Quantitative evaluation method and device for filling capacity of oil gas to river channel sand body along fault

Abstract

The invention discloses a quantitative evaluation method and device for the filling capacity of oil gas to a river channel sand body along a fault, and the method comprises the steps: firstly, carrying out the recognition of an oil gas reservoir forming period according to the analysis of a fluid inclusion, and determining the oil gas reservoir forming period and time; according to the seismic data interpretation result, the configuration relation between the fault and the hydrocarbon source rock is analyzed, and a gas source fault is determined; then combining the configuration relation and evolution of the fault and the sand body, the porosity evolution recovery result and the historical data of the porosity-permeability relation to obtain the filling capacity evaluation parameters of the key reservoir forming period; and then combining the filling capacity evaluation parameters with the gas content relationship of the sand bodies, determining weight coefficients of influences of different parameters on natural gas filling, and further calculating the filling capacity coefficient of each river channel sand body, so as to obtain the selective filling strength of oil gas to each river channel sand body along the fault. According to the method, quantitative evaluation of the filling capacity of oil gas to the river channel sand body along the fault is achieved, and the river channel sand body with favorable gas content can be further predicted based on the evaluation result.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas exploration, and in particular to a quantitative evaluation method and device for the filling capacity of oil and gas into a river channel sand body along a fault. Background Art

[0002] In the vertical migration of oil and gas, faults are of great significance as transport elements. Their configuration relationship with reservoirs greatly affects the distribution and accumulation of oil and gas in various connected reservoirs. In many continental oil and gas basins, various river sand bodies are often developed on both sides of the faults. Effectively identifying the amount of oil and gas migration and accumulation in different river sand bodies is of great significance for guiding oil and gas exploration deployment and reducing exploration risks.

[0003] In the past, there were few evaluations on the degree of oil and gas filling into the sand bodies connected to them along faults, and they were mainly based on qualitative or semi-quantitative analysis. The main methods are as follows: (1) Tian Lixin et al. (2018) considered the cross-sectional morphology of the oil-source fault and its contact relationship with the mature source rock section, and used numerical simulation methods to evaluate the oil and gas filling capacity along the fault into the sand body; (2) Hu Wenge et al. (2022) considered the internal structure of the fault zone, the local strain intensity, and the magnitude and direction of the current ground stress, and evaluated the oil and gas filling efficiency of the strike-slip fault zone; (3) Wang Zhe (2022) analyzed the characteristics of faults, reservoirs, and caprocks and their interrelationships to study the main controlling factors of differential oil and gas filling between sand groups. None of the above methods can achieve quantitative evaluation of the selective filling of oil and gas into the river channel sand bodies along faults.

[0004] For example, the invention patent with publication number CN116840904A discloses a "quantitative identification method for oil and gas migration mode in fault-sand transport system". The research content of this scheme is mainly the evaluation of oil and gas migration mode. It uses current parameters to judge whether oil and gas continue to migrate along the fault or migrate to the fault, and does not involve quantitative evaluation of filling capacity. Summary of the invention

[0005] In order to solve the problems and shortcomings existing in the above-mentioned prior art, the present invention proposes a quantitative evaluation method and device for the oil and gas injection capacity into river channel sand bodies along faults, which solves the previous problem of difficulty in quantitatively evaluating the difficulty of natural gas injection into different river channel sand bodies along faults, so that the evaluation results of selective injection of oil and gas into river channel sand bodies along faults are more in line with actual geological conditions, the results are more accurate, and can further predict favorable gas-containing river channel sand bodies, effectively reducing drilling risks.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0007] A quantitative evaluation method for the filling capacity of oil and gas along faults into river channel sand bodies. The method mainly includes identification of oil and gas accumulation period, identification of gas source faults, analysis of the angle between faults and river channel sand bodies and their evolution, calculation of the docking area between faults and river channel sand bodies, calculation of the physical properties of river channel sand bodies and their evolution, and evaluation of the filling capacity of river channel sand bodies. The specific steps are as follows:

[0008] Step S101. Identify the oil and gas accumulation period by analyzing the fluid inclusions, and determine the oil and gas accumulation period and time;

[0009] Step S102. Analyze the configuration relationship between faults and source rocks based on the seismic data interpretation results, so as to determine the gas source faults;

[0010] Step S103. Combine the configuration relationship and evolution of the fault and the sand body to obtain the angle θ between the fault and the river channel sand body during the critical reservoir formation period. i2 The sine value of and the interface area S between the fault and the channel sand body i ;

