Source-sink system quantitative analysis and inspection method for recent system gravity flow

Abstract

The invention relates to the technical field of oil-gas exploration and deposition research, in particular to a source-sink system quantitative analysis and inspection method for recent system gravity flow, which comprises the following steps: S1, determining a source area corresponding to a target sand body, determining a deposition range of the target sand body and obtaining a deposition area, then obtaining the characteristics of the target sand body in the sedimentary area; s2, calculating gravity annual sand transport from a river to a seabed fan in the provenance area; s3, predicting the development period of the seabed fan, the area of the seabed fan in each period, the flattening thickness of the seabed fan and the sand content of the seabed fan, and then calculating the required annual sand supply amount of the sedimentary area; s4, comparing the gravity yearly sand transportation amount with the required yearly sand supply amount, if the gravity yearly sand transportation amount is greater than or equal to the required yearly sand supply amount, determining that the sand body prediction reliability of the deposition area at the moment is high, and outputting the development period of the seabed fan, the area of the seabed fan in each period, the flattening thickness of the seabed fan and the sand content of the seabed fan; otherwise, returning to S3. The reservoir risk of oil-gas exploration can be reduced, and the exploration success rate is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas exploration and sedimentation research, and more specifically, to a quantitative analysis and inspection method for a source-sink system of Neogene gravity flow. Background Art

[0002] The study of the source-sink system of sedimentary basins is one of the key contents for the implementation of oil and gas reservoirs, especially the quantitative analysis of the source-sink system can significantly improve the accuracy of reservoir prediction. At present, the study of the source-sink system in oil and gas exploration is mainly based on the analysis of elements such as source, ditch, slope, and fan, to clarify whether the provenance area can provide sandy debris to the basin and characterize the distribution characteristics of the reservoir. In recent years, the main research directions for the quantitative analysis of the source-sink system are: the material distribution in the denudation area is carried out by restoring the paleo-geomorphological parameters such as the terrain height difference, catchment area, and ditch-valley interface of the provenance area and dividing the source-sink unit, so as to predict the relative scale and distribution characteristics of the sedimentary sand body; and the construction of a conceptual model based on the sedimentary characteristics of the study area. On this basis, based on the principles of hydrodynamics, the filling evolution process of the basin is quantitatively evaluated by simulating parameters such as sea level changes and provenance conditions. Although the above methods can promote the quantitative study of source-sink systems, they are mainly aimed at sedimentary bodies formed by primary transportation such as deltas, and are mainly based on the methods of denudation zone restoration and forward modeling. There is a lack of quantitative research on secondary transport sedimentary bodies such as gravity flow, and it is unclear whether the prediction of sand bodies is reasonable. As a result, it is difficult to effectively judge whether the prediction of gravity flow sand bodies is reliable in oil and gas exploration. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a quantitative analysis and inspection method for the source-sink system of Neogene gravity flow, which can quantitatively characterize the various elements of the source-sink system for secondary transport sedimentary bodies such as gravity flow, improve the rationality of sand body prediction, reduce the reservoir risk of oil and gas exploration, and improve the success rate of exploration.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A quantitative analysis and verification method for the source-sink system of Neogene gravity flow is provided, comprising the following steps:

[0006] S1. Clarify the provenance area corresponding to the target sand body, clarify the deposition range of the target sand body and obtain the deposition area, and then obtain the characteristics of the target sand body in the deposition area;

[0007] S2. Calculate the annual gravity sediment transport from the rivers in the provenance area to the submarine fan;

[0008] S3. Based on the characteristics of the target sand body in the sedimentary area and the tracking interpretation of the submarine fan, the submarine fan development stages, the submarine fan area of ​​each stage, the flattened thickness of each stage, and the sand content of each stage of the submarine fan are predicted, and then the required annual sand supply of the sedimentary area is calculated;

[0009] S4. Compare the annual sand transport volume by gravity flow with the required annual sand supply volume. If the annual sand transport volume by gravity flow is greater than or equal to the required annual sand supply volume, execute step S5, otherwise execute step S6;

[0010] S5. At this time, the sand body prediction of the sedimentary area is highly reliable, and the submarine fan development stages, the submarine fan area of ​​each stage, the flattened thickness of each stage, and the sand content of each stage of the submarine fan are output;

[0011] S6. At this time, the sand body prediction reliability of the sedimentary area is low, and the process returns to step S3.

