency of the data, providing high-quality data support for subsequent phase identification.

[0032] S3. Calculate the principal components of the target formation according to the phase prediction indicators, and establish a geological-logging-integrated phase prediction chart based on multiple sample points and principal component projection points.

[0033] In some embodiments of the application, refer to Figure 2 , the method for calculating the principal components of the target formation according to the phase prediction indicators is as follows: S31. Standardize the phase prediction indicators to obtain the standardized phase prediction indicators. Standardizing the phase prediction indicators can reduce errors and eliminate the influencing factors of different logging parameters.

[0034] S32. Calculate principal component I and principal component II respectively; Principal component I = 0.27 * A1 - 0.10 * A2 - 0.22 * A3 + 0.56 * A4 + 0.56 * A5 - 0.34 * A6 - 0.34 * A7 Principal Component II = -0.61*A1 + 0.25*A2 + 0.65*A3 + 0.18*A4 + 0.21*A5 - 0.19*A6 - 0.13*A7 Wherein, A1 is the sonic transit time DT after standardization, A2 is the gamma value GR after standardization, A3 is the resistivity value R after standardization, A4 is the gas logging value Tg after standardization, A5 is the gas logging value C1 after standardization, A6 is the hydrocarbon humidity ratio Wh after standardization, and A7 is the difference between the hydrocarbon humidity ratio Wh and the hydrocarbon equilibrium ratio Bh after standardization.

[0035] In the embodiments of the present application, the principal component analysis method is adopted to calculate Principal Component I and Principal Component II through specific weight coefficients, which can effectively extract key information, reduce the data dimension, and at the same time retain the most important geological and fluid characteristics. This helps to simplify the constructed phase state prediction model and improve the stability and prediction accuracy of the model.

[0036] S4. According to the classification standard for discriminating the oil and gas phase state types based on the gas logging response values of the hydrocarbon components in the oil and gas samples, superimpose the classification standard on the integrated geophysical-logging-phase state prediction chart to form a phase state prediction chart including the critical phase state types.

[0037] In some embodiments of the application, refer to Figure 3 , the method for discriminating the classification standard for the oil and gas phase state types based on the gas logging response values of the hydrocarbon components in the oil and gas samples is as follows: S41. Calculate φ 1 parameter according to the gas logging response values of the hydrocarbon components in the oil and gas samples;

[0038] Wherein, C1, C2, C3, C4, C5 + are respectively the gas logging response values of the corresponding hydrocarbon components; S42. Obtain the classification standard for the oil and gas phase state types according to the calculated φ 1 parameter.

[0039] In the embodiments of the present application, by calculating φ 1 parameter and classifying the oil and gas phase state types accordingly, a quantitative and standardized phase state discrimination method is provided. This method can avoid the subjectivity of human experience, make the phase state discrimination more objective and accurate, and is convenient for popularization and application in different regions and oil and gas reservoirs.

[0040] In some embodiments of the application, the method for obtaining the classification standard for the oil and gas phase state types according to the calculated φ 1 parameter is as follows: when φ 1 ≤ 2.5, the oil and gas phase state type is black oil, wherein, when φ 1 ≤ 1, the oil and gas phase state type is a high-viscosity heavy oil reservoir, when 1 < φWhen 1 ≤ 2.5, the oil and gas phase type is a common black oil reservoir; when 2.5 < φ <1 ≤ 15, the oil and gas phase type is volatile oil. Among them, when 2.5 < φ <1 ≤ 7, the oil and gas phase type is a volatile oil reservoir; when 7 < φ <1 ≤ 15, the oil and gas phase type is a condensate gas cap oil reservoir; when φ > 15, the oil and gas phase type is condensate gas. Among them, when 15 < φ <1 ≤ 80, the oil and gas phase type is a condensate gas reservoir with an oil ring; when φ > 80, the oil and gas phase type is a condensate gas reservoir without an oil ring.

[0041] In the embodiments of the present application, the oil and gas phase types corresponding to different φ parameter value ranges are detailedly divided, including black oil, volatile oil, condensate gas, etc., and the specific situations of each type are further subdivided. This refined division standard can more accurately reflect the phase characteristics of the oil and gas reservoir, providing a more detailed basis for the classification evaluation and development strategy formulation of the oil and gas reservoir.

