Evaluation Method of Factors Affecting Turbidity Channels

Abstract

The present invention provides an evaluation method for factors affecting turbidite channels, comprising the following steps: analyzing the geological background of the current region and the formation conditions of turbidite channels to characterize the boundaries of turbidite channels; restoring the paleo-geomorphology of turbidite channels during the sedimentary period to obtain the true morphology of turbidite channels during the sedimentary period; intercepting multiple seismic profiles perpendicular to the direction of the turbidite channels, and calculating the morphological characterization parameters of the turbidite channels in each seismic profile; recording the parameters of various influencing factors of the period in which the turbidite channels are located; using the grey correlation method to calculate the correlation between the morphological characterization parameters and the parameters of various influencing factors to determine the degree of influence of the parameters of various influencing factors on the morphology of turbidite channels. The present invention can more effectively evaluate the degree of influence of influencing factors in the paleo-geological historical period on the morphology of turbidite channels, and has the advantages of small error, high credibility, strong operability, and quantitative-semi-quantitative.

Description

Technical Field

[0001] The invention relates to the technical field of deepwater oil and gas geological exploration, and in particular to an evaluation method for factors affecting turbidite channels. Background Art

[0002] Seismic profile is also called seismic record profile. It is a seismic data map that marks a certain survey line. According to the different physical dimensions used in the vertical axis, seismic record profiles can be divided into time profiles and depth profiles. In general, the quantifier of seismic profile is "line".

[0003] Gravity flow sediment, also known as "gravity sediment", is a density flow sediment containing a large amount of dispersed matter driven by gravity on land, underwater or in water bodies. Sediments maintain clear boundaries and flow as a whole during gravity flow. According to the support mechanism of suspended particles in gravity flow, underwater gravity flow sediments are divided into four types: debris flow sediments, particle flow sediments, liquefied sediment flow sediments and turbidity flow sediments.

[0004] The earliest research on gravity flow deposition can be traced back to the naval voyage in 1872. In 1950, Kuenen proposed that graded bedding is a sign of turbidity current, marking the beginning of turbidity current deposition. Scholars have conducted a series of studies on gravity flow deposition and have proposed concepts such as Bouma sequence, Walker fan, high-density turbidity current, low-density turbidity current, and sandy debris flow. The concepts, flow states, dynamic mechanisms, genetic models, and phase transformations of gravity flow have sprung up like mushrooms after rain, and have been gradually applied to oil and gas exploration practices.

[0005] With the continuous development of onshore and shallow-medium oil and gas and the advancement of drilling technology, the direction of global oil and gas exploration has shifted from onshore to offshore, and from shallow-medium to deep and deepwater. In the past 40 years, thousands of oil and gas fields have been discovered in deepwater areas around the world, involving the Atlantic deepwater basin group, the East African continental margin deepwater basin group, the Western Pacific deepwater basin group, the circum-Arctic deepwater basin group, and the Neo-Tethys deepwater basin group, in which gravity flow deposition plays an important role.

[0006] The continental margin basins in the northern part of the South China Sea are rich in oil and gas resources, and the Qiongdongnan Basin is the main block for deepwater oil and gas exploration. Since the breakthrough of the Lingshui 22-1 gas field in 2010, the central canyon waterway in the Qiongdongnan Basin has continued to make breakthroughs, and Lingshui 17-2, my country's first 100 billion cubic meter self-operated deepwater gas field, has also been put into production, indicating the huge exploration potential of deep-sea gravity flow deposits.

[0007] As a type of gravity flow sedimentation, turbidite channels play an important role in it. At present, the research on turbidite channels focuses on the profile characteristics and planar distribution of turbidite channels, while the research on the influencing factors of turbidite channels is relatively weak, and there are even fewer quantitative or semi-quantitative evaluation methods for the influencing factors of turbidite channels.

[0008] The existing Chinese patent (application number: CN202111262807.9) discloses a method, device and computer equipment for rapid evaluation of deep-sea channel reservoirs. It can avoid drilling wells and relying heavily on logging data, is suitable for working conditions with no wells or few wells, and can also evaluate specific phase units according to specific working conditions. However, the evaluation method of the existing Chinese patent is not suitable for evaluating the influencing factors of turbidite channels. Summary of the invention

[0009] In view of the shortcomings of the prior art mentioned above, the technical problem to be solved by the present invention is to provide an evaluation method for the influencing factors of turbidite channels, which can more effectively evaluate the influence of the influencing factors in the ancient geological history period on the morphology of turbidite channels, and has the advantages of small error, high credibility, strong operability, and quantitative-semi-quantitative.