[0012] Further, step S2 includes the following steps:

[0013] S21. Obtain the total annual sediment transport volume of all rivers in the provenance area that can provide the provenance;

[0014] S22. Determine the gravity flow transport coefficient;

[0015] S23. Calculate the annual sand transport volume by gravity flow:

[0016] G2 = G × f;

[0017] In the formula, G2 represents the annual sand transport volume of gravity flow, G represents the total annual sand transport volume, and f represents the gravity flow transport coefficient. Further, in step S22, the formula of the gravity flow transport coefficient is:

[0018] f = -19.9ln(D) + 135.09;

[0019] Where D represents the width of the continental shelf, and D is less than 850 km.

[0020] Further, step S3 includes the following steps:

[0021] S31. Obtaining the development stages of submarine fans and the areas of submarine fans in each stage;

[0022] S32. Obtaining the flattening thickness of the submarine fan at each stage;

[0023] S33. Obtaining the sand content of each period of submarine fans;

[0024] S34. Calculate the sand volume of the sedimentary area:

[0025]

[0026] In the formula, V represents the volume of sand body, i represents the development stage of submarine fan, S i represents the area of ​​the submarine fan in the i-th period, h i represents the thickness of the submarine fan flattened in the i-th period, f i represents the sand content of the submarine fan in the i-th period;

[0027] S35. Calculate the sand mass of the sedimentary area:

[0028] S36. Calculate the required annual sand supply for the sedimentation area:

[0029] G1=W / (T×10 6 )

[0030] Where G1 represents the required annual sand supply, W represents the quality of the sand body, and T represents the duration of submarine fan deposition.

[0031] Further, step S31 includes the following steps:

[0032] S311. Based on the characteristics of the target sand body in the sedimentary area, obtain the development stages of the submarine fan and establish a high-frequency sequence framework;

[0033] S312. Extract interlayer seismic attributes based on the high-frequency sequence framework and the reflection characteristics of the submarine fan sand body on the seismic section; trace and interpret the submarine fan with reference to the interlayer seismic attributes, determine the sedimentary phase boundary, and then compile the plane sedimentary phase map of each period of the submarine fan according to the sedimentary phase boundary;

[0034] S313. Obtain the area of ​​the submarine fan of each period according to the planar sedimentary phase map.

[0035] Further, step S32 includes the following steps:

[0036] S321. Based on the tracking interpretation of the submarine fan, the bottom depth and top depth of each part of the submarine fan are obtained;

[0037] S322. Obtain the thickness of each part of the submarine fan according to the difference between the bottom depth and the top depth;

[0038] S323. Obtaining a submarine fan thickness map according to the thickness of each part of the submarine fan;

[0039] S324. Calculate the flattening thickness of the submarine fan in each period based on the submarine fan thickness map.

[0040] Furthermore, in step S33, the sand content of each period of submarine fans is obtained by statistically analyzing the lithology revealed by drilling; or, the sand content of each period of submarine fans is obtained by predicting the lithology of different regions based on seismic wave resistance and taking the average value.

[0041] Furthermore, in step S35, the sand mass calculation formula of the sedimentation area is:

[0042] W=ρ×V

[0043] Where W represents the mass of sand body, ρ represents the density of sedimentary sand body, and V represents the volume of sand body.

[0044] Further, in step S35, the density of the sedimentary sand body is obtained based on a drilling density logging curve.

[0045] Further, in step S36, the calculation formula for the submarine fan deposition duration is:

[0046] T=t1-t2

[0047] Where t1 represents the geological age of the bottom boundary of the submarine fan, and t2 represents the geological age of the top boundary of the submarine fan.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] The present invention provides a quantitative analysis and inspection method for the source-sink system of Neogene gravity flow. The method can compare the required annual sand supply with the annual sand transport of gravity flow for secondary transport sedimentary bodies such as gravity flow. If the annual sand transport of gravity flow is greater than or equal to the required annual sand supply, it indicates that the sand body prediction reliability of the sedimentary area is high at this time, the sand body scale prediction is reasonable, and the reservoir distribution model can be constructed and the drilling deployment can be carried out according to the current data; if the annual sand transport of gravity flow is less than the required annual sand supply, it indicates that the sand body prediction reliability of the sedimentary area is low at this time, and the submarine fan development stage, the submarine fan area of ​​each stage, the flattened thickness of each stage, and the sand content of each stage submarine fan need to be re-acquired; the present invention can improve the rationality of sand body prediction, reduce the reservoir risk of oil and gas exploration, and improve the exploration success rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a flow chart of a quantitative analysis and verification method of the source-sink system of Neogene gravity flow according to the present invention;

[0051] Figure 2 A schematic diagram of obtaining the characteristics of the target sand body in the sedimentary area in step S1 of the present invention and obtaining the development stage of the submarine fan based on the characteristics of the target sand body in the sedimentary area in step S311;

[0052] Figure 3 The planar sedimentary phase map and the interlayer root mean square amplitude attribute map compiled in step S31 of the present invention;

[0053] Figure 4 This is a comparison chart obtained in step S36 of the present invention regarding the duration of submarine fan deposition. DETAILED DESCRIPTION

[0054] The present invention is further described below in conjunction with specific implementation methods. The accompanying drawings are only used for exemplary descriptions and are only schematic diagrams, not actual drawings, and cannot be understood as limiting this patent; in order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the accompanying drawings may be omitted.

[0055] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0056] Example 1

[0057] like Figure 1 to Figure 2 The first embodiment of the quantitative analysis and verification method of the source-sink system of Neogene gravity flow according to the present invention is shown, which includes the following steps:

[0058] S1. Clarify the provenance area corresponding to the target sand body, clarify the deposition range of the target sand body and obtain the deposition area, and then obtain the characteristics of the target sand body in the deposition area; where:

[0059] Based on any one of the analogies of heavy mineral characteristics, zircon age, and parent rock type, combined with the analysis of paleo-geomorphology, sand transport channels, and submarine fan progradation characteristics, the source area corresponding to the target sand body is determined; based on well-seismic calibration, the development position and corresponding event axis of the target sand body on the seismic profile are clarified, and it is pointed out that the sand body presents low-frequency and strong-amplitude reflection characteristics on the seismic profile, and the characteristics of the target sand body in the sedimentary area are obtained, such as Figure 2 It should be noted that the implementation of the provenance area and the sedimentation area is prior art, so it will not be described in detail here.

[0060] S2. Calculate the annual gravity sediment transport from rivers in the provenance area to the submarine fan;

[0061] S3. Based on the characteristics of the target sand body in the sedimentary area and the tracking interpretation of the submarine fan, predict the development stages of the submarine fan, the area of ​​the submarine fan in each stage, the flattened thickness of the submarine fan in each stage, and the sand content of the submarine fan in each stage, and then calculate the required annual sand supply of the sedimentary area;

[0062] S4. Compare the annual sand transport volume by gravity flow with the required annual sand supply. If the annual sand transport volume by gravity flow is greater than or equal to the required annual sand supply, execute step S5, otherwise execute step S6;

[0063] S5. At this time, the sand body prediction of the sedimentary area is highly reliable, and the submarine fan development stages, the submarine fan area of ​​each stage, the flattened thickness of each stage, and the sand content of each stage of the submarine fan are output;

[0064] S6. At this time, the sand body prediction reliability of the sedimentary area is low, so return to step S3.

