Restoration method and system for micro-paleomorphological evolution process in wellless delta sedimentary area

Abstract

The present invention relates to a method for restoring the micro-paleomorphological evolution process of a wellless deltaic sedimentary area, comprising: constructing a plane range that completely covers the delta for a target area where deltaic deposits are present in a three-dimensional seismic data volume; calculating the thickness of the layer segment in which the delta is located based on the top and bottom surfaces of the layer segment, and using this thickness as the initial paleogeomorphology of the layer segment; setting a series of seismic events in the layer segment with an "S"-shaped progradational reflection characteristic and wedge-shaped events as a progradational composite lobe; calculating the thickness of each progradational composite lobe; based on the initial paleogeomorphology, sequentially superimposing the thickness of the progradational composite lobe from bottom to top, and using the map with each thickness superimposition as the paleogeomorphology before the deposition of the next progradational composite lobe; and sequentially arranging the series of paleogeomorphological maps superimposed with the thickness of the progradational composite lobe from bottom to top to complete the restoration of the micro-paleomorphological evolution process of the target area. The present invention can be widely applied in the field of oil and gas exploration technology.

Description

Technical Field

[0001] The present invention relates to a method and system for restoring the micro-paleomorphological evolution process of a wellless delta sedimentary area, belonging to the technical field of oil and gas exploration. Background Art

[0002] Predicting sandbody distribution is essential in oil and gas exploration. Paleogeomorphology can influence sediment distribution, and micro-paleogeomorphology, in particular, has a significant impact on sandbody-rich areas. Traditional paleogeomorphology reconstruction has undergone a complex series of development stages. Previous studies have employed a variety of methods, including geophysical methods, impression methods, sequence stratigraphy, sedimentology, and the residual thickness method. Others have also used lithofacies and trace element analysis of sedimentary environments based on core samples to reconstruct paleogeomorphology.

[0003] The residual thickness method uses the thickness of the stratigraphic layers remaining in a region as its starting point. The thickness of the stratigraphic layers today is a prerequisite for paleogeomorphological reconstruction, and the distribution of stratigraphic layers today can also roughly reconstruct the general distribution trend of the paleogeomorphology. This method is quite intuitive and easy to understand, and it semi-quantitatively reflects the general outline of the paleogeomorphology. However, the residual thickness method is subject to significant errors and needs to consider the amount of erosion and pre-depositional topography.

[0004] On the basis of the above methods, backstripping, filling and leveling, structural sedimentation simulation and other methods have also been developed. At present, the relatively quantitative backstripping method is generally used, which is based on the analysis of the sedimentation history. The analysis of the sedimentation history of the basin requires the correction of parameters such as compaction, paleowater depth and sea (lake) level change in order to draw the total sedimentation curve; the total sedimentation needs to be divided into the sedimentation caused by tectonic driving force and the sedimentation caused by sedimentary load, and the tectonic sedimentation curve is given. However, the backstripping method works better when the stratum has significant erosion and the data on stratum rock parameters, porosity, etc. are relatively sufficient. However, there may be large errors in areas where the stratum has no erosion or no significant erosion and the stratum parameters are unclear.

[0005] In well-free areas, the lack of data on formation porosity, rock logging, and sand-to-ground ratios makes it impossible to perform tasks such as formation compaction recovery, paleowater depth calculation, and sea-level change analysis. This is especially true when studying the micro-paleomorphological evolution within a target interval within a small region. Basin-level provenance analysis and sedimentary evolution span a long timeframe, leading to large errors in micro-paleomorphological recovery. Consequently, the application of methods such as backstripping, impression, residual thickness, and seismic reflection amplitude analysis, which rely on formation compaction recovery, is limited.

[0006] In summary, the existing calculation methods for micro-paleogeomorphological restoration have the problem of strong dependence on parameters such as formation porosity, logging data, and sand-to-ground ratio. For single layer sections in small areas that have not been drilled, there is generally a lack of a set of methods that do not rely on drilling data and can quickly reflect the evolution of micro-paleogeomorphology. Summary of the Invention

