Method and system for evaluating the sealing performance of submarine fan lithologic traps with canyon channel side seals

Abstract

This invention provides a method and system for evaluating the sealing performance of submarine fan lithological traps enclosed by canyon channel walls. It determines evaluation parameters for the degree of damage, thickness, and closure of the canyon channel wall to be evaluated; identifies the canyon channel enclosed by the canyon channel wall to be evaluated; and determines evaluation parameters for the sand-richness and overlapping relationships of the canyon channel. By combining these evaluation parameters, the sealing performance of the submarine fan lithological traps enclosed by the canyon channel wall is quantitatively calculated and evaluated. This invention not only comprehensively considers various geological factors of the canyon channel wall to be evaluated, accurately and objectively evaluating the sealing performance of submarine fan lithological traps enclosed by the canyon channel wall, but also quantitatively calculates and evaluates the sealing performance of submarine fan lithological traps enclosed by the canyon channel wall, providing clear and detailed guidance for oil and gas exploration.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas exploration technology, and in particular relates to a method and system for evaluating the sealing performance of submarine fan lithological traps on the side walls of canyons and waterways. Background Technology

[0002] As oil and gas exploration deepens, favorable large-scale structural traps are becoming increasingly scarce, and lithological traps have become the main source of oil and gas discoveries and increased reserves and production both domestically and internationally. Since 2020, for the first time, the proportion of oil and gas reserves discovered within lithological traps in my country's offshore waters has exceeded that of structural and buried hill oil and gas reservoirs; lithological traps have become the main force driving the growth of reserves in China's nearshore waters, and China's nearshore waters have fully entered the lithological trap exploration stage.

[0003] In the deep ocean, submarine fans, as an important type of oil and gas reservoir, can form large-scale lithological traps. However, these submarine fans are often eroded and cut by later canyons and channels, which may destroy the effectiveness of submarine fan lithological traps. When the top structural high (updip direction) of a submarine fan is cut by a canyon, if the canyon channel wall on the updip direction of the submarine fan acts as a sealing layer for oil and gas migration, a submarine fan lithological trap can be formed; conversely, if the canyon channel wall on the updip direction of the submarine fan acts as a conduit for oil and gas migration, a submarine fan lithological trap cannot be formed. Therefore, the ability to effectively evaluate the sealing effect of canyon channel walls on submarine fan lithological traps is crucial for oil and gas exploration in submarine fan lithological traps.

[0004] The existing "method for evaluating the sealing performance of canyon channel walls on submarine fan lithological traps" has the following two major problems:

[0005] First, existing methods for evaluating the sealing capacity of canyon channel walls for submarine fan lithological traps are primarily qualitative, failing to quantitatively assess the sealing capacity of canyon channel walls. For example, You Li (2021) argues that if a submarine fan connects to mudstone on the inner side of a canyon channel wall, the canyon channel wall acts as a seal, forming a submarine fan lithological trap associated with the canyon channel wall; however, if a submarine fan connects to sandstone on the inner side of a canyon channel wall, the canyon channel wall acts as a transporter, failing to form a submarine fan lithological trap associated with the canyon channel wall.

[0006] Second, existing methods for evaluating the sealing performance of canyon channel walls to submarine fan lithological traps often only consider a single factor, such as the connection between the lithology inside and outside the canyon channel wall, without comprehensively considering multiple geological factors that affect the sealing performance of the canyon channel wall. Summary of the Invention

[0007] The main objective of this invention is to propose a method and system for evaluating the sealing performance of submarine fan lithological traps on the side walls of canyons, aiming to solve the technical problem that existing technologies cannot quantitatively evaluate the sealing performance of submarine fan lithological traps.

[0008] To achieve the above objectives, the present invention provides a method for evaluating the sealing capacity of submarine fan lithological traps on the sidewalls of canyons, the method comprising:

[0009] Seismic data of a specified submarine fan is obtained, and the canyon channel wall of the lithological trap of the side-sealed submarine fan is determined based on the seismic data as the canyon channel wall to be evaluated. Seismic profiles perpendicular to the canyon channel wall to be evaluated are obtained.

[0010] Based on the seismic profile to be evaluated and the preset geological conditions, the evaluation parameters for the degree of damage, thickness, and degree of closure of the canyon waterway wall to be evaluated are determined.

[0011] Identify the canyon waterway to be evaluated, which is enclosed by the walls of the canyon waterway to be evaluated, and determine the sand-richness evaluation parameters and the overlapping relationship evaluation parameters of the canyon waterway to be evaluated.

[0012] The sealing performance of the submarine fan lithological trap of the canyon waterway wall side seal is quantitatively calculated and evaluated by combining the damage degree evaluation parameters, the thickness evaluation parameters, the sand-rich degree evaluation parameters, the overlapping relationship evaluation parameters, and the closure degree evaluation parameters.

[0013] In this embodiment of the invention, the quantitative evaluation of the sealing performance of the submarine fan lithological trap on the side wall of the canyon channel to be evaluated includes:

[0014] The sealing coefficient of the submarine fan lithological trap on the side wall of the canyon channel to be evaluated is quantitatively calculated using the following formula:

[0015] B i =D a *(0.4T b +0.3S c +0.2M d +0.1C e (i,a,b,c,d,e=1,2,3),

[0016] Among them, B i D is the blocking coefficient. a T is the parameter for evaluating the degree of damage. b S is the thickness evaluation parameter. c M is the parameter for evaluating the degree of sand enrichment. d C is the evaluation parameter for the overlapping relationship. e The closure degree evaluation parameter;

[0017] The sealing performance of the submarine fan lithological trap on the side wall of the canyon waterway to be evaluated is quantitatively evaluated based on the sealing coefficient and the preset evaluation coefficient.

[0018] In this embodiment of the invention, the quantitative evaluation of the sealing performance of the submarine lithological trap of the canyon channel wall side seal based on the sealing coefficient and the preset evaluation coefficient includes:

[0019] B i =0, the sealing of the submarine fan lithological trap on the side wall of the canyon waterway to be evaluated has failed;

[0020] B i <0.25, indicating that the sealing performance of the submarine fan lithological trap on the side wall of the canyon waterway to be evaluated is poor;

[0021] 0.25 i <0.6, indicating that the sealing performance of the submarine fan lithological trap on the side wall of the canyon channel to be evaluated is good;

[0022] B i >0.6, indicating that the sealing performance of the submarine fan lithological trap on the side wall of the canyon waterway to be evaluated is excellent.

[0023] In this embodiment of the invention, determining the canyon channel wall of the lithological trap of the submarine fan lateral enclosure based on the seismic data as the canyon channel wall to be evaluated includes:

[0024] Identify V-shaped or U-shaped seismic reflection units in the seismic data that are located at the bottom of the canyon waterway, cut through and traverse near-horizontal seismic reflections, and are composed of a preset number of seismic reflection phase axes, as canyon waterway walls;

[0025] Obtain the top surface structure diagram of the specified submarine fan and the location where the canyon channel to be evaluated cuts the specified submarine fan. Search and determine the canyon channel wall that cuts the submarine fan and whose outer side shows a decrease in the contour lines of the top surface structure of the submarine fan, and use it as the canyon channel wall to be evaluated.

[0026] In this embodiment of the invention, determining the evaluation parameters for the degree of damage to the canyon waterway wall based on the seismic profile to be evaluated and preset geological conditions includes:

[0027] Determine whether the canyon waterway wall on the seismic profile to be evaluated is a diapir-pierced canyon waterway wall, a turbidity flow-cutted canyon waterway wall, or a canyon waterway wall that is intact and uninterrupted.

[0028] When the canyon waterway wall to be evaluated is either the diapiric waterway wall or the turbid waterway wall, the evaluation parameter for the degree of damage to the canyon waterway wall to be evaluated is the first damage parameter.

[0029] If the canyon waterway wall to be evaluated is intact and uninterrupted, the evaluation parameter for the degree of damage to the canyon waterway wall to be evaluated is the second damage parameter.

[0030] ​In this embodiment of the invention, determining the thickness evaluation parameters of the canyon waterway wall to be evaluated based on the seismic profile to be evaluated and preset geological conditions includes:

[0031] If the wall of the canyon to be evaluated is identified as having continuous crests and troughs, and the strata inside and outside the canyon to be evaluated have different attitudes and the seismic reflection unit characteristics inside and outside the canyon to be evaluated are different, then the thickness evaluation parameter is determined to be the first thickness parameter.

[0032] If the wall of the canyon channel to be evaluated is identified as having continuous crests and troughs, and there are continuous seismic reflection units with consistent strata attitude inside or outside the wall of the canyon channel to be evaluated, then the thickness evaluation parameter is determined to be the second thickness parameter.

[0033] If the wall of the canyon channel to be evaluated is identified as having continuous peaks and troughs, and if both the interior and exterior of the canyon channel wall to be evaluated exhibit continuous reflections with consistent orientation, then the thickness evaluation parameter is determined to be the third thickness parameter.

[0034] In this embodiment of the invention, the evaluation parameters for determining the degree of closure of the canyon waterway wall to be evaluated include:

[0035] Obtain the coverage area ratio of the medium-strong amplitude, medium-high frequency, and medium-high continuous reflection submarine fan sand at the top of the canyon waterway wall to be evaluated;

[0036] The evaluation parameters for the degree of closure of the canyon waterway wall to be evaluated are determined based on the coverage ratio and the preset closure interval.

[0037] In this embodiment of the invention, the parameters for determining the sand-richness of the canyon waterway to be evaluated include:

[0038] Obtain the total cross-sectional area of ​​the canyon waterway to be evaluated and the sand area of ​​the canyon waterway within the canyon waterway to be evaluated, and calculate the ratio of the sand area of ​​the canyon waterway to the sand-rich area of ​​the total cross-sectional area.

[0039] The sand-richness evaluation parameters of the canyon waterway to be evaluated are determined based on the sand-rich area ratio and the preset sand-rich interval.

[0040] In this embodiment of the invention, determining the evaluation parameters for the overlapping relationship of the canyon waterway to be evaluated includes:

[0041] Determine whether the canyon waterway to be evaluated is undergoing disordered migration, unidirectional migration, or ordered migration;

[0042] When the canyon waterway to be evaluated is in a state of disordered migration, the overlapping relationship evaluation parameter of the canyon waterway to be evaluated is determined as the first overlapping parameter.

[0043] When the canyon waterway to be evaluated is unidirectionally migrating, the overlapping relationship evaluation parameter of the canyon waterway to be evaluated is determined as the second overlapping parameter;

[0044] When the canyon waterway to be evaluated is in an orderly migration, the overlapping relationship evaluation parameter of the canyon waterway to be evaluated is determined as the third overlapping parameter.

[0045] This invention also proposes an evaluation system for the sealing performance of submarine fan lithological traps on the sidewalls of canyons, the evaluation system comprising:

[0046] The image processing module acquires seismic data of a specified submarine fan, determines the canyon channel wall of the side-sealed submarine fan lithological trap based on the seismic data, and uses it as the canyon channel wall to be evaluated, and acquires the seismic profile to be evaluated perpendicular to the canyon channel wall to be evaluated.

[0047] The parameter identification module determines the damage degree evaluation parameters, thickness evaluation parameters, and closure degree evaluation parameters of the canyon waterway wall to be evaluated based on the seismic profile to be evaluated and the preset geological conditions. It also identifies the canyon waterway to be evaluated enclosed by the canyon waterway wall and determines the sand-rich degree evaluation parameters and the overlapping relationship evaluation parameters of the canyon waterway to be evaluated.

[0048] The calculation and evaluation module, in combination with the damage degree evaluation parameters, the thickness evaluation parameters, the sand-rich degree evaluation parameters, the overlapping relationship evaluation parameters, and the closure degree evaluation parameters, quantitatively calculates and evaluates the sealing performance of the submarine fan lithological trap on the side wall of the canyon waterway to be evaluated.

[0049] Through the above technical solution, the method for evaluating the sealing performance of submarine fan lithological traps on the side of canyon waterway walls provided by the embodiments of the present invention has the following beneficial effects:

[0050] First, canyon channel walls capable of laterally sealing submarine fan lithological traps are identified as the canyon channel walls to be evaluated, and seismic profiles of these walls are obtained. This provides a precise identification area for subsequent quantitative calculations and evaluations. Furthermore, based on the seismic profiles and pre-defined geological conditions, evaluation parameters for the degree of damage, thickness, and closure of the canyon channel walls are determined. This approach considers multiple geological factors of the canyon channel walls, avoiding the limitations of existing methods that only consider a single factor when evaluating the sealing performance of canyon channel walls in submarine fan lithological traps. This allows for a more accurate and objective evaluation of the sealing performance of canyon channel walls in laterally sealing submarine fan lithological traps. Compared to existing technologies that only provide qualitative analysis and fail to quantitatively evaluate the sealing performance of canyon channel walls, this invention quantifies the geological factors affecting the sealing performance of submarine fan lithological traps on the sidewalls of the canyon channel to be evaluated. Furthermore, by combining parameters for sand content and overlapping relationships within the canyon channel to be evaluated, it enables quantitative calculation and evaluation of the sealing performance of submarine fan lithological traps on the sidewalls of the canyon channel to be evaluated, providing clear and detailed guidance for oil and gas exploration. This invention not only comprehensively considers the multi-dimensional geological factors of the canyon channel to be evaluated, accurately and objectively evaluating the sealing performance of submarine fan lithological traps on the sidewalls of the canyon channel, but also quantitatively calculates and evaluates the sealing performance of submarine fan lithological traps on the sidewalls of the canyon channel to be evaluated, providing clear and detailed guidance for oil and gas exploration.