[0065] The present invention can be used to judge the rationality of source-sink system analysis and sand body prediction for secondary transport sediment bodies such as gravity flow through mutual constraint and verification of required annual sand supply and annual sand transport of gravity flow. If the annual sand transport of gravity flow is greater than or equal to the required annual sand supply, it means that the reliability of sand body prediction in the sedimentary area is high at this time, the prediction of sand body scale is reasonable, and the reservoir distribution model can be constructed and drilling can be deployed according to the current data; if the annual sand transport of gravity flow is less than the required annual sand supply, it means that the reliability of sand body prediction in the sedimentary area is low at this time, and it is necessary to re-acquire the development stage of submarine fans, the area of ​​submarine fans in each stage, the flattening thickness of submarine fans in each stage, and the sand content of submarine fans in each stage; the present invention can improve the rationality of sand body prediction, reduce the reservoir risk of oil and gas exploration, and improve the success rate of exploration.

[0066] Example 2

[0067] This embodiment is similar to embodiment 1, except that, in this embodiment, the present application is mainly aimed at the Neogene strata deposited since 23 Ma. For this set of strata, since it is relatively close to the present time, the annual sand transport of the river can be implemented based on the current river hydrological and river survey data. In step S1, the submarine fan of the Ledong Formation of the Quaternary System in the Qiongdongnan Basin is selected as the target sand body. Among them, step S2 includes the following steps:

[0068] S21. Obtain the total annual sand transport of all rivers that can provide material sources in the provenance area; wherein, the annual sand transport of each river can be estimated through the survey of the current annual sand transport of rivers or through the hydrological parameters such as river sand content and flow, and then the annual sand transport of each river is added together to obtain the total annual sand transport in the provenance area. In this embodiment, it can be clearly seen that the Ningyuan River and Wanglou River in Hainan Island and the Qiuben River from Vietnam can all provide material sources for the submarine fan of the Ledong Formation of the Quaternary System in the Qiongdongnan Basin; according to the survey, the annual sand transport of the Ningyuan River is 2.2×10 8 kg, and the annual sediment transport capacity of Wanglou River is 1.3×10 8 kg, and the annual sediment transport capacity of the Thu Bon River is 21.2×10 8 kg; thus, the total annual sand transport volume is 24.7×108 kg.

[0069] S22. Determine the gravity flow transport coefficient; wherein the formula of the gravity flow transport coefficient is:

[0070] f = -19.9ln(D) + 135.09;

[0071] Where D represents the width of the continental shelf, and D < 850 km;

[0072] It should be noted that the gravity flow transport coefficient is the ratio of the secondary gravity flow sand transport volume to the total river sand transport volume. Since the gravity flow sand transport volume is related to the river source supply and the width of the continental shelf, the following Table 1 is obtained based on the existing data:

[0073]

[0074] By fitting the current river data in Table 1, the formula for the gravity flow transport coefficient can be obtained; wherein, since the result approaches 0 or is a negative number when the shelf width is greater than 850 km, the above formula for the gravity flow transport coefficient is applicable to areas less than 850 km; in this embodiment, since the material source mainly comes from Vietnam and Hainan Island in the western part of the basin, the shelf width is about 133 km, and the gravity flow transport coefficient is 0.378.

[0075] S23. Calculate annual sand transport by gravity flow:

[0076] G2 = G × f;

[0077] Where G2 represents the annual sand transport by gravity flow, G represents the total annual sand transport, and f represents the gravity flow transport coefficient.

[0078] Based on the above data, the annual sediment transport capacity of gravity flow is 9.34×10 8 kg / yr.