[0010] In order to solve the above technical problems, the present invention provides a method for evaluating factors affecting turbidity waterways, comprising the following steps:

[0011] Analyze the geological background of the current area and the formation conditions of the turbidite channel to characterize the boundaries of the turbidite channel;

[0012] Restore the paleo-geomorphology of the turbidite channel during the sedimentation period to obtain the true morphology of the turbidite channel during the sedimentation period;

[0013] Cut multiple seismic sections perpendicular to the direction of the turbidite channel, calculate the morphological characterization parameters of the turbidite channel in each seismic section; record the parameters of various influencing factors of the period in which the turbidite channel is located;

[0014] The grey correlation method is used to calculate the correlation between the morphological characterization parameters and the parameters of various influencing factors, so as to determine the influence degree of various influencing factor parameters on the morphology of turbidite waterways.

[0015] Preferably, the step of respectively calculating the morphological characterization parameters of the turbidite channel in each seismic profile comprises the following steps:

[0016] The true curvature of the boundary of the turbidite channel is calculated in each seismic profile to characterize the curvature of the boundary of the turbidite channel; the inclination of the side wall of the turbidite channel is determined to determine the contact relationship between the turbidite channel and the surrounding rock formation; the angle between the two side walls of the turbidite channel is determined to quantify the overall incision degree of the turbidite channel.

[0017] Preferably, the step of respectively recording the parameters of various influencing factors of the period in which the turbidity waterway is located comprises the following steps:

[0018] The various influencing parameters of the turbidite channel during its period are recorded separately, including altitude, burial depth and distance from the fault.

[0019] Preferably, the step of calculating the true curvature of the boundary of the turbidite channel comprises the following steps:

[0020] The real cross section of the turbidite channel is obtained from the seismic profile. In the middle of the turbidite channel, a reference interface S that runs horizontally through the turbidite channel is drawn according to the interpolation method of the top and bottom interfaces of the formation. The real curvatures of the two side walls at the junction of the reference interface S and the turbidite channel are calculated and recorded as K1 and K2.

[0021] Preferably, the step of determining the angle between the two side walls of the turbidite channel comprises the following steps:

[0022] The real cross section of the turbidite channel is obtained from the seismic profile, and a reference interface S that runs horizontally through the turbidite channel is drawn in the middle of the turbidite channel according to the interpolation method of the top and bottom interfaces of the formation;

[0023] The intersection point of the reference interface S and one side wall of the turbidite channel is marked as B, the side wall tangent M of the turbidite channel passing through point B is drawn, and the angle β between the reference interface S and the side wall tangent M is calculated; the intersection point of the reference interface S and the other side wall of the turbidite channel is marked as B', the side wall tangent M' of the turbidite channel passing through point B' is drawn, and the angle β' between the reference interface S and the side wall tangent M' is calculated.

[0024] Preferably, the step of determining the angle between the two side walls of the turbidite channel further comprises the following steps:

[0025] The acute angle γ between the sidewall tangent line M and the sidewall tangent line M' of the turbidite channel is calculated using trigonometric functions.

[0026] Preferably, the step of intercepting a plurality of seismic profiles perpendicular to the direction of the turbidite channel comprises the following steps:

[0027] The turbidite channel is divided into the initial stage, development stage, mature stage and decline stage, and multiple seismic profiles perpendicular to the direction of the turbidite channel are intercepted in each period.

[0028] Preferably, the step of calculating the correlation between the morphological characterization parameters and the parameters of the various influencing factors by using the grey correlation method further comprises the following steps:

[0029] With the morphological characterization parameters as the parent sequence and the parameters of various influencing factors as the subsequences, a grey correlation matrix was constructed, and the correlation between the morphological characterization parameters and the parameters of various influencing factors was calculated. Based on the numerical value of the correlation, the influence of the parameters of various influencing factors on the morphological characterization parameters of the turbidite waterway was determined.

