Method for determining migration degree of deep-sea channel, storage medium and computer device

Abstract

The application discloses a method for determining the migration degree of a deep-sea channel, a storage medium and computer equipment, and comprises the following steps: dividing a deep-sea composite channel on a deep-sea channel planar distribution map into a plurality of curved segments; for each curved segment, the following steps are performed: determining the vertical migration amount and the lateral migration amount of a deep-sea single channel corresponding to the curved segment on a seismic amplitude profile corresponding to the curved segment; calculating a channel migration index of the curved segment according to the vertical migration amount and the lateral migration amount of the deep-sea single channel corresponding to the curved segment; and analyzing the migration degree of the deep-sea channel of the curved segment according to the channel migration index of each curved segment. The migration evolution degree of the deep-sea single channel can be quantified through the channel migration index, which not only enriches the morphological parameters of the deep-sea channel, but also plays an important supporting role in the quantitative sedimentology and sedimentary system research of the deep-sea channel.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas geology or sedimentary geology analysis technology, specifically relating to a method for determining the degree of deep-sea channel migration, a storage medium, and a computer device. Background Technology

[0002] Deep-sea channels are an important type of sedimentary feature on deep-sea continental slopes and a promising target for current deep-sea oil and gas exploration. The migration characteristics of deep-sea channels are a crucial aspect of quantitative deep-sea sedimentology research. The migration and evolution of deep-sea channels in different historical periods have resulted in their diverse current distribution patterns. Analyzing the migration patterns and quantifying the degree of migration of deep-sea channels provides important support for predicting the sedimentary patterns of deep-sea channels and the distribution of sand bodies.

[0003] In existing technologies, on the one hand, research on the migration and evolution patterns of deep-water channels has been published. Taking a deep-water channel in a certain area of ​​the Niger lower slope as an example, stratigraphic slices were used to demonstrate the morphology and changes of the channel in different phases. Cutting and filling are a pair of driving forces for the channel's tortuous deformation. The channel mainly includes three migration forms: lateral oscillation, downward migration, and mixed lateral and downward migration. On the other hand, research based on high-resolution 3D seismic data, using seismic attributes and frequency division techniques, has been published to study the sedimentary configuration, genesis, and sedimentary process of Quaternary deep-water tortuous channels in the Mooney Basin. This research suggests that deep-water tortuous channels consist of channels and embankments. Early deep-water channels were low-torsional channels, gradually evolving into high-torsional channels later. The meandering channels are mainly composed of two modes: vertical accretion and lateral migration. A deep-water unidirectional migration channel sedimentary system is also disclosed, which is believed to have unidirectional migration characteristics as a whole, formed by the combined action of gravity flow and isobath current, with the migration direction of the channel roughly the same as the direction of isobath current movement. Furthermore, an in-depth study of the development types of deep-water channels in the Middle Miocene of the Lower Congo Basin, as well as the evolutionary process of the occurrence, development, decline, and extinction of complex channel systems, is disclosed. It is believed that the deep-water channels in the study area can be divided into four basic types: single-stage incision, single-stage accretion, vertical accretion complex, and lateral migration complex. The sea-level change in West Africa controls the development of the third-order sequence and restricts the development scale of deep-water channel complexes.

[0004] On the other hand, regarding the quantitative study of the geometric morphology of deep-sea channels, a study was conducted using the deep-water channels of the Rio Muni Basin in West Africa as the research object. The study measured the slope of the basin's continental slope and the corresponding tortuosity of the deep-water channels in segments. It was concluded that the tortuosity of the deep-water channels has a power function relationship with the slope of the continental slope; within a certain range, the greater the tortuosity of the channel, the smaller the slope. The study also revealed the main differences in migration and evolution between normal meandering channels and deep-water meandering channels: in the early stages, deep-water meandering channels are mainly characterized by lateral migration and accretion, accompanied by scouring and cutting at the bottom; in the later stages, they are mainly characterized by vertical accretion. High-energy and persistent fluids at the bottom form significant cutting and erosion; high-energy and short-lived fluids in the middle section mostly exhibit lateral migration and superposition, forming thick sand bodies; and low-energy and... Longer-duration fluid flows tend to exhibit vertical accretion, forming thin interlayers of sand and mud, while meandering channels are primarily characterized by lateral accretion, exhibiting a combination of features from point dams to floodplains, presenting a typical "binary" structure. Furthermore, based on high-resolution 3D seismic data from a West African slope region, a study was conducted on the profile and planar morphology of Quaternary slope gravity-flow channels using quantitative analysis of seismic attributes and parameters. The study suggests that topographic slope and distance from the channel head control the profile and planar morphology of deep-water channels. As the slope decreases and the distance from the channel head increases, the channel width decreases. Additionally, the curvature of highly meandering channels is also controlled by topographic slope.

[0005] In summary, the current state of technology in this field is as follows: Deep-sea channels are important sedimentary units within deep-sea sedimentary systems, and tortuous deep-sea channels represent a significant type of deep-sea sedimentation. Their sedimentary morphology and processes have attracted widespread attention. The migration process of deep-sea channels plays a crucial role in controlling their sedimentary morphology. Current research focuses on their migration and superposition patterns, with scholars generally agreeing that the main migration patterns include lateral, vertical, and mixed lateral-vertical migration. Furthermore, some quantitative studies have been conducted on the geometric morphology of highly tortuous deep-sea channels, using commonly used geometric parameters such as tortuosity, channel length and width, breakwater length and width, and width-to-depth ratio. These research methods are relatively mature. However, no reports have been found on techniques and parameters related to the degree of deep-sea channel migration and evolution. Therefore, further research is needed on techniques related to the degree of deep-sea channel migration and evolution.

[0006] There is an urgent need for a method, storage medium, and computer equipment for determining the degree of deep-sea channel migration. Summary of the Invention

[0007] To address the above problems, the present invention provides a method for determining the degree of migration in deep-sea channels, a storage medium, and a computer device.