[0007] The present invention aims to address at least one of the technical problems existing in the prior art. To this end, the present invention provides a method and system for recovering the micro-paleomorphic evolution process in wellless deltaic sedimentary areas. This method aims to reduce the requirement for drilling data in the study area, avoid the need for long-term basin-level analysis, and achieve the reconstruction of micro-paleomorphic evolution in undrilled, small areas, and single intervals. This method has important guiding significance for predicting the distribution of deltaic sedimentary sand bodies in specific areas and target intervals.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] In the first aspect, the present invention provides a method for restoring the micro-paleomorphological evolution process of a wellless delta sedimentary area, comprising the following steps: setting a plane range that completely covers the delta sedimentary target area where drilling is expected; compiling a thickness map of the target layer section expected to be drilled within the plane range; determining the main provenance direction of the target layer section during the deposition period of the expected drilling; drawing a straight line along the main provenance direction with the center of the plane range as the origin in the three-dimensional seismic work area, and extracting seismic profiles with different angles to the main provenance direction; in the extracted seismic profiles, starting from the bottom boundary of the target layer section, from bottom to top, observing the unique delta sedimentation characteristics. Seismic reflection characteristics are used to identify and track progradational composite lobes; for each progradational composite lobe, a series of seismic profiles are extracted using seismic profile grid density, parallel to and perpendicular to the provenance direction; the top and bottom interfaces of the progradational composite lobe are tracked; a progradational composite lobe thickness map is compiled based on the obtained top and bottom interfaces of the progradational composite lobe; based on the thickness map of the target layer for expected drilling, the progradational composite lobe thickness maps are superimposed from bottom to top to compile a micro-paleomorphological map after the deposition of the progradational composite lobe; the micro-paleomorphological maps are arranged in sequence to restore the micro-paleomorphological evolution process of the target area of ​​wellless delta deposition.

[0010] In the recovery method, preferably, the planar range of the delta deposition target area where drilling is expected is set as follows: for the delta deposition target area where drilling is expected in the three-dimensional seismic data volume, a rectangular frame that can completely cover the delta deposition target area is constructed, and the delta deposition target area is placed in the center of the rectangular frame.

[0011] In the recovery method, preferably, the deltaic deposition target area for expected drilling in the three-dimensional seismic data volume is determined by geological analysis, which includes structural interpretation, oil and gas migration direction, cap rock characteristics, and trap element characteristics.

[0012] The restoration method, preferably, the preparation of the target layer section thickness map for the planned drilling is specifically: based on the top and bottom surface structural maps of the target layer section for the planned drilling, a thickness map of the target layer section for the planned drilling within the rectangular frame is prepared as the initial paleogeomorphology of the target layer section.

[0013] The restoration method preferably determines the main provenance direction of the target layer during the deposition period of the drilling target based on regional geological background research and literature research methods;

[0014] Among them, the regional geological background research includes tectonic activity, stratigraphic occurrence, sedimentary filling process, and heavy mineral distribution characteristics, and the literature survey includes regional paleogeomorphology, sedimentary phase distribution, and source-sink system.

[0015] In the restoration method, preferably, in each progradational composite lobe, the section with the most obvious progradational characteristics is set as the provenance direction, and the direction with an angle of 90° with the provenance direction is set as the perpendicular provenance direction;

[0016] Among them, the section with the most obvious foreset characteristics refers to the section where the angle between the “S”-shaped foreset line and the bottom boundary after flattening is the largest after the bottom boundary of the target layer is flattened.

[0017] The recovery method, preferably, includes tracking the top and bottom interfaces of the progradational composite lobe: in each progradational composite lobe, the two upper and lower adjacent 0° phases of the wedge-shaped seismic phase axis are used as its top and bottom interfaces, and the top and bottom interfaces of each progradational composite lobe are tracked in the seismic profile grid respectively. The tracking is terminated when the phase axis pinches out, disappears, is disconnected, or intersects with other phase axes, and the point where the tracking ends is set as the boundary of the progradational composite lobe.