[0051] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0052] The accompanying drawings are provided to illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0053] Figure 1 This is a flowchart illustrating the method for evaluating the sealing performance of a submarine fan lithological trap on the side of a canyon channel wall according to an embodiment of the present invention.

[0054] Figure 2 These are typical seismic reflection characteristics and examples of diapiric waterway walls piercing canyon walls and turbidity currents cutting through canyon walls.

[0055] Figure 3 These are typical profiles of seismic reflection characteristics and examples of the sidewall thickness of different types of canyon waterway walls;

[0056] Figure 4 These are typical profiles and examples of seismic reflection characteristics of different types of canyon waterways with varying sand content.

[0057] Figure 5 These are typical cross-sectional seismic reflection characteristics and examples of overlapping relationships between different types of canyons and waterways;

[0058] Figure 6 These are typical profiles and examples of seismic reflection characteristics of different types of canyon waterway sidewall closure.

[0059] Figure 7 This is an example of quantitatively evaluating the sealing performance of the LS25-1 section of the central canyon waterway wall, which is a lateral sealing lithological trap of the Meishan Formation submarine fan.

[0060] Figure 8 This is a quantitative example of the sealing performance of the LS25-5 segment of the central canyon waterway wall, which is a lateral sealing lithological trap of the Meishan Formation submarine fan. Detailed Implementation

[0061] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0062] The following describes, with reference to the accompanying drawings, a method for evaluating the sealing performance of submarine fan lithological traps on the side walls of canyons according to the present invention.

[0063] like Figure 1 As shown, in an embodiment of the present invention, the method for evaluating the sealing performance of the submarine fan lithological trap on the canyon channel wall includes:

[0064] Step S1: Obtain seismic data of the specified submarine fan, determine the canyon channel wall of the side-sealed submarine fan lithological trap based on the seismic data, and use it as the canyon channel wall to be evaluated. Obtain the seismic profile to be evaluated perpendicular to the canyon channel wall to be evaluated.

[0065] Step S2: Based on the seismic profile to be evaluated and the preset geological conditions, determine the evaluation parameters for the degree of damage, thickness, and degree of closure of the canyon waterway wall to be evaluated.

[0066] Step S3: Identify the canyon waterway to be evaluated, which is enclosed by the canyon waterway wall, and determine the sand-richness evaluation parameters and the overlapping relationship evaluation parameters of the canyon waterway to be evaluated.

[0067] Step S4: Combine the damage degree evaluation parameters, thickness evaluation parameters, sand-rich degree evaluation parameters, overlapping relationship evaluation parameters, and closure degree evaluation parameters to quantitatively calculate and evaluate the sealing performance of the submarine fan lithological trap on the side wall of the canyon channel to be evaluated.

[0068] In this embodiment, canyon channel walls capable of laterally sealing submarine fan lithological traps are first identified as the canyon channel walls to be evaluated, and seismic profiles of these walls are obtained, providing accurate identification areas for subsequent quantitative calculations and evaluations. Furthermore, based on the seismic profiles and preset geological conditions, evaluation parameters for the degree of damage, thickness, and closure of the canyon channel walls are determined. This approach combines multi-dimensional geological factors of the canyon channel walls, avoiding the limitation of existing methods that only consider a single factor when evaluating the sealing performance of canyon channel walls in submarine fan lithological traps. This allows for a more accurate and objective evaluation of the sealing performance of canyon channel walls in laterally sealing submarine fan lithological traps. Compared to existing technologies that can only qualitatively analyze but not quantitatively evaluate the sealing performance of canyon channel walls, this embodiment quantifies the geological factors affecting the sealing performance of submarine fan lithological traps on the side walls of the canyon channel to be evaluated. Furthermore, by combining the evaluation parameters of the sand-richness and overlapping relationship of the canyon channel to be evaluated, it is possible to quantitatively calculate and evaluate the sealing performance of submarine fan lithological traps on the side walls of the canyon channel to be evaluated, providing clear and detailed guidance for oil and gas exploration.

[0069] This embodiment not only comprehensively considers the multi-dimensional geological factors of the canyon channel wall to be evaluated, and accurately and objectively evaluates the sealing performance of the submarine fan lithological traps on the side of the canyon channel wall, but also quantitatively calculates and evaluates the sealing performance of the submarine fan lithological traps on the side of the canyon channel wall to be evaluated, providing clear and detailed guidance for oil and gas exploration.

[0070] It should be noted that the three seismic reflection parameters—amplitude, frequency, and continuity—in the seismic profile to be evaluated can be identified based on the reflection characteristics of the acquired seismic profile. Specifically, the three levels of seismic reflection amplitude—strong, moderate, and weak—can be determined by the depth of the seismic reflection color; the lighter the color, the weaker the amplitude, and vice versa. The three levels of seismic reflection frequency—high, moderate, and low—can be determined by the thickness of the seismic reflection; the thinner the thickness, the higher the frequency, and vice versa. Finally, the three levels of seismic reflection continuity—good, moderate, and poor—can be determined by the degree of lateral continuity of the seismic reflection; the lower the degree of lateral continuity, the worse the continuity, and vice versa.

[0071] In one embodiment, the quantitative evaluation of the sealing performance of the submarine fan lithological trap on the sidewall of the canyon channel to be evaluated includes:

[0072] The sealing coefficient of the submarine fan lithological trap on the side wall of the canyon channel to be evaluated is quantitatively calculated using the following formula:

[0073] B i =D a *(0.4T b +0.3S c +0.2M d +0.1C e(i,a,b,c,d,e=1,2,3),

[0074] Among them, B i D is the blocking coefficient. a T is the parameter for evaluating the degree of damage. b S is the thickness evaluation parameter. c M is the parameter for evaluating the degree of sand enrichment. d C is the evaluation parameter for the overlapping relationship. e The closure degree evaluation parameter;

[0075] The sealing performance of the submarine fan lithological trap on the side wall of the canyon waterway to be evaluated is quantitatively evaluated based on the sealing coefficient and the preset evaluation coefficient.

[0076] This embodiment combines evaluation parameters for degree of damage, thickness, sand content, overlapping relationship, and closure. Based on the above calculation formulas, the sealing coefficient can be accurately and quantitatively calculated. By combining the sealing coefficient and the preset evaluation coefficient, the sealing performance of the submarine fan lithological trap on the side wall of the canyon channel to be evaluated can be accurately evaluated.

[0077] In this embodiment of the invention, the quantitative evaluation of the sealing performance of the submarine lithological trap of the canyon channel wall side seal based on the sealing coefficient and the preset evaluation coefficient includes:

[0078] B i =0, the sealing of the submarine fan lithological trap on the side wall of the canyon waterway to be evaluated has failed;

[0079] B i <0.25, indicating that the sealing performance of the submarine fan lithological trap on the side wall of the canyon waterway to be evaluated is poor;

[0080] 0.25 i <0.6, indicating that the sealing performance of the submarine fan lithological trap on the side wall of the canyon channel to be evaluated is good;

[0081] B i >0.6, indicating that the sealing performance of the submarine fan lithological trap on the side wall of the canyon waterway to be evaluated is excellent.

