Quantitative evaluation method and device for oil and gas charging capacity along fault to channel sand body

Abstract

The application discloses a kind of quantitative evaluation method and device of oil and gas along fault to river channel sand body filling capacity, first, according to fluid inclusion analysis, oil and gas reservoir forming period is identified, and oil and gas reservoir forming period and time are determined;Then, according to the result of seismic data interpretation, the configuration relationship of fault and hydrocarbon source rock is analyzed, and gas source fault is determined;Then, in combination with the configuration relationship of fault and sand body, its evolution and the recovery result of porosity evolution, and the historical data of porosity-permeability relationship, the filling capacity evaluation parameter of key reservoir forming period is obtained;Then, in combination with the relationship between filling capacity evaluation parameter and sand body gas content, the weight coefficient of different parameters on the influence of natural gas filling is determined, and then the filling capacity coefficient of each river channel sand body is calculated, so that the selective filling strength of oil and gas along fault to each river channel sand body is obtained.The application realizes the quantitative evaluation of oil and gas along fault to river channel sand body filling capacity, and based on the evaluation result, favorable gas-bearing river channel sand body can be further predicted.

Description

Technical Field

[0001] This invention relates to the field of oil and gas exploration technology, specifically to a quantitative evaluation method and apparatus for assessing the ability of oil and gas to be injected into river sand bodies along faults. Background Technology

[0002] Faults play a crucial role as conduits during the vertical migration of oil and gas, and their relationship with reservoirs significantly influences the distribution and accumulation of oil and gas in interconnected reservoirs. In many continental oil and gas basins, various channel sand bodies often develop on both sides of faults. Effectively identifying the amount of oil and gas migration and accumulation in different channel sand bodies is of great significance for guiding oil and gas exploration deployment and reducing exploration risks.

[0003] Previous evaluations of the extent of hydrocarbon injection along faults into connected sand bodies have been limited, and have primarily relied on qualitative or semi-quantitative analyses. The main methods are as follows: (1) Tian Lixin et al. (2018) considered factors such as the cross-sectional morphology of oil-source faults and their contact relationship with mature source rock sections, using numerical simulation to evaluate the hydrocarbon injection capacity along faults into sand bodies; (2) Hu Wenge et al. (2022) considered factors such as the internal structure of the fault zone, local strain intensity, and the magnitude and direction of current geostress to evaluate the hydrocarbon injection efficiency of strike-slip fault zones; (3) Wang Zhe (2022) analyzed the characteristics of faults, reservoirs, and caprocks and their interrelationships to study the main controlling factors of differential hydrocarbon injection between sand groups. None of these methods have achieved a quantitative evaluation of the selective injection of hydrocarbons along faults into channel sand bodies.

[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 determine whether oil and gas continue to migrate along the fault or migrate towards the fault, and does not involve the quantitative evaluation of the charging capacity. Summary of the Invention

[0005] To address the problems and shortcomings of the existing technologies, this invention proposes a quantitative evaluation method and apparatus for assessing the ability of oil and gas to be injected into channel sand bodies along faults. This method solves the previous difficulty in quantitatively evaluating the ease or difficulty of natural gas injection into different channel sand bodies along faults, making the evaluation results of selective injection of oil and gas into channel sand bodies along faults more consistent with actual geological conditions and more accurate. Furthermore, it can further predict favorable gas-bearing channel sand bodies, effectively reducing drilling risks.

[0006] To achieve the above-mentioned objectives, the technical solution of the present invention is as follows:

[0007] A quantitative evaluation method for the capacity of hydrocarbons to inject into channel sand bodies along faults is proposed. This method mainly includes the identification of hydrocarbon accumulation period, identification of gas source faults, analysis of the angle between the fault and the channel sand body and its evolution, calculation of the docking area between the fault and the channel sand body, calculation of the physical properties and evolution of the channel sand body, and evaluation of the channel sand body's charging capacity. The specific steps are as follows:

[0008] Step S101. Through fluid inclusion analysis, the hydrocarbon accumulation period is determined, and the hydrocarbon accumulation period and time are identified.