[0030] As described above, the evaluation method of the influencing factors of the turbidite channel of the present invention has the following beneficial effects: first, the geological background of the current area and the formation conditions of the turbidite channel are analyzed to characterize the boundary of the turbidite channel; second, the paleo-geomorphology of the turbidite channel during the sedimentary period is restored to obtain the true morphology of the turbidite channel during the sedimentary period; then, a plurality of seismic profiles perpendicular to the direction of the turbidite channel are intercepted, and the morphological characterization parameters of the turbidite channel are calculated in each seismic profile; the parameters of the various influencing factors of the period in which the turbidite channel is located are recorded respectively; finally, the grey correlation method is used to calculate the correlation between the morphological characterization parameters and the parameters of the various influencing factors to determine the degree of influence of the various influencing factor parameters on the morphology of the turbidite channel. The main innovation of the above-mentioned turbidite channel influencing factor evaluation method is: determining the parent sequence in the grey correlation method by the influencing factors of the paleogeological historical period, determining the subsequence in the grey correlation method by using the morphological characterization parameters of the waterway under the real model of the paleogeological historical period, and obtaining the influence degree of the influencing factors of the paleogeological historical period on the waterway morphology by calculating and comparing the correlation degree. Compared with the linear correlation method involved in the existing tight sandstone reservoir, the turbidite channel influencing factor evaluation method has the advantages of small error, high credibility, strong operability, and quantitative-semi-quantitative. Therefore, the evaluation method of the turbidite channel influencing factor of the present invention can more effectively evaluate the influence degree of the influencing factors of the paleogeological historical period on the morphology of the turbidite channel, and has the advantages of small error, high credibility, strong operability, and quantitative-semi-quantitative. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Shown is a flow chart of the method for evaluating factors affecting turbidity waterways of the present invention;

[0032] Figure 2 Schematic diagram showing the top and bottom interfaces of a turbidite channel in a seismic section;

[0033] Figure 3 Schematic diagram showing the true curvature of the two side walls at the junction of the turbidite channel and the reference interface;

[0034] Figure 4 Schematic diagram showing the angle between the tangent line of the side wall of the turbidite channel and the reference interface;

[0035] Figure 5 Schematic diagram showing the angle between two tangent lines to the sidewalls of a turbidite channel. DETAILED DESCRIPTION

[0036] The following is a description of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0037] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0038] like Figure 1 and Figure 2 As shown, the present invention provides a method for evaluating factors affecting turbidity waterways, comprising the following steps:

[0039] Analyze the geological background of the current area and the formation conditions of the turbidite channel to characterize the boundaries of the turbidite channel;

[0040] Restore the paleo-geomorphology of the turbidite channel during the sedimentation period to obtain the true morphology of the turbidite channel during the sedimentation period;

[0041] Cut multiple seismic sections perpendicular to the direction of the turbidite channel, calculate the morphological characterization parameters of the turbidite channel in each seismic section; record the parameters of various influencing factors of the period in which the turbidite channel is located;

[0042] The grey correlation method is used to calculate the correlation between the morphological characterization parameters and the parameters of various influencing factors, so as to determine the influence degree of various influencing factor parameters on the morphology of turbidite waterways.

[0043] In the present invention, firstly, the geological background of the current area and the formation conditions of the turbidite channel are analyzed to characterize the boundary of the turbidite channel ( Figure 2The dotted part shown in the figure); secondly, the paleogeomorphology of the turbidite channel during the sedimentary period is restored to obtain the real morphology of the turbidite channel during the sedimentary period; then, multiple seismic profiles perpendicular to the direction of the turbidite channel are intercepted (the quantifier of the seismic profile is usually "line"), and the morphological characterization parameters of the turbidite channel are calculated in each seismic profile; the parameters of various influencing factors of the period in which the turbidite channel is located are recorded respectively; finally, the grey correlation method is used to calculate the correlation between the morphological characterization parameters and the parameters of various influencing factors to determine the influence of various influencing factor parameters on the morphology of the turbidite channel. The main innovation of the above-mentioned method for evaluating the influencing factors of turbidite channels is: determining the parent sequence in the grey correlation method through the influencing factors of the paleogeological historical period, determining the subsequence in the grey correlation method using the morphological characterization parameters of the waterway under the real model of the paleogeological historical period, and obtaining the degree of influence of the influencing factors of the paleogeological historical period on the waterway morphology through the calculation and comparison of the correlation degrees. Compared with the existing linear correlation methods involving tight sandstone reservoirs, this method for evaluating the influencing factors of turbidite channels has the advantages of small error, high credibility, strong operability, and quantitative-semi-quantitative.