[0011] Step S104. Based on the existing porosity evolution recovery results and porosity-permeability relationship (porosity evolution recovery results and porosity-permeability relationship historical data), the porosity and permeability of the river channel sand body during the key reservoir formation period are derived and calculated;

[0012] Step S105. Angle θ between the fault and the river sand body during the critical reservoir formation period i2 The sine value of the fault and the interface area S between the fault and the channel sand body i and the porosity of the channel sand body φ i1 and permeability K i1 Together they constitute the evaluation parameters for the filling capacity of oil and gas along faults into river sand bodies. Therefore, combined with the relationship between the filling capacity evaluation parameters in the key accumulation period and the gas content of the sand bodies, the weight coefficients of the influence of different parameters on natural gas filling can be determined, and then the filling capacity coefficients of each river sand body can be obtained by calculation. The filling capacity can be judged according to the filling capacity coefficient, and finally the filling capacity of natural gas along faults into each river sand body can be quantitatively evaluated.

[0013] In the present invention, the analysis of fluid inclusions to identify the oil and gas accumulation period and determine the oil and gas accumulation period and time includes:

[0014] Sand reservoir samples from each river channel were selected, inclusion thin sections were prepared, the types and distribution of reservoir inclusions were observed, the development stages of hydrocarbon inclusions were identified, and the brine inclusions associated with hydrocarbon inclusions of different stages were determined; then the homogenization temperature of the brine inclusions associated with hydrocarbon inclusions of different stages was measured, and the main distribution range of the homogenization temperature was counted, combined with the burial thermal evolution history of the reservoir at the depth of the samples, to determine the stage and time of oil and gas accumulation.

[0015] In the present invention, the analysis of the configuration relationship between faults and source rocks based on the seismic data interpretation results to determine the gas source faults includes:

[0016] By using the existing seismic data interpretation results, the vertical cutting layer system of the fault is determined to judge whether the fault cuts the underlying hydrocarbon source rock layer. If it does, the fault is judged to be a gas source fault and can be used as a channel for vertical transportation of natural gas. Otherwise, the fault is invalid and does not have the ability to transport vertically.

[0017] In the present invention, the sine value of the angle between the fault and the channel sand body during the critical reservoir formation period is obtained by combining the configuration relationship and evolution of the fault and the sand body, including:

[0018] Using the seismic interpretation section that crosses the gas source fault and along the direction of the river channel sand body, the angle θ between the current fault and each river channel sand body is determined. i1 , if the angle θ i1 If the angle θ is acute, the fault dip is consistent with the sand body dip, which is conducive to the injection of natural gas into the sand body along the fault. i1 If the angle is obtuse, the fault inclination is opposite to the sand body inclination, which is not conducive to the injection of natural gas into the sand body along the fault; therefore, the smaller the angle, the more conducive it is to the injection of natural gas into the sand body; further, based on the denudation thickness distribution results of previous studies (historical data of denudation thickness distribution results), the back-stripping method is used to restore the structural evolution history of the fault-sand configuration relationship section corresponding to the seismic interpretation section, so as to determine the angle θ between the fault and each channel sand body during the key accumulation period i2 , then according to the angle θ i2 The corresponding sine value of the angle can be directly calculated.

[0019] In the present invention, the configuration relationship and evolution of the fault and the sand body are combined to obtain the docking area of ​​the fault and the river channel sand body during the key reservoir formation period, including:

[0020] According to the distribution of faults and channel sand bodies interpreted from seismic data, the cross-sectional morphology of each channel sand body docking with the fault is analyzed, and the docking area S in the key reservoir formation period is calculated using different geometric formulas according to different geometric cross-sectional morphologies. i .

[0021] In the present invention, the porosity and permeability of the river channel sand body during the key reservoir formation period are obtained based on the porosity evolution recovery results and the historical data of the porosity-permeability relationship, including:

[0022] For the channel sand bodies connected to the fault, the porosity of each channel sand body near the fault is calculated by using the measured physical property data or logging interpretation data. i1 and permeability K i1Then, combined with the previous restoration results of the porosity evolution of the river channel sand body (historical data of the restoration results of the porosity evolution of the river channel sand body), the porosity φ of the river channel sand body in the key reservoir formation period was obtained. i2 , combined with the exponential correlation between current porosity and permeability, the porosity-permeability calculation formula (1) is fitted. According to the fitted formula (1), combined with the porosity φ in the key reservoir formation period i2 , and thus calculate the permeability K corresponding to the porosity during the critical reservoir formation period i2 ;

[0023] K=a·eR φ +b formula (1);

[0024] Where K represents permeability, φ represents porosity, and a and b are constants.