[0082] The preset evaluation coefficients in this embodiment include 0, 0.25 and 0.6, which can accurately divide the sealing properties of the submarine fan lithological traps on the side walls of the canyon waterway to be evaluated into 4 gradients. This can avoid the situation where the gradient is too large and the oil and gas exploration cannot be accurate, and also avoid the situation where the workload of oil and gas exploration is too large, thus providing an accurate and effective evaluation basis for oil and gas exploration.

[0083] In this embodiment of the invention, determining the canyon channel wall of the lithological trap of the submarine fan lateral enclosure based on the seismic data as the canyon channel wall to be evaluated includes:​

[0084] Identify V-shaped or U-shaped seismic reflection units in the seismic data that are located at the bottom of the canyon waterway, cut through and traverse near-horizontal seismic reflections, and are composed of a preset number of seismic reflection phase axes, as canyon waterway walls;

[0085] Obtain the top surface structure diagram of the specified submarine fan and the location where the canyon channel to be evaluated cuts the specified submarine fan. Search and determine the canyon channel wall that cuts the submarine fan and whose outer side shows a decrease in the contour lines of the top surface structure of the submarine fan, and use it as the canyon channel wall to be evaluated.

[0086] The top surface structure diagram in this embodiment can be drawn based on the seismic data of the specified submarine fan. In this embodiment, the canyon channel wall is first accurately obtained by combining location information, seismic reflection information, and seismic reflection phase axis information. Then, by combining the top surface structure diagram of the specified submarine fan and the location where the evaluation channel cuts the specified submarine fan, the canyon channel wall to be evaluated is determined. The canyon channel wall that cuts the submarine fan and whose outer side shows a decrease in the top surface structure contour lines of the submarine fan is taken as the canyon channel wall to be evaluated. This avoids interference from other canyon channel walls, effectively narrows the scope of quantitative evaluation of sealing capacity, and improves the efficiency of quantitative evaluation of sealing capacity. Figure 3 As shown, the number of seismic reflection phase axes can be 1, 2, or 3.

[0087] In this embodiment of the invention, determining the evaluation parameters for the degree of damage to the canyon waterway wall based on the seismic profile to be evaluated and preset geological conditions includes:

[0088] Determine whether the canyon waterway wall on the seismic profile to be evaluated is a diapir-pierced canyon waterway wall, a turbidity flow-cutted canyon waterway wall, or a canyon waterway wall that is intact and uninterrupted.

[0089] When the canyon waterway wall to be evaluated is either the diapiric waterway wall or the turbid waterway wall, the evaluation parameter for the degree of damage to the canyon waterway wall to be evaluated is the first damage parameter.

[0090] If the canyon waterway wall to be evaluated is intact and uninterrupted, the evaluation parameter for the degree of damage to the canyon waterway wall to be evaluated is the second damage parameter.

[0091] like Figure 2 As shown, Figure 2 On the left is the Diapi piercing the canyon waterway wall. When identifying the Diapi piercing the canyon waterway wall, it can be found on the seismic profile that it is located at the bottom of the canyon waterway, passing through and cutting through the near-horizontal seismic reflection, and is composed of V-shaped or U-shaped seismic reflection units consisting of 1 to 3 seismic reflection phase axes. It is interrupted by columnar, chaotic reflections with the center of the axis tilting upward. Figure 2On the right is the turbidity flow cutting through the canyon channel wall. When identifying the turbidity flow cutting through the canyon channel wall, it can be found on the seismic profile at the bottom of the canyon channel, passing through and cutting through the V-shaped or U-shaped seismic reflection unit composed of 1 to 3 seismic reflection phase axes that are close to the horizontal seismic reflection, and being interrupted by the flat-topped and convex-bottomed filling seismic reflection.

[0092] When identifying the integrity and uninterrupted characteristics of canyon channel walls, V-shaped or U-shaped canyon channel walls located at the bottom of the canyon channel on the seismic profile, which are relatively intact and composed of 1 to 3 in-phase seismic reflection axes, and are not cut or interrupted by diapirs or turbidity currents. When the canyon channel wall to be evaluated is either pierced by a diapir or cut by a turbidity current, the damage assessment parameter of the canyon channel wall to be evaluated is 0; when the canyon channel wall to be evaluated is intact and uninterrupted, the damage assessment parameter of the canyon channel wall to be evaluated is assigned a value of 1, the first damage parameter is 0, and the second damage parameter is 1. In this embodiment, by determining the interruption method, the types of cutting of the canyon channel wall to be evaluated are classified, and the damage degree of the canyon channel wall to be evaluated is specifically divided into three types and assigned values ​​respectively, which improves the accuracy of damage degree identification.

[0093] In this embodiment of the invention, determining the thickness evaluation parameters of the canyon waterway wall to be evaluated based on the seismic profile to be evaluated and preset geological conditions includes:

[0094] If the wall of the canyon to be evaluated is identified as having continuous crests and troughs, and the strata inside and outside the canyon to be evaluated have different attitudes and the seismic reflection unit characteristics inside and outside the canyon to be evaluated are different, then the thickness evaluation parameter is determined to be the first thickness parameter.

[0095] If the wall of the canyon channel to be evaluated is identified as having continuous crests and troughs, and there are continuous seismic reflection units with consistent strata attitude inside or outside the wall of the canyon channel to be evaluated, then the thickness evaluation parameter is determined to be the second thickness parameter.

[0096] If the wall of the canyon channel to be evaluated is identified as having continuous peaks and troughs, and if both the interior and exterior of the canyon channel wall to be evaluated exhibit continuous reflections with consistent orientation, then the thickness evaluation parameter is determined to be the third thickness parameter.

[0097] like Figure 3 As shown in 3(a) and 3(a`) on the left, the following can be identified on the seismic profile: the canyon channel wall is a continuous crest / trough reflection, and seismic reflection units with different strata attitudes and characteristics are developed inside and outside the canyon channel wall; the canyon channel wall has one seismic reflection phase axis, and the thickness of the sidewall of the canyon channel wall to be evaluated is determined to be <1 / 4λ, and the canyon channel wall to be evaluated has one reflection phase axis, with a thickness evaluation parameter of 0.2.

[0098] like Figure 3 As shown in sections 3(b) and 3(b'), the following can be identified on the seismic profile: the canyon channel wall is a continuous wave crest / trough, and continuous reflections with consistent orientation are seen inside or outside the canyon channel wall. It is determined that 1 / 4λ < the thickness of the sidewall of the canyon channel wall to be evaluated < 1 / 2λ, and the canyon channel wall to be evaluated has two seismic reflection phase axes. The thickness evaluation parameter is 0.5.

