Suitable for fault basin slope zone turbidite sand body comprehensive evaluation method

Abstract

The application provides a turbidite sand body comprehensive evaluation method suitable for a faulted basin slope zone, and the turbidite sand body comprehensive evaluation method suitable for the faulted basin slope zone comprises the following steps: step 1, fine structure interpretation is carried out on a work area; step 2, a sand body flattening thickness is obtained as a coefficient H, and a sand body distribution area is obtained as a coefficient S; step 3, a sand body oil and gas containing probability L is calculated; step 4, abnormal pressure prediction is carried out on the sand body, and an abnormal pressure coefficient is used as a probability coefficient p; and step 5, comprehensive evaluation parameters are quantitatively represented, Z is defined as the comprehensive evaluation parameter, Z=H*S*L*p, and a target is optimized based on this. The turbidite sand body comprehensive evaluation method suitable for the faulted basin slope zone comprehensively considers main control factors of turbidite sand body development in the slope zone and quantitatively represents the main control factors, and has strong operability, and can be widely popularized in turbidite sand body prediction in the slope zone.

Description

Technical Field

[0001] This invention relates to the field of oilfield exploration and development technology, and in particular to a comprehensive evaluation method for turbidite sand bodies in the slope zone of a rift basin. Background Technology

[0002] Graben basins are extensional basins formed by the collision and subduction of oceanic plates, resulting in back-arc extension, rifting, and subsidence of the coastal continental region. In recent years, with increased exploration, turbidite sand bodies in the slope zones of graben basins have become favorable exploration targets for oil and gas development. Turbidite sand bodies in slope zones are a type of near-source rapid deposition. Due to the intense tectonic activity and complex geomorphological features of continental graben basins, secondary growth faults are often developed in steep slope zones. Deep-water turbidite sand bodies associated with the sedimentary deposits of sandstone and conglomerate bodies in the uplifted block of these secondary growth faults are frequently found in the downlifted block.

[0003] Currently, the following problems exist in the resource assessment of deep-water turbidite sand bodies: First, because the overlying strata are deep-lacustrine mudstones with abundant calcareous material, when using 3D seismic interpretation technology to depict deep-water turbidite sand bodies, the concentrated calcareous mudstone sections exhibit continuous strong reflections on seismic profiles, similar to the seismic characteristics of turbidite sand bodies. This makes it difficult to depict the boundaries of turbidite sand bodies using seismic reflection characteristics when determining their distribution range, leading to significant errors in determining the extent and thickness of turbidite sand bodies during actual exploration. Second, the rift basins where deep-water turbidite sand bodies are located have complex tectonic conditions and highly developed faults. Whether the turbidite sand body is in contact with oil-source faults, and the specific nature of the contact between the turbidite sand body and adjacent oil-source faults, all significantly impact the resource assessment of turbidite sand bodies. Previous studies have often provided qualitative descriptions and specific quantitative analyses. Finally, formation pore pressure plays an important role in controlling the porosity and permeability of turbidite sand bodies. When the formation pore pressure is high, the pore skeleton of turbidite sand bodies can often withstand greater overlying pressure, resulting in larger pore volumes and the accumulation of more oil and gas.

[0004] Currently, there is no effective comprehensive evaluation method for the resource quantity of turbidite sand bodies in deep-water slope zones of rift basins. On the one hand, early exploration of turbidite reservoirs focused on turbidite sand bodies formed by potato-shaped slumps. On the other hand, the sand bodies are affected by multiple tectonic movements and source transport after deposition, and the controlling factors such as the sand body size, the basic relationship with the oil source fault, and the influence of formation pore pressure are quite complex and have not been quantitatively characterized.

[0005] Chinese patent application CN200710061369.3 relates to a 3D seismic optimal time window technology for predicting and evaluating channel sandbody reservoirs. Technical Field: 3D seismic reservoir prediction and evaluation. Technical Problem: Traditional methods have insufficient resolution for channel prediction. Technical Solution: A 3D visualization scan is performed along the layer at 1-2 ms intervals. The optimal time window is determined based on the range of the target channel, and the corresponding sub-body is cut out. Perspective scanning is performed on time window attributes such as root mean square amplitude and wave impedance. Automatic tracking is performed to extract the top and bottom surfaces, calculate time isopymaps, convert them into sandbody isopymaps, and convert time-depth to obtain the top surface structure map. Curve reconstruction is used to evaluate reservoir properties, thereby achieving the prediction and evaluation of the planar morphology, vertical thickness, and reservoir properties of channel sandbody. This method effectively suppresses interference with the optimal time window, is applicable to various data volumes, and can effectively predict and evaluate thin channel sandbody thicknesses much less than 1 / 4 wavelength under conditions of frequent interbedded sandstone and mudstone, including channel sandbody thicknesses that do not correspond to wave peaks or troughs. It has shown good application results in oil exploration and development.