[0025] Therefore, when calculating the permeability during the key accumulation period, the porosity φ of the river channel sand body during the key accumulation period is analyzed. i2 Substituting into the above formula (1), we can obtain the permeability K in the critical reservoir formation period: i2 .

[0026] The parameters such as angle and porosity mentioned in the present invention are based on the condition that the river sand body and the fault are connected. If the fault and the river sand body are not connected, then the oil and gas will not be injected into the river sand body along the fault. In general, the angle θ between the fault and each river sand body during the critical accumulation period is i2 And the interface area S between the fault and each channel sand body i It is obtained through the evolution of break sand configuration, while the porosity and permeability of the channel sand body in the key reservoir formation period are derived through the previous porosity evolution recovery results and the porosity-permeability relationship.

[0027] In the present invention, the above-mentioned key reservoir evaluation parameters and the relationship between the gas content of the sand body are combined to determine the weight coefficients of the influence of different parameters on the natural gas charging, calculate the charging capacity coefficient of each channel sand body, and finally obtain the selective charging intensity of natural gas along the fault to each channel sand body, including:

[0028] Based on the above analysis, the sine value of the angle between the fault and the river sand body during the critical reservoir formation period is i2 , the interface area S between the fault and the river channel sand body i 、Sand body porosity φ i2 and sand body permeability K i2 , normalized according to the linear normalization formula, thereby eliminating the dimension and making the values ​​of each parameter distributed in the range of 0 to 1, which is convenient for comparison between different parameters. The normalization formula is as follows:

[0029]

[0030] Where x′ represents the normalized value, x represents the initial value, min(x) represents the minimum value, and max(x) represents the maximum value;

[0031] Then, the relationship between each evaluation parameter and the gas content of the river channel (single well production capacity, gas saturation) during the normalized key reservoir formation period is compared to determine the influence of the sine value of the angle between the fault and the sand body, the docking area between the fault and the river channel sand body, the porosity of the sand body, and the permeability of the sand body on the natural gas injection, and the weight coefficient corresponding to each parameter is determined according to the correlation.

[0032] The normalized sine value of the angle between the fault and the sand body, the docking area between the fault and the river channel sand body, the porosity of the sand body and the permeability of the sand body are comprehensively considered and multiplied by the corresponding weight coefficients to calculate the filling capacity coefficient T of each river channel sand body. i , the calculation formula is as follows:

[0033] T i =-X j1 sinθ i2 ′+X i2 ·S i ′+X i3 ·φ i2 +X i4 ·K i2 ′ Formula (3);

[0034] Among them, T i represents the filling capacity coefficient of the fault into the river channel, X i1 , X i2 , X i3 and X i4 They represent the weight coefficients of fault-sand body angle, fault-joined channel sand body area, channel sand body porosity and channel sand body permeability during the critical reservoir formation period, sinθ i2 ′ is the normalized sine value of the angle between the fault and the channel sand body during the critical reservoir formation period, S i ′ is the normalized interface area between the fault and the channel sand body, φ i2 is the normalized sand body porosity during the critical reservoir formation period, K i2 ′ is the normalized sand body permeability during the critical accumulation period, and i represents the i-th channel sand body.

[0035] Through the above calculations, the charging capacity of each channel sand body can be obtained, thereby obtaining the selective charging intensity of natural gas along the fault into each channel sand body, and finally quantitatively evaluating the charging capacity of natural gas along the fault into each channel sand body.

[0036] Based on the same inventive concept, the present invention also proposes a quantitative evaluation device for the filling capacity of oil and gas along faults into river sand bodies, the device is used to implement the above filling capacity quantitative evaluation method, and the term "unit" or "module" used below can implement a combination of software and / or hardware with predetermined functions. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable. Specifically, the device may include:

[0037] The oil and gas accumulation period identification module identifies the oil and gas accumulation period through fluid inclusion analysis and determines the oil and gas accumulation period and time;

[0038] The gas source fault identification module obtains the results of seismic data interpretation, analyzes the configuration relationship between faults and source rocks, and then identifies and determines the gas source faults;

[0039] The charging capacity evaluation parameter calculation module combines the configuration relationship and evolution of faults and sand bodies, as well as the porosity evolution recovery results and historical data on the porosity-permeability relationship, to obtain the charging capacity evaluation parameters during the key reservoir formation period, including the sine value of the angle between the fault and the channel sand body, the area of ​​the fault and the channel sand body, and the porosity and permeability of the channel sand body;

[0040] The module for evaluating the selective charging intensity of natural gas along faults into channel sand bodies combines the relationship between the parameters of the key accumulation period and the gas content of the sand bodies to determine the weight coefficients of the influence of different parameters on natural gas charging, calculates the charging capacity coefficients of each channel sand body, and finally obtains the selective charging intensity of natural gas along faults into each channel sand body.