[0044] Therefore, the evaluation method of the influencing factors of turbidity waterways of the present invention can more effectively evaluate the degree of influence of the influencing factors in the paleogeological history on the waterway morphology, and has the advantages of small error, high credibility, strong operability, and quantitative-semi-quantitative. Now, how to evaluate turbidity waterways is specifically described:

[0045] The above-mentioned step of analyzing the geological background of the current area and the formation conditions of the turbidite channel to depict the boundary of the turbidite channel includes the following steps: analyzing the regional geological background of the turbidite channel to be evaluated, clarifying the tectonic unit, tectonic evolution process, material source supply conditions, paleogeomorphic characteristics and sedimentary evolution pattern, analyzing the seismic reflection characteristics and the incision morphological pattern of the turbidite channel, and tracing the top and bottom interfaces of the turbidite channel on the premise of confirming that the turbidite channel has developed, so as to depict the top and bottom interfaces of the turbidite channel.

[0046] The above-mentioned steps of restoring the paleo-geomorphology of the turbidite channel during the sedimentary period to obtain the true shape of the turbidite channel during the sedimentary period include the following steps: using the residual thickness method and utilizing the tracking results of the above-mentioned top interface and bottom interface to flatten the top interface of the stratum where the turbidite channel is located, thereby restoring the paleo-geomorphology of the channel during the sedimentary period.

[0047] The step of respectively calculating the morphological characterization parameters of the turbidite channel in each seismic profile comprises the following steps:

[0048] The true curvature of the boundary of the turbidite channel is calculated in each seismic profile to characterize the curvature of the boundary of the turbidite channel; the inclination of the side wall of the turbidite channel is determined to determine the contact relationship between the turbidite channel and the surrounding rock formation; the angle between the two side walls of the turbidite channel is determined to quantify the overall incision degree of the turbidite channel.

[0049] The step of respectively recording the parameters of various influencing factors of the period in which the turbidity channel is located comprises the following steps:

[0050] The various influencing parameters of the turbidite channel during its period are recorded separately, including altitude, burial depth and distance from the fault.

[0051] like Figure 3 As shown, the step of calculating the true curvature of the boundary of the turbidite channel includes the following steps:

[0052] The real cross section of the turbidite channel is obtained from the seismic profile, and a reference interface S that crosses the turbidite channel is drawn in the middle of the turbidite channel according to the interpolation method of the top and bottom interfaces of the formation, and the real curvatures of the two side walls at the junction of the reference interface S and the turbidite channel are calculated, which are recorded as K1 and K2. Specifically, in one implementation scheme:

[0053] On the basis of restoring the turbidite channel in the ancient geological history, the seismic section perpendicular to the direction of the turbidite channel was selected as the typical section. In the middle of the turbidite channel, the reference interface S running through the turbidite channel was drawn according to the interpolation method of the top and bottom interfaces of the stratum. The formula is as follows:

[0054]

[0055] Among them, K is the true curvature, that is, the angle of the tangent on the unit arc segment; Δα is the angle of the tangent; Δs is the length of the arc segment where the tangent point moves.

[0056] For details, please refer to Figure 3 ,

[0057]

[0058] Wherein, K1 is the true curvature of the left wall of the turbidite channel; Δα is the angle between the side wall tangent L1 passing through point A and the side wall tangent L2 passing through point A'; Δs is the length of the arc segment between points A and A'.

[0059]

[0060] Among them, K2 is the true curvature of the right wall of the turbidite channel; Δα′ is the angle between the side wall tangent L2′ passing through point B and the side wall tangent L1′ passing through point B′; Δs′ is the length of the arc segment between points B and B′.