[0006] Chinese patent application CN201710548210.8 discloses a method for describing thin reservoirs and determining reservoir growth scale based on subdivided stratigraphic systems, belonging to the field of petroleum exploration and development technology. First, in fault-lithology and lithological trap development areas, subdivided stratigraphic systems are used to characterize geological thin reservoirs and predict seismic reservoirs. Combining these two methods, seismic attribute slices that match the sedimentary characteristics of thin reservoirs are selected to characterize single sand body boundaries. Next, the distribution areas of high-quality thin reservoirs and the locations of lithological sealing zones are systematically analyzed layer by layer to achieve a detailed description of the thin reservoir distribution characteristics. Then, effectiveness analysis is conducted on the identified thin reservoir stratigraphic systems to determine the lower limit of effective reservoir properties, screen and remove poor-quality layers, and delineate the spatial distribution area of ​​effective reservoirs. Finally, oil-bearing analysis of traps is conducted in the effective reservoir distribution area to obtain the reservoir growth scale of a single layer. Then, the reservoir growth scale of the target potential area is determined according to the stratigraphic superposition model, achieving an overall evaluation of the block's resource potential.

[0007] Chinese patent application CN201811558447.5 discloses a novel method and apparatus for reservoir evaluation based on well logging data. This method includes: Step 1, selecting and preprocessing data; Step 2, using the preprocessed data to predict porosity and permeability in non-core sections; Step 3, identifying interlayers using the predicted porosity and permeability; and Step 4, synthesizing comprehensive parameters for reservoir evaluation. This novel method and apparatus for reservoir evaluation can quantify reservoir evaluation and avoid inaccuracies caused by using a single parameter. It utilizes well logging data to develop effective reservoir evaluation parameters and fully leverages core experimental data to enhance reliability.

[0008] The existing technologies described above are significantly different from the present invention and have failed to solve the technical problem we want to address. Therefore, we have invented a new comprehensive evaluation method for turbidite sand bodies in the slope zone of a fault basin. Summary of the Invention

[0009] The purpose of this invention is to provide a simple and comprehensive evaluation method for turbidite sand bodies in the slope zone of rift basins, which takes into account factors such as sediment supply, fault activity, and paleogeography under the complex tectonic background of rift basins.

[0010] The objective of this invention can be achieved through the following technical measures: a comprehensive evaluation method for turbidite sand bodies in the slope zone of a rift basin, which includes:

[0011] Step 1: Perform detailed structural interpretation of the work area;

[0012] Step 2: Calculate the flattened thickness of the sand body as coefficient H and the spread area of ​​the sand body as coefficient S.

[0013] Step 3: Calculate the probability L of oil and gas in the sand body;

[0014] Step 4: Predict abnormal pressure on the sand body, using the abnormal pressure coefficient as the probability coefficient p;

[0015] Step 5: Quantify and characterize the comprehensive evaluation parameters, define Z as the comprehensive evaluation parameter, Z = H*S*L*p, and select the target based on this.

[0016] The objective of this invention can also be achieved through the following technical measures:

[0017] In step 1, the seismic, geological, and well logging data of the work area are used to conduct a detailed structural interpretation of the work area, including stratigraphic sequence division, stratigraphic positioning, fault interpretation, stratigraphic interpretation, velocity analysis, and structural mapping, so as to clarify the structural evolution model of the area.

[0018] In step 2, seismic inversion is performed on the work area to describe the distribution of sand bodies. Based on the inversion results, the intensity of the seismic response is assigned a probability coefficient for the degree of sand body development. The predicted flattening thickness of the sand body is used as the coefficient H, and the distribution area of ​​the sand body is used as the coefficient S.

[0019] In step 2, using 3D seismic and well logging data, the turbidite sand bodies in the study area are interpreted through stratigraphic calibration and stratigraphic correlation to obtain the sand body distribution area S of the turbidite sand bodies in the slope zone.