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

[0010] Step S103. Based on the configuration relationship and evolution of faults and sand bodies, obtain the angle θ between faults and channel sand bodies during the key hydrocarbon accumulation period. i2 The sine value 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 (historical data on porosity evolution recovery results and porosity-permeability relationship), the porosity and permeability of the channel sand body during the key hydrocarbon accumulation period are derived and calculated.

[0012] Step S105. The angle θ between the fault and the channel sand body during the key hydrocarbon accumulation period. i2 The sine value, the interface area S between the fault and the channel sand body i and the porosity φ of the riverbed sand body i1 and penetration rate K i1 These parameters together constitute the evaluation parameters for the injection capacity of oil and gas into channel sand bodies along faults. Therefore, by combining the relationship between the evaluation parameters for each injection capacity during the key reservoir formation period and the gas content of the sand bodies, the weighting coefficients of the influence of different parameters on natural gas injection can be determined. Then, the injection capacity coefficients of each channel sand body can be calculated, and the injection capacity can be judged based on the injection capacity coefficients. Finally, the injection capacity of natural gas into each channel sand body along faults can be quantitatively evaluated.

[0013] In this invention, the step of identifying hydrocarbon accumulation periods and determining the sequence and timing of hydrocarbon accumulation periods through fluid inclusion analysis includes:

[0014] Samples from sandstone reservoirs in various channels were selected, and thin sections of inclusions were prepared to observe the types and distribution of reservoir inclusions, identify the development stages of hydrocarbon inclusions, and determine the brine inclusions associated with hydrocarbon inclusions at different stages. Then, the homogenization temperature of the brine inclusions associated with hydrocarbon inclusions at different stages was measured, and the main distribution range of homogenization temperature was statistically analyzed. Combined with the burial thermal evolution history of the reservoir at the sample depth, the stages and times of hydrocarbon accumulation were determined.

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

[0016] By interpreting existing seismic data, we can determine the longitudinal cutting layers of the fault and whether the fault cuts the underlying source rock layers. If it does, the fault is identified as a gas source fault and can serve as a channel for vertical natural gas transmission. Otherwise, the fault is invalid and does not have vertical transmission capacity.

[0017] In this invention, obtaining the sine value of the angle between the fault and the channel sand body during the key hydrocarbon accumulation period, by combining the configuration relationship and evolution of the fault and the sand body, includes:

[0018] Using seismic interpretation profiles that traverse gas source faults and run along the direction of channel sand bodies, the angle θ between the present fault and each channel sand body is determined. i1 If the included angle θ i1 If the angle is acute, the fault dip is consistent with the sand body dip, which is conducive to natural gas injection into the sand body along the fault. However, if the included angle is θ... i1 An obtuse angle indicates that the fault dip is opposite to the sand body dip, which is unfavorable for natural gas injection along the fault into the sand body. Therefore, the smaller the angle, the more favorable it is for natural gas injection into the sand body. Furthermore, based on previous research on erosion thickness distribution (historical data on erosion thickness distribution), the back-stripping method is used to reconstruct the tectonic evolution history of the fault-sand configuration profile corresponding to the seismic interpretation profile, thereby determining the angle θ between the fault and each channel sand body during the key hydrocarbon accumulation period. i2 Then, based on the included angle θ i2 The corresponding sine value of the included angle can be directly calculated.

[0019] In this invention, obtaining the connection area between the fault and the channel sand body during the key hydrocarbon accumulation period, based on the configuration relationship and evolution of the fault and sand body, includes:

[0020] Based on the fault distribution and channel sandbody distribution interpreted from seismic data, the cross-sectional morphology of each channel sandbody that connects with the fault is analyzed, and the connection area S during the key hydrocarbon accumulation period is calculated using different geometric formulas according to different geometric cross-sectional morphologies. i .