[0018] In the second aspect, the present invention provides a restoration system for the micro-paleogeomorphological evolution process of a wellless delta sedimentary area, comprising: a first processing unit for setting a plane range that completely covers the delta sedimentary target area where drilling is expected; a second processing unit for compiling a thickness map of the target layer section for expected drilling within the plane range; a third processing unit for determining the main provenance direction of the target layer section during the deposition period of the expected drilling; a fourth processing unit for drawing a straight line along the main provenance direction with the center of the plane range as the origin in the three-dimensional seismic work area, and extracting seismic profiles with different angles to the main provenance direction; a fifth processing unit for observing the geological features unique to delta sedimentation from the bottom up, starting from the bottom boundary of the target layer section in the extracted seismic profile. seismic reflection characteristics to identify and track the progradational composite lobe; the sixth processing unit is used to extract a series of seismic profiles for each progradational composite lobe, parallel to the provenance direction and perpendicular to the provenance direction, respectively, using the seismic profile grid density; the seventh processing unit is used to track the top and bottom interfaces of the progradational composite lobe; the eighth processing unit is used to compile a progradational composite lobe thickness map based on the obtained progradational composite lobe top and bottom interfaces; the ninth processing unit is used to superimpose the progradational composite lobe thickness maps from bottom to top based on the thickness map of the target layer for expected drilling, and compile a micro-paleomorphological map after the deposition of the progradational composite lobe; the tenth processing unit is used to arrange the micro-paleomorphological maps in sequence to restore the micro-paleomorphological evolution process of the target area of ​​wellless delta deposition.

[0019] In a third aspect, the present invention provides a computer storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for restoring the micro-paleogeomorphological evolution process of the wellless delta sedimentary area described in the first aspect of the present invention.

[0020] In a fourth aspect, the present invention provides a computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method for restoring the micro-paleogeomorphological evolution process of a wellless delta sedimentary area as described in the first aspect of the present invention when executing the computer program.

[0021] The present invention has the following advantages due to the adoption of the above technical solution:

[0022] 1. The present invention can avoid dependence on drilling data, improve the thickness accuracy of the micro-paleomorphological evolution process, achieve the purpose of rapid recovery of the micro-paleomorphological evolution process in undrilled areas, and provide an effective basis for sedimentary microfacies analysis and favorable sand body distribution prediction in oil and gas exploration.

[0023] 2. The present invention improves the thickness accuracy of the micro-paleomorphic evolution process to the thickness of a seismic event, that is, as the seismic resolution increases, the thickness accuracy of the micro-paleomorphic evolution process also increases.

[0024] 3. The present invention can realize the rapid recovery of micro-paleomorphological evolution process in well-free delta sedimentary areas, which is of great significance for sedimentary microfacies analysis, favorable sand body distribution prediction, well location optimization, etc.

[0025] In summary, the present invention can be applied to a method and system for quickly and quantitatively determining the distribution of favorable sand bodies in undrilled areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. Throughout the drawings, the same reference numerals are used to denote the same components. In the drawings:

[0027] Figure 1 is a flowchart of a recovery method provided by an embodiment of the present invention;

[0028] Figure 2 is an approximate initial paleogeomorphological map of the target area provided by one embodiment of the present invention;

[0029] Figure 3 This is a planar position diagram of a series of seismic sections taken through the center of a work area provided by one embodiment of the present invention;

[0030] Figure 4 1 is a schematic diagram of identifying a foreset complex using an "S"-shaped foreset feature and a wedge-shaped feature according to an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of identifying a pre-depositional composite lobe along the source direction provided by an embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of the top and bottom boundaries of a composite lobe body provided by an embodiment of the present invention;

[0033] Figure 7 This is a diagram of the thickness of a pre-deposited composite lobe provided by one embodiment of the present invention;

[0034] Figure 8 It is a schematic diagram of the micro-paleomorphological evolution process of the target area provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0035] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0036] In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the systems or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the use of terms such as "first" and "second" to define components is solely for the purpose of distinguishing those components. Unless otherwise stated, these terms have no special meanings and should not be construed as indicating or implying relative importance.

[0037] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "installed," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0038] Hereinafter, the method and system for restoring the micro-paleomorphological evolution process of a wellless delta sedimentary area provided by the embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0039] Example 1:

[0040] like Figure 1 As shown, this embodiment provides a method for restoring the micro-paleomorphological evolution process of a wellless delta sedimentary area, comprising the following steps:

[0041] S101. Set a plane range that completely covers the delta deposition target area where drilling is expected: for the delta deposition target area where drilling is expected in the 3D seismic data volume, construct a rectangular frame A that can completely cover the delta deposition target area, and place the delta deposition target area in the center of rectangular frame A.

[0042] Among them, the deltaic sedimentary target area for drilling in the 3D seismic data volume is determined by geological analysis, which includes structural interpretation, oil and gas migration direction, cap rock characteristics, and closure element characteristics.

[0043] S102. Prepare a thickness map of the target layer section for planned drilling: Based on the top and bottom surface structural maps of the target layer section for planned drilling, prepare a thickness map G1 of the target layer section for planned drilling within rectangular frame A, and use the thickness map G1 as the initial paleogeomorphology of the target layer section.