[0061] See also Figure 4 The step of determining the angle between the two side walls of the turbidite channel comprises the following steps:

[0062] The real cross section of the turbidite channel is obtained from the seismic profile, and a reference interface S that runs horizontally through the turbidite channel is drawn in the middle of the turbidite channel according to the interpolation method of the top and bottom interfaces of the formation;

[0063] The intersection point of the reference interface S and one of the side walls of the turbidite channel is marked as B, the side wall tangent M of the turbidite channel passing through point B is drawn, and the angle β between the reference interface S and the side wall tangent M is calculated, that is, the inclination angle of the left wall of the turbidite channel; the intersection point of the reference interface S and the other side wall of the turbidite channel is marked as B', the side wall tangent M' of the turbidite channel passing through point B' is drawn, and the angle β' between the reference interface S and the side wall tangent M' is calculated, that is, the inclination angle of the right wall of the turbidite channel.

[0064] Further, such as Figure 5 As shown, the step of determining the angle between the two side walls of the turbidite channel also includes the following steps:

[0065] The acute angle γ between the sidewall tangent line M and the sidewall tangent line M' of the turbidite channel is calculated using trigonometric functions.

[0066] The intersection point of the left wall tangent M and the right wall tangent M' of the turbidity channel is recorded as C, and the acute angle γ between the left wall tangent M and the right wall tangent M' of the turbidity channel is calculated as follows:

[0067]

[0068] The step of intercepting a plurality of seismic profiles perpendicular to the direction of the turbidite channel comprises the following steps:

[0069] The turbidite channel is divided into the initial stage, development stage, mature stage and decline stage, and multiple seismic profiles perpendicular to the direction of the turbidite channel are intercepted in each period.

[0070] The step of using the grey correlation method to calculate the correlation between the morphological characterization parameters and the parameters of the various influencing factors also includes the following steps:

[0071] With the morphological characterization parameters as the parent sequence and the parameters of various influencing factors as the subsequences, a grey correlation matrix was constructed, and the correlation between the morphological characterization parameters and the parameters of various influencing factors was calculated. Based on the numerical value of the correlation, the influence of the parameters of various influencing factors on the morphological characterization parameters of the turbidite waterway was determined.

[0072] In one embodiment, the morphological characterization parameter is one of the true curvature, the inclination of the side wall of the turbidite channel, and the angle between the two side walls of the turbidite channel, and the influencing factor parameter is multiple of the altitude H, the burial depth h of the top interface of the turbidite channel, and the distance L between the turbidite channel and the deep fault. The specific calculation process of the above correlation degree is as follows:

[0073] Five seismic profiles perpendicular to the direction of the turbidite channel were selected in the initial stage, development stage, mature stage and decline stage of the turbidite channel, and K1, K2, β, β', γ of the turbidite channel were calculated in each seismic profile. The altitude H of the corresponding period of the turbidite channel, the burial depth h of the top interface of the turbidite channel, and the distance L between the turbidite channel and the deep fault were recorded.

[0074] Taking K1 as an example, several seismic profiles of K1 are selected as the parent sequence, and the corresponding H1, h1, and L1 are selected as subsequences to construct the grey correlation matrix.

[0075] The K1 mother sequence is recorded as: K (0) (0) = {K1 (0) (0), K2 (0) (0), K3 (0) (0), K4 (0) (0), ... K n (0) (0)}; where n is the number of seismic profiles in the selected area;

[0076] The first influencing factor is the subsequence of the values ​​of the altitude H in each seismic profile period, denoted as H (0) (1) = {H1 (0) (1), H2 (0) (1), H3 (0) (1), H4 (0) (1), ... H n (0) (1)};

[0077] The second influencing factor is the subsequence of the burial depth h of the top interface of the turbidite channel in the period of each seismic profile, denoted as h (0) (2) = {h1 (0) (2), h2 (0) (2), h3 (0) (2), h4 (0) (2), ...h n (0) (2)};

[0078] The third influencing factor is the subsequence of the distance L between the turbidite channel and the deep fault in each seismic profile, denoted as L (0) (3) = {L1(0) (3), L2 (0) (3), L3 (0) (3), L4 (0) (3), ... L n (0) (3)};

[0079] The grey incidence matrix is ​​recorded as

[0080]

[0081] After standardization and normalization, the correlation coefficient and correlation degree of H1, h1, L1 and K1 are calculated.

[0082] Similarly, the correlations of H, h, L and K1, K2, β, β', γ are calculated respectively. By comparing the correlations, the influence of altitude, burial depth, and distance from the fracture on the true curvature of the left and right walls of the turbidite channel, the inclination of the tangents of the left and right walls of the turbidite channel, and the angle between the two tangents of the left and right walls of the turbidite channel are determined, thereby determining the main influencing factors of the turbidite channel morphology.