[0079] Example 3

[0080] This embodiment is similar to Embodiment 1 or 2, except that, in this embodiment, step S3 includes the following steps:

[0081] S31. Obtaining the development stages of submarine fans and the areas of submarine fans in each stage; including the following steps:

[0082] S311. Based on the characteristics of the target sand body in the sedimentary area, obtain the development stages of the submarine fan and establish a high-frequency sequence framework;

[0083] Specifically, Figure 2The figure shows the identification and characterization of the sand body seismic response characteristics of the submarine fan of the Quaternary Ledong Formation in the Qiongdongnan Basin. It can be found that the submarine fan has six high-frequency cycles, with sand bodies developed at the bottom of each cycle and deep-sea mud at the top. Combined with the reflection characteristics of continuous strong amplitude on the seismic profile of each high-frequency cycle interface, it is pointed out that the submarine fan of the Quaternary Ledong Formation in the Qiongdongnan Basin has nine high-frequency cycles, corresponding to nine high-frequency sequences SQ1 to SQ9, among which the submarine fan sand bodies are mainly developed in the high-frequency sequences SQ1 to SQ6, thus establishing a high-frequency sequence framework.

[0084] S312. Based on the high-frequency sequence framework and the reflection characteristics of the submarine fan sand body on the seismic section, extract the interlayer seismic attributes; refer to the interlayer seismic attributes to trace and interpret the submarine fan, determine the sedimentary phase boundary, and then compile the plane sedimentary phase map of each period of the submarine fan according to the sedimentary phase boundary; among them, the interlayer seismic attributes can be selected from the interlayer root mean square amplitude attributes, such as Figure 3 As shown;

[0085] Specifically, based on the high-frequency sequence framework, the seismic phase axes corresponding to each sequence interface are identified, and each interface is traced and interpreted in the sedimentary area and its vicinity, so that the interpretation range is larger than the distribution range of the identified sand bodies; then, the sedimentary phase boundaries are determined and a planar sedimentary phase map is compiled. Figure 3 Shown are the planar sedimentary facies diagram and root mean square amplitude attribute diagram of six stages of submarine fans.

[0086] S313. Obtain the area of ​​the submarine fan of each period based on the planar sedimentary facies map.

[0087] S32. Obtaining the flattening thickness of the submarine fan at each stage; including the following steps:

[0088] S321. Based on the tracking interpretation of the submarine fan, the bottom depth and top depth of each part of the submarine fan are obtained;

[0089] S322. Obtain the thickness of each part of the submarine fan according to the difference between the bottom depth and the top depth;

[0090] S323. Obtaining a submarine fan thickness map according to the thickness of each part of the submarine fan;

[0091] S324. Obtain the flattened thickness of the submarine fan in each period according to the submarine fan thickness map;

[0092] It should be noted that the calculation of the flattened thickness of the submarine fan can be based on the submarine fan thickness map and obtained by flattening through DSG software, or it can be obtained by calculating the average thickness of each part of the submarine fan.

[0093] S33. Obtain the sand content of each period of submarine fans; wherein, the sand content of each period of submarine fans is obtained by statistically revealing the lithology through drilling; or, the sand content of each period of submarine fans is obtained by predicting the lithology of different regions based on seismic wave resistance and taking the average value.

[0094] In this embodiment, a statistical table of quantitative parameters of submarine fans of each period of the Ledong Formation is obtained, as shown in Table 2 below:

[0095]

[0096]

[0097] S34. Calculate the sand volume in the sedimentary area:

[0098]

[0099] In the formula, V represents the volume of sand body, i represents the development stage of submarine fan, S i represents the area of ​​the submarine fan in the i-th period, h i represents the thickness of the submarine fan flattened in the i-th period, f i Represents the sand content of the submarine fan in the i-th period.

[0100] In this example, based on the above data, the volume of the submarine fan sand body of the Quaternary Ledong Formation in the Qiongdongnan Basin is about 253.088×10 9 m 3 .

[0101] S35. Calculate the sand mass in the sedimentation area:

[0102] W=ρ×V

[0103] In the formula, W represents the mass of sand body, ρ represents the density of sedimentary sand body, and V represents the volume of sand body;

[0104] The density of the sedimentary sand body is obtained based on the drilling density logging curve. In this embodiment, according to the RHOB density logging curve, the density of the sandstone is about 2.1×10 3 kg / m 3 ; From the above data, it can be obtained that the mass of the sand body is about 531.4848×10 12 kg.