[0041] The above-described systems, devices, models or units can be implemented by computer chips or entities, or by products with certain functions. For the convenience of description, in this specification, the above devices are described in various units according to their functions. Of course, when implementing the present invention, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0042] Furthermore, in the present specification, adjectives such as first and second may be used merely to distinguish one element or action from another, without necessarily or implying any actual such relationship or order.

[0043] A computer device comprises a memory, a processor and a computer program stored in the memory and executable in the processor. When the processor executes the computer program, the steps of the quantitative evaluation method for the injection capacity of oil and gas into river channel sand bodies along faults are implemented.

[0044] A computer-readable storage medium stores a computer program, which, when executed in a computer processor, implements the steps of the above-mentioned method for quantitatively evaluating the filling capacity of oil and gas into a river channel sand body along a fault.

[0045] Beneficial effects of the present invention:

[0046] 1. The present invention realizes quantitative evaluation of the difficulty of natural gas injection into different river sand bodies along faults, so that the evaluation results of selective injection of oil and gas into river sand bodies along faults are more in line with actual geological conditions and more accurate. Moreover, based on the evaluation results, favorable gas-bearing river sand bodies can be further predicted, effectively reducing drilling risks.

[0047] 2. The present invention takes into account the natural gas accumulation period, the angle between the gas source fault and the river channel sand body and its evolution, the docking area between the gas source fault and the sand body, the porosity and permeability of the sand body and their evolution, and normalizes different parameters respectively. Considering the weight coefficients of different parameters, the filling capacity coefficient of each river channel sand body is calculated, and the selective filling capacity evaluation of oil and gas along the fault into the river channel sand body is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The foregoing and following detailed description of the present invention will become more apparent when read in conjunction with the following drawings, in which:

[0049] Figure 1 is a flow chart of the method of the present invention;

[0050] Figure 2 It is a structural diagram of the device of the present invention;

[0051] Figure 3-Figure 4 This is a cross-sectional view of the Jiao 1-1 gas source fault and its configuration relationship with the river channel sand body in an embodiment of the present invention;

[0052] Figure 5 This is a schematic diagram of the relationship between the natural gas filling coefficient of the channel sand bodies of the No. 6, 7, and 8 sand groups from the Angle 1-1 fault in an embodiment of the present invention and the daily production of a typical well.

[0053] In the figure:

[0054] 201. Oil and gas accumulation period identification module; 202. Gas source fault identification module; 203. Charging capacity evaluation parameter calculation module; 204. Charging capacity evaluation module. DETAILED DESCRIPTION

[0055] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions for achieving the purpose of the present invention will be further described below through several specific embodiments. It should be noted that the technical solutions claimed for protection in the present invention include but are not limited to the following embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work shall fall within the scope of protection of the present invention.

[0056] In the vertical migration of oil and gas, faults are of great significance as transport elements. Their configuration relationship with reservoirs greatly affects the distribution and accumulation of oil and gas in various connected reservoirs. In many continental oil and gas basins, various river sand bodies are often developed on both sides of the faults. Effectively identifying the amount of oil and gas migration and accumulation in different river sand bodies is of great significance for guiding oil and gas exploration deployment and reducing exploration risks.

[0057] In the past, the evaluation of oil and gas filling into sand bodies along faults mostly focused on basic factors such as fault conductivity or fault reservoir cap, and qualitatively or semi-quantitatively analyzed the filling capacity of oil and gas into reservoirs. The dynamic evolution of fault-sand configuration and the quantitative characterization of the degree of fault-sand configuration during the key accumulation period were obviously insufficient, making it difficult to achieve quantitative evaluation of the selective filling of oil and gas into river sand bodies along faults, affecting the understanding of the laws of selective filling of oil and gas into river sand bodies along faults, reducing the accurate evaluation of oil and gas reserves in river sand bodies, and affecting the success rate of drilling.