[0083] The corresponding calculation example:

[0084] Five seismic profiles of turbidite channels were selected and dissected. A reference interface S running through the turbidite channel was selected in each seismic profile, and the true curvatures K1 and K2 of the left and right walls at the junction of the reference interface S and the turbidite channel were calculated. For the convenience of expression, the left and right curvatures of the nth seismic profile are Kn1 and Kn2, respectively. The calculation results of the five selected seismic profiles are: K11 = 0.0039, K12 = 0.0036; K21 = 0.0109, K22 = 0.0073; K31 = 0.0040, K32 = 0.0072; K41 = 0.0180, K42 = 0.0124; K51 = 0.0267, K52 = 0.0219.

[0085] The angles between the reference interface S of the nth seismic profile and the tangent lines M and M' of the left and right walls of the turbidite channel are recorded as βn and β'n in radians. The calculation results of the five selected seismic profiles are: β1 = 0.6910, β1' = 0.4093; β1 = 0.4984, β1' = 0.3275; β1 = 0.4814, β1' = 0.5142; β1 = 0.7186, β1' = 0.7221; β1 = 0.8678, β1' = 0.5792.

[0086] For the convenience of expression, the acute angle between the tangent line of the left wall of the waterway and the tangent line of the right wall of the waterway in the nth seismic profile is recorded as γn. The calculation results of the five selected seismic profiles are: γ1 = 2.0413, γ2 = 2.3158, γ3 = 2.1460, γ4 = 1.7009, γ5 = 1.6945.

[0087] For the convenience of description, the altitude of the turbidite channel in the nth seismic profile, the burial depth of the top interface of the turbidite channel, and the distance of the turbidite channel from the deep fault are recorded as Hn, hn, and Ln respectively. For the five selected seismic profiles, the measurement results are: H1 = 130m, h1 = 3850m, L1 = 10600km; H2 = 120m, h2 = 3750m, L2 = 300m; H3 = 130m, h3 = 3620m, L3 = 300m; H4 = 115m, h4 = 3700m, L4 = 1000m; H5 = 110m, h5 = 3650m, L5 = 1900m.

[0088] Taking the five selected seismic profiles K1 as an example, a grey correlation sequence is constructed:

[0089]

[0090] Taking the first column as the benchmark, all columns are standardized and normalized, and the correlation coefficients between K1 and H, h, and L are calculated to obtain the degree of correlation.

[0091] The calculation results show that the correlation between H and K1 is 0.6154, the correlation between h and K1 is 0.6150, and the correlation between L and K1 is 0.5185.

[0092] Similarly, the correlations between H and K2, β, β', and γ are 0.5927, 0.6777, 0.6796, and 0.8814, respectively; the correlations between h and K2, β, β', and γ are 0.5952, 0.7193, 0.6760, and 0.8111, respectively; and the correlations between L and K2, β, β', and γ are 0.4994, 0.3948, 0.4152, and 0.3929, respectively.

[0093] From the calculation results, the distance of the turbidity channel from the deep fault has the least impact on the turbidity channel, and the correlation is generally lower than 0.5, while the altitude and burial depth of the turbidity channel have a relatively large impact on the turbidity channel, and the correlation is mostly higher than 0.6. In addition, by comparison, it can be seen that the sharp angle between the left wall tangent and the right wall tangent of the turbidity channel is most affected by the altitude and burial depth, and the correlation is as high as 0.8 or more.

[0094] It can be seen from the above technical scheme that the present invention tracks the boundary of the turbidite channel and restores the paleogeomorphology through the seismic profile perpendicular to the turbidite channel, calculates the true curvature of the boundary of the turbidite channel, restores the inclination of the side wall of the turbidite channel, determines the angle between the two side walls of the turbidite channel, calculates the degree of correlation between the geometric parameters of the turbidite channel and the altitude, burial depth, and distance from the fracture, and quantitatively evaluates the influencing factors of the turbidite channel. Since the geometric parameters of the paleogeological historical period are calculated through the restoration of paleogeomorphology, and the influencing factors of the turbidite channel are obtained through dimensionless processing of the original data column, calculation of the correlation coefficient, determination of the correlation degree, and comparison of the correlation degree, this method has the advantages of high credibility, strong operability, and quantitative-semi-quantitative relative to the prior art.