[0099] like Figure 3 As shown in Figures 3(c) and 3(c') on the right, the canyon channel wall can be identified on the seismic profile as having continuous peaks / troughs, with continuous reflections of consistent orientation both inside and outside the canyon channel wall. It is determined that 1 / 2λ < the thickness of the canyon channel wall sidewall to be evaluated < 3 / 4λ, and the canyon channel wall to be evaluated has three in-phase reflection axes, with a thickness evaluation parameter of 1.0. In this embodiment, the thickness of the canyon channel wall sidewall and the in-phase reflection axes are determined by comparing the seismic reflections inside and outside the canyon channel wall to be evaluated, thus accurately obtaining the thickness evaluation parameter of the canyon channel wall to be evaluated. Figures a', b', and c' can be identified, interpreted, and delineated from Figures a, b, and c, where λ is the wavelet wavelength of the obtained seismic data, i.e., the thickest corresponding to the three axes, the middle two axes, and the thinnest axis.

[0100] In this embodiment of the invention, the evaluation parameters for determining the degree of closure of the canyon waterway wall to be evaluated include:

[0101] Obtain the coverage area ratio of the medium-strong amplitude, medium-high frequency, and medium-high continuous reflection submarine fan sand at the top of the canyon waterway wall to be evaluated;

[0102] The evaluation parameters for the degree of closure of the canyon waterway wall to be evaluated are determined based on the coverage ratio and the preset closure interval.

[0103] like Figure 6 As shown in 6(a) and 6(a') on the left, the top of the canyon channel wall to be evaluated is completely covered by submarine fan sand with strong amplitude, medium-high frequency, and medium-high continuous reflection; the canyon channel wall to be evaluated is determined to have a low degree of closure; as Figure 6 6(b) in the middle and Figure 6 As shown in (b'), nearly half of the top of the canyon channel wall to be evaluated is covered by submarine fan sand with strong amplitude, medium-high frequency, and medium-high continuous reflection; the canyon channel wall to be evaluated is determined to have a moderate degree of closure; as Figure 6As shown in 6(c) and 6(c') on the right, the top of the canyon channel wall to be evaluated is completely covered by deep-sea sludge with weak amplitude, low to medium frequency, and high continuous reflection; the canyon channel wall to be evaluated is determined to have a high degree of closure. Among them, the closure evaluation parameter of the canyon channel wall to be evaluated with a low degree of closure is 0.2, the closure evaluation parameter of the canyon channel wall to be evaluated with a medium degree of closure is 0.8, and the closure evaluation parameter of the canyon channel wall to be evaluated with a high degree of closure is 1.0.

[0104] In this embodiment, the degree of closure of the canyon channel wall to be evaluated is determined by determining the ratio of the area covered by seafloor fan sand at the top of the canyon channel wall to be evaluated, and the evaluation parameters of the degree of closure of the canyon channel wall to be evaluated are determined according to the coverage area ratio and the preset closure interval. The preset closure interval can be less than 0.5 and greater than 0.5.

[0105] In this embodiment of the invention, the parameters for determining the sand-richness of the canyon waterway to be evaluated include:

[0106] Obtain the total cross-sectional area of ​​the canyon waterway to be evaluated and the sand area of ​​the canyon waterway within the canyon waterway to be evaluated, and calculate the ratio of the sand area of ​​the canyon waterway to the sand-rich area of ​​the total cross-sectional area.

[0107] The sand-richness evaluation parameters of the canyon waterway to be evaluated are determined based on the sand-rich area ratio and the preset sand-rich interval.

[0108] like Figure 4 As shown in 4(a) and 4(a') on the left, the ratio of the area of ​​the canyon waterway sand with strong amplitude, low to medium frequency, and low to medium continuous reflection to the total cross-sectional area of ​​the canyon waterway being evaluated is greater than 50%; that is, the canyon waterway mud with weak amplitude, medium to high frequency, and medium to high continuous reflection is relatively small in the canyon waterway being evaluated, and the sand content is high; as Figure 4 As shown in sections 4(b) and 4(b'), the ratio of the area of ​​the canyon channel with strong amplitude-low frequency-low continuous reflection to the total profile area of ​​the canyon channel under evaluation is less than 50% but greater than 10%, indicating a moderate degree of sand enrichment; as Figure 4 As shown in 4(c) and 4(c`) on the right, the ratio of the area of ​​the canyon waterway sand with strong amplitude, low to medium frequency and low to medium continuous reflection to the total cross-sectional area of ​​the canyon waterway to be evaluated is less than 10%; that is, the canyon waterway mud with weak amplitude, medium to high frequency and medium to high continuous reflection accounts for the majority of the canyon waterway to be evaluated, and the sand content is low.

[0109] When the sand-richness of the canyon channel enclosed by the canyon wall to be evaluated is high, medium, or low, the sand-richness evaluation parameter is assigned values ​​of 0.2, 0.5, and 1.0, respectively. In this embodiment, the sand-richness evaluation parameter of the canyon channel is determined by calculating the ratio of the sand area of ​​the canyon channel to the sand-rich area of ​​the total profile area. This allows for accurate acquisition of the sand-richness evaluation parameter and further improves the quantitative evaluation accuracy of the sealing performance of the submarine fan lithological traps sealed by the canyon channel wall.

[0110] In this embodiment of the invention, determining the evaluation parameters for the overlapping relationship of the canyon waterway to be evaluated includes:

[0111] Determine whether the canyon waterway to be evaluated is undergoing disordered migration, unidirectional migration, or ordered migration;

[0112] When the canyon waterway to be evaluated is in a state of disordered migration, the overlapping relationship evaluation parameter of the canyon waterway to be evaluated is determined as the first overlapping parameter.

[0113] When the canyon waterway to be evaluated is unidirectionally migrating, the overlapping relationship evaluation parameter of the canyon waterway to be evaluated is determined as the second overlapping parameter;

[0114] When the canyon waterway to be evaluated is in an orderly migration, the overlapping relationship evaluation parameter of the canyon waterway to be evaluated is determined as the third overlapping parameter.