[0105] S36. Calculate the required annual sand supply for the sedimentation area:

[0106] G1=W / (T×10 6 )

[0107] T=t1-t2

[0108] Where G1 represents the annual sand supply required, W represents the quality of the sand body, T represents the duration of submarine fan deposition, t1 represents the geological age of the bottom boundary of the submarine fan, and t2 represents the geological age of the top boundary of the submarine fan.

[0109] In this example, the duration of submarine fan deposition is based on paleontological analysis, mainly through the combination of the last appearance of two types of fossils, foraminifera and calcareous nanostructures, and the regional sequence stratigraphic framework; Figure 4 The figure shows the comparison of the paleontology of the submarine fan of the Ledong Formation with the Xike 1 well and the global glacial age. Among them, the paleontology of the submarine fan of the Ledong Formation in the Quaternary in the Qiongdongnan Basin reveals S 18 About 1.93Ma near the interface, S 14 The interface is about 1.47 Ma. Combining the paleomagnetic reversal sequence of Well Xike 1 and the global glacial evolution, the bottom boundary of the submarine fan of the Ledong Formation, S 20 About 2.08 Ma, the top S 12 The sedimentation time of submarine fan is about 1.39Ma, so the duration T of submarine fan sedimentation is 0.69Ma. Based on the above data, the required annual sand supply is 7.7×10 8 kg / yr.

[0110] Therefore, in step S4 of this embodiment, the annual sand transport volume G2 of gravity flow is set to 9.34×10 8 kg / yr and the required annual sand supply G1 is 7.7×10 8 kg / yr for comparison, G2>G1, and step S5 is executed, indicating that the sand body prediction reliability of the current sedimentary area is high. The submarine fan of the Ledong Formation of the Quaternary in the Qiongdongnan Basin can be used to construct a reservoir distribution model and deploy drilling based on the currently predicted submarine fan development stages, the submarine fan area of ​​each stage, the submarine fan flattening thickness, and the submarine fan sand content data.

[0111] It should be noted that if G2<G1 occurs, it means that the reliability of the sand body prediction in the sedimentary area at this time in step S6 is low, indicating that the prediction results of one or more of the data in the current submarine fan development stage, the submarine fan area of ​​each stage, the submarine fan flattening thickness, and the submarine fan sand content are inaccurate, and it is necessary to return to step S3, re-track and interpret the submarine fan, and adjust one or more of the data in the submarine fan development stage, the submarine fan area of ​​each stage, the submarine fan flattening thickness, and the submarine fan sand content accordingly, so that the final result of G2≥G1 is obtained and output.

[0112] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A quantitative analysis and verification method for the source-sink system of Neogene gravity flow, characterized in that: The steps include: S1. Clarify the provenance area corresponding to the target sand body, clarify the deposition range of the target sand body and obtain the deposition area, and then obtain the characteristics of the target sand body in the deposition area; S2. Calculate the annual gravity sediment transport from the rivers in the provenance area to the submarine fan; S3. Based on the characteristics of the target sand body in the sedimentary area and the tracking interpretation of the submarine fan, the submarine fan development stages, the submarine fan area of ​​each stage, the flattened thickness of each stage, and the sand content of each stage of the submarine fan are predicted, and then the required annual sand supply of the sedimentary area is calculated; S4. Compare the annual sand transport volume by gravity flow with the required annual sand supply volume. If the annual sand transport volume by gravity flow is greater than or equal to the required annual sand supply volume, execute step S5, otherwise execute step S6; S5. At this time, the sand body prediction of the sedimentary area is highly reliable, and the submarine fan development stages, the submarine fan area of ​​each stage, the flattened thickness of each stage, and the sand content of each stage of the submarine fan are output; S6. At this time, the sand body prediction reliability of the sedimentary area is low, and the process returns to step S3.