[0044] S103. Based on regional geological background research and literature research methods, determine the main provenance direction of the target layer during the sedimentary period of the planned drilling.

[0045] Among them, the regional geological background research includes tectonic activity, stratigraphic occurrence, sedimentary filling process, and heavy mineral distribution characteristics, and the literature survey includes regional paleogeomorphology, sedimentary phase distribution, and source-sink system.

[0046] S104. In the 3D seismic work area, with the center of rectangular frame A as the origin, draw straight lines along the main source direction to extract seismic profiles with angles of 0°, ±15°, ±30°, and ±45° (the angles can be appropriately increased depending on the specific situation) with the main source direction.

[0047] S105. In the extracted seismic profile, starting from the bottom boundary of the target interval and working from bottom to top, observe the seismic reflection characteristics unique to deltaic sediments to identify and track the progradational complex lobe:

[0048] A series of seismic events with an S-shaped foreset reflection and a wedge-shaped event combination are set as a foreset composite lobe. Within the target layer segment and within the rectangular frame A, the found foreset composite lobe is set as DTi (i = 1, 2, 3, ...), where the serial number 1 indicates that the position point with the largest depth value of the composite lobe is closest to the bottom boundary of the target layer and is deposited earliest. A higher serial number i indicates that it is farther away from the bottom boundary of the target layer and has a later deposition time.

[0049] S106. In each progradational composite lobe DTi (i=1, 2, 3...), the section with the most obvious progradational characteristics is set as the provenance direction, and the direction with an angle of 90° with the provenance direction is set as the perpendicular provenance direction; for each progradational composite lobe, a series of seismic profiles are extracted parallel to the provenance direction and the perpendicular provenance direction using a 10×10 seismic profile grid density.

[0050] Among them, the section with the most obvious foreset characteristics refers to the section where the angle between the “S”-shaped foreset line and the bottom boundary after flattening is the largest after the bottom boundary of the target layer is flattened.

[0051] S107. Tracking the top and bottom interfaces of the progradational composite lobe: In each progradational composite lobe DTi (i=1, 2, 3....), the two upper and lower adjacent 0° phases of the wedge-shaped seismic event are used as its top and bottom interfaces, and the top and bottom interfaces of each progradational composite lobe DTi are tracked in the seismic profile grid of the above step S106. The tracking is terminated when the event pinches out, disappears, is disconnected, or intersects with other events, and the point where the tracking ends is set as the boundary of the progradational composite lobe.

[0052] S108. Based on the top and bottom interfaces of the pre-deposited composite lobe obtained in step S107, a thickness map of the pre-deposited composite lobe is prepared, and the maps are set as Ti (i = 1, 2, 3, ...);

[0053] S109. Compile a micro-paleomorphological map Gj (i = 1, 2, 3, ....) of the progradational composite lobe after deposition, where Gj = G1 + Ti, (i = 1, 2, 3, ....; j = i + 1);

[0054] S110. Arrange the micro-paleomorphological maps Gj in order to restore the micro-paleomorphological evolution process of the target area of ​​wellless delta deposition.

[0055] The following describes in detail the restoration method of the micro-paleomorphic evolution process of the wellless delta sedimentary area of ​​the present invention, taking the delta sedimentary area of ​​the Miocene Huangliu Formation of the Haikou A structure in the Yingbei District of the Yinggehai Basin, China as a specific example:

[0056] 1) For the deltaic deposition target area where drilling is expected in the 3D seismic data volume of the Haikou A structure, a rectangular frame A is constructed that can completely cover the deltaic deposition target area, and the deltaic deposition target area is placed in the center of the rectangular frame A.

[0057] 2) As the target layer of the well is expected to be the first member of the Huangliu Formation, the thickness map G1 of the first member of the Huangliu Formation within the rectangular frame A is obtained by subtracting the depth structure map of the bottom surface T31 from the depth structure map of the top surface T30 of the first member of the Huangliu Formation within the rectangular frame A. The thickness map G1 is used as the initial paleogeomorphology of the first member of the Huangliu Formation (e.g. Figure 2 shown).

[0058] 3) Determine the main provenance of the target layer during its deposition period based on regional geological background research and literature research methods.

[0059] The target area is in a depression stage, with little influence from fault activity. The strata as a whole tilt toward the southwest. The main provenance comes from the northeast delta, and the delta sand body is transported from the northeast to the southwest as a whole.