[0020] In step 2, using well logging data from the turbidite sand bodies in the study area, and through stratigraphic division and correlation, combined with actual drilling data, the thickness of the target layer in each well is obtained and denoted as h. i，Through mathematical statistical analysis, the flattened thickness H of the turbidite sand body was obtained.

[0021] In step 2, using 3D seismic data, actual drilling data, and velocity data, the target layer thickness h at all known well locations within the turbidite sandstone body of the slope zone is calculated. i Let i represent the number of well locations within the turbidite sand body. The smoothing thickness H of the turbidite sand body is calculated using the smoothing thickness method.

[0022]

[0023] In step 3, the structural map and coherence map of the region where the turbidite sand body is located are obtained by using seismic tectonic interpretation. The oil-bearing probability coefficient of the turbidite sand body is introduced as L. The distance between the sand body and the oil source fault is analyzed and divided into two cases: the oil source fault cuts the sand body and the oil source fault does not cut the sand body.

[0024] In step 3, the oil source fault cuts the sand body, and the probability coefficient is taken as L = 1; if the sand body is not cut, the reciprocal of the vertical distance d between the oil source fault and the center of the thickness of the turbidite sand body is selected as the probability coefficient L = 1 / d.

[0025] In step 4, using actual drilling data and well seismic data, seismic velocity spectrum, a velocity field is established to predict abnormal pressure in the sand body, and the abnormal pressure coefficient is used as the probability coefficient p.

[0026] In step 4, for sand bodies for which the actual drilling pressure coefficient has been obtained, the actual drilling pressure coefficient is used as the pressure probability coefficient p of the sand body; for sand bodies for which no actual drilling has been obtained, the pressure probability coefficient p of the sand body is predicted by using seismic velocity, combined with logging sonic velocity, by establishing a suitable pressure prediction model and adopting a well-seismic combined method.

[0027] In step 5, based on the seismic reflection characteristics of the turbidite sand bodies analyzed from the drilled wells, the turbidite is described using high-density seismic data. Combined with the distance from the fault, the distribution of abnormal formation pressure, and the size of the turbidite resources, the turbidite is comprehensively evaluated. The comprehensive evaluation parameters are quantified and characterized, and Z is defined as the comprehensive evaluation parameter, Z = H*S*L*p. Based on this, the target is selected.

[0028] The comprehensive evaluation method for turbidite sand bodies in the slope zone of rift basins, as described in this invention, clarifies the main controlling factors of deep-water turbidite sand body size. It selects two parameters—the flattened thickness of the slope zone sedimentary sand body and the planar size of the sand body—to quantitatively characterize the size of turbidite sand bodies in the slope zone. While simplifying the method to the greatest extent possible, it fully considers the main controlling factors affecting the size of turbidite sand bodies in the slope zone. Therefore, this invention has important reference value for the comprehensive evaluation of turbidite sand body resources in the deep-water slope zone of rift basins and provides strong support for the effectiveness of sand body description in deep-water turbidite sand body exploration.

[0029] Compared with existing technologies, the present invention has the following advantages:

[0030] This invention is applicable to a comprehensive evaluation method for the resource quantity of deep-water turbidite sand bodies in the downthrown block of the second step fault in a rift basin. It has three advantages: (1) When determining the thickness of turbidite sand bodies in the slope zone, unlike the average thickness usually adopted, the thickness of the turbidite sand bodies is characterized by the leveled thickness of actual drilled wells, which can more accurately reflect the true thickness of the turbidite sand bodies. (2) In the process of determining the distribution scale of turbidite sand bodies, based on the stratigraphic interpretation of seismic data, seismic inversion technology is used to further process the strong reflection interference of argillaceous limestone on the seismic profile, which can more accurately characterize the distribution range of turbidite sand bodies. (3) Previous evaluations of turbidite sand body resource quantity rarely introduced the control factor of formation pore pressure. This method establishes a velocity field by combining well logging data such as actual drilled sonic data with seismic layer velocity. It can not only take into account the heterogeneity of turbidite sand bodies, but also differ from the traditional single prediction method that only uses sonic data or only uses seismic layer velocity, and can more accurately characterize the pore pressure of turbidite sand bodies. Attached Figure Description

[0031] Figure 1 This is a flowchart of a specific embodiment of the comprehensive evaluation method for turbidite sand bodies in the slope zone of a rift basin according to the present invention;

[0032] Figure 2 This is a schematic diagram illustrating the determination of formation pore pressure p in a specific embodiment of the present invention. Detailed Implementation

[0033] To make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings.