[0042] S5. Identify the oil and gas phase type of the target layer in the study area according to the phase prediction chart plate including the critical phase type.

[0043] For the above oil and gas phase type identification method of the present application, see Figure 4 . In the embodiments of the second aspect of the present application, an oil and gas phase type identification system is provided for implementing the oil and gas phase type identification method described in the first aspect of the present application, including: An acquisition module 1 for acquiring the logging data and mud logging data of the target layer in the study area; A selection module 2 for selecting the phase prediction index of the target layer in the study area based on the logging data and multiple sample points with known phase types based on the mud logging data; A calculation module 3 for calculating the principal component of the target formation according to the phase prediction index; A chart plate construction module 4 for establishing a geology-logging-mud logging integrated phase prediction chart plate by plotting points according to the acquired multiple sample points and the calculated principal component; A division standard discrimination module 5 for discriminating the division standard of the oil and gas phase type according to the gas logging response value of the hydrocarbon components of the oil and gas sample; An overlay module 6 for overlaying the division standard on the geology-logging-mud logging integrated phase prediction chart plate to form a phase prediction chart plate including the critical phase type; The phase state type identification module 7 identifies the oil and gas phase state type of the target layer in the study area according to the phase state prediction chart containing the critical phase state type. The above oil and gas phase state type identification system of the present application realizes the full-process automation and systematization from data acquisition to phase state identification through modular design. Each module has a clear division of labor and works collaboratively, which not only improves work efficiency but also reduces errors in manual operations. This systematic solution can better meet the needs of large-scale oil and gas exploration and development and provide strong support for the digital management of oil and gas fields.

[0044] To verify the effectiveness of the above-mentioned oil and gas phase state type identification method and system of the present application, the following specific embodiments are described for illustration.

[0045] Embodiment: Taking Wells A and B in a certain study area as examples.

[0046] Sort out the gas logging and logging response parameters, and select seven phase state prediction indicators: acoustic travel time DT, gamma value GR, resistivity value R, gas logging value Tg, gas logging value C1, hydrocarbon humidity ratio Wh, and the difference between hydrocarbon humidity ratio Wh and hydrocarbon balance ratio Bh. Standardize the seven phase state prediction indicators to obtain the standardized phase state prediction indicators. At the same time, 475 sample points with known phase state types in Wells A and B are selected.

[0047] Use the principal component analysis method to calculate the principal component I and principal component II of Wells A and B respectively through the above principal component I calculation formula and principal component II calculation formula.

[0048] Based on the 475 sample points, the principal component I and principal component II of Well A, and the principal component I and principal component II of Well B, plot points to establish an integrated geological-logging-gas logging phase state prediction chart.

[0049] According to the classification standard for discriminating the oil and gas phase state type based on the gas logging response value of the hydrocarbon components of the oil and gas sample, superimpose the classification standard on the integrated geological-logging-gas logging phase state prediction chart to form a phase state prediction chart containing the critical phase state type (see Figure 5 ).

[0050] Figure 6 , 7 The figure shown in

[0051] Figure 8 is the result chart of the oil and gas phase state type identification of Well A using the phase state prediction chart containing the critical phase state type. After plotting points, it is identified that the C layer section of Well A is a high-viscosity heavy oil reservoir, and the D layer section is a condensate gas reservoir without an oil rim.

[0052] The above embodiments are used to explain the present application rather than limit the present application. Any modifications and changes made to the present application within the spirit and scope of the claims of the present application fall within the protection scope of the present application.

Claims

1. A method for identifying oil and gas phase types, characterized in that: The steps are: Obtain well logging data and mud logging data of the target layer in the study area; Select the phase prediction index of the target layer in the study area based on the well logging data, and select multiple sample points of known phase types of the target layer in the study area based on the logging data; Calculate the principal components of the target stratum according to the phase prediction index, and establish a ground-measurement-recording integrated phase prediction chart based on multiple sample points and principal component projection points; The classification standard of oil and gas phase types is determined according to the gas test response value of hydrocarbon components in oil and gas samples, and the classification standard is superimposed on the ground-test-record integrated phase prediction chart to form a phase prediction chart containing critical phase types; The oil and gas phase types of the target layer in the study area are identified based on the phase prediction map containing critical phase types.