[0008] In a first aspect, the present invention provides a method for determining the degree of migration in deep-sea channels, comprising:

[0009] The deep-sea complex waterway on the deep-sea waterway plan is divided into multiple curved sections;

[0010] For each curved segment, perform the following steps:

[0011] On the seismic amplitude profile corresponding to the curved segment, determine the vertical and lateral migration of the deep-sea single channel corresponding to the curved segment.

[0012] The channel migration index of the curved section is calculated based on the vertical and lateral migration of the deep-sea single channel corresponding to the curved section.

[0013] The degree of deep-sea channel migration in each bend is analyzed based on the channel migration index.

[0014] According to an embodiment of the present invention, preferably, the deep-sea channel plan distribution map is a plan map of the root mean square amplitude attribute of isochronous stratigraphic slices extracted based on high-frequency seismic data, and the step of dividing the deep-sea composite channel on the deep-sea channel plan distribution map into multiple curved segments includes:

[0015] Based on the degree of planar curvature of the deep-sea composite channel in the root mean square amplitude attribute plane diagram, the deep-sea composite channel is divided into multiple curved segments.

[0016] According to an embodiment of the present invention, preferably, determining the vertical and lateral migration amounts of a single deep-sea channel corresponding to the curved segment on the seismic amplitude profile corresponding to the curved segment includes:

[0017] On the seismic amplitude profile corresponding to the curved section, multiple deep-sea single channels are interpreted based on the faulting of the seismic axes in the same direction inside the deep-sea composite channel.

[0018] Based on the migration trajectories of the multiple deep-sea single channels, the vertical and lateral migration amounts of the multiple single channels are determined.

[0019] According to an embodiment of the present invention, preferably, determining the vertical and lateral migration amounts of the plurality of single deep-sea channels based on their migration trajectories includes:

[0020] The migration trajectories of the multiple deep-sea single channels are decomposed vertically and laterally to obtain the vertical and lateral migration amounts of the multiple single channels.

[0021] According to an embodiment of the present invention, preferably, the channel migration index of the curved segment is calculated based on the vertical and lateral migration amounts of the deep-sea single channel corresponding to the curved segment using the following expression:

[0022] M = L / V

[0023] Wherein, M is the channel migration index of the curved section, L is the lateral migration of the deep-sea single channel corresponding to the curved section, and V is the vertical migration of the deep-sea single channel corresponding to the curved section.

[0024] According to an embodiment of the present invention, preferably, the step of analyzing the deep-sea channel migration degree of each bend segment based on the channel migration index includes:

[0025] For each bend, the larger the channel migration index of the bend, the stronger the lateral swinging ability of the deep-sea channel in that bend; the smaller the channel migration index of the bend, the stronger the downcutting ability of the deep-sea channel in that bend.

[0026] According to an embodiment of the present invention, preferably, the method further includes:

[0027] The degree of deep-sea channel migration in each bend segment was verified based on the channel migration index analysis.

[0028] According to an embodiment of the present invention, preferably, the verification of the deep-sea channel migration degree of the bend segment analyzed based on the channel migration index of each bend segment includes:

[0029] Calculate the waterway curvature for each bend.

[0030] The correlation between the waterway migration index and waterway curvature of the same bend segment is analyzed based on the waterway migration index and waterway curvature corresponding to each bend segment in multiple bend segments.

[0031] Based on the correlation analysis results between the waterway migration index and waterway curvature of the same bend, it is determined whether the degree of deep-sea waterway migration of the bend segment analyzed based on the waterway migration index of each bend segment is verified.

[0032] Secondly, the present invention provides a storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the method for determining the degree of deep-sea channel migration described above.

[0033] Thirdly, the present invention provides a computer device including a memory and a processor, wherein the memory stores a computer program that, when executed by the processor, implements the steps of the method for determining the degree of deep-sea channel migration described above.

[0034] Compared with the prior art, one or more embodiments of the above solutions may have the following advantages or beneficial effects:

[0035] The method for determining the migration degree of deep-sea channels according to the present invention divides the deep-sea complex channels on the deep-sea channel planar distribution map into multiple bends. For each bend, the following steps are performed: determining the vertical and lateral migration amounts of the deep-sea single channel corresponding to the bend on the seismic amplitude profile corresponding to the bend; calculating the channel migration index of the bend based on the vertical and lateral migration amounts of the deep-sea single channel corresponding to the bend; and analyzing the deep-sea channel migration degree of each bend based on the channel migration index. This method can quantify the migration and evolution degree of a deep-sea single channel through the channel migration index, which not only enriches the morphological parameters of deep-sea channels but also provides important support for quantitative sedimentology and sedimentary system research of deep-sea channels.

[0036] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0037] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0038] Figure 1 A flowchart of the method for determining the degree of deep-sea channel migration according to Embodiment 1 of the present invention is shown;

[0039] Figure 2 A flowchart illustrating the method for determining the degree of deep-sea channel migration according to Embodiment 2 of the present invention is shown;

[0040] Figure 3 A flowchart of the method for determining the degree of deep-sea channel migration according to Embodiment 3 of the present invention is shown;

[0041] Figure 4(a) shows a planar diagram of the root mean square amplitude attribute used to reflect the planar distribution pattern of deep-sea channels in Embodiment 3 of the present invention.

[0042] Figure 4(b) shows a schematic diagram of the main current lines of different single waterways extracted from the deep-sea composite waterway in Embodiment 3 of the present invention;

[0043] Figure 4(c) shows a schematic diagram of the single waterway migration stacking pattern reflected by high-curvature and low-curvature sections with different curvature degrees in Embodiment 3 of the present invention.

[0044] Figure 5(a) shows the seismic reflection characteristics of different curved sections of the deep-sea channel in Embodiment 3 of the present invention;

[0045] Figure 5(b) shows a schematic diagram of the migration patterns and migration amounts of different curved waterways in Embodiment 3 of the present invention;

[0046] Figure 6(a) shows a schematic diagram of the morphology of the composite channel downcut valley reflected by the original seismic amplitude profile in a deep-sea channel in a certain area of ​​the Lower Congo Basin in West Africa, according to Embodiment 3 of the present invention.