[0095] In summary, the present invention can more effectively evaluate the influence of factors in the paleogeological history on the waterway morphology, and has the advantages of small error, high credibility, strong operability, and quantitative-semi-quantitative. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0096] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for evaluating factors affecting turbidity waterways, characterized in that: The following steps are involved: Analyze the geological background of the current area and the formation conditions of the turbidite channel to characterize the boundaries of the turbidite channel; Restore the paleo-geomorphology of the turbidite channel during the sedimentation period to obtain the true morphology of the turbidite channel during the sedimentation period; Cut multiple seismic sections perpendicular to the direction of the turbidite channel, calculate the morphological characterization parameters of the turbidite channel in each seismic section; record the parameters of various influencing factors of the period in which the turbidite channel is located; The grey correlation method is used to calculate the correlation between the morphological characterization parameters and the parameters of various influencing factors, so as to determine the influence degree of various influencing factor parameters on the morphology of turbidity waterways. The morphological characterization parameters are used as the parent sequence and the parameters of various influencing factors are used as the child sequence to construct a grey correlation matrix, and the correlation between the morphological characterization parameters and the parameters of various influencing factors is calculated; based on the numerical value of the correlation, the influence degree of various influencing factor parameters on the morphological characterization parameters of turbidity waterways is determined.

2. The method for evaluating factors affecting turbidity waterways according to claim 1, characterized in that: The step of respectively calculating the morphological characterization parameters of the turbidite channel in each seismic profile comprises the following steps: The true curvature of the boundary of the turbidite channel is calculated in each seismic profile to characterize the curvature of the boundary of the turbidite channel; the inclination of the side wall of the turbidite channel is determined to determine the contact relationship between the turbidite channel and the surrounding rock formation; the angle between the two side walls of the turbidite channel is determined to quantify the overall incision degree of the turbidite channel.

3. The method for evaluating factors affecting turbidity waterways according to claim 1, characterized in that: The step of respectively recording the parameters of various influencing factors of the period in which the turbidity channel is located comprises the following steps: The various influencing parameters of the turbidite channel during its period are recorded separately, including altitude, burial depth and distance from the fault.

4. The method for evaluating factors affecting turbidity waterways according to claim 2, characterized in that: The step of calculating the true curvature of the turbidite channel boundary comprises the following steps: The real cross section of the turbidite channel is obtained from the seismic profile. In the middle of the turbidite channel, a reference interface S that runs horizontally through the turbidite channel is drawn according to the interpolation method of the top and bottom interfaces of the formation. The real curvatures of the two side walls at the junction of the reference interface S and the turbidite channel are calculated and recorded as K1 and K2.

5. The method for evaluating factors affecting turbidity waterways according to claim 2, characterized in that: The step of determining the angle between the two side walls of the turbidite channel comprises the following steps: The real cross section of the turbidite channel is obtained from the seismic profile, and a reference interface S that runs horizontally through the turbidite channel is drawn in the middle of the turbidite channel according to the interpolation method of the top and bottom interfaces of the formation; The intersection point of the reference interface S and one side wall of the turbidite channel is marked as B, the side wall tangent M of the turbidite channel passing through point B is drawn, and the angle β between the reference interface S and the side wall tangent M is calculated; the intersection point of the reference interface S and the other side wall of the turbidite channel is marked as B', the side wall tangent M' of the turbidite channel passing through point B' is drawn, and the angle β' between the reference interface S and the side wall tangent M' is calculated.

6. The method for evaluating factors affecting turbidity waterways according to claim 5, characterized in that: The step of determining the angle between the two side walls of the turbidite channel also includes the following steps: The acute angle γ between the sidewall tangent line M and the sidewall tangent line M' of the turbidite channel is calculated using trigonometric functions.

7. The method for evaluating factors affecting turbidity waterways according to claim 1, characterized in that: The step of intercepting a plurality of seismic profiles perpendicular to the direction of the turbidite channel comprises the following steps: The turbidite channel is divided into the initial stage, development stage, mature stage and decline stage, and multiple seismic profiles perpendicular to the direction of the turbidite channel are intercepted in each period.

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