[0021] In this invention, based on the porosity evolution recovery results and historical data on the porosity-permeability relationship, the porosity and permeability of the channel sand bodies during the key hydrocarbon accumulation period are obtained, including:

[0022] For channel sand bodies connected to faults, the porosity φ of each existing channel sand body near the fault is statistically analyzed using measured physical property data or well logging interpretation data. i1 and penetration rate K i1Then, combining the previous results of the reconstruction of channel sand body porosity evolution (historical data of channel sand body porosity evolution reconstruction results), the porosity φ of channel sand bodies during the key hydrocarbon accumulation period was analyzed and obtained. i2 Based on the current exponential correlation between porosity and permeability, a porosity-permeability calculation formula (1) is obtained. Then, based on the fitted formula (1) and the porosity φ during the key hydrocarbon accumulation period... i2 This allows for the calculation of the permeability K corresponding to the porosity during the critical hydrocarbon accumulation period. i2 ;

[0023] K = a·eR φ +b Equation (1);

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

[0025] Therefore, when calculating the permeability during the critical hydrocarbon accumulation period, the porosity φ of the channel sand bodies obtained during the critical hydrocarbon accumulation period will be analyzed. i2 Substituting into formula (1) above, the permeability K during the key hydrocarbon accumulation period can be obtained. i2 .

[0026] The parameters such as the included angle and porosity mentioned in this invention are based on the condition that the channel sand body is connected to the fault. If the fault and the channel sand body are not connected, then oil and gas will not be injected into the channel sand body along the fault. In general, the included angle θ between the fault and each channel sand body during the key hydrocarbon accumulation period is... i2 and the area S of the connection between the fault and the sand bodies in each channel. i The porosity and permeability of the channel sand bodies during the critical sedimentation period were obtained through the evolution of the sand configuration, while the porosity and permeability of the channel sand bodies during the critical sedimentation period were derived from the existing porosity evolution recovery results and the porosity-permeability relationship.

[0027] In this invention, the process of combining the aforementioned key reservoir-forming period evaluation parameters with the gas-bearing properties of sand bodies to determine the weighting coefficients of the influence of different parameters on natural gas injection, calculating the injection capacity coefficients of each channel sand body, and finally obtaining the selective injection intensity of natural gas along faults into each channel sand body includes:

[0028] Based on the aforementioned analysis, the sine value of the angle between the fault and the channel sand body during the key hydrocarbon accumulation period, sinθ, is used. i2 The interface area S between the fault and the channel sand body i Sand body porosity φ i2 and sand body permeability K i2 Normalization is performed according to the linear normalization formula to eliminate dimensions and ensure that the values ​​of each parameter are distributed within the range of 0 to 1, facilitating 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, by comparing the relationship between each evaluation parameter and the gas content of the channel (single well productivity, gas saturation) during the key reservoir formation period after normalization, the influence of the sine of the angle between the fault and the 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 on natural gas injection is determined, and the weight coefficients corresponding to each parameter are determined according to the correlation.

[0032] Taking into account the normalized sine of the angle between the fault and the sand body, the contact area between the fault and the channel sand body, the porosity of the sand body, and the permeability of the sand body, and multiplying them by the corresponding weighting coefficients, the infill capacity coefficient T of each channel sand body is calculated. 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 Equation (3);

[0034] Among them, T i X represents the filling capacity coefficient of the fault into the river channel. i1 X i2 X i3 and X i4 The weighting coefficients for sinθ represent the fault-sandbody angle during the key hydrocarbon accumulation period, the area of ​​the fault-connected channel sandbody, the porosity of the channel sandbody, and the permeability of the channel sandbody, respectively. i2 ′ represents the sine of the angle between the fault and the channel sand body during the key hydrocarbon accumulation period after normalization, S i ′ represents the normalized interface area between the fault and the channel sand body, φ i2 K represents the normalized porosity of the sand body during the critical hydrocarbon accumulation period. i2 ′ represents the normalized permeability of the sand body during the critical hydrocarbon accumulation period, and i represents the i-th channel sand body.