[0060] 4) In the 3D seismic work area, take the center of the rectangular frame A as the origin, draw a straight line along the northeast-southwest direction, and extract the seismic profiles with angles of 0°, ±15°, ±30°, and ±45° with the straight line. The positions of the profile lines are as follows: Figure 3 shown.

[0061] 5) In the extracted seismic profile, starting from the bottom boundary of the target interval and working from bottom to top, observe the seismic reflection characteristics unique to deltaic sediments to identify and track the progradational complex lobe:

[0062] A series of seismic events with an S-shaped foreset reflection and a wedge-shaped event combination is considered a foreset composite lobe (e.g. Figure 4In the target layer and within the rectangular frame A, five progradational composite lobes were found and set as DTi (i=1, 2, 3, 4, 5), where DT1 represents the composite lobe with the largest depth value, which is closest to the bottom boundary of the target layer and deposited the earliest; DT5 represents the composite lobe which is farthest from the bottom boundary of the target layer and deposited the latest.

[0063] 6) In DT1, DT2, DT3, DT4, and DT5, for each progradational composite lobe, the section with the most obvious progradational characteristics was set as the provenance direction, and the direction with an angle of 90° to the provenance direction was set as the perpendicular provenance direction; for each progradational composite lobe, a series of seismic sections were extracted using a 10 × 10 seismic section grid density parallel to the provenance direction and the perpendicular provenance direction, respectively.

[0064] like Figure 5 As shown in a, the angle between the “S”-shaped foreset line and the flattened bottom boundary in the northeast-southwest direction of DT2 is the direction with the largest angle value in the foreset complex body, which is the provenance direction of DT2; Figure 5 As shown in b, the angle between the "S"-shaped foreset line in the SE-NW direction and the bottom boundary after flattening in DT4 is the direction with the largest angle value in the foreset complex body, which is the provenance direction of DT4.

[0065] 7) In DT1, DT2, DT3, DT4, and DT5, the upper and lower adjacent 0° phases of the wedge-shaped seismic event are used as the top and bottom interfaces of the progradational composite lobe. The top and bottom interfaces of DT1, DT2, DT3, DT4, and DT5 are tracked in the seismic profile grid described in step 6). The tracking is terminated when the event pinches out, disappears, is disconnected, or intersects with other events, and the point where the tracking ends is set as the boundary of the progradational composite lobe (e.g., Figure 6 shown).

[0066] 8) Based on the top and bottom interfaces of DT1, DT2, DT3, DT4 and DT5 obtained in step 7), prepare thickness maps of DT1, DT2, DT3, DT4 and DT5 according to the thickness map preparation method (such as Figure 7 As shown), they are set to Ti (i=1, 2, 3, 4, 5) respectively.

[0067] 9) Set Gj = G1 + Ti, (i = 1, 2, 3, 4, 5; j = i + 1), where Gj is the micro-paleomorphology map after the deposition of the progradational composite lobe DTi.

[0068] 10) Arrange the micro-paleomorphological maps Gj in order to obtain the micro-paleomorphological evolution process map of the undrilled delta deposition target area (such as Figure 8 shown).

[0069] According to this embodiment, the micro-paleomorphological evolution process of the delta sedimentary area of ​​the Miocene Huangliu Formation in the Haikou A structure in the Yingbei area of ​​the Yinggehai Basin without wells can be quickly restored, thereby guiding the sedimentary microfacies analysis and the prediction of favorable sand body distribution, and further guiding the well location deployment of the Haikou A structure in the Yingbei area.

[0070] Example 2:

[0071] The above-mentioned embodiment 1 provides a method for restoring the micro-paleogeomorphological evolution process of a well-less deltaic sedimentary area. Correspondingly, this embodiment provides a system for restoring the micro-paleogeomorphological evolution process of a well-less deltaic sedimentary area. The system for restoring the micro-paleogeomorphological evolution process of a well-less deltaic sedimentary area provided in this embodiment can implement the method for restoring the micro-paleogeomorphological evolution process of a well-less deltaic sedimentary area of ​​embodiment 1. The restoration system can be implemented by software, hardware, or a combination of software and hardware. For example, the restoration system may include integrated or separate functional modules or functional units to execute the corresponding steps in each method of embodiment 1. Since the system for restoring the micro-paleogeomorphological evolution process of a well-less deltaic sedimentary area of ​​this embodiment is basically similar to the method embodiment, the process described in this embodiment is relatively simple. For relevant matters, please refer to the partial description of embodiment 1. The system for restoring the micro-paleogeomorphological evolution process of a well-less deltaic sedimentary area of ​​this embodiment is merely schematic.