2. The method for quantitative analysis and verification of source-sink system for Neogene gravity flow according to claim 1, characterized in that: Step S2 includes the following steps: S21. Obtain the total annual sediment transport volume of all rivers in the provenance area that can provide the provenance; S22. Determine the gravity flow transport coefficient; S23. Calculate the annual sand transport volume by gravity flow: G2 = G × f; Where G2 represents the annual sand transport by gravity flow, G represents the total annual sand transport, and f represents the gravity flow transport coefficient.

3. The method for quantitative analysis and verification of source-sink system for Neogene gravity flow according to claim 2, characterized in that: In step S22, the formula of the gravity flow transport coefficient is: f = -19.9ln(D) + 135.09; Where D represents the width of the continental shelf, and D is less than 850 km.

4. The method for quantitative analysis and verification of source-sink system for Neogene gravity flow according to claim 1, characterized in that: Step S3 includes the following steps: S31. Obtaining the development stages of submarine fans and the areas of submarine fans in each stage; S32. Obtaining the flattening thickness of the submarine fan at each stage; S33. Obtaining the sand content of each period of submarine fans; S34. Calculate the sand volume of the sedimentary area: In the formula, V represents the volume of sand body, i represents the development stage of submarine fan, S i represents the area of ​​the submarine fan in the i-th period, h i represents the thickness of the submarine fan flattened in the i-th period, f i represents the sand content of the submarine fan in the i-th period; S35. Calculate the sand mass of the sedimentary area; S36. Calculate the required annual sand supply for the sedimentation area: G1=W / (T×10 6 ) Where G1 represents the required annual sand supply, W represents the quality of the sand body, and T represents the duration of submarine fan deposition.

5. The method for quantitative analysis and verification of source-sink system for Neogene gravity flow according to claim 4, characterized in that: Step S31 includes the following steps: S311. Based on the characteristics of the target sand body in the sedimentary area, obtain the development stages of the submarine fan and establish a high-frequency sequence framework; S312. Extract interlayer seismic attributes based on the high-frequency sequence framework and the reflection characteristics of the submarine fan sand body on the seismic section; trace and interpret the submarine fan with reference to the interlayer seismic attributes, determine the sedimentary phase boundary, and then compile the plane sedimentary phase map of each period of the submarine fan according to the sedimentary phase boundary; S313. Obtain the area of ​​the submarine fan of each period according to the planar sedimentary phase map.

6. The method for quantitative analysis and verification of source-sink system for Neogene gravity flow according to claim 4, characterized in that: Step S32 includes the following steps: S321. Based on the tracking interpretation of the submarine fan, the bottom depth and top depth of each part of the submarine fan are obtained; S322. Obtain the thickness of each part of the submarine fan according to the difference between the bottom depth and the top depth; S323. Obtaining a submarine fan thickness map according to the thickness of each part of the submarine fan; S324. Calculate the flattening thickness of the submarine fan in each period based on the submarine fan thickness map.

7. The method for quantitative analysis and verification of source-sink system for Neogene gravity flow according to claim 4, characterized in that: In step S33, the sand content of each period of submarine fans is obtained by statistically analyzing the lithology revealed by drilling; or, the sand content of each period of submarine fans is obtained by predicting the lithology of different regions based on seismic wave resistance and taking the average value.

8. The method for quantitative analysis and verification of source-sink system for Neogene gravity flow according to claim 4, characterized in that: In step S35, the sand mass calculation formula of the sedimentation area is: W=ρ×V Where W represents the mass of sand body, ρ represents the density of sedimentary sand body, and V represents the volume of sand body.

9. The method for quantitative analysis and verification of source-sink system for Neogene gravity flow according to claim 8, characterized in that: In step S35, the density of the sedimentary sand body is obtained based on the drilling density logging curve.

10. The method for quantitative analysis and verification of source-sink system for Neogene gravity flow according to claim 4, characterized in that: In step S36, the calculation formula for the submarine fan deposition duration is: T=t1-t2 Where t1 represents the geological age of the bottom boundary of the submarine fan, and t2 represents the geological age of the top boundary of the submarine fan.

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