[0058] Based on this, an embodiment of the present invention proposes a quantitative evaluation method and device for the filling capacity of oil and gas along a fault into a river channel sand body. The present invention identifies the oil and gas accumulation period based on fluid inclusion analysis to determine the oil and gas accumulation period and time; analyzes the configuration relationship between the fault and the source rock based on the seismic data interpretation results to determine the gas source fault; then, combining the configuration relationship between the fault and the sand body and its evolution as well as the porosity evolution recovery results and the historical data of the porosity-permeability relationship, obtains the filling capacity evaluation parameters including the angle between the fault and the river channel sand body, the docking area between the fault and the river channel sand body, and the porosity and permeability of the river channel sand body during the key accumulation period; finally, combining the above-mentioned filling capacity evaluation parameters with the gas content of the sand body, determines the weight coefficient of different factors affecting natural gas filling, and then calculates the filling capacity coefficient of each river channel sand body, thereby obtaining the selective filling intensity of natural gas along the fault into each river channel, and finally realizes the quantitative evaluation of the filling capacity of natural gas along the fault into the river channel sand body.

[0059] This embodiment discloses a quantitative evaluation method for the filling capacity of oil and gas into river channel sand bodies along faults. Taking the research method of selective filling of natural gas into river channel sand bodies along faults in the Middle Jurassic Shaximiao Formation of Jinqiu Gas Field in Central Sichuan as an example, the method mainly comprises the following steps:

[0060] (1) Identification of oil and gas accumulation period

[0061] Using typical gas-producing reservoir samples from the Jinqiu gas field, inclusion thin sections were prepared, and the types and distribution of reservoir inclusions were observed under a microscope. It was believed that gaseous hydrocarbon inclusions were mainly developed in fracture cements and quartz enlarged edges. Then, the homogenization temperature of brine inclusions associated with gas hydrocarbon inclusions of different periods was determined using hot and cold stage equipment. Combined with the corresponding burial thermal evolution history, the natural gas accumulation period was determined to be the late Early Cretaceous and the late Miocene.

[0062] (2) Identification of gas source faults

[0063] Using seismic data from the central Sichuan region and combining the configuration relationship between faults and the Xujiahe Formation source rock strata, a major gas source fault was identified, namely the Jiao 1-1 fault ( Figure 3-Figure 4 , Figure 3 Schematic diagram of earthquake section. Figure 4 (Fig. 1 is a schematic diagram of the cross-section of the fault sand configuration). The fault connects with the channel sand bodies of the 6th, 7th and 8th sand groups in the Sha 2 1 sub-section.

[0064] (3) Analysis of the angle between fault and channel sand body and its evolution

[0065] The channel sand body section across the Angle 1-1 fault was selected, and the fault-sand body configuration relationship at the end of the Early Cretaceous and the end of the Miocene was restored. The angles (θ i3 ,θ i4 ), as shown in Table 1. At the end of the Early Cretaceous, the angles between the Jiao 1-1 fault and the sand bodies of the No. 6 and No. 8 rivers to its north were 77.8° and 107.06°, respectively, and the angles between the Jiao 1-1 fault and the sand bodies of the No. 6, No. 7, and No. 8 rivers to its south were 98.84°, 78.37°, and 71.59°, respectively; at the end of the Miocene, the angles between the Jiao 1-1 fault and the sand bodies of the No. 6 and No. 8 rivers to its north were 79.31° and 108.57°, respectively, and the angles between the Jiao 1-1 fault and the sand bodies of the No. 6, No. 7, and No. 8 rivers to its south were 97.31°, 76.86°, and 70.58°, respectively.

[0066] (4) Calculation of the interface area between fault and river channel sand body

[0067] According to the cross-sectional and planar docking relationship between the fault and each channel sand body, the length and width of the docking surface between the fault and each channel sand body are measured, and then the area S of the docking surface is calculated. i Among them, the docking area between the Jiao 1-1 fault and the sand bodies of the No. 6 and No. 8 channels in the north is 23622m 2 、25715m 2 The connecting areas of the Jiao 1-1 fault and the No. 6, No. 7, and No. 8 river channel sand bodies in its south are 25309m 2 、6321m 2、25852m 2 The specific results are shown in Table 1.

[0068] (4) Calculation of physical properties and evolution of sand bodies in each channel

[0069] For the channel sand bodies connected to the fault, the current porosity ф of each channel sand body near the fault is obtained by using the measured physical property data or logging interpretation data. i1 and permeability K i1 Among them, the porosity of the river channel sand bodies of the No. 6 and No. 8 sand groups in the north of the Jiao 1-1 fault are 8.47% and 7.73%, and the permeability are 10.7mD and 0.58mD respectively; the porosity of the river channel sand bodies of the No. 6, No. 7 and No. 8 sand groups in the south of the Jiao 1-1 fault are 13.17%, 7.89% and 11.9%, and the permeability are 6.42mD, 0.11mD and 0.2mD respectively.