[0115] Since a single canyon waterway to be evaluated contains multiple canyon waterways to be evaluated, it can be determined according to, for example... Figure 5 As shown by the dotted lines in 5(a) and 5(a') on the left, the bottom envelope surfaces of the flat-topped and convex-bottomed infill reflections of multiple canyon waterways to be evaluated exhibit disordered oscillation from left to right and disordered superposition from bottom to top on the seismic profile; it can be determined that the overlapping relationship of multiple canyon waterways to be evaluated is disordered migration; as shown in Figure 5(a) on the left. Figure 5 As shown by the dotted lines in 5(b) and 5(b') in the middle section, the bottom envelope of the flat-topped, convex-bottomed filling reflection of the canyon channel to be evaluated continuously and stably migrates and oscillates in one direction from left to right on the seismic profile, and is orderly superimposed from bottom to top; it can be determined that the overlapping relationship of multiple canyon channels to be evaluated is unidirectional migration; such as Figure 5 As shown by the dotted lines in 5(c) and 5(c`) in the middle section, the bottom envelope of the flat-topped and convex-bottomed filling reflection of the canyon waterway to be evaluated does not show obvious migration or swaying from left to right on the seismic profile, but continuously and stably superimposes and migrates upward from bottom to top. Moreover, the deepest point of the bottom envelope of these flat-topped and convex-bottomed filling reflections is on the same vertical direction, which can determine that the overlapping relationship of multiple canyon waterways to be evaluated is an ordered migration.

[0116] When the waterway to be evaluated, enclosed by the walls of the waterway wall, exhibits overlapping relationships of disordered migration, unidirectional migration, and ordered migration, the overlapping relationship evaluation parameters are assigned values ​​of 0.4, 0.8, and 1.0, respectively. The first overlapping parameter, the second overlapping parameter, and the third overlapping parameter are 0.4, 0.8, and 1.0, respectively. In this embodiment, by identifying the migration and superposition mode of the bottom envelope surface of the waterway to be evaluated, the overlapping relationship evaluation parameters of the waterway to be evaluated are determined, enabling intuitive and accurate acquisition of the overlapping relationship evaluation parameters.

[0117] This invention also proposes an evaluation system for the sealing performance of submarine fan lithological traps on the sidewalls of canyons, the evaluation system comprising:

[0118] The image processing module acquires seismic data of a specified submarine fan, determines the canyon channel wall of the side-sealed submarine fan lithological trap based on the seismic data, and uses it as the canyon channel wall to be evaluated, and acquires the seismic profile to be evaluated perpendicular to the canyon channel wall to be evaluated.

[0119] The parameter identification module determines the damage degree evaluation parameters, thickness evaluation parameters, and closure degree evaluation parameters of the canyon waterway wall to be evaluated based on the seismic profile to be evaluated and the preset geological conditions. It also identifies the canyon waterway to be evaluated enclosed by the canyon waterway wall and determines the sand-rich degree evaluation parameters and the overlapping relationship evaluation parameters of the canyon waterway to be evaluated.

[0120] The calculation and evaluation module, in combination with the damage degree evaluation parameters, the thickness evaluation parameters, the sand-rich degree evaluation parameters, the overlapping relationship evaluation parameters, and the closure degree evaluation parameters, quantitatively calculates and evaluates the sealing performance of the submarine fan lithological trap on the side wall of the canyon waterway to be evaluated.

[0121] like Figure 7 As shown, the sealing performance of the Meishan Formation submarine fan lithological trap, which is laterally sealed by the canyon channel wall, is quantitatively calculated and evaluated using the evaluation method for the sealing performance of the canyon channel wall side-sealing submarine fan lithological trap.

[0122] First, determine the specific location of the canyon channel wall that can laterally seal the submarine fan lithological trap, and obtain a seismic profile perpendicular to the canyon channel wall to be evaluated:

[0123] like Figure 7 As shown in (a), the contour lines of the Meishan Formation submarine fan decrease towards the southeast, and this area is obstructed by the LS25-1 segment of the central canyon channel wall. The LS25-1 segment of the central canyon channel wall laterally obstructs the Meishan Formation submarine fan. Based on this, a typical seismic profile perpendicular to the LS25-1 segment of the central canyon channel wall was obtained using 3D seismic data. This seismic profile is shown below. Figure 7(b) shows that the seismic profile was used to quantitatively evaluate the sealing performance of the LS25-1 segment of the central canyon waterway wall, which is a lateral sealing of the Meishan Formation submarine fan lithological trap based on the present invention.

[0124] The extent of damage to the canyon waterway walls to be evaluated can be determined, and the parameters for evaluating the extent of damage can be established.

[0125] In such Figure 7 (b) On the seismic profile shown, the LS25-1 segment of the central canyon waterway wall to be evaluated was not cut or traversed by columnar, upward-tilting, chaotic reflections or flat-topped, convex-bottomed, filling seismic reflections. The LS25-1 segment of the central canyon waterway wall is determined to be intact and uninterrupted, and the corresponding damage assessment parameter is 1.0.

[0126] Interpret the sidewall thickness of the canyon waterway wall to be evaluated, and determine the thickness evaluation parameters:

[0127] In such Figure 7 (b) On the seismic profile, the LS25-1 segment of the central canyon waterway wall to be evaluated exhibits continuous wave valley reflections, and has continuous wave peak reflections with consistent orientations inside. The LS25-1 segment of the central canyon waterway wall has two reflection phase axes, and 1 / 4λ < the thickness of the sidewall of the canyon waterway wall to be evaluated < 1 / 2λ, corresponding to a thickness evaluation parameter of 0.5.

[0128] Analyze the sand-richness of the canyon waterway to be evaluated and determine the sand-richness evaluation parameters:

[0129] In such Figure 7 (b) On the seismic profile, the area of ​​canyon water channel sand with strong amplitude, low frequency and medium-low continuous reflection in the canyon water channel enclosed by the LS25-1 segment of the central canyon water channel wall to be evaluated accounts for 51% of the total profile area of ​​the canyon water channel to be evaluated. The canyon water channel enclosed by the LS25-1 segment of the central canyon water channel wall has a high degree of sand enrichment, and the corresponding sand enrichment evaluation parameter is 0.2.

[0130] Identify the overlapping and cutting relationships of the canyon waterways to be evaluated, and determine the evaluation parameters for these relationships:

[0131] In such Figure 7 (b) shows a seismic profile where a flat-topped, convex-bottomed filling reflection is developed within the canyon channel enclosed by the LS25-1 segment of the central canyon channel wall to be evaluated. This indicates a first-stage canyon channel filling. The deepest point of the bottom envelope of this flat-topped, convex-bottomed filling reflection is almost on the same vertical direction as the deepest point of the LS25-1 segment of the central canyon channel wall. This confirms that the canyon channel enclosed by the LS25-1 segment of the central canyon channel wall exhibits an ordered migration and overlapping relationship, with the corresponding overlapping relationship evaluation parameter being 1.0.

[0132] Define the degree of closure of the canyon waterway walls to be evaluated, and determine the evaluation parameters for the degree of closure:

[0133] On the seismic profile as shown in Figure 7 (b), the top of the LS25-1 section of the central canyon channel wall to be evaluated is completely covered by deep-sea draped mud with weak amplitude - low frequency - high continuity reflections, and there are no sandy submarine fans or channel deposits developed inside this mudstone. It is determined that the closure degree of the LS25-1 section of the central canyon channel wall is high, and the corresponding closure degree evaluation parameter is 1.0.