[0035] The above calculations can be used to obtain the injection capacity of each channel sand body, thereby obtaining the selective injection intensity of natural gas into each channel sand body along the fault, and finally quantitatively evaluating the injection capacity of natural gas into each channel sand body along the fault.

[0036] Based on the same inventive concept, this invention also proposes a quantitative evaluation device for the capacity of oil and gas to be injected into channel sand bodies along faults. This device is used to implement the aforementioned quantitative evaluation method for injection capacity. Hereinafter, the terms "unit" or "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated. Specifically, the device may include:

[0037] The hydrocarbon accumulation period identification module uses fluid inclusion analysis to identify hydrocarbon accumulation periods and determine the number and timing of hydrocarbon accumulation periods.

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

[0039] The module for calculating the charging capacity evaluation parameters combines the configuration relationship and evolution of faults and sand bodies, as well as historical data on the porosity evolution recovery results and porosity-permeability relationship, to obtain charging capacity evaluation parameters for key hydrocarbon accumulation periods, including the sine value of the angle between faults and channel sand bodies, the contact area between faults and channel sand bodies, and the porosity and permeability of channel sand bodies.

[0040] The selective charging intensity evaluation module for natural gas along faults into channel sand bodies combines the relationship between parameters during key reservoir formation periods and the gas content of sand bodies to determine the weighting 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 systems, devices, models, or units described above can be implemented by computer chips or physical entities, or by products with certain functions. For ease of description, the above devices are described in this specification as functionally divided into various units. Of course, in implementing this invention, the functions of each unit can be implemented in one or more software and / or hardware.

[0042] Furthermore, in this specification, adjectives such as first and second may only be used to distinguish an element or action, without necessarily implying any actual such relationship or order.

[0043] A computer device includes a memory, a processor, and a computer program stored in the memory and executable in the processor. When the processor executes the computer program, it implements the steps of the above-mentioned quantitative evaluation method for the ability of oil and gas to be injected into channel sand bodies along faults.

[0044] A computer-readable storage medium storing a computer program, which, when executed in a computer processor, implements the steps of the above-described quantitative evaluation method for the ability of oil and gas to be injected into channel sand bodies along faults.

[0045] The beneficial effects of this invention are:

[0046] 1. This invention enables quantitative evaluation of the ease or difficulty of natural gas injection into different channel sand bodies along faults, making the evaluation results of selective injection of oil and gas into channel sand bodies along faults more consistent with actual geological conditions and more accurate. Furthermore, based on these evaluation results, favorable gas-bearing channel sand bodies can be further predicted, effectively reducing drilling risks.

[0047] 2. This invention considers the natural gas accumulation period, the angle between the gas source fault and the 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 weighting coefficients of different parameters, the charging capacity coefficient of each channel sand body is calculated, realizing the selective charging capacity evaluation of oil and gas into the channel sand body along the fault. Attached Figure Description

[0048] The foregoing and hereinafter detailed description of the invention becomes clearer when read in conjunction with the following drawings, in which:

[0049] Figure 1 This is a flowchart of the method of the present invention;

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

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

[0052] Figure 5 This is a schematic diagram showing the relationship between the natural gas injection coefficient of the angle 1-1 fault into the channel sand bodies of sand groups 6, 7, and 8 and the daily production of a typical well in an embodiment of the present invention.

[0053] In the picture:

[0054] 201. Oil and gas accumulation period identification module; 202. Gas source fault identification module; 203. Recharge capacity evaluation parameter calculation module; 204. Recharge capacity evaluation module. Detailed Implementation

[0055] To enable those skilled in the art to better understand the technical solutions of this invention, several specific embodiments will be used to further illustrate the technical solutions for achieving the objectives of this invention. It should be noted that the technical solutions claimed by this invention include, but are not limited to, the following embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort should fall within the scope of protection of this invention.

[0056] Faults play a crucial role as conduits during the vertical migration of oil and gas, and their relationship with reservoirs significantly influences the distribution and accumulation of oil and gas in interconnected reservoirs. In many continental oil and gas basins, various channel sand bodies often develop on both sides of faults. Effectively identifying the amount of oil and gas migration and accumulation in different channel sand bodies is of great significance for guiding oil and gas exploration deployment and reducing exploration risks.