[0072] This embodiment provides a system for restoring the micro-paleomorphological evolution process of a wellless delta sedimentary area, the restoration system comprising:

[0073] A first processing unit is used to set a plane range that completely covers the delta deposition target area where the well is expected to be drilled;

[0074] The second processing unit is used to compile a target layer thickness map for expected drilling within a plane range;

[0075] The third processing unit is used to determine the main provenance direction during the deposition period of the target layer section to be drilled;

[0076] The fourth processing unit is used to draw a straight line along the main source direction with the center of the plane range as the origin in the three-dimensional seismic work area, and extract seismic sections with different angles to the main source direction;

[0077] The fifth processing unit is used to observe the seismic reflection characteristics unique to deltaic sedimentation, i.e., the "S"-shaped progradational reflection of the seismic phase axis, starting from the bottom boundary of the target layer and working from bottom to top in the extracted seismic profile;

[0078] The sixth processing unit is used to extract a series of seismic profiles for each progradational composite lobe, parallel to the provenance direction and perpendicular to the provenance direction respectively, using the seismic profile grid density;

[0079] The seventh processing unit is used to track the top and bottom interfaces of the pre-deposition composite lobe;

[0080] An eighth processing unit is configured to compile a thickness map of the pre-deposition composite lobe according to the obtained top and bottom interfaces of the pre-deposition composite lobe;

[0081] The ninth processing unit is used to sequentially superimpose the thickness map of the progradational composite lobe from bottom to top based on the thickness map of the target layer section to be drilled, and to compile a micro-paleomorphological map after the deposition of the progradational composite lobe;

[0082] The tenth processing unit is used to arrange the micro-paleomorphological maps in sequence and restore the micro-paleomorphological evolution process of the wellless delta deposition target area.

[0083] Example 3:

[0084] This embodiment provides a processing device for implementing the method for restoring the micro-paleomorphological evolution process of the wellless delta sedimentary area provided in this embodiment 1. The processing device can be a processing device for a client, such as a mobile phone, laptop computer, tablet computer, desktop computer, etc., to execute the restoration method of embodiment 1.

[0085] The processing device includes a processor, a memory, a communication interface, and a bus. The processor, memory, and communication interface are connected via the bus to facilitate communication between them. The memory stores a computer program executable on the processor. When the processor executes the computer program, it executes the method for restoring the micro-paleogeomorphological evolution process of a wellless delta sedimentary area provided in Example 1.

[0086] Preferably, the memory may be a high-speed random access memory (RAM), and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0087] Preferably, the processor may be a central processing unit (CPU), a digital signal processor (DSP), or other general-purpose processors of various types, which are not limited here.

[0088] Example 4:

[0089] The method for restoring the micro-paleomorphological evolution process of the wellless delta sedimentary area of ​​this embodiment 1 can be specifically implemented as a computer program product. The computer program product may include a computer-readable storage medium on which computer-readable program instructions for executing the restoration method described in this embodiment 1 are loaded.

[0090] Computer readable storage media can be tangible devices that hold and store instructions used by instruction execution devices. Computer readable storage media can be, for example, but not limited to, electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any combination thereof.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for restoring the micro-paleomorphological evolution process of a wellless delta sedimentary area, characterized in that: The steps include: Setting a plan range that completely covers the deltaic deposition target area where drilling is planned; Prepare a thickness map of the target layer for drilling within the plane range; Determine the main provenance direction of the target layer during the sedimentary period of the drilling target; In the 3D seismic work area, take the center of the plane range as the origin, draw a straight line along the main source direction, and extract seismic sections with different angles to the main source direction; In the extracted seismic profile, starting from the bottom boundary of the target interval and moving upward, the unique seismic reflection characteristics of deltaic sediments are observed to identify and track the progradational complex lobe. For each progradational complex lobe, a series of seismic sections are extracted using seismic section grid density, parallel to the provenance direction and perpendicular to the provenance direction. Track the top and bottom interfaces of the pre-depositional composite lobes; According to the obtained top and bottom interfaces of the pre-depositional composite lobe, a thickness map of the pre-depositional composite lobe is compiled; Based on the thickness map of the target interval of the expected drilling, the thickness map of the progradational composite lobe is superimposed from bottom to top to compile the micro-paleomorphology map after the deposition of the progradational composite lobe; The micro-paleomorphological maps were arranged in sequence to restore the micro-paleomorphological evolution process of the target area of ​​wellless delta deposition.