[0134] Quantitatively calculate the sealing coefficient according to the formula, B = 1.0×(0.4×0.5 + 0.3×0.2 + 0.2×1.0 + 0.1×1.0) = 0.56, 0.25 < B < 0.6; it is determined that the sealing property of the LS25-1 section of the central canyon channel wall side-sealing the Meishan Formation submarine fan is good, and it can form an effective submarine fan lithologic trap, which is a good oil and gas exploration target. As shown in Figure 8 shown, use the evaluation method for the sealing property of the canyon channel wall side-sealing submarine fan lithologic trap to quantitatively calculate and evaluate the sealing property of the LS25-5 section of the central canyon channel wall side-sealing the Meishan Formation submarine fan lithologic trap:

[0135] Determine the specific position of the canyon channel wall that can side-seal the submarine fan lithologic trap, and obtain the seismic profile perpendicular to the canyon channel wall to be evaluated:

[0136] As shown in Figure 8 (a), the structural contour line of the top surface of the Meishan Formation submarine fan decreases towards the north-northwest side, and this place is cut and blocked by the LS25-5 section of the central canyon channel wall; use 3D seismic data to obtain a typical seismic profile perpendicular to the LS25-5 section of the central canyon channel wall, and this seismic profile is as shown in Figure 8 (b), use this seismic profile to quantitatively evaluate the sealing property of the LS25-5 section of the central canyon channel wall side-sealing the Meishan Formation submarine fan lithologic trap based on the present invention.

[0137] Find out the damage degree of the canyon channel wall to be evaluated, and determine the damage degree evaluation parameter:

[0138] On the seismic profile as shown in Figure 8 (b), the LS25-5 section of the central canyon channel wall to be evaluated is cut and penetrated by columnar, chaotic reflections with the axis center tilted upwards. It can be determined that the corresponding damage degree evaluation parameter of the LS25-5 section of the central canyon channel wall is 0.

[0139] Interpret the side wall thickness of the canyon channel wall and determine the thickness evaluation parameter:

[0140] On the seismic profile as shown in Figure 8On the seismic profile shown in (b), the LS25-5 segment of the central canyon channel wall to be evaluated exhibits continuous wave trough reflections, with continuous wave crest reflections of consistent orientation developed within the sidewall. It can be determined that the strata thickness of the canyon channel sidewall of the LS25-5 segment of the central canyon channel wall is equivalent to two in-phase reflection axes (1 / 4λ < sidewall thickness of the canyon channel wall to be evaluated < 1 / 2λ), corresponding to a thickness evaluation parameter of 0.5.

[0141] Analyze the sand-richness of the canyon waterway to be evaluated and determine the sand-richness evaluation parameters:

[0142] In such Figure 8 (b) On the seismic profile, the area of ​​canyon channel sand with strong amplitude, medium frequency, and medium-low continuous reflections within the canyon channel enclosed by the LS25-5 segment of the central canyon channel wall to be evaluated accounts for 55% of the total profile area of ​​the canyon channel to be evaluated. Therefore, the canyon channel to be evaluated enclosed by the LS25-5 segment of the central canyon channel wall has a high degree of sand enrichment, corresponding to a sand enrichment evaluation parameter of 0.2.

[0143] Identify the overlapping and cutting relationships of the canyon waterways to be evaluated, and determine the evaluation parameters for these relationships:

[0144] In such Figure 8 (b) On the seismic profile shown, the deepest point of the bottom envelope surface of the canyon channel under evaluation, which is characterized by a flat-topped and convex-bottomed filling reflection within the canyon channel enclosed by the LS25-5 segment of the central canyon channel wall, is almost on the same vertical direction as the deepest point of the LS25-5 segment of the central canyon channel wall. It can be determined that the canyon channel under evaluation enclosed by the LS25-5 segment of the central canyon channel wall exhibits an ordered migration and overlapping relationship, and the corresponding overlapping relationship evaluation parameter is 1.0.

[0145] Define the degree of closure of the canyon waterway sidewalls to be evaluated, and determine the evaluation parameters for the degree of closure:

[0146] In such Figure 8 (b) shows the seismic profile where the top of the LS25-5 segment of the Central Canyon Channel Wall to be evaluated is completely covered by deep-sea mudstone with weak amplitude, low frequency, and high continuous reflection. It can be determined that the LS25-5 segment of the Central Canyon Channel Wall has a high degree of closure, and the corresponding closure evaluation parameter is 1.0.

[0147] B=0×(0.4×0.5+0.3×0.2+0.2×1.0+0.1×1.0)=0

[0148] Therefore, B=0; it can be determined that the sealing of the Meishan Formation submarine fan on the side of the LS25-5 section of the central canyon waterway wall has failed, and it cannot form an effective submarine fan lithological trap, and cannot be used as an oil and gas exploration target.

[0149] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0150] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0151] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0152] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for evaluating the sealing performance of submarine fan lithological traps on the sidewalls of canyons, characterized in that, The evaluation method for the sealing performance of submarine fan lithological traps on the sidewalls of canyons includes: Seismic data of a specified submarine fan is obtained, and the canyon channel wall of the lithological trap of the side-sealed submarine fan is determined based on the seismic data as the canyon channel wall to be evaluated. Seismic profiles perpendicular to the canyon channel wall to be evaluated are obtained. Based on the seismic profile to be evaluated and the preset geological conditions, the evaluation parameters for the degree of damage, thickness, and degree of closure of the canyon waterway wall to be evaluated are determined. Identify the canyon waterway to be evaluated, which is enclosed by the walls of the canyon waterway to be evaluated, and determine the sand-richness evaluation parameters and the overlapping relationship evaluation parameters of the canyon waterway to be evaluated. The sealing performance of the submarine fan lithological trap of the canyon waterway wall side seal is quantitatively calculated and evaluated by combining the damage degree evaluation parameters, the thickness evaluation parameters, the sand richness evaluation parameters, the shear-overlap relationship evaluation parameters, and the closure degree evaluation parameters. The quantitative evaluation of the sealing performance of the submarine fan lithological traps on the sidewalls of the canyon channel to be evaluated includes: The sealing coefficient of the submarine fan lithological trap on the side wall of the canyon channel to be evaluated is quantitatively calculated using the following formula: B i =D a *(0.4T b +0.3S c +0.2M d +0.1C e ),i,a,b,c,d,e=1,2,3, Among them, B i D is the blocking coefficient. a T is the parameter for evaluating the degree of damage. b S is the thickness evaluation parameter. c M is the parameter for evaluating the degree of sand enrichment. d C is the evaluation parameter for the overlapping relationship. e The closure degree evaluation parameter; The sealing performance of the submarine fan lithological trap on the side wall of the canyon waterway to be evaluated is quantitatively evaluated based on the sealing coefficient and the preset evaluation coefficient.