[0057] Previous assessments of oil and gas injection into sand bodies along faults have primarily focused on basic elements such as fault conduction capacity or fault-reservoir caps, and have qualitatively or semi-quantitatively analyzed the injection capacity of oil and gas into reservoirs. However, they have been insufficient in quantitatively characterizing the dynamic evolution of fault-sand configuration and the degree of fault-sand configuration during key reservoir formation periods. This has made it difficult to achieve a quantitative assessment of selective oil and gas injection into channel sand bodies along faults, which has affected the understanding of the patterns of selective oil and gas injection into channel sand bodies, reduced the accuracy of oil and gas reserves in channel sand bodies, and affected drilling success rates.

[0058] Based on this, embodiments of the present invention propose a quantitative evaluation method and apparatus for the capacity of oil and gas to be injected into channel sand bodies along faults. The present invention identifies the oil and gas accumulation period based on fluid inclusion analysis, determining the accumulation period and time; analyzes the configuration relationship between faults and source rocks based on seismic data interpretation results, identifying the gas source fault; then, combining the configuration relationship and evolution of faults and sand bodies, as well as historical data based on porosity evolution recovery results and porosity-permeability relationships, it obtains charging capacity evaluation parameters for key accumulation periods, including the angle between faults and channel sand bodies, the contact area between faults and channel sand bodies, and the porosity and permeability of channel sand bodies; finally, combining the above charging capacity evaluation parameters with the gas-bearing properties of sand bodies, it determines the weighting coefficients of different factors affecting natural gas charging, and then calculates the charging capacity coefficients of each channel sand body, thereby obtaining the selective charging intensity of natural gas along faults into each channel, ultimately achieving a quantitative evaluation of the capacity of natural gas to be injected into channel sand bodies along faults.

[0059] This embodiment discloses a quantitative evaluation method for the ability of oil and gas to be injected into channel sand bodies along faults. Taking the selective injection of natural gas from the Middle Jurassic Shaximiao Formation into channel sand bodies along faults in the Jinqiu Gas Field in central Sichuan as an example, the method mainly includes the following steps:

[0060] (1) Identification of hydrocarbon accumulation period

[0061] Using typical gas-producing reservoir samples from the Jinqiu gas field, inclusion thin sections were prepared. Microscopic observation of reservoir inclusion types and distribution revealed that gaseous hydrocarbon inclusions mainly developed in fracture cement and quartz enlarged margins. Furthermore, the homogenization temperature of brine inclusions associated with gaseous hydrocarbon inclusions of different phases was determined using a hot-cold stage. Combined with the corresponding burial thermal evolution history, the natural gas accumulation period was determined to be the late Early Cretaceous and late Miocene.

[0062] (2) Identification of gas source faults

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

[0064] (3) Angle between fault and channel sand body and its evolution analysis

[0065] Select a channel sand body profile through fault 1-1 and reconstruct the fault-sand body configuration relationship at the end of the Early Cretaceous and the end of the Miocene. Use a protractor to measure the angles (θ) between the fault and each channel sand body at the end of the Early Cretaceous and the end of the Miocene. 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 No. 6 and No. 8 channel sand bodies to its north were 77.8° and 107.06°, respectively, and the angles between the Jiao 1-1 fault and the No. 6, No. 7, and No. 8 channel sand bodies 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 No. 6 and No. 8 channel sand bodies to its north were 79.31° and 108.57°, respectively, and the angles between the Jiao 1-1 fault and the No. 6, No. 7, and No. 8 channel sand bodies to its south were 97.31°, 76.86°, and 70.58°, respectively.