[0034] This invention provides a comprehensive evaluation method for turbidite sand bodies in slope zones of rift basins. Utilizing single-point high-density seismic data, combined with inversion and reservoir fine-structure interpretation results, a probability coefficient for the sand body development degree is assigned. The predicted sand body thickness is used as coefficient H, and the sand body distribution area as coefficient S. The distance between the sand body and the oil-source fault is analyzed. The contact situation between the sand body and the oil-source fault is divided into two categories: when the oil-source fault cuts the sand body, the probability coefficient is set to 1; when the oil-source fault does not cut the sand body, the reciprocal of the distance is used as the probability coefficient L. Anomaly pressure analysis is performed on the turbidites in the slope zone. Using actual drilling data, well-seismic data, and seismic velocity spectra, a velocity field is established to predict the abnormal pressure of the sand body, using the abnormal pressure coefficient as the probability coefficient p. In summary, the sand body resource quantity is comprehensively evaluated, and the comprehensive evaluation parameters are quantitatively characterized. Z is defined as the comprehensive evaluation parameter, Z = H * S * L * p.

[0035] This invention provides a comprehensive evaluation method for the resource quantity of turbidite sand bodies in deep-water slope zones of rift basins. It not only solves the problem of the influence of calcareous mudstone on the determination of sand body size, but also quantifies the contact relationship between the sand body and the oil source fault, and considers the control factor of formation pore pressure on resource quantity evaluation, thus solving the problems existing in the prior art.

[0036] The following are several specific embodiments of the application of the present invention.

[0037] Example 1

[0038] In a specific embodiment 1 of the present invention, the comprehensive evaluation method for turbidite sand bodies in the slope zone of a rift basin includes the following steps:

[0039] Step 1: Utilize seismic, geological, and well logging data of the work area to conduct detailed structural interpretation of the work area, including stratigraphic sequence division, stratigraphic positioning, fault interpretation, stratigraphic interpretation, velocity analysis, and structural mapping, thereby clarifying the structural evolution model of the area.

[0040] Step 2: Use geophysical application software to perform seismic inversion on the work area to describe the distribution of sand bodies. Based on the inversion results and the strength of the seismic response, assign probability coefficients to the degree of sand body development. Use the predicted flattening thickness of the sand body as coefficient H and the distribution area of ​​the sand body as coefficient S.

[0041] Based on a comprehensive analysis of the 3D seismic data, velocity data, and well data of the study area, the thickness of the turbidite sand bodies is inferred mainly by referring to the sand body calibration of the well logging curves and seismic data.

[0042] Step 3: Analyze the distance between the sand body and the oil source fault. If the oil source fault cuts the sand body, the probability coefficient is taken as L = 1. If it does not cut the sand body, the reciprocal of the distance d is used as the probability coefficient L = 1 / d.

[0043] Step 4: Using actual drilling data and well seismic data, seismic velocity spectrum, establish velocity field, predict abnormal pressure of sand body, and use abnormal pressure coefficient as probability coefficient p; for areas with high exploration degree in the study area, draw target layer structure contour map through drilling measurement data, and read the distance of sand body from oil source fault.

[0044] Step 5: Based on the seismic reflection characteristics of the turbidite sandstone bodies analyzed from the drilled wells, high-density seismic data is used to describe the turbidites. Combining the distance to faults, the distribution of abnormal formation pressures, and the resource quantity of the turbidites, a comprehensive evaluation of the turbidites is conducted. The comprehensive evaluation parameters are quantified and defined as Z, where Z = H*S*L*p. Based on this, target selection is performed. The comprehensive evaluation parameter mainly refers to the resource quantity of the sandstone body, which is the product of the sandstone body volume, the probability coefficient of hydrocarbon bearing, and the abnormal pressure coefficient.

[0045] Example 2

[0046] In a specific embodiment 2 of the present invention, such as Figure 1 As shown in this embodiment, the comprehensive evaluation method for turbidite sand bodies in the slope zone of a rift basin includes:

[0047] Step 101: Using 3D seismic data, actual drilling data, and velocity data, calculate the target layer thickness h at all known well locations within the turbidite sandstone body of the slope zone. i (i: number of well locations within the turbidite sand body), calculate the smoothing thickness of the turbidite sand body using the smoothing thickness method.

[0048]

[0049] Step 102: Based on drilling and logging data, according to the thickness L of the deep-water turbidite sand body in the area with a high degree of exploration in the study area, and taking the thickness of the sandstone and conglomerate as the critical value of the deep-water turbidite sand body, draw the sand body thickness contour map in this area, thereby determining the distribution area S of the deep-water turbidite sand body in the area with a high degree of exploration.