2. The recovery method according to claim 1, characterized in that: The setting of the plane range that completely covers the delta deposition target area for the planned drilling is specifically as follows: for the delta deposition target area for the planned drilling in the three-dimensional seismic data volume, a rectangular frame that can completely cover the delta deposition target area is constructed, and the delta deposition target area is placed in the center of the rectangular frame.

3. The recovery method according to claim 2, characterized in that: The deltaic sedimentary target areas for planned drilling in the 3D seismic data volume are determined by geological analysis, which includes structural interpretation, oil and gas migration direction, cap rock characteristics, and trap element characteristics.

4. The recovery method according to claim 2, characterized in that: The preparation of the target layer thickness map for the expected drilling is specifically as follows: based on the top and bottom surface structural maps of the target layer for the expected drilling, the thickness map of the target layer for the expected drilling within the rectangular frame is prepared as the initial paleogeomorphology of the target layer.

5. The recovery method according to claim 1, wherein: Determine the main provenance direction of the target layer during the sedimentary period of the planned drilling based on regional geological background research and literature research methods; Among them, the regional geological background research includes tectonic activity, stratigraphic occurrence, sedimentary filling process, and heavy mineral distribution characteristics, and the literature survey includes regional paleogeomorphology, sedimentary phase distribution, and source-sink system.

6. The recovery method according to claim 1, characterized in that: In each progradational complex lobe, the section with the most obvious progradational characteristics is set as the provenance direction, and the direction with an angle of 90° to the provenance direction is set as the perpendicular provenance direction; Among them, the section with the most obvious foreset characteristics refers to the section where the angle between the "S"-shaped foreset line and the bottom boundary after flattening is the largest when the bottom boundary of the target layer is flattened.

7. The recovery method according to claim 4, characterized in that: The method of tracking the top and bottom interfaces of the progradational composite lobe is as follows: in each progradational composite lobe, the two upper and lower adjacent 0° phases of the wedge-shaped seismic event are used as its top and bottom interfaces, and the top and bottom interfaces of each progradational composite lobe are tracked in the seismic profile grid respectively. The tracking is terminated when the event pinches out, disappears, is disconnected, or intersects with other events, and the point where the tracking ends is set as the boundary of the progradational composite lobe.

8. A restoration system for the micro-paleomorphological evolution process of a wellless delta sedimentary area, characterized in that: include: A first processing unit is used to set a plane range that completely covers the delta deposition target area where the well is expected to be drilled; The second processing unit is used to compile a target layer thickness map for expected drilling within a plane range; The third processing unit is used to determine the main provenance direction during the deposition period of the target layer section to be drilled; The fourth processing unit is used to draw a straight line along the main source direction with the center of the plane range as the origin in the three-dimensional seismic work area, and extract seismic sections with different angles to the main source direction; The fifth processing unit is used to observe the seismic reflection characteristics unique to deltaic sediments from the bottom boundary of the target layer in the extracted seismic profile, so as to identify and track the progradational complex lobe; The sixth processing unit is used to extract a series of seismic profiles for each progradational composite lobe, parallel to the provenance direction and perpendicular to the provenance direction respectively, using the seismic profile grid density; The seventh processing unit is used to track the top and bottom interfaces of the pre-deposition composite lobe; An eighth processing unit is configured to compile a thickness map of the pre-deposition composite lobe according to the obtained top and bottom interfaces of the pre-deposition composite lobe; The ninth processing unit is used to sequentially superimpose the thickness map of the progradational composite lobe from bottom to top based on the thickness map of the target layer section to be drilled, and to compile a micro-paleomorphological map after the deposition of the progradational composite lobe; The tenth processing unit is used to arrange the micro-paleomorphological maps in sequence and restore the micro-paleomorphological evolution process of the wellless delta deposition target area.

9. A computer storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for restoring the micro-paleomorphological evolution process of a wellless delta sedimentary area according to any one of claims 1 to 7 are implemented.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method for restoring the micro-paleomorphological evolution process of the wellless delta sedimentary area described in any one of claims 1 to 7 are implemented.

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