[0047] Figure 6(b) shows a schematic diagram of the evolution of a single waterway in a seismic reflection profile of a deep-sea waterway in a region of the Lower Congo Basin in West Africa, based on the proportional interpolation of six stratigraphic slices inside the waterway complex in Embodiment 3 of the present invention.

[0048] Figure 7(a) shows a schematic diagram of the distribution pattern of a single deep-sea channel in a certain area of ​​the Lower Congo Basin in West Africa, based on the analysis of the migration and evolution of the single channel in different periods using equal-scale slices in Embodiment 3 of the present invention.

[0049] Figure 7(b) shows a schematic diagram of the migration index and corresponding curvature of samples selected at different locations of the deep-sea single channel in a region of the Lower Congo Basin in West Africa, in the analysis of the migration evolution law of the deep-sea single channel in Embodiment 3 of the present invention.

[0050] Figure 8 This paper presents a schematic diagram illustrating the statistical relationship between the curvature of deep-sea channels and the migration index in a certain region of the Lower Congo Basin in West Africa, according to Embodiment 3 of the present invention. Detailed Implementation

[0051] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings and examples, so that the process of how the present invention uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that, as long as there is no conflict, the various embodiments and features in the various embodiments of the present invention can be combined with each other, and the resulting technical solutions are all within the protection scope of the present invention.

[0052] Example 1

[0053] To address the aforementioned technical problems in the prior art, embodiments of the present invention provide a method for determining the degree of migration in deep-sea channels.

[0054] Reference Figure 1 The method for determining the degree of deep-sea channel migration in this embodiment includes:

[0055] S11 divides the deep-sea complex waterway on the deep-sea waterway plan into multiple curved sections;

[0056] S12, For each curved segment, determine the vertical and lateral migration amounts of the deep-sea single channel corresponding to the curved segment on the seismic amplitude profile corresponding to the curved segment.

[0057] S13, Calculate the channel migration index of the curved section based on the vertical and lateral migration of the deep-sea single channel corresponding to the curved section.

[0058] S14, Analyze the degree of deep-sea channel migration in each bend based on the channel migration index of each bend.

[0059] S15 verifies the degree of deep-sea channel migration in each bend segment based on the channel migration index analysis.

[0060] In this embodiment, in step S13, the channel migration index of the curved section is calculated based on the vertical and lateral migration amounts of the deep-sea single channel corresponding to the curved section using the following expression:

[0061] M = L / V

[0062] Wherein, M is the channel migration index of the curved section, L is the lateral migration of the deep-sea single channel corresponding to the curved section, and V is the vertical migration of the deep-sea single channel corresponding to the curved section.

[0063] In this embodiment, step S14, analyzing the deep-sea channel migration degree of each bend segment based on the channel migration index, includes:

[0064] For each bend, the larger the channel migration index of the bend, the stronger the lateral swinging ability of the deep-sea channel in that bend; the smaller the channel migration index of the bend, the stronger the downcutting ability of the deep-sea channel in that bend.

[0065] The method for determining the degree of deep-sea channel migration in this embodiment, from a geometric morphological perspective, defines and calculates the channel migration index by measuring the lateral and vertical migration of a single channel, quantifies the degree of migration and evolution of a single deep-sea channel, enriches the morphological parameters of deep-sea channels, and plays an important supporting role in the quantitative sedimentology and sedimentary system research of deep-sea channels.

[0066] Example 2

[0067] To address the aforementioned technical problems in the prior art, this invention provides a method for determining the degree of deep-sea channel migration based on Embodiment 1. The method for determining the degree of deep-sea channel migration in this invention improves upon steps S11, S12, and S15 in Embodiment 1. In this embodiment, the deep-sea channel planar distribution map is a planar map of the root mean square amplitude attribute of isochronous stratigraphic slices extracted from high-frequency seismic data.

[0068] Reference Figure 2 The method for determining the degree of deep-sea channel migration in this embodiment includes the following steps:

[0069] S21. Based on the degree of planar curvature of the deep-sea composite channel in the root mean square amplitude attribute plane diagram, the deep-sea composite channel is divided into multiple curved segments.

[0070] S221, For each curved segment, multiple deep-sea single channels are interpreted based on the faulting of the seismic axis in the same direction inside the deep-sea composite channel on the seismic amplitude profile corresponding to the curved segment.

[0071] S222, Based on the migration trajectories of the multiple deep-sea single waterways, determine the vertical migration amount and lateral migration amount of the multiple single waterways;

[0072] S23, calculate the channel migration index of the curved section based on the vertical and lateral migration of the deep-sea single channel corresponding to the curved section.

[0073] S24, Analyze the degree of deep-sea channel migration in each bend based on the channel migration index of each bend.

[0074] S251, calculate the waterway curvature of each bend;

[0075] S252, based on the waterway migration index and waterway curvature corresponding to each of the multiple bends, analyze the correlation between the waterway migration index and waterway curvature of the same bend.

[0076] S253, based on the correlation analysis results between the waterway migration index and the waterway curvature of the same bend, determine whether the degree of deep-sea waterway migration of the bend segment analyzed according to the waterway migration index of each bend segment has passed the verification.

[0077] In this embodiment, step S222, determining the vertical and lateral migration amounts of the multiple deep-sea single channels based on their migration trajectories, includes:

[0078] The migration trajectories of the multiple deep-sea single channels are decomposed vertically and laterally to obtain the vertical and lateral migration amounts of the multiple single channels.

[0079] In this embodiment, in step S253, when there is a positive correlation between the waterway migration index and the waterway curvature of the same bend, it is determined that the degree of deep-sea waterway migration of the bend segment analyzed based on the waterway migration index of each bend segment has passed the verification.

[0080] Example 3

[0081] To address the aforementioned technical problems in the prior art, this invention provides an example of applying the method for determining the degree of deep-sea channel migration based on Embodiment 2 to a typical deep-sea channel sedimentation block.

[0082] Reference Figure 3 The method for determining the degree of deep-sea channel migration in this embodiment includes the following steps:

[0083] Step 1: Analysis of the Horizontal Migration Characteristics of Deep-Sea Channels

[0084] Typical deep-sea channel sedimentary blocks were selected, and three-dimensional seismic attributes that clearly reflect the characteristics of channel sedimentation, such as root-mean-square amplitude (RMS) attributes, were preferred. Based on the Landmark or Petrel software platform, these attributes were extracted through isochronous stratigraphic slices to obtain... Figure 4a The diagram shown is a planar migration characteristic distribution map of deep-sea channels, specifically a root-mean-square amplitude attribute plane map. This plane map clearly reflects the tortuous distribution pattern of deep-sea complex channels, which are often formed by the superposition of multiple single deep-sea channels, such as... Figure 4b As shown, different individual channel main current lines migrate and overlap within a deep-sea composite channel to form a composite deep-sea channel. Different curves represent individual channels at different times. Based on the planar curvature (i.e., the degree of curvature) of the deep-sea channel, the deep-sea composite channel can be roughly divided into low-curvature and high-curvature sections. The curvature of the low-curvature section is less than 1.3, while the curvature of the high-curvature section is greater than or equal to 1.3. Furthermore, the overlapping patterns of individual channels within different curvature sections differ. For example... Figure 4c As shown, the single channel stacking pattern in the low-curvature section is a mixed stacking pattern, while the single channel stacking pattern in the high-curvature section is a lateral oblique stacking pattern. Obviously, the different stacking patterns are caused by the different migration characteristics of the channels, and further analysis of the migration changes of the channels from the cross-section is needed.

[0085] The second step is the analysis of the migration characteristics of deep-sea channel profiles.

[0086] Based on the deep-sea channel plan distribution map obtained in the first step, three-dimensional seismic amplitude profiles are extracted along the direction perpendicular to the channel flow direction in both the low-curvature and high-curvature sections, as shown below. Figure 5a As shown. (Refer to...) Figure 5a Deep-sea composite channels exhibit a distinct downcut "U"-shaped feature in seismic profile reflections. The interior of this "U"-shaped composite channel displays significant amplitude disorder, with medium to strong amplitudes reflecting the superimposed distribution of individual channels. The discontinuity of the seismic axis clearly explains multiple small downcut "U"-shaped individual channels. Furthermore, the continuity of the seismic axis and the superimposed range of individual channels reveal the top and bottom of the migration patterns of these deep-sea channels. Therefore, seismic reflection profiles clearly reveal the migration and superimposition patterns of composite channels and their individual components. Further quantitative research on the migration characteristics of these individual channels is needed.

[0087] Step 3: Definition and Calculation of Deep-Sea Channel Migration Index

[0088] Based on the superimposed patterns of waterway profile migration in different curved sections obtained in the second step, a quantitative study of the waterway migration process is conducted. For example... Figure 5b As shown, the migration trajectory of a single deep-sea channel can be decomposed into vertical migration and lateral migration in the cross-section. Vertical migration, denoted by V (in meters), reflects the degree of incision of the deep-sea channel during deposition. A greater degree of incision results in a larger vertical migration (V), indicating a thicker channel-sedimentary sand body. Lateral migration, denoted by L (in meters), reflects the intensity of lateral oscillation during the deposition of a single deep-sea channel. A greater intensity of lateral oscillation results in a larger lateral migration (L), indicating a larger planar distribution range of the channel sand body. The above describes the migration of deep-sea channels quantitatively. To further accurately reflect the migration patterns of deep-sea channels, a channel migration index is defined. The channel migration index, denoted by M, is the ratio of lateral migration (L) to vertical migration (V) and is dimensionless. The definition of the channel migration index, M = L / V, reflects the oscillation ability of a single deep-sea channel during sedimentation: when lateral migration ability is strong, vertical migration ability is often weaker; that is, the larger L is, the smaller V tends to be; conversely, when L is small, V tends to increase. This indicates that a larger channel migration index reflects a stronger lateral oscillation ability of the channel, while a smaller index reflects a stronger downcutting ability. To further clarify whether the pattern reflected by this index is consistent with the understanding gained from channel sedimentology research, further analysis from the perspective of changes in channel tortuosity is needed.

[0089] Step 4: Correlation analysis between deep-sea channel migration index and channel curvature.

[0090] Channel tortuosity refers to the ratio of the length of the curved line to the length of the straight line between the start and end points of a channel. It reflects the strength of the tortuosity of deep-sea channels, denoted by the letter S, with a value range of ≥1 and is dimensionless. As can be seen from the meaning of tortuosity, the greater the degree of tortuosity, the greater the migration index of the channel, and the two should have a linear / non-linear relationship. Typical deep-sea curved channels are selected, and the migration index of typical curved segments is calculated based on the methods in steps one through three. Simultaneously, the channel tortuosity of the corresponding segments is calculated. With a sufficient sample size, the correlation between the two is statistically analyzed. If the correlation is good, it indicates that the proposed method is relatively reliable and reasonable.

[0091] The following analysis uses a block in the Lower Congo Basin of West Africa as an example to examine the correlation between the deep-sea channel migration index and channel curvature.

[0092] The shallow Pliocene strata in the Lower Congo Basin of West Africa contain typical deep-sea channels. The seismic data has high resolution (dominant frequency > 70 Hz), which can clearly identify the morphological characteristics of the deep-sea channels.

[0093] (1) Based on the Landmark seismic interpretation software platform, a seismic profile perpendicular to the direction of the deep-sea channel extension was selected, from... Figure 6a It can be seen that the boundaries of the composite channel are relatively clear, and the internal medium-to-strong amplitude superposition shows a combination of multiple single channels. Based on the thickness of the composite channel from top to bottom, six stratigraphic slices are interpolated proportionally. Figure 6b The stratigraphic slices, numbered ① to ⑥, possess a certain degree of isochronism, reflecting the migration location of a single deep-sea channel at different times to deduce its evolution process.

[0094] (2) Seismic root mean square amplitude attribute plane maps were extracted from six stratigraphic slices. The magnitude of the attribute values ​​reflects the morphology of waterway distribution. Figure 7a It can be seen that from the bottommost first sub-layer to the topmost sixth sub-layer, the individual waterways in each sub-layer exhibit certain tortuous characteristics, and the tortuosity of the waterways increases as you go up, which also indicates that the lateral migration ability of the deep-sea waterways is stronger as you go up.

[0095] (3) Extract the waterway distribution patterns of layers ① to ⑥ and overlay them according to their spatial relative positions to obtain a composite waterway distribution composed of 6 layers of single waterways (e.g., Figure 7b The overlay map clearly shows the migration direction and curvature of individual channels at different locations. Based on our understanding of the study area, the sediment source direction of the deep-sea channels is northeast, which helps to determine the changes in migration characteristics from near-source to distant-source channels.

[0096] (4) To further measure parameters such as waterway migration index and curvature, 15 seismic profiles (1-15) were extracted as sample points along the direction of the vertical composite waterway. The waterway migration index corresponding to each sample point was calculated based on the above method. In addition, the waterway curvature at the location of each sample point was measured for subsequent statistical analysis. Based on the above process, Table 1, a statistical table of deep-sea waterway morphological parameters in the study area, was obtained. Table 1 is a statistical table of geometric morphological parameters of deep-sea waterways in a certain area of ​​the Lower Congo Basin in West Africa (partial parameter display). As shown in Table 1, the vertical migration is between 65 and 135 m, the lateral migration is between 400 and 1100 m, the migration index is between 6 and 12, and the curvature is between 1.1 and 1.9.

[0097] Table 1

[0098]

[0099]

[0100] (5) Cross-analysis of the calculated waterway migration index and the corresponding curvature revealed a good positive correlation between the two. Figure 8The correlation coefficient R can be expressed by the formula M = 8.5ln(S) + 6.1, where M represents the waterway migration index, S represents the waterway tortuosity, and R is the correlation coefficient. 2 =0.92, indicating a high correlation between curvature and migration index. A high correlation indicates that the calculation of the channel migration index is reasonable and accurate, and further verifies the accuracy and reliability of the deep-sea channel migration index calculation method in this embodiment, ensuring the reliability of providing a basis and support for the study of quantitative sedimentology and sedimentary evolution processes in deep-sea channels.

[0101] The method for determining the degree of deep-sea channel migration in this embodiment quantifies the migration and evolution process of deep-sea meandering channels, enriches the morphological parameters of deep-sea channels, and provides necessary basis and support for quantitative sedimentology and sedimentary evolution research of deep-sea channels.

[0102] The method for determining the degree of deep-sea channel migration in this embodiment is based on deep-sea high-frequency seismic data. The low-curvature and high-curvature sections of deep-sea channel deposition are divided by the planar migration characteristics of a single channel. The vertical and lateral migration amounts of the deep-sea channel are obtained by the migration characteristics of a single channel profile, and the channel migration index is calculated. Finally, the correlation between the curvature of the deep-sea channel and the migration index is statistically analyzed through case studies to ensure the accuracy of the analysis results of the degree of deep-sea channel migration in the curvature section.

[0103] Example 4

[0104] To address the aforementioned technical problems in the prior art, embodiments of the present invention also provide a storage medium.

[0105] The storage medium of this embodiment stores a computer program, which, when executed by a processor, implements the steps of the method for determining the degree of deep-sea channel migration described in the above embodiment:

[0106] S11 divides the deep-sea complex waterway on the deep-sea waterway plan into multiple curved sections;

[0107] S12, For each curved segment, determine the vertical and lateral migration amounts of the deep-sea single channel corresponding to the curved segment on the seismic amplitude profile corresponding to the curved segment.

[0108] S13, Calculate the channel migration index of the curved section based on the vertical and lateral migration of the deep-sea single channel corresponding to the curved section.

[0109] S14, Analyze the degree of deep-sea channel migration in each bend based on the channel migration index of each bend.

[0110] S15 verifies the degree of deep-sea channel migration in each bend segment based on the channel migration index analysis.

[0111] In this embodiment, in step S13, the channel migration index of the curved section is calculated based on the vertical and lateral migration amounts of the deep-sea single channel corresponding to the curved section using the following expression:

[0112] M = L / V

[0113] Wherein, M is the channel migration index of the curved section, L is the lateral migration of the deep-sea single channel corresponding to the curved section, and V is the vertical migration of the deep-sea single channel corresponding to the curved section.

[0114] In this embodiment, step S14, analyzing the deep-sea channel migration degree of each bend segment based on the channel migration index, includes:

[0115] For each bend, the larger the channel migration index of the bend, the stronger the lateral swinging ability of the deep-sea channel in that bend; the smaller the channel migration index of the bend, the stronger the downcutting ability of the deep-sea channel in that bend.

[0116] The storage medium of this embodiment stores a computer program, which, when executed by a processor, also implements the steps of the method for determining the degree of deep-sea channel migration described in the above embodiment:

[0117] S21. Based on the degree of planar curvature of the deep-sea composite channel in the root mean square amplitude attribute plane diagram, the deep-sea composite channel is divided into multiple curved segments.

[0118] S221, For each curved segment, multiple deep-sea single channels are interpreted based on the faulting of the seismic axis in the same direction inside the deep-sea composite channel on the seismic amplitude profile corresponding to the curved segment.

[0119] S222, Based on the migration trajectories of the multiple deep-sea single waterways, determine the vertical migration amount and lateral migration amount of the multiple single waterways;

[0120] S23, calculate the channel migration index of the curved section based on the vertical and lateral migration of the deep-sea single channel corresponding to the curved section.