[0050] Step 103 involves analyzing the distance between the sand body and the oil source fault, dividing it into two cases: the oil source fault cutting through the sand body and the oil source fault not cutting through the sand body. When the oil source fault cuts through the sand body, the probability coefficient for oil content is defined as L = 1. When the oil source fault does not cut through the sand body, the reciprocal of the vertical distance d between the oil source fault and the center of the turbidite sand body thickness is selected as the probability coefficient L = 1 / d.

[0051] Step 104: Using actual drilling data and well-seismic data, combined with seismic velocity spectrum, establish well-seismic combined velocity field to predict formation pore pressure of sand body, and use formation pore pressure coefficient as probability coefficient p.

[0052] Step 105: Based on the size of the turbidite sand body analyzed from the drilled wells, combined with the distance from the fault, the distribution of abnormal formation pressure, and the amount of turbidite resources, comprehensively evaluate the turbidite, quantify the comprehensive evaluation parameters, and define Z as the comprehensive evaluation parameter, Z = H*S*L*p, and select the target based on this.

[0053] Example 3

[0054] In a specific embodiment 3 of the present invention, the comprehensive evaluation method for turbidite sand bodies in the slope zone of a rift basin includes the following steps:

[0055] In step 1, using 3D seismic and well logging data, the turbidite sand bodies in the study area are interpreted through stratigraphic calibration and correlation to obtain the S-shape of the turbidite sand bodies in the slope zone. The process then proceeds to step 2.

[0056] In step 2, using well logging data from the turbidite sand bodies in the study area, and through stratigraphic division and correlation, combined with actual drilling data, the thickness of the target layer in each well is obtained and denoted as h.i， Through mathematical statistical analysis, the flattened thickness H of the turbidite sand body was obtained. The process then proceeds to step 3;

[0057] In step 3, the structural map and bedding coherence map of the region containing the turbidite sand body are obtained using seismic tectonic interpretation. An oil-bearing probability coefficient L is introduced for the turbidite sand body. When the turbidite sand body is in contact with an oil-source fault, L = 1. When the oil-source fault is not in contact with the sand body, L is equal to the reciprocal of the distance d between the oil-source fault and the turbidite sand body, i.e., L = 1 / d. The process then proceeds to step 4.

[0058] In step 4, using seismic data, well logging data, and actual drilling formation data, the pore fluid pressure field within the turbidite sandstone body is established. Specifically, for sandstone bodies with known actual drilling pressure coefficients, these coefficients are used as the pressure probability parameter *p*. For sandstone bodies without actual drilling data, seismic velocity is combined with well logging sonic velocity to establish a suitable pressure prediction model. A combined well-seismic-well logging approach is then used to establish a combined well-seismic-well logging pressure field and predict the pressure coefficient of the sandstone body. Figure 2 As shown, Figure 2 In a specific embodiment of the present invention, a formation pore pressure model is first established using actual drilling data, and then, combined with seismic layer velocity parameters, a schematic diagram of the formation pore pressure p is determined. The process proceeds to step 5;

[0059] In step 5, the resource quantity of turbidite sand bodies in the slope zone of the study area is calculated using the formula L = H * S * L * p, and then evaluated and optimized based on the resource quantity. The process ends.

[0060] The comprehensive evaluation method for turbidite sandstone resources in the slope zone of a rift basin, as presented in this invention, considers the main controlling factors of deep-water turbidite sandstone resources. It selects four parameters—planar sandstone distribution area, sandstone thickness after leveling, hydrocarbon probability coefficient, and formation pressure coefficient—to quantitatively characterize the resource quantity of turbidite sandstones in the slope zone. While simplifying the method to the greatest extent possible, it fully considers the main controlling factors of turbidite sandstone resources in the slope zone and quantifies them. The method is reasonable and has broad application value in the exploration of sandstone and conglomerate bodies in steep slope zones of rift basins.

[0061] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0062] Except for the technical features described in the specification, all other technologies are known to those skilled in the art.