[0070] The porosity and permeability data of multiple channel sand bodies on both sides of the fault were statistically analyzed, and the correlation scatter plots of the porosity and permeability of each channel sand body were drawn to fit the exponential relationship formula between porosity and permeability (Formula 1, Formula 2 and Formula 3).

[0071] No. 6 sand group channel sand body:

[0072] No. 7 sand group channel sand body:

[0073] No. 8 sand group channel sand body:

[0074] Among them, K1, K2, K3 represent permeability (mD), ф1, ф2, ф3 represent porosity (%).

[0075] Then, based on the porosity evolution history proposed by predecessors and combined with the current porosity, the porosity of each channel sand body during the main reservoir formation period was calculated, and then the permeability of each channel sand body during the main reservoir formation period was calculated using the fitted porosity and permeability formula. The results show that at the end of the Early Cretaceous, the porosity of the 6th and 8th sand bodies in the northern part of the Angle 1-1 fault was 6.99% and 5.65%, and the permeability was 0.63mD and 0.07mD, respectively; the porosity of the 6th, 7th, and 8th sand bodies in the southern part of the Angle 1-1 fault was 10.41%, 5.76%, and 8.74%, respectively, and the permeability was 2.33mD, 0.06mD, and 0.14mD, respectively. D; At the end of the Miocene, the porosity of the river channel sand bodies of the No. 6 and 8 sand groups in the north of the Jiao 1-1 fault were 10.53% and 9.21%, and the permeability were 7.64mD and 0.24mD, respectively; the porosity of the river channel sand bodies of the No. 6, 7 and 8 sand groups in the south of the Jiao 1-1 fault were 15.67%, 8.68% and 14.17%, and the permeability were 12.74mD, 0.14mD and 0.69mD, respectively.

[0076] Table 1 Statistical table of the fault angle, docking area and physical properties of the 6th, 7th and 8th sand groups of the corner 1-1 fault docking

[0077]

[0078] (6) Evaluation of river channel sand filling capacity

[0079] Based on the above analysis, the sine value of the angle between the fault and the sand body during the key reservoir formation period, the docking area between the fault and the river channel sand body, the porosity of the sand body and the permeability of the sand body are normalized according to the linear normalization formula. This not only eliminates the dimension, but also makes the values ​​of each parameter distributed in the range of 0 to 1, which is convenient for comparison between different parameters. The normalization formula is as follows:

[0080]

[0081] Where x′ represents the normalized value, x represents the initial value, min(x) represents the minimum value, and max(x) represents the maximum value;

[0082] The normalized results are shown in Table 2 below:

[0083] Table 2 Statistics of normalized data of filling capacity evaluation parameters of No. 6, 7, and 8 sand groups at the corner 1-1 fault connection

[0084]

[0085] Then, the relationship between the above evaluation parameters and the gas saturation of the river channel during the normalized key accumulation period is compared to determine the influence of each evaluation parameter on natural gas charging, and the corresponding weight coefficient value (Xi1 , X i2 , X i3 , X i4 ), as shown in Table 3 below.

[0086] Table 3 Calculation results of weight coefficients of evaluation parameters of No. 6, 7, and 8 sand groups for the corner 1-1 fault docking

[0087]

[0088] Taking into account the normalized sine value of the angle between the fault and the sand body, the docking area between the fault and the river channel sand body, the porosity of the sand body and the permeability of the sand body, and multiplying them by the corresponding weight coefficients, the filling capacity coefficient T of each river channel sand body is calculated according to Formula 5. i The calculation results are shown in Table 4.

[0089] T i =-X i1 sinθ i2 ′+X i2 ·S i ′+X i3 ·φ i2 +X i4 ·K i2 ′ Formula (5);

[0090] Among them, T i represents the filling capacity coefficient of the fault into the river channel, X i1 , X i2 , X i3 and X i4 Respectively represent the weight coefficients of fault-sand body angle, fault-joined channel sand body area, channel sand body porosity, and channel sand body permeability, sinθ i2 ′ is the normalized sine value of the angle between the fault and the channel sand body during the critical accumulation period, S i ′ is the normalized interface area between the fault and the channel sand body, φ i2 is the normalized sand body porosity during the critical reservoir formation period, K i2 ′ is the normalized sand body permeability during the critical accumulation period, and i represents the i-th channel sand body.

