Reconstruction type depression prototype recovery and reconstruction method and device

Abstract

The invention discloses a reformed depression prototype recovery and reconstruction method, which comprises the following steps of: dissecting and analyzing a depression structure of a research area, and identifying the characteristics of the depression structure of the research area; identifying a stratigraphic framework in a main sedimentary period of the research area; identifying and counting the fault point and fault displacement of the fault in the depression structure, and recovering the vertical fault displacement of the fault; the vertical augmentation of the depression structure is recognized, and the vertical augmentation amount is recovered; horizontal extension of the depression structure is recognized, and the horizontal extension amount is recovered; a residual stratum deposition boundary in the research area is tracked and depicted, and key occurrence information of the residual stratum is extracted; and restoring and reconstructing the original distribution form of the target stratum in the depression structure based on the extracted key occurrence information of the residual stratum. According to the method, basin residual stratum deposition and structure information can be fully utilized, and prototype recovery and reconstruction can be accurately and conveniently carried out on the reformed depression by finely depicting and constraining the deposition boundary.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas resource exploration and development, and in particular to a method for restoring and reconstructing a reformed depression prototype based on high-precision sedimentary boundary constraints. Background Art

[0002] The structure and evolution of the prototype basin control the development of the sedimentary system, the distribution of source rocks, and the process of oil and gas migration and enrichment in important historical periods. Its restoration and reconstruction are of great significance to petroleum geology. In-depth restoration and reconstruction of the prototype basin is of great significance for the analysis of the sedimentary system in the basin, the clarification of the distribution range of high-quality source rocks, and the prediction of favorable reservoirs. It is the basