Strike-slip fault band pass-source quantitative evaluation method

Abstract

The invention relates to a strike-slip fault band pass-source quantitative evaluation method, and belongs to the technical field of oil-gas exploration and development. According to the strike-slip fracture zone pass-source quantitative evaluation method, the pass-source of the strike-slip fracture zone in the corresponding period is evaluated according to the configuration characteristic parameters of each active period of the strike-slip fracture zone, and the accuracy of the evaluation result can be improved. In addition, when the kinematic model constitutive equation is adopted to calculate the thickness of the brittle stratum of the strike-slip fault zone, namely, the source opening depth, the method is not affected by the resolution ratio of deep seismic data, and the evaluation result is more stable. The strike-slip fault zone pass-source quantitative evaluation method is suitable for quantitative evaluation of whether deep oil gas passes through vertical transportation and accumulation of a strike-slip-stretching structural zone or not, and has a production guidance value for reducing the drilling risk of an oil-gas exploration target of a deep-ultra-deep strike-slip fault zone before drilling.

Description

TECHNICAL FIELD

[0001] The present application relates to a strike-slip fault zone pass-source quantitative evaluation method, belonging to the technical field of oil and gas exploration and development. BACKGROUND

[0002] A large number of drilling results at home and abroad show that the fault-controlled oil and gas reservoirs related to strike-slip faults are characterized by vertical migration and accumulation from the source to the overlying reservoir. Therefore, the effectiveness of strike-slip faults in connecting the underlying source kitchen and enabling oil and gas to vertically migrate along the fault zone to the overlying target layer is called "pass-source of strike-slip fault zone". According to the contact relationship between strike-slip faults and present-day source rocks, the structural style and activity intensity of the faults, researchers (Ma Qingyou et al., 2020) qualitatively evaluated the pass-source of strike-slip fault zone, and divided the strike-slip fault zone into three pass-source structural patterns: "upper and lower multi-layer through" strong pass-source type, "lower through and upper hidden" medium pass-source type, and "upper and lower not through" weak pass-source type. In addition, the correlation between pass-source and oil and gas enrichment can be discussed in combination with production capacity: (1) for the "upper and lower multi-layer through" strong pass-source type of strike-slip fault zone, oil and gas is often most enriched, and the production capacity is good; (2) for the "lower through and upper hidden" medium pass-source type of strike-slip fault zone, the degree of oil and gas enrichment is weakened, and the production capacity is poor-medium; (3) for the "upper and lower not through" weak pass-source type of strike-slip fault zone, the oil and gas production capacity is usually very low or even failed.

[0003] However, this qualitative evaluation method of pass-source has two limitations: first, the relationship between strike-slip fault zone and source kitchen and trap reflects the present framework, not the state during oil and gas migration and accumulation, so the error of the evaluation results of this method is large; second, the downward extension state of strike-slip fault zone is limited by the resolution of three-dimensional seismic data and small vertical fault throw, and there is uncertainty. In addition, the above method is a qualitative evaluation method, so far, there is no report on the quantitative evaluation of the pass-source of strike-slip fault zone.

[0004] The downward extension of strike-slip faults is not only a hot topic in natural earthquake research (focal depth) (Ampuero and Mao, 2017. Upper limit on damage zone thickness controlled by seismogenic depth. In: Marion Y. Thomas, Thomas M. Mitchell, and Harsha S. Bhat (eds.). Fault Zone Dynamic Processes: Evolution of Fault Properties During Seismic Rupture, Geophysical Monograph, 227:243-253), but also a problem that urgently needs to be solved in the current assessment of the sourceability of deep and ultra-deep hydrocarbons in basins. Therefore, it is urgent to develop a quantitative assessment method for the sourceability of strike-slip fault zones. Summary of the Invention

[0005] The purpose of this invention is to provide a quantitative evaluation method for the source of strike-slip fault zones, which can solve the problem that the current evaluation methods for the source of strike-slip fault zones have large errors in the evaluation results.

[0006] To achieve the above objectives, the technical solution adopted by the quantitative evaluation method for the source of strike-slip fault zones of the present invention is as follows:

[0007] A quantitative evaluation method for the source of strike-slip fault zones includes the following steps: First, a geological conceptual model reflecting the morphological characteristics of each active phase of the strike-slip fault zone is established. Then, a planar projection overlay map of the en echelon faults and the main displacement zone is established. The main displacement zone is segmented, and the model parameters of each en echelon fault within each segment of the main displacement zone are measured. Then, based on the measured model parameters, the thickness of the brittle strata of the strike-slip fault zone within each segment of the main displacement zone is calculated using the kinematic model constitutive equation. The model parameters include the en echelon fault depth and the en echelon tectonic torsion angle.

[0008] The quantitative evaluation method for the source connectivity of strike-slip fault zones of this invention evaluates the source connectivity of each active phase of the strike-slip fault based on the structural characteristic parameters of that phase, thereby improving the accuracy of the evaluation results. Furthermore, the kinematic model constitutive equation used in this invention to calculate the thickness of brittle strata in strike-slip fault zones is unaffected by the resolution of seismic data, resulting in more stable evaluation results. This quantitative evaluation method for the source connectivity of strike-slip fault zones is applicable to the quantitative evaluation of whether deep oil and gas are vertically transported and accumulated through strike-slip-extensional structural zones, and has production guidance value for reducing drilling risks for oil and gas exploration targets in deep to ultra-deep strike-slip-extensional structural zones before drilling.

[0009] The present invention provides a quantitative evaluation method for the source-transmission properties of strike-slip fault zones. Based on 3D seismic, logging, and drilling data, it studies the characteristics, structural style, and internal configuration of the negative-flower-shaped structural zone formed by strike-slip-extension structural zones. The depth of the negative-flower-shaped structural zone is obtained by measurement, and the source-transmission depth of the strike-slip fault is quantitatively calculated using a rock fracture theory model. This provides a scientific basis for evaluating the hydrocarbon accumulation and transport conditions of strike-slip-extension structural zones.

[0010] Preferably, the attribute fusion technology is three-dimensional seismic enhanced coherence, positive and negative curvature, and fault morphology index.

[0011] Preferably, the grid density used for stratigraphic interpretation, fracture interpretation, and fracture combination is no greater than 8km × 8km.

[0012] Preferably, the model parameters also include the goose-flight fracture interval or the goose-flight fracture distance; when the model parameters also include the goose-flight fracture distance, the calculation formula for the goose-flight fracture interval is: S=S'×sin(ω), where S is the goose-flight fracture interval, S' is the goose-flight fracture distance, and ω is the goose-flight structural torsion angle.

[0013] Preferably, the method for calculating the thickness of brittle formations is as follows:

[0014]

[0015] In the formula, S is the en echelon fracture interval, in km; h is the en echelon fracture depth, in km; and ρ is the density of the medium within the fracture region, in kg / m³. 3 g is the acceleration due to gravity, which is equal to 9.8 m / s². 2 C0 represents the cohesion within the brittle formation, measured in kPa; C1 represents the cohesion within the fracture surface, measured in kPa. μ is the internal friction coefficient of the fractured region. f Let be the coefficient of internal friction of the fracture surface. It is the internal friction angle. ω is the en echelon tectonic twist angle, in °; H is the thickness of the brittle strata, in km.

[0016] Preferably, the cohesive force is determined by the following formula:

[0017]

[0018] In the formula, C is the rock cohesion, in MPa; e is the natural constant, dimensionless; K v Let K be the stratigraphic integrity coefficient, which is dimensionless. Preferably, the stratigraphic integrity coefficient K... v Determined by the following formula:

[0019] K v =(V pm / Vpr ) 2

[0020] In the formula, V pm V represents the elastic longitudinal wave velocity of rock, measured in m / s. pr The elastic shear wave velocity of rock is expressed in m / s. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating the quantitative evaluation method for the source of strike-slip fault zones according to an embodiment of the present invention.

[0022] Figure 2 This is a flowchart illustrating the key steps of the quantitative evaluation method for the source of strike-slip fault zones according to an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the stratigraphic interpretation and fracture interpretation results based on the main survey line 1942 in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the cross-sectional stratigraphic interpretation and fracture interpretation results based on the connecting survey line 1708 in an embodiment of the present invention.

[0025] Figure 5 This is a schematic cross-sectional view of the evolutionary stages of the back-shaped negative flower-like structural zone in an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram illustrating the structural genesis of the back-shaped negative flower-like structural zone in an embodiment of the present invention;

[0027] Figure 7 This is a schematic diagram of the geological concept model (geological concept model of a right-lateral strike-slip fault zone with developing negative flower-shaped en echelon faults) established in the embodiments of the present invention;

[0028] Figure 8 This is a planar projection superimposed diagram of the en echelon fracture of the flower-like structural zone and the main displacement zone (PDZ) compiled in an embodiment of the present invention;

[0029] Figure 9 This is a comprehensive evaluation diagram of a high-density three-dimensional work area in an embodiment of the present invention. Detailed Implementation

[0030] The method for quantitatively evaluating the source of strike-slip fault zones of the present invention is a pioneering invention. The method for quantitatively evaluating the source of strike-slip fault zones of the present invention includes the following steps:

[0031] (1) The internal configuration of strike-slip faults is carved in layers using attribute fusion technology. Then, the stratigraphic interpretation, fault interpretation and fault combination are carried out. Then, the interface structure map corresponding to the formation period of each type of structure is compiled. Then, the mirror plane between each type of structure is determined. Then, the vertical stratification of each type of structure is determined according to the drilling VSP calibration. The boundary of the fault damage zone is determined according to the "inflection point" of the cumulative fracture density curve obtained by the fault morphology index conversion, that is, the lateral zoning. Then, the types of strike-slip fault uplift section, pull section, translation section and overlapping section are summarized and the internal configuration of fault core and damage zone is carved. A geological concept model is established including the main displacement zone (PDZ) of the main strike-slip fault, the attitude of the en echelon fault (length L, average interval S, distance S', torsion angle ω, en echelon fault depth h) and the thickness of the brittle strata penetrated by the main strike-slip fault, that is, the source depth (H).

[0032] (2) Compile a planar projection superposition diagram of the en echelon faults of the flower-shaped structural zone associated with the strike-slip fault zone and the main displacement zone. Divide the main displacement zone into segments and measure the model parameters of each en echelon fault in each segment of the main displacement zone. Then, based on the measured model parameters, calculate the en echelon fault depth (h) and brittle stratum thickness (H) of each en echelon fault in each segment of the main displacement zone.

[0033] In some preferred embodiments, the attribute fusion technique is three-dimensional seismic enhanced coherence, positive and negative curvature, and fault morphology index.

[0034] In some preferred embodiments, the survey network density used for stratigraphic interpretation, fracture interpretation, and fracture combination is no greater than 8km × 8km.

[0035] In some preferred embodiments, the thickness of the brittle formation is calculated as follows:

[0036]

[0037] In the formula, S is the en echelon fracture interval, in km; h is the en echelon fracture depth, in km; and ρ is the density of the medium within the fracture region, in kg / m³. 3 g is the acceleration due to gravity, which is equal to 9.8 m / s². 2 C0 represents the cohesion within the brittle formation, measured in kPa; C1 represents the cohesion within the fracture surface, measured in kPa. μ is the internal friction coefficient of the fractured region. f Let be the coefficient of internal friction of the fracture surface. It is the internal friction angle. ω is the en echelon tectonic twist angle, in °; H is the thickness of the brittle strata, in km.

[0038] In some preferred embodiments, the cohesive force C is determined by the following formula:

[0039]

[0040] In the formula, C is the rock cohesion, in MPa; e is the natural constant, dimensionless; K v Let K be the formation integrity coefficient, which is dimensionless. In some preferred embodiments, the formation integrity coefficient K is... v Determined by the following formula:

[0041] K v =(V pm / V pr ) 2

[0042] In the formula, V pm V represents the elastic longitudinal wave velocity of rock, measured in m / s. pr The elastic shear wave velocity of rock is expressed in m / s.

[0043] In some preferred embodiments, the formation integrity factor K v Determined by the degree of rock integrity; when the rock integrity is complete, 1 ≤ K. v <0.75; when the rock is relatively intact, 0.75≤K v <0.55; when the rock is relatively fragmented, 0.55≤K v <0.35; when the rock integrity is fractured, 0.35≤K v <0.15; when the rock is extremely fragmented, 0.15≤K v <0.

[0044] In this invention, the calculated thickness of the brittle strata is the source depth (H) of the strike-slip fault zone. Therefore, H can be used to evaluate what depth of source rocks the strike-slip fault zone can transport and accumulate hydrocarbons. This is the most effective way to date for quantitatively evaluating the deep-to-ultra-deep hydrocarbon accumulation conditions in a basin and reducing pre-drilling exploration risks.

[0045] The present invention provides a quantitative evaluation method for the source potential of strike-slip fault zones. Based on the multi-attribute fusion model of the internal structure of strike-slip fault zones using 3D seismic data, and based on the principles of rock fracture mechanics in strike-slip faults, it employs the Riedel shear discrete element model (Donzé et al., 2021) and the stress-masking theory-stress-rise function model for fully plastic media (Yin et al., 2016) to calculate the flower-like structural depth h and the brittle strata thickness H (also known as the "source potential") of the strike-slip fault zone boundary area. This achieves the purpose of quantitatively evaluating the source potential of strike-slip fault zones. This method has significant theoretical and practical value for oil and gas exploration evaluation in strike-slip-extensional structural zones and for calculating the reserves of fault-controlled reservoirs.

[0046] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0047] Example

[0048] The quantitative evaluation method for the source of strike-slip fault zones in this embodiment takes a strike-slip tectonic zone in a high-density three-dimensional work area as the research object, such as... Figure 1 and Figure 2 As shown, the specific steps include:

[0049] (1) Using the fusion technology of attributes such as three-dimensional seismic enhanced coherence, positive and negative curvature and fault morphology index, the internal structure of strike-slip faults is carved in layers;

[0050] In this embodiment, attribute fusion technology (three-dimensional seismic enhanced coherence, positive and negative curvature and fault morphology index) is used to analyze the NNE-trending extensional-strike-slip negative flower-shaped structure and NWW-trending transformation structure formed by extensional-torsional forces in the NW282°~SE102° of the Sha-4 to Sha-3 period, the NNE-trending positive flower-shaped structure and NEE-trending R-shear en echelon strike-slip fault system formed by compressional-torsional forces in the NW350°~SE170° of the Sha-2 to Dongying period, and the back-shaped negative flower-shaped structure formed by thermal subsidence in the Guantao-Minghuazhen period.

[0051] (2) Detailed interpretation of stratigraphy, detailed interpretation of fractures, and fracture combination analysis were performed according to a stratigraphic network density of 8km×8km. In this embodiment, the results of detailed interpretation of stratigraphy and detailed interpretation of fractures in a certain area of ​​a high-density 3D survey area are as follows: Figure 3 and Figure 4 As shown; a typical strike-slip-extensional tectonic zone in a high-density three-dimensional work area, such as... Figure 9 As shown; Figure 3 and Figure 4 In the diagram, the arc drawn from top to bottom represents a fault, the nearly horizontal line represents the seismic horizon, and the curve next to the drill string is the wave impedance curve. Figures 3-4 These are seismic survey lines interpreted from different directions, with the key changes in interpretation reflecting variations in the fault structure.

[0052] (3) Structural maps of the interfaces of the Sha-4 to Sha-3, Sha-2 to Dongying and Guantao to Minghuazhen periods were compiled by using the time-depth conversion curve stratification system; among them, the time-depth conversion curve was established by the following method: using the synthetic seismic records of the wells drilled in a certain high-density three-dimensional work area, and calibrating them with the seismic profiles through the wells, a time-depth data pair scatter sequence was formed, and then the intersection and fitting were performed in the rectangular coordinate system to establish the time-depth conversion curve;

[0053] (4) Since one structural reversal corresponds to one mirror plane, there is only one structural reversal in this embodiment. Therefore, the mirror plane between the NNE-trending negative flower-shaped structure and the NWW-trending transformation structure of the Sha-4 to Sha-3 periods and the NNE-trending positive flower-shaped structure of the Sha-2 to Dongying periods is determined, namely the top interface of the Sha-2 segment.

[0054] (5) Qualitatively classify the vertical stratification and lateral zonation of strike-slip structural zones and back-shaped negative flower-like structural zones (back-shaped negative flower-like structural zones are composite structural zones formed in three stages: early rifting, middle compression back-shaped, and late thermal subsidence and collapse), then carry out the summarization of structural styles and types and the carving of internal configurations, and establish a geological concept model.

[0055] Schematic diagrams of the evolutionary stages and tectonic genesis models of the dorsal negative flower-like structural zone are shown below. Figure 5 and Figure 6 As shown in the figure, the geological conceptual model (geological conceptual model of a right-lateral strike-slip fault zone with developing negative en echelon faults) established in this embodiment is illustrated in the following diagram. Figure 7 As shown;

[0056] In this step, the vertical stratification of the negative flower-shaped structural zone is determined based on the drilling VSP calibration, and the boundary of the fault damage zone, i.e. the lateral zoning, is determined based on the "inflection point" of the cumulative fracture density curve converted by the fault morphology index. Then, the types of strike-slip fault uplift sections, pull-out sections, strike-slip sections and overlapping sections are summarized, and the internal configuration of the fault core and damage zone is sculpted. A geological concept model is established, including parameters such as the main displacement zone (PDZ) of the main strike-slip fault and the attitude of the en echelon fault (length L, average interval S, distance S', torsion angle ω, en echelon fault depth h).

[0057] (6) Select a single strike-slip fault zone and compile a planar projection overlay diagram of the en echelon fault of the flower-like tectonic zone and the main displacement zone (PDZ). The results are as follows: Figure 8 ( Figure 8 As shown in the figure, the different colored lines represent different segments of the en echelon fault. Based on the segmentation of the main displacement zone (PDZ), four segments a, b, c and d are selected as the research objects. The relevant model parameters of each en echelon fault in each segment of the main displacement zone are measured. The back-shaped negative flower structure is a structure associated with the main strike-slip fault. It belongs to the strike-slip fault zone and conforms to the Reid shear mode. However, the back-shaped negative flower structure is superimposed with late-stage collapse modification.

[0058] (7) Based on the relevant model parameters measured, the en echelon fracture depth h of each flower-shaped structural zone within each main displacement zone segment is calculated using the following formula:

[0059]

[0060] In the formula, ω is the torsional angle of the en echelon structure in °, S is the en echelon fault interval in m, and h is the en echelon fault depth in m. On a plane, the en echelon fault depth h can be calculated by measuring the torsional angle ω and the en echelon fault interval S of the en echelon strike-slip fault zone. This calculation formula is based on the Riedel shear discrete element model (DEM), which is an empirical relation obtained by fitting experimental data using the nonlinear least squares method of trigonometric functions. The en echelon fault distance refers to the length S' of each pair of en echelon faults on the PDZ line segment; the en echelon fault interval refers to the vertical distance S between each pair of en echelon faults.

[0061] In this embodiment, the model parameters and calculation results required to calculate the en echelon fracture depth h of the flower-like structural zone are shown in Table 1. The en echelon structural torsion angle (i.e., the angle between the en echelon fault and the PDZ) and the en echelon fracture interval in Table 1 are obtained by measurement. The en echelon fracture depth includes the calculated average value and the measured average value. The calculated average value is the average value of the en echelon fracture depth of each flower-like structural zone in each main displacement zone segment calculated according to formula (1). The measured average value is determined by the following method: in the planar projection superposition diagram of the en echelon fracture of the flower-like structural zone and the main displacement zone (PDZ), the en echelon fracture depth of each en echelon fracture in each main displacement zone segment is measured, and then the average value is calculated to obtain the measured average value of the en echelon fracture depth of each main displacement zone segment. According to the comparison between the calculated average value and the measured average value of the en echelon fracture depth, it can be seen that the en echelon fracture depth calculated by the simple shear model has obvious limitations and there is a large difference between it and the measured value.

[0062] Table 1. Model parameters and calculation results required for calculating the depth h of the en echelon fracture in the flower-like tectonic zone.

[0063]

[0064] (8) Assuming the geological body under study is an ideal plastic medium, the uniform interval of the en echelon fault (i.e., the even space of the en echelon fault) is correlated with the thickness of the brittle layer developed by the fault using a physical model of brittle crustal deformation based on elastic rheology. The physical model relationship between the uniform interval S of the en echelon fault and the thickness H of the brittle layer developed by the fault is derived (as shown in the following formula). Then, based on the measured relevant model parameters, the source depth of the strike-slip fault zone (i.e., the thickness of the brittle strata in the en echelon fault) H is calculated using the following formula:

[0065]

[0066] In the formula, S is the en echelon fault interval in km; h is the en echelon fault depth in km; and ρ is the density of the medium (strata) within the fault region in kg / m³. 3 g is the acceleration due to gravity, which is equal to 9.8 m / s². 2C0 represents the cohesion within the brittle formation region, in kPa; C1 represents the cohesion within the fracture surface (the cohesion within the fracture surface refers to the cohesion within the stress concentration core), in kPa. The internal friction coefficient of the fracture region (the internal friction coefficient of the fracture region refers to the internal friction coefficient of the entire fault damage zone, i.e., the average friction coefficient); μ f This is the internal friction coefficient of the fracture surface (the internal friction coefficient of the fracture surface refers to the friction coefficient of the stress concentration nucleus). It is the internal friction angle. ω is the en echelon structural twist angle, in °; H is the thickness of the brittle strata in the boundary region (i.e., the thickness of the brittle strata of the en echelon fault), in km; according to the analysis in step (7), in order to obtain higher accuracy, the depth of the en echelon fault needs to be measured, specifically in the planar projection overlay of the en echelon fault and the main displacement zone (PDZ) in the flower-like structural zone. The en echelon fault interval can be obtained by measuring in the planar projection overlay of the en echelon fault and the main displacement zone (PDZ) in the flower-like structural zone, or by calculating the en echelon fault distance S' and the en echelon structural twist angle, and the results are consistent. In this embodiment, the en echelon fault interval is calculated by the en echelon fault distance S' and the en echelon structural twist angle, and the calculation formula is: S=S'×sin(ω), where S is the en echelon fault interval, S' is the en echelon fault distance, and ω is the en echelon structural twist angle.

[0067] The cohesive force C is determined by the following formula:

[0068]

[0069] In the formula, C is the rock cohesion, in MPa; e is the natural constant, approximately 2.71828, dimensionless; K v is the stratigraphic integrity coefficient, which is dimensionless;

[0070] Stratigraphic integrity coefficient K v This is a parameter for evaluating the degree of rock fragmentation, and it can be determined by the following formula:

[0071] K v =(V pm / V pr ) 2 (4)

[0072] In the formula, V pm V represents the elastic longitudinal wave velocity of rock, measured in m / s. pr The elastic shear wave velocity of rock is expressed in m / s.

[0073] Using the stratigraphic integrity coefficient K v The criteria for evaluating the degree of rock fragmentation are shown in Table 2.

[0074] Table 2. Rock Fragmentation Degree (Rock Integrity Degree) and Stratigraphic Integrity Coefficient K v Relationship table

[0075] Completeness Complete More complete More fragmented Fragmented Very fragmented K v ]]> 1≤K v <0.75]]> 0.75≤K v <0.55 0.55≤K v <0.35 0.35≤K v <0.15 0.15≤K v <0

[0076] In this embodiment, the model parameters required to calculate the source depth H of the strike-slip fault zone are shown in Table 3, and the calculated source depth H of each segment of the strike-slip fault zone are shown in Table 4 (the en echelon angle in Table 4 and the en echelon structural torsion angle in Table 1 can be calculated using the conversion formula between radians and angles: 1° = π / 180rad). "Use values ​​from Table 2" in Table 3 refers to using the fracture development to determine the degree of rock fragmentation, and then using this to calculate the stratigraphic integrity coefficient K based on Table 2. v The value of can be determined by the following formula: When sufficient data on the P-wave and S-wave velocities of the rock are available, the formation integrity coefficient K can also be calculated using the above formula. v ;

[0077] Table 3. Model parameters required to calculate the source depth H of the strike-slip fracture zone in segment A of the main displacement zone.

[0078]

[0079] Table 4. Relevant parameters for measuring the source depth H of each segment of the strike-slip fault zone.

[0080]

[0081] In this embodiment, the comprehensive evaluation diagram of a high-density three-dimensional work area is as follows: Figure 9 As shown.

[0082] Application examples

[0083] (1) The exploration and evaluation of the back-shaped negative flower-shaped structural belt formed by the strike-slip-extension structural belt in the southwest depression clarified that the shallow oil source of the second member of the Shahejie Formation mainly comes from the source rocks of the third and fourth members of the Shahejie Formation. The patent results supported the deployment of three exploration wells in the study area.

[0084] (2) Exploration of oil and gas reservoirs in the NEE-trending strike-slip fault zone of the Dongpu Depression to support the evaluation of exploration potential; the specific evaluation method is as follows: First, determine the location and depth of source rock development; then, sculpt the geometric features of a strike-slip fault in the distribution area of ​​source rock and establish a geological concept model; next, extract the model parameters and calculate the source depth H of the strike-slip fault; finally, compare whether H reaches the depth of source rock development. If it does, the strike-slip fault zone is considered to have good source connectivity, that is, it has the ability to effectively transport oil and gas generated in the source rock to form reservoirs, which means it has a low exploration risk; otherwise, it has a high exploration risk.

Claims

1. A quantitative evaluation method of a strike-slip fault zone passage source, characterized by, The method comprises the following steps: First, a geological conceptual model reflecting the configuration characteristics of each active period of the strike-slip fault zone is established, then a plane projection superimposition diagram of the echelon faults and the main displacement zone is established, the main displacement zone is segmented, and the model parameters of each echelon fault in each segment of the main displacement zone are measured, then the brittle stratum thickness of the strike-slip fault zone in each echelon fault in each segment of the main displacement zone is calculated by using the constitutive equation of the kinematic model according to the measured model parameters; the model parameters include the echelon fault depth and the echelon structure torsion angle.

2. The strike-slip fault zone passivity quantitative evaluation method according to claim 1, characterized in that, The attribute fusion technology is used for 3D seismic enhancement of coherence, positive and negative curvature and fault shape index.

3. The strike-slip fault zone passivity quantitative evaluation method according to claim 1, characterized in that, The surveying network density used for profile horizon interpretation, fault interpretation and fault combination is not greater than 8km*8km.

4. The strike-slip fault zone passivity quantitative evaluation method according to claim 1, characterized in that, The model parameters further include echelon fault interval or echelon fault distance; when the model parameters further include echelon fault distance, the calculation formula of the echelon fault interval is S=S' * sin(ω), wherein S is the echelon fault interval, S' is the echelon fault distance, and ω is the echelon structure torsion angle.

5. The quantitative evaluation method of strike-slip fault zone channeling according to any one of claims 1 to 4, wherein, The calculation method of the brittle stratum thickness is as follows: In the formula, S is the en echelon fracture interval, in km; h is the en echelon fracture depth, in km; and ρ is the density of the medium within the fracture region, in kg / m³. 3 g is the acceleration due to gravity, which is equal to 9.8 m / s². 2 C0 represents the cohesion within the brittle formation, measured in kPa; C1 represents the cohesion within the fracture surface, measured in kPa. μ is the internal friction coefficient of the fractured region. f Let be the coefficient of internal friction of the fracture surface. It is the internal friction angle. ω is the en echelon tectonic twist angle, in °; H is the thickness of the brittle strata, in km.

6. The strike-slip fault zone passivity quantitative evaluation method according to claim 5, characterized in that, The cohesion is determined by calculation through the following formula: In the formula, C is the rock cohesion, with the unit of MPa; e is a natural constant, dimensionless; K v is the formation integrity coefficient, dimensionless.

7. The strike-slip fault zone passivity quantitative evaluation method according to claim 6, characterized in that, Formation integrity factor K v Determined by calculation with the formula: K v = (V pm / V pr ) 2 wherein V pm is the rock elastic longitudinal wave velocity in m / s; V pr is the rock elastic transverse wave velocity in m / s.

Images