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

[0067] Based on the cross-sectional and planar connections between the fault and each channel sand body, the length and width of the connection surfaces between the fault and each channel sand body were measured, and then the area S of the connection surfaces was calculated. i Among them, the contact area between the Corner 1-1 fault and the No. 6 and No. 8 river channel sand bodies to its north is 23,622 m². 2 25715m 2 The contact area between the Jiao 1-1 fault and the No. 6, 7, and 8 river channel sand bodies to its south is 25309 m². 2 6321m 225852m 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 channel sand bodies connected to faults, the current porosity φ of each channel sand body near the fault is statistically obtained using measured physical property data or well logging interpretation data. i1 and penetration rate K i1 The porosity of the channel sand bodies in the No. 6 and No. 8 sand groups in the northern part of the Jiao 1-1 fault is 8.47% and 7.73%, respectively, and the permeability is 10.7 mD and 0.58 mD, respectively. The porosity of the channel sand bodies in the No. 6, No. 7 and No. 8 sand groups in the southern part of the Jiao 1-1 fault is 13.17%, 7.89% and 11.9%, respectively, and the permeability is 6.42 mD, 0.11 mD and 0.2 mD, respectively.

[0070] By statistically analyzing multiple porosity and permeability data of river sand bodies on both sides of the fault, and plotting the correlation scatter plot of porosity and permeability of each river sand body, an exponential relationship formula between porosity and permeability (Formula 1, Formula 2, and Formula 3) was fitted.

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

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

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

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

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

[0076] Table 1. Statistics on the angle, docking area, and physical properties of sand groups 6, 7, and 8 of the Angle 1-1 Fault Connection.

[0077]

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

[0079] Based on the foregoing analysis, the sinusoidal angle between the fault and the sand body, the contact 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 hydrocarbon accumulation period were normalized using a linear normalization formula. This not only eliminated the dimensions but also ensured that the values ​​of each parameter were distributed within the range of 0 to 1, facilitating comparisons 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 normalization results are shown in Table 2 below:

[0083] Table 2. Normalized data statistics of filling capacity evaluation parameters for sand groups 6, 7, and 8 of the Jiao 1-1 fault connection.

[0084]

[0085] Then, by comparing the relationship between the above evaluation parameters and the gas saturation of the river channel during the normalized key reservoir formation period, the magnitude of the influence of each evaluation parameter on natural gas injection is determined, and the corresponding weight coefficient value (X) is determined according to the correlation.i1 X i2 X i3 X i4 ), as shown in Table 3 below.

[0086] Table 3 shows the calculation results of the weight coefficients for each evaluation parameter of sand groups 6, 7, and 8 in the connection of fault angle 1-1.

[0087]

[0088] Taking into account the normalized sine of the angle between the fault and the sand body, the contact area between the fault and the channel sand body, the porosity of the sand body, and the permeability of the sand body, and multiplying them by the corresponding weighting coefficients, the infill capacity coefficient T of each 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 Equation (5);

[0090] Among them, T i X represents the filling capacity coefficient of the fault into the river channel. i1 X i2 X i3 and X i4 The weighting coefficients for sinθ represent the fault-sand body angle, the area of ​​the channel sand body connected to the fault, the porosity of the channel sand body, and the permeability of the channel sand body, respectively. i2 ′ represents the sine of the angle between the fault and the channel sand body during the key hydrocarbon accumulation period after normalization, S i ′ represents the normalized interface area between the fault and the channel sand body, φ i2 K represents the normalized porosity of the sand body during the critical hydrocarbon accumulation period. i2 ′ represents the normalized permeability of the sand body during the critical hydrocarbon accumulation period, and i represents the i-th channel sand body.

[0091] Table 4 shows the calculation results of natural gas charging coefficients for sand groups 6, 7, and 8 of the Jiao 1-1 fault connection and the daily natural gas production of typical wells.