2. The method for evaluating the sealing performance of submarine fan lithological traps on the sidewalls of canyons according to claim 1, characterized in that, The quantitative evaluation of the sealing performance of the submarine fan lithological trap on the side wall of the canyon channel to be evaluated, based on the sealing coefficient and the preset evaluation coefficient, includes: B i =0, the sealing failure of the submarine fan lithological trap on the side wall of the canyon waterway to be evaluated; B i <0.25, indicating that the sealing performance of the submarine fan lithological trap on the side wall of the canyon waterway to be evaluated is poor; 0.25 i <0.6, indicating that the sealing performance of the submarine fan lithological trap on the side wall of the canyon channel to be evaluated is good;​ B i >0.6, indicating that the sealing performance of the submarine fan lithological trap on the side wall of the canyon waterway to be evaluated is excellent.

3. The method for evaluating the sealing performance of submarine fan lithological traps on the sidewalls of canyons according to claim 1, characterized in that, The canyon channel walls identified based on the seismic data as lateral sealing submarine fan lithological traps, as canyon channel walls to be evaluated, include: Identify V-shaped or U-shaped seismic reflection units in the seismic data that are located at the bottom of the canyon waterway, cut through and traverse near-horizontal seismic reflections, and are composed of a preset number of seismic reflection phase axes, as canyon waterway walls; Obtain the top surface structure diagram of the specified submarine fan and the location where the canyon channel to be evaluated cuts the specified submarine fan. Search and determine the canyon channel wall that cuts the submarine fan and whose outer side shows a decrease in the contour lines of the top surface structure of the submarine fan, and use it as the canyon channel wall to be evaluated.

4. The method for evaluating the sealing performance of submarine fan lithological traps on the sidewalls of canyons according to any one of claims 1 to 3, characterized in that, The evaluation parameters for determining the degree of damage to the canyon waterway wall under evaluation, based on the seismic profile to be evaluated and the preset geological conditions, include: Determine whether the canyon waterway wall on the seismic profile to be evaluated is a diapir-pierced canyon waterway wall, a turbidity flow-cutted canyon waterway wall, or a canyon waterway wall that is intact and uninterrupted. When the canyon waterway wall to be evaluated is either the diapiric waterway wall or the turbid waterway wall, the evaluation parameter for the degree of damage to the canyon waterway wall to be evaluated is the first damage parameter. If the canyon waterway wall to be evaluated is intact and uninterrupted, the evaluation parameter for the degree of damage to the canyon waterway wall to be evaluated is the second damage parameter.

5. The method for evaluating the sealing performance of submarine fan lithological traps on the sidewalls of canyons according to any one of claims 1 to 3, characterized in that, The determination of the thickness evaluation parameters of the canyon waterway wall to be evaluated based on the seismic profile to be evaluated and the preset geological conditions includes: If the wall of the canyon to be evaluated is identified as having continuous crests and troughs, and the strata inside and outside the canyon to be evaluated have different attitudes and the seismic reflection unit characteristics inside and outside the canyon to be evaluated are different, then the thickness evaluation parameter is determined to be the first thickness parameter. If the wall of the canyon channel to be evaluated is identified as having continuous crests and troughs, and there are continuous seismic reflection units with consistent strata attitude inside or outside the wall of the canyon channel to be evaluated, then the thickness evaluation parameter is determined to be the second thickness parameter. If the wall of the canyon channel to be evaluated is identified as having continuous peaks and troughs, and if both the interior and exterior of the canyon channel wall to be evaluated exhibit continuous reflections with consistent orientation, then the thickness evaluation parameter is determined to be the third thickness parameter.

6. The method for evaluating the sealing performance of submarine fan lithological traps on the sidewalls of canyons according to any one of claims 1 to 3, characterized in that, The evaluation parameters for determining the degree of closure of the canyon waterway wall to be evaluated include: Obtain the coverage area ratio of the medium-strong amplitude, medium-high frequency, and medium-high continuous reflection submarine fan sand at the top of the canyon waterway wall to be evaluated; The evaluation parameters for the degree of closure of the canyon waterway wall to be evaluated are determined based on the coverage ratio and the preset closure interval.

7. The method for evaluating the sealing performance of submarine fan lithological traps on the sidewalls of canyons according to any one of claims 1 to 3, characterized in that, The parameters for determining the sand-richness of the canyon waterway to be evaluated include: Obtain the total cross-sectional area of ​​the canyon waterway to be evaluated and the sand area of ​​the canyon waterway within the canyon waterway to be evaluated, and calculate the ratio of the sand area of ​​the canyon waterway to the sand-rich area of ​​the total cross-sectional area. The sand-richness evaluation parameters of the canyon waterway to be evaluated are determined based on the sand-rich area ratio and the preset sand-rich interval.

8. The method for evaluating the sealing performance of submarine fan lithological traps on the sidewalls of canyons according to any one of claims 1 to 3, characterized in that, The evaluation parameters for determining the overlapping relationship of the canyon waterway to be evaluated include: Determine whether the canyon waterway to be evaluated is undergoing disordered migration, unidirectional migration, or ordered migration; When the canyon waterway to be evaluated is in a state of disordered migration, the overlapping relationship evaluation parameter of the canyon waterway to be evaluated is determined as the first overlapping parameter. When the canyon waterway to be evaluated is unidirectionally migrating, the overlapping relationship evaluation parameter of the canyon waterway to be evaluated is determined as the second overlapping parameter; When the canyon waterway to be evaluated is in an orderly migration, the overlapping relationship evaluation parameter of the canyon waterway to be evaluated is determined as the third overlapping parameter.

9. A system for evaluating the sealing capacity of submarine fan lithological traps on the sidewalls of canyons, applied to the method for evaluating the sealing capacity of submarine fan lithological traps on the sidewalls of canyons as described in any one of claims 1 to 8, characterized in that... The evaluation system for the sealing performance of submarine fan lithological traps along the canyon waterway walls includes: The image processing module acquires seismic data of a specified submarine fan, determines the canyon channel wall of the side-sealed submarine fan lithological trap based on the seismic data, and uses it as the canyon channel wall to be evaluated, and acquires the seismic profile to be evaluated perpendicular to the canyon channel wall to be evaluated. The parameter identification module determines the damage degree evaluation parameters, thickness evaluation parameters, and closure degree evaluation parameters of the canyon waterway wall to be evaluated based on the seismic profile to be evaluated and the preset geological conditions. It also identifies the canyon waterway to be evaluated enclosed by the canyon waterway wall and determines the sand-rich degree evaluation parameters and the overlapping relationship evaluation parameters of the canyon waterway to be evaluated. The calculation and evaluation module, in combination with the damage degree evaluation parameters, the thickness evaluation parameters, the sand-rich degree evaluation parameters, the overlapping relationship evaluation parameters, and the closure degree evaluation parameters, quantitatively calculates and evaluates the sealing performance of the submarine fan lithological trap on the side wall of the canyon waterway to be evaluated.

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