[0091] Table 4 Calculation results of natural gas filling coefficients of No. 6, 7, and 8 sand groups at the corner 1-1 fault junction and daily natural gas production of typical wells

[0092]

[0093] Therefore, according to the above calculation results of natural gas filling coefficient, it can be known that at the end of Early Cretaceous, the natural gas filling coefficient of each river sand body was between 0 and 1.79, and the filling capacity of different sand groups in the river channel was from large to small: No. 8 sand group in the south of the fault, No. 6 sand group in the south of the fault, No. 6 sand group in the north of the fault, No. 7 sand group in the south of the fault, and No. 8 sand group in the north of the fault; at the end of Miocene, the natural gas filling coefficient of each river sand body was between 0.03 and 1.7, and the filling capacity of different sand groups in the river channel was from large to small: No. 6 sand group in the south of the fault, No. 8 sand group in the south of the fault, No. 6 sand group in the north of the fault, No. 8 sand group in the north of the fault, and No. 7 sand group in the south of the fault. By summing the natural gas filling coefficients at the end of the Early Cretaceous and the end of the Miocene, the total filling coefficient of each sand group channel can be obtained, which is distributed in the range of 0.03-3.48. The filling capacity is from large to small: sand group 6 in the south of the fault, sand group 8 in the south of the fault, sand group 6 in the north of the fault, sand group 7 in the south of the fault, and sand group 8 in the north of the fault. Combined with the daily natural gas production of typical wells in the sand bodies of different sand groups, it can be seen that the filling capacity of each sand body in the river channel has a significant positive correlation with the daily natural gas production ( Figure 5 ).

[0094] according to Figure 5 The positive correlation between the filling capacity of each channel sand body and the daily production of natural gas can be fitted to calculate the daily production of natural gas under different filling capacity coefficients, as shown in Formula 6:

[0095] y=10.8·T i +5.77 (6);

[0096] Where y represents the predicted daily natural gas production, 10 4 m 3 , T i Represents the filling capacity coefficient of the fault into the river channel.

[0097] To verify the accuracy of the formula, the natural gas filling coefficient of the sand body of the 2nd member of the Shahejie Formation in the northern part of the Jianyang 1 fault in the central Sichuan region was calculated. The filling coefficient and the total filling coefficient at the end of the Early Cretaceous and the end of the Miocene were 0.6, 0.61, and 1.21, respectively. Using formula 6, the natural gas production was calculated to be 18.8×10 4 m 3 The actual daily production of drilling is 14.36×10 4 m 3 The results are relatively close, which reflects that the research method has good accuracy.

[0098] The above description is only a preferred embodiment of the present invention and does not constitute any form of hindrance to the present invention. Any simple modification or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A quantitative evaluation method for the filling capacity of oil and gas into river sand bodies along faults, characterized in that: The following steps are involved: Through fluid inclusion analysis, the oil and gas accumulation period is judged and the period and time of oil and gas accumulation are determined; According to the interpretation results of seismic data, analyze the configuration relationship between faults and source rocks and determine the gas source faults; Combined with the configuration relationship and evolution of faults and sand bodies, as well as the porosity evolution recovery results and historical data on the porosity-permeability relationship, the filling capacity evaluation parameters including the sine value of the angle between the fault and the channel sand body, the area of ​​the fault and the channel sand body, and the porosity and permeability of the channel sand body in the key reservoir formation period are obtained; Combining the relationship between the evaluation parameters and the gas content of the sand bodies during the above-mentioned key accumulation period, the weight coefficients of the influence of different parameters on natural gas charging are determined, and then the charging capacity coefficients of the sand bodies in each channel are calculated, and finally the selective charging intensity of natural gas along the fault into the sand bodies in each channel is obtained.

2. The quantitative evaluation method for the oil and gas filling capacity into the river sand body along the fault according to claim 1 is characterized in that: The analysis of fluid inclusions is used to identify the oil and gas accumulation period and determine the oil and gas accumulation period and time, including: Sand reservoir samples from each river channel were selected, inclusion thin sections were prepared, the types and distribution of reservoir inclusions were observed, the development stages of hydrocarbon inclusions were identified, and the brine inclusions associated with hydrocarbon inclusions of different stages were determined; then the homogenization temperature of the brine inclusions associated with hydrocarbon inclusions of different stages was measured, and the main distribution range of the homogenization temperature was counted, combined with the burial thermal evolution history of the reservoir at the depth of the samples, to determine the stage and time of oil and gas accumulation.

3. The quantitative evaluation method for the oil and gas filling capacity into the river sand body along the fault according to claim 1 is characterized in that: The above-mentioned analysis of the configuration relationship between faults and source rocks based on the interpretation results of seismic data and determination of gas source faults includes: By using the existing seismic data interpretation results, the vertical cutting layer system of the fault is determined to judge whether the fault cuts the underlying hydrocarbon source rock layer. If it does, the fault is identified as a gas source fault.