[0092]

[0093] Therefore, based on the above calculation results of natural gas charging coefficients, it can be seen that at the end of the Early Cretaceous, the natural gas charging coefficients of each channel sand body ranged from 0 to 1.79, and the charging capacity of different sand groups from largest to smallest was as follows: Sand Group 8 in the south of the fault, Sand Group 6 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; at the end of the Miocene, the natural gas charging coefficients of each channel sand body ranged from 0.03 to 1.7, and the charging capacity of different sand groups from largest to smallest was as follows: 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 8 in the north of the fault, and Sand Group 7 in the south of the fault. Summing the natural gas charging coefficients from the late Early Cretaceous and late Miocene yields the total charging coefficient for each sand group's channel, ranging from 0.03 to 3.48. The charging capacity, from largest to smallest, is as follows: Sand Group 6 in the southern fault zone, Sand Group 8 in the southern fault zone, Sand Group 6 in the northern fault zone, Sand Group 7 in the southern fault zone, and Sand Group 8 in the northern fault zone. Furthermore, combining this with the daily natural gas production of typical wells in different sand groups' channel sand bodies reveals a clear positive correlation between the charging capacity of each channel sand body and its daily natural gas production. Figure 5 ).

[0094] according to Figure 5 The positive correlation between the injection capacity of sand bodies in various channels and the daily production of natural gas allows us to fit a formula for calculating the daily production of natural gas under different injection capacity coefficients, as shown in Formula 6:

[0095] y = 10.8·T i +5.77 Equation (6);

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

[0097] To verify the accuracy of the formula, the natural gas charging coefficient of the Sha-2 sandstone body, which is connected to the northern part of the Jianyang 1 fault in central Sichuan, was calculated. The charging coefficients and total charging coefficients 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 × 10⁻⁶. 4 m 3 The actual daily production from drilling was 14.36 × 10⁻⁶. 4 m 3 The results were quite close, reflecting that the research method had good accuracy.

[0098] The above description is merely a preferred embodiment of the present invention and is not intended to hinder the present invention in any way. Any simple modifications 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 ability of oil and gas to inject into channel sand bodies along faults, characterized in that, Includes the following steps: Fluid inclusion analysis is used to identify hydrocarbon accumulation periods and determine the number and timing of hydrocarbon accumulation periods. Based on the interpretation of seismic data, the configuration relationship between faults and source rocks is analyzed to identify gas source faults; By combining the configuration relationship and evolution of faults and sand bodies, as well as the historical data on the porosity evolution recovery results and porosity-permeability relationship, we obtained the charging capacity evaluation parameters for key hydrocarbon accumulation periods, including the sine value of the angle between faults and channel sand bodies, the contact area between faults and channel sand bodies, and the porosity and permeability of channel sand bodies. By combining the evaluation parameters of the key hydrocarbon accumulation period and the gas content of the sand body, the weighting coefficients of the influence of different parameters on natural gas injection are determined, and then the injection capacity coefficient of each channel sand body is calculated. Finally, the selective injection intensity of natural gas along the fault into each channel sand body is obtained. The process of identifying hydrocarbon accumulation periods and determining the sequence and timing of these periods through fluid inclusion analysis includes: Samples from sandstone reservoirs in various channels were selected, and thin sections of inclusions were prepared to observe the types and distribution of reservoir inclusions, identify the development stages of hydrocarbon inclusions, and determine the brine inclusions associated with hydrocarbon inclusions at different stages. Then, the homogenization temperature of the brine inclusions associated with hydrocarbon inclusions at different stages was measured, and the main distribution range of homogenization temperature was statistically analyzed. Combined with the burial thermal evolution history of the reservoir at the sample depth, the stages and times of hydrocarbon accumulation were determined.

2. The quantitative evaluation method for the ability of oil and gas to be injected into channel sand bodies along faults as described in claim 1, characterized in that, The process of analyzing the relationship between faults and source rocks based on seismic data interpretation results to determine gas-source faults includes: Using existing seismic data interpretation results, the longitudinal cutting strata of the fault are determined, and it is determined whether the fault cuts the underlying source rock strata. If it does, the fault is identified as a gas source fault.