2. The method for identifying the oil and gas phase type according to claim 1, characterized in that: The phase prediction indexes include acoustic time difference DT, gamma value GR, resistivity value R, gas measurement value Tg, gas measurement value C1, hydrocarbon moisture ratio Wh, and the difference between hydrocarbon moisture ratio Wh and hydrocarbon equilibrium ratio Bh.

3. The method for identifying the oil and gas phase type according to claim 2, characterized in that: The acoustic time difference DT, gamma value GR, resistivity value R, gas measurement value Tg, and gas measurement value C1 are directly read from the well logging curve of the target layer in the study area; the hydrocarbon moisture ratio Wh and hydrocarbon balance ratio Bh are calculated based on the gas measurement response value of the hydrocarbon components of the oil and gas samples; Wherein, C1, C2, C3, C4, C5, iC4, nC4, iC5, and nC5 are the gas measurement response values ​​of the corresponding hydrocarbon components.

4. The method for identifying the oil and gas phase type according to claim 3, characterized in that: The method for calculating the principal components of the target layer according to the phase prediction index is: The phase state prediction index is standardized to obtain a standardized phase state prediction index; Calculate principal component I and principal component II respectively; Principal component I = 0.27*A1-0.10*A2-0.22*A3+0.56*A4+0.56*A5-0.34*A6-0.34*A7 Principal component II = -0.61*A1+0.25*A2+0.65*A3+0.18*A4+0.21*A5-0.19*A6-0.13*A7 Wherein, A1 is the standardized acoustic time difference DT, A2 is the standardized gamma value GR, A3 is the standardized resistivity value R, A4 is the standardized gas measurement value Tg, A5 is the standardized gas measurement value C1, A6 is the standardized hydrocarbon moisture ratio Wh, and A7 is the difference between the standardized hydrocarbon moisture ratio Wh and the hydrocarbon balance ratio Bh.

5. The method for identifying oil and gas phase types according to claim 1, characterized in that: The method for distinguishing the classification standard of oil and gas phase types based on the gas test response value of hydrocarbon components in oil and gas samples is: Calculated based on the gas test response value of hydrocarbon components in oil and gas samples φ 1 parameter; In the formula, C1, C2, C3, C4, C5 + are the gas measurement response values ​​corresponding to the hydrocarbon components; According to the calculated φ 1 parameter to obtain the classification standard of oil and gas phase types.

6. The method for identifying the oil and gas phase type according to claim 5, characterized in that: According to the calculated φ 1 parameter to obtain the classification standard of oil and gas phase types: φ When 1≤2.5, the oil and gas phase type is black oil. φ When 1≤1, the oil and gas phase type is a high-viscosity heavy oil reservoir. When 1< φ When 1≤2.5, the oil and gas phase type is ordinary black oil reservoir; when 2.5< φ When 1≤15, the oil and gas phase type is volatile oil. φ When 1≤7, the oil and gas phase type is volatile oil reservoir, when 7< φ When 1≤15, the oil and gas phase type is condensate gas cap reservoir; when φ When 1>15, the oil and gas phase type is condensate gas. φ When 1≤80, the oil and gas phase type is a condensate gas reservoir with oil ring; φ When 1>80, the oil and gas phase type is a condensate gas reservoir without oil ring.

7. An oil and gas phase type identification system, used to implement the oil and gas phase type identification method according to any one of claims 1 to 6, characterized in that: include: Acquisition module, used to acquire well logging data and mud logging data of the target layer in the study area; Selection module, which selects the phase state prediction index of the target layer in the study area based on the logging data, and multiple sample points with known phase state types based on the logging data; A calculation module calculates the principal components of the target layer according to the phase prediction index; The chart construction module builds a ground-measurement-recording integrated phase state prediction chart based on multiple sample points obtained and the calculated principal component projection points; The classification standard identification module determines the classification standard of oil and gas phase types according to the gas test response value of hydrocarbon components of oil and gas samples; The superposition module superimposes the classification standard onto the ground-measurement-recording integrated phase state prediction chart to form a phase state prediction chart containing critical phase state types; The phase type identification module identifies the oil and gas phase type of the target layer in the study area based on the phase prediction map containing the critical phase type.

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