[0121] S24, Analyze the degree of deep-sea channel migration in each bend based on the channel migration index of each bend.

[0122] S251, calculate the waterway curvature of each bend;

[0123] S252, based on the waterway migration index and waterway curvature corresponding to each of the multiple bends, analyze the correlation between the waterway migration index and waterway curvature of the same bend.

[0124] S253, based on the correlation analysis results between the waterway migration index and the waterway curvature of the same bend, determine whether the degree of deep-sea waterway migration of the bend segment analyzed according to the waterway migration index of each bend segment has passed the verification.

[0125] In this embodiment, step S222, determining the vertical and lateral migration amounts of the multiple deep-sea single channels based on their migration trajectories, includes:

[0126] The migration trajectories of the multiple deep-sea single channels are decomposed vertically and laterally to obtain the vertical and lateral migration amounts of the multiple single channels.

[0127] The storage medium of this embodiment stores a computer program, which, when executed by a processor, also implements the steps of the method for determining the degree of deep-sea channel migration described in the above embodiment:

[0128] Step 1: Analysis of the Horizontal Migration Characteristics of Deep-Sea Channels

[0129] Typical deep-sea channel sedimentary blocks were selected, and three-dimensional seismic attributes that clearly reflect the characteristics of channel sedimentation, such as root-mean-square amplitude (RMS) attributes, were preferred. Based on the Landmark or Petrel software platform, these attributes were extracted through isochronous stratigraphic slices to obtain... Figure 4a The diagram shown is a planar migration characteristic distribution map of deep-sea channels, specifically a root-mean-square amplitude attribute plane map. This plane map clearly reflects the tortuous distribution pattern of deep-sea complex channels, which are often formed by the superposition of multiple single deep-sea channels, such as... Figure 4b As shown, different individual channel main current lines migrate and overlap within a deep-sea composite channel to form a composite deep-sea channel. Different curves represent individual channels at different times. Based on the planar curvature (i.e., the degree of curvature) of the deep-sea channel, the deep-sea composite channel can be roughly divided into low-curvature and high-curvature sections. The curvature of the low-curvature section is less than 1.3, while the curvature of the high-curvature section is greater than or equal to 1.3. Furthermore, the overlapping patterns of individual channels within different curvature sections differ. For example... Figure 4c As shown, the single channel stacking pattern in the low-curvature section is a mixed stacking pattern, while the single channel stacking pattern in the high-curvature section is a lateral oblique stacking pattern. Obviously, the different stacking patterns are caused by the different migration characteristics of the channels, and further analysis of the migration changes of the channels from the cross-section is needed.

[0130] The second step is the analysis of the migration characteristics of deep-sea channel profiles.

[0131] Based on the deep-sea channel plan distribution map obtained in step one, three-dimensional seismic amplitude profiles are extracted along the direction perpendicular to the channel flow direction in both the low-curvature and high-curvature sections, as shown below. Figure 5a As shown. (Refer to...) Figure 5a Deep-sea composite channels exhibit a distinct downcut "U"-shaped feature in seismic profile reflections. The interior of this "U"-shaped composite channel displays significant amplitude disorder, with medium to strong amplitudes reflecting the superimposed distribution of individual channels. The discontinuity of the seismic axis clearly explains multiple small downcut "U"-shaped individual channels. Furthermore, the continuity of the seismic axis and the superimposed range of individual channels reveal the top and bottom of the migration patterns of these deep-sea channels. Therefore, seismic reflection profiles clearly reveal the migration and superimposition patterns of composite channels and their individual components. Further quantitative research on the migration characteristics of these individual channels is needed.

[0132] Step 3: Definition and Calculation of Deep-Sea Channel Migration Index

[0133] Based on the superimposed patterns of waterway profile migration in different curved sections obtained in step two, a quantitative study of the waterway migration process is conducted. For example... Figure 5b As shown, the migration trajectory of a single deep-sea channel can be decomposed into vertical migration and lateral migration in the cross-section. Vertical migration, denoted by V (in meters), reflects the degree of incision of the deep-sea channel during deposition. A greater degree of incision results in a larger vertical migration (V), indicating a thicker channel-sedimentary sand body. Lateral migration, denoted by L (in meters), reflects the intensity of lateral oscillation during the deposition of a single deep-sea channel. A greater intensity of lateral oscillation results in a larger lateral migration (L), indicating a larger planar distribution range of the channel sand body. The above describes the migration of deep-sea channels quantitatively. To further accurately reflect the migration patterns of deep-sea channels, a channel migration index is defined. The channel migration index, denoted by M, is the ratio of lateral migration (L) to vertical migration (V) and is dimensionless. The definition of the channel migration index, M = L / V, reflects the oscillation ability of a single deep-sea channel during sedimentation: when lateral migration ability is strong, vertical migration ability is often weaker; that is, the larger L is, the smaller V tends to be; conversely, when L is small, V tends to increase. This indicates that a larger channel migration index reflects a stronger lateral oscillation ability of the channel, while a smaller index reflects a stronger downcutting ability. To further clarify whether the pattern reflected by this index is consistent with the understanding gained from channel sedimentology research, further analysis from the perspective of changes in channel tortuosity is needed.

[0134] Step 4: Correlation analysis between deep-sea channel migration index and channel curvature.

[0135] Channel tortuosity refers to the ratio of the length of the curved line to the length of the straight line between the start and end points of a channel. It reflects the strength of the tortuosity of deep-sea channels, denoted by the letter S, with a value range of ≥1 and is dimensionless. As can be seen from the meaning of tortuosity, the greater the degree of tortuosity, the greater the migration index of the channel, and the two should have a linear / non-linear relationship. Typical deep-sea curved channels are selected, and the migration index of typical curved segments is calculated based on the methods in steps one through three. Simultaneously, the channel tortuosity of the corresponding segments is calculated. With a sufficient sample size, the correlation between the two is statistically analyzed. If the correlation is good, it indicates that the proposed method is relatively reliable and reasonable.

[0136] Example 5

[0137] To address the aforementioned technical problems in the prior art, embodiments of the present invention also provide a computer device.

[0138] The computer device of this embodiment includes a memory and a processor. The memory stores a computer program, which, when executed by the processor, implements the steps of the method for determining the degree of deep-sea channel migration described above.

[0139] S11 divides the deep-sea complex waterway on the deep-sea waterway plan into multiple curved sections;

[0140] S12, For each curved segment, determine the vertical and lateral migration amounts of the deep-sea single channel corresponding to the curved segment on the seismic amplitude profile corresponding to the curved segment.

[0141] S13, Calculate the channel migration index of the curved section based on the vertical and lateral migration of the deep-sea single channel corresponding to the curved section.

[0142] S14, Analyze the degree of deep-sea channel migration in each bend based on the channel migration index of each bend.

[0143] S15 verifies the degree of deep-sea channel migration in each bend segment based on the channel migration index analysis.

[0144] In this embodiment, in step S13, the channel migration index of the curved section is calculated based on the vertical and lateral migration amounts of the deep-sea single channel corresponding to the curved section using the following expression:

[0145] M = L / V

[0146] Wherein, M is the channel migration index of the curved section, L is the lateral migration of the deep-sea single channel corresponding to the curved section, and V is the vertical migration of the deep-sea single channel corresponding to the curved section.

[0147] In this embodiment, step S14, analyzing the deep-sea channel migration degree of each bend segment based on the channel migration index, includes:

[0148] For each bend, the larger the channel migration index of the bend, the stronger the lateral swinging ability of the deep-sea channel in that bend; the smaller the channel migration index of the bend, the stronger the downcutting ability of the deep-sea channel in that bend.

[0149] The computer device of this embodiment includes a memory and a processor. The memory stores a computer program, which, when executed by the processor, also implements the steps of the method for determining the degree of deep-sea channel migration described above:

[0150] S21. Based on the degree of planar curvature of the deep-sea composite channel in the root mean square amplitude attribute plane diagram, the deep-sea composite channel is divided into multiple curved segments.

[0151] S221, For each curved segment, multiple deep-sea single channels are interpreted based on the faulting of the seismic axis in the same direction inside the deep-sea composite channel on the seismic amplitude profile corresponding to the curved segment.

[0152] S222, Based on the migration trajectories of the multiple deep-sea single waterways, determine the vertical migration amount and lateral migration amount of the multiple single waterways;

[0153] S23, calculate the channel migration index of the curved section based on the vertical and lateral migration of the deep-sea single channel corresponding to the curved section.

[0154] S24, Analyze the degree of deep-sea channel migration in each bend based on the channel migration index of each bend.

[0155] S251, calculate the waterway curvature of each bend;

[0156] S252, based on the waterway migration index and waterway curvature corresponding to each of the multiple bends, analyze the correlation between the waterway migration index and waterway curvature of the same bend.

[0157] S253, based on the correlation analysis results between the waterway migration index and the waterway curvature of the same bend, determine whether the degree of deep-sea waterway migration of the bend segment analyzed according to the waterway migration index of each bend segment has passed the verification.

[0158] In this embodiment, step S222, determining the vertical and lateral migration amounts of the multiple deep-sea single channels based on their migration trajectories, includes:

[0159] The migration trajectories of the multiple deep-sea single channels are decomposed vertically and laterally to obtain the vertical and lateral migration amounts of the multiple single channels.

[0160] The computer device of this embodiment includes a memory and a processor. The memory stores a computer program, which, when executed by the processor, also implements the steps of the method for determining the degree of deep-sea channel migration described above:

[0161] Step 1: Analysis of the Horizontal Migration Characteristics of Deep-Sea Channels

[0162] Typical deep-sea channel sedimentary blocks were selected, and three-dimensional seismic attributes that clearly reflect the characteristics of channel sedimentation, such as root-mean-square amplitude (RMS) attributes, were preferred. Based on the Landmark or Petrel software platform, these attributes were extracted through isochronous stratigraphic slices to obtain... Figure 4a The diagram shown is a planar migration characteristic distribution map of deep-sea channels, specifically a root-mean-square amplitude attribute plane map. This plane map clearly reflects the tortuous distribution pattern of deep-sea complex channels, which are often formed by the superposition of multiple single deep-sea channels, such as... Figure 4b As shown, different individual channel main current lines migrate and overlap within a deep-sea composite channel to form a composite deep-sea channel. Different curves represent individual channels at different times. Based on the planar curvature (i.e., the degree of curvature) of the deep-sea channel, the deep-sea composite channel can be roughly divided into low-curvature and high-curvature sections. The curvature of the low-curvature section is less than 1.3, while the curvature of the high-curvature section is greater than or equal to 1.3. Furthermore, the overlapping patterns of individual channels within different curvature sections differ. For example... Figure 4c As shown, the single channel stacking pattern in the low-curvature section is a mixed stacking pattern, while the single channel stacking pattern in the high-curvature section is a lateral oblique stacking pattern. Obviously, the different stacking patterns are caused by the different migration characteristics of the channels, and further analysis of the migration changes of the channels from the cross-section is needed.

[0163] The second step is the analysis of the migration characteristics of deep-sea channel profiles.

[0164] Based on the deep-sea channel plan distribution map obtained in step one, three-dimensional seismic amplitude profiles are extracted along the direction perpendicular to the channel flow direction in both the low-curvature and high-curvature sections, as shown below. Figure 5a As shown. (Refer to...) Figure 5aDeep-sea composite channels exhibit a distinct downcut "U"-shaped feature in seismic profile reflections. The interior of this "U"-shaped composite channel displays significant amplitude disorder, with medium to strong amplitudes reflecting the superimposed distribution of individual channels. The discontinuity of the seismic axis clearly explains multiple small downcut "U"-shaped individual channels. Furthermore, the continuity of the seismic axis and the superimposed range of individual channels reveal the top and bottom of the migration patterns of these deep-sea channels. Therefore, seismic reflection profiles clearly reveal the migration and superimposition patterns of composite channels and their individual components. Further quantitative research on the migration characteristics of these individual channels is needed.

[0165] Step 3: Definition and Calculation of Deep-Sea Channel Migration Index

[0166] Based on the superimposed patterns of waterway profile migration in different curved sections obtained in step two, a quantitative study of the waterway migration process is conducted. For example... Figure 5b As shown, the migration trajectory of a single deep-sea channel can be decomposed into vertical migration and lateral migration in the cross-section. Vertical migration, denoted by V (in meters), reflects the degree of incision of the deep-sea channel during deposition. A greater degree of incision results in a larger vertical migration (V), indicating a thicker channel-sedimentary sand body. Lateral migration, denoted by L (in meters), reflects the intensity of lateral oscillation during the deposition of a single deep-sea channel. A greater intensity of lateral oscillation results in a larger lateral migration (L), indicating a larger planar distribution range of the channel sand body. The above describes the migration of deep-sea channels quantitatively. To further accurately reflect the migration patterns of deep-sea channels, a channel migration index is defined. The channel migration index, denoted by M, is the ratio of lateral migration (L) to vertical migration (V) and is dimensionless. The definition of the channel migration index, M = L / V, reflects the oscillation ability of a single deep-sea channel during sedimentation: when lateral migration ability is strong, vertical migration ability is often weaker; that is, the larger L is, the smaller V tends to be; conversely, when L is small, V tends to increase. This indicates that a larger channel migration index reflects a stronger lateral oscillation ability of the channel, while a smaller index reflects a stronger downcutting ability. To further clarify whether the pattern reflected by this index is consistent with the understanding gained from channel sedimentology research, further analysis from the perspective of changes in channel tortuosity is needed.

[0167] Step 4: Correlation analysis between deep-sea channel migration index and channel curvature.

[0168] Channel tortuosity refers to the ratio of the length of the curved line to the length of the straight line between the start and end points of a channel. It reflects the strength of the tortuosity of deep-sea channels, denoted by the letter S, with a value range of ≥1 and is dimensionless. As can be seen from the meaning of tortuosity, the greater the degree of tortuosity, the greater the migration index of the channel, and the two should have a linear / non-linear relationship. Typical deep-sea curved channels are selected, and the migration index of typical curved segments is calculated based on the methods in steps one through three. Simultaneously, the channel tortuosity of the corresponding segments is calculated. With a sufficient sample size, the correlation between the two is statistically analyzed. If the correlation is good, it indicates that the proposed method is relatively reliable and reasonable.

[0169] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and changes in form and detail of the implementation without departing from the spirit and scope disclosed herein; however, the scope of protection of this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A method for determining the degree of migration in deep-sea channels, characterized in that, include: The deep-sea complex waterway on the deep-sea waterway plan is divided into multiple curved sections; For each curved segment, perform the following steps: On the seismic amplitude profile corresponding to the curved segment, determine the vertical and lateral migration of the deep-sea single channel corresponding to the curved segment. The channel migration index of the curved section is calculated based on the vertical and lateral migration of the deep-sea single channel corresponding to the curved section. The degree of deep-sea channel migration in each bend is analyzed based on the channel migration index. The deep-sea channel planar distribution map is a planar map of the root mean square amplitude attribute of isochronous stratigraphic slices extracted from high-frequency seismic data. The deep-sea composite channel on the deep-sea channel planar distribution map is divided into multiple curved segments, including: Based on the degree of planar curvature of the deep-sea composite channel in the root mean square amplitude attribute plane diagram, the deep-sea composite channel is divided into multiple curved segments. Determining the vertical and lateral migration of the deep-sea single channel corresponding to the curved segment on the seismic amplitude profile corresponding to the curved segment includes: On the seismic amplitude profile corresponding to the curved section, multiple deep-sea single channels are interpreted based on the faulting of the seismic axes in the same direction inside the deep-sea composite channel. Based on the migration trajectories of the multiple deep-sea single channels, the vertical migration amount and lateral migration amount of the multiple single channels; The step of determining the vertical and lateral migration amounts of the multiple deep-sea single channels based on their migration trajectories includes: The migration trajectories of the multiple deep-sea single channels are decomposed vertically and laterally to obtain the vertical migration amount and lateral migration amount of the multiple single channels. The channel migration index of the curved section is calculated based on the vertical and lateral migration amounts of the deep-sea single channel corresponding to the curved section using the following expression: M=L / V Wherein, M is the waterway migration index of the curved section, L is the lateral migration of the deep-sea single waterway corresponding to the curved section, and V is the vertical migration of the deep-sea single waterway corresponding to the curved section. The analysis of the deep-sea channel migration degree of each bend segment based on the channel migration index includes: For each bend, the larger the channel migration index of the bend, the stronger the lateral swinging ability of the deep-sea channel in that bend; the smaller the channel migration index of the bend, the stronger the downcutting ability of the deep-sea channel in that bend.

2. The method according to claim 1, characterized in that, The method further includes: The degree of deep-sea channel migration in each bend segment was verified based on the channel migration index analysis.

3. The method according to claim 2, characterized in that, The verification of the deep-sea channel migration degree of each bend segment, analyzed based on the channel migration index, includes: Calculate the waterway curvature for each bend. The correlation between the waterway migration index and waterway curvature of the same bend segment is analyzed based on the waterway migration index and waterway curvature corresponding to each bend segment in multiple bend segments. Based on the correlation analysis results between the waterway migration index and waterway curvature of the same bend, it is determined whether the degree of deep-sea waterway migration of the bend segment analyzed based on the waterway migration index of each bend segment is verified.

4. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 3.

5. A computer device comprising a memory and a processor, characterized in that, The memory stores a computer program that, when executed by a processor, implements the steps of the method according to any one of claims 1 to 3.

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