3. The quantitative evaluation method for the ability of oil and gas to be injected into channel sand bodies along faults according to claim 1, characterized in that, The configuration relationship and evolution of faults and sand bodies are combined to obtain the sine value of the angle between faults and channel sand bodies during key hydrocarbon accumulation periods, including: Based on historical data of erosion thickness distribution, the back-stripping method is used to reconstruct the tectonic evolution history of the fault-sand configuration profile corresponding to the seismic interpretation profile, determine the angle between the fault and each channel sand body during the key hydrocarbon accumulation period, and then calculate the sine value of the angle.

4. The quantitative evaluation method for the ability of oil and gas to be injected into channel sand bodies along faults according to claim 1, characterized in that, The configuration relationship and evolution of the faults and sand bodies are combined to obtain the interface area between the faults and channel sand bodies during the key hydrocarbon accumulation period, including: Based on the fault distribution and channel sand body distribution interpreted from seismic data, the cross-sectional morphology of each channel sand body that connects with the fault is analyzed, and the connection area of ​​the key hydrocarbon accumulation period is calculated based on the different cross-sectional morphologies.

5. The quantitative evaluation method for the ability of oil and gas to be injected into channel sand bodies along faults according to claim 1, characterized in that, Based on the porosity evolution reconstruction results and historical data on the porosity-permeability relationship, the porosity and permeability of the channel sand bodies during the key hydrocarbon accumulation period were obtained, including: For channel sand bodies connected to faults, the porosity and permeability of each channel sand body near the fault are statistically analyzed using measured physical property data or well logging interpretation data. Then, combined with historical data on the porosity evolution and reconstruction of channel sand bodies, the porosity of channel sand bodies during key hydrocarbon accumulation periods is obtained. Finally, by combining the exponential correlation between current porosity and permeability, a porosity-permeability calculation formula is fitted to calculate the permeability corresponding to the porosity during the key hydrocarbon accumulation period.

6. The quantitative evaluation method for the ability of oil and gas to be injected into channel sand bodies along faults according to claim 1, characterized in that, The method combines the evaluation parameters of the key hydrocarbon accumulation periods mentioned above with the gas-bearing properties of sand bodies to determine the weighting coefficients of the influence of different parameters on natural gas injection, and then calculates the injection capacity coefficient of each channel sand body. Finally, it obtains the selective injection intensity of natural gas along the fault into each channel sand body, including: The sine value of the angle between the fault and the channel sand body during the key hydrocarbon accumulation period, the docking area between the fault and the channel sand body, the sand body porosity and the sand body permeability were normalized respectively. By comparing the relationship between each evaluation parameter and the gas content of the river channel during the key reservoir formation period after normalization, the influence of each evaluation parameter on natural gas charging is determined, and the weight coefficients corresponding to the evaluation parameters are determined according to the correlation. Taking into account the normalized evaluation parameters, the corresponding weighting coefficients are multiplied to calculate the injection capacity coefficient of each channel sand body, thereby obtaining the injection capacity of each channel sand body and finally obtaining the selective injection intensity of natural gas along the fault into each channel.

7. A quantitative evaluation device for assessing the capacity of oil and gas to inject into channel sand bodies along faults, the device being used to implement the quantitative evaluation method described in any one of claims 1-6, characterized in that, include: The hydrocarbon accumulation period identification module uses fluid inclusion analysis to identify hydrocarbon accumulation periods and determine the number and timing of hydrocarbon accumulation periods. The gas source fault identification module acquires seismic data interpretation results, analyzes the configuration relationship between faults and source rocks, and then identifies and determines gas source faults. The module for calculating the charging capacity evaluation parameters combines the configuration relationship and evolution of faults and sand bodies, as well as historical data on the porosity evolution recovery results and porosity-permeability relationship, to obtain charging capacity evaluation parameters for key hydrocarbon accumulation periods, including the angle between faults and channel sand bodies, the contact area between faults and channel sand bodies, and the porosity and permeability of channel sand bodies. The charging capacity evaluation module combines the charging capacity evaluation parameters of key reservoir formation periods with the gas content of sand bodies to determine the weighting 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.

8. 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, it implements the method described in any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed in a computer processor, implements the method described in any one of claims 1-6.

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