Claims

1. A comprehensive evaluation method for turbidite sand bodies in the slope zone of a rift basin, characterized in that, This comprehensive evaluation method applicable to turbidite sand bodies in the slope zone of rift basins includes: Step 1: Perform detailed structural interpretation of the work area; Step 2: Calculate the flattened thickness of the sand body as coefficient H and the spread area of ​​the sand body as coefficient S; Step 3: Calculate the oil-bearing probability coefficient L of the sand body; Step 4: Predict abnormal pressure on the sand body, using the abnormal pressure coefficient as the probability coefficient p; Step 5: Quantify and characterize the comprehensive evaluation parameters, define Z as the comprehensive evaluation parameter, Z = H*S*L*p, and select the target based on this. In step 3, the structural map and coherence map of the area where the turbidite sand body is located are obtained by using seismic tectonic interpretation. The oil-bearing probability coefficient of the turbidite sand body is introduced as L. The distance between the sand body and the oil source fault is analyzed and divided into two cases: the oil source fault cuts the sand body and the oil source fault does not cut the sand body. When the oil source fault cuts the sand body, the probability coefficient is taken as L=1; when it does not cut the sand body, the reciprocal of the vertical distance d between the oil source fault and the center of the thickness of the turbidite sand body is selected as the probability coefficient L=1 / d.

2. The comprehensive evaluation method for turbidite sand bodies in the slope zone of a fault basin according to claim 1, characterized in that, In step 1, the seismic, geological, and well logging data of the work area are used to perform detailed structural interpretation of the work area, including stratigraphic sequence division, stratigraphic calibration, fault interpretation, stratigraphic interpretation, velocity analysis, and structural mapping, so as to clarify the tectonic evolution model of the area.

3. The comprehensive evaluation method for turbidite sand bodies in the slope zone of a fault basin according to claim 1, characterized in that, In step 2, seismic inversion is performed on the work area to describe the distribution of sand bodies. Based on the inversion results, the intensity of the seismic response is assigned a probability coefficient for the degree of sand body development. The predicted flattening thickness of the sand body is used as the coefficient H, and the distribution area of ​​the sand body is used as the coefficient S.

4. The comprehensive evaluation method for turbidite sand bodies in the slope zone of a fault basin according to claim 3, characterized in that, In step 2, using 3D seismic and well logging data, the turbidite sand bodies in the study area are interpreted through stratigraphic calibration and stratigraphic correlation to obtain the sand body distribution area S of the turbidite sand bodies in the slope zone.

5. The comprehensive evaluation method for turbidite sand bodies in the slope zone of a fault basin according to claim 3, characterized in that, In step 2, using well logging data from the turbidite sand bodies in the study area, and through stratigraphic division and correlation, combined with actual drilling data, the thickness of the target layer in each well is obtained and denoted as h. i， Through mathematical statistical analysis, the flattened thickness H of the turbidite sand body was obtained.

6. The comprehensive evaluation method for turbidite sand bodies in the slope zone of a rift basin according to claim 5, characterized in that, In step 2, using 3D seismic data, actual drilling data, and velocity data, the target h of all known well locations within the turbidite sand bodies of the slope zone is statistically analyzed. ji The layer thickness is h i , i is the number of well locations in the turbid sand body, and the smoothing thickness H of the turbid sand body is calculated using the smoothing thickness method; 。 7. The comprehensive evaluation method for turbidite sand bodies in the slope zone of a fault basin according to claim 1, characterized in that, In step 4, using actual drilling data and well seismic data, seismic velocity spectrum, a velocity field is established to predict abnormal pressure in the sand body, and the abnormal pressure coefficient is used as the probability coefficient p.

8. The comprehensive evaluation method for turbidite sand bodies in the slope zone of a fault basin according to claim 7, characterized in that, In step 4, for sand bodies for which the actual drilling pressure coefficient has been obtained, the actual drilling pressure coefficient is used as the pressure probability coefficient p of the sand body; for sand bodies for which no actual drilling has been obtained, the pressure probability coefficient p of the sand body is predicted by using seismic velocity and well logging sonic velocity, by establishing a pressure prediction model and adopting a well-seismic combined method.

9. The comprehensive evaluation method for turbidite sand bodies in the slope zone of a fault basin according to claim 1, characterized in that, In step 5, based on the seismic reflection characteristics of the turbidite sand bodies analyzed from the drilled wells, the turbidite is described using high-density seismic data. Combined with the distance from the fault, the distribution of abnormal formation pressure, and the size of the turbidite resources, the turbidite is comprehensively evaluated. The comprehensive evaluation parameters are quantified and characterized, and Z is defined as the comprehensive evaluation parameter, Z = H*S*L*p. Based on this, the target is selected.

Images