4. The quantitative evaluation method for the oil and gas filling capacity into the river sand body along the fault according to claim 1 is characterized in that: The configuration relationship and evolution of the fault and sand body are combined to obtain the sine value of the angle between the fault and the river channel sand body during the key reservoir formation period, including: Based on the historical data of erosion thickness distribution results, the back-stripping method is used to restore the tectonic evolution history of the fault-sand configuration relationship section corresponding to the seismic interpretation section, determine the angle between the fault and each river sand body during the key accumulation period, and then calculate the sine value of the angle.

5. The quantitative evaluation method for the oil and gas filling capacity into the river sand body along the fault according to claim 1 is characterized in that: The above-mentioned configuration relationship and evolution of the fault and sand body are combined to obtain the docking area of ​​the fault and the river channel sand body during the key reservoir formation period, including: According to the distribution of faults and channel sand bodies interpreted from seismic data, the cross-sectional morphology of each channel sand body docking with the fault is analyzed, and the docking area during the critical reservoir formation period is calculated based on different cross-sectional morphologies.

6. The quantitative evaluation method for the oil and gas filling capacity into the river sand body along the fault according to claim 1 is characterized in that: Based on the porosity evolution recovery results and historical data on the porosity-permeability relationship, the porosity and permeability of the channel sand body during the key reservoir formation period are obtained, including: For the channel sand bodies connected to the faults, the porosity and permeability of the current channel sand bodies near the faults are statistically analyzed using the measured physical property data or logging interpretation data. Then, the porosity of the channel sand bodies during the key reservoir formation period is analyzed and obtained by combining the historical data of the porosity evolution recovery results of the channel sand bodies. Then, combined with the exponential correlation between the current porosity and permeability, the porosity-permeability calculation formula is fitted to obtain the permeability corresponding to the porosity during the key reservoir formation period, thereby calculating the permeability corresponding to the porosity during the key reservoir formation period.

7. The quantitative evaluation method for the oil and gas filling capacity into the river sand body along the fault according to claim 1 is characterized in that: The above-mentioned relationship between the evaluation parameters and the gas content of the sand body during the key accumulation period is combined to determine the weight coefficients of the influence of different parameters on the natural gas charging, and then calculate the charging capacity coefficient of each channel sand body, and finally obtain the selective charging intensity of natural gas along the fault to each channel sand body, including: The sine value of the angle between the fault and the channel sand body, the docking area between the fault and the channel sand body, the porosity of the sand body and the permeability of the sand body during the key reservoir formation period were normalized respectively. Compare the relationship between each evaluation parameter and the gas content of the river channel during the key accumulation period after normalization, determine the influence of each evaluation parameter on natural gas charging, and determine the weight coefficient corresponding to the evaluation parameter according to the correlation; Taking the normalized evaluation parameters into consideration, they are multiplied by the corresponding weight coefficients to calculate the charging capacity coefficient of each channel sand body, thereby obtaining the charging capacity of each channel sand body and finally obtaining the selective charging intensity of natural gas along the fault to each channel.

8. A quantitative evaluation device for the filling capacity of oil and gas into a river sand body along a fault, the device being used to implement the quantitative evaluation method according to any one of claims 1 to 7, characterized in that: include: The oil and gas accumulation period identification module identifies the oil and gas accumulation period through fluid inclusion analysis and determines the oil and gas accumulation period and time; The gas source fault identification module obtains the results of seismic data interpretation, analyzes the configuration relationship between faults and source rocks, and then identifies and determines the gas source faults; The charging capacity evaluation parameter calculation module combines the configuration relationship and evolution of faults and sand bodies, as well as the porosity evolution recovery results and historical data of porosity-permeability relationship to obtain the charging capacity evaluation parameters including the angle between faults and river channel sand bodies, the docking area between faults and river channel sand bodies, and the porosity and permeability of river channel sand bodies during the key reservoir formation period; The charging capacity evaluation module combines the relationship between the charging capacity evaluation parameters in the key accumulation period and the gas content of the sand body, determines the weight coefficients of the influence of different parameters on natural gas charging, calculates the charging capacity coefficients of each channel sand body, and finally obtains the selective charging intensity of natural gas along the fault to each channel sand body.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable in the processor, characterized in that: When the processor executes the computer program, the method steps described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed in a computer processor, the method according to any one of claims 1 to 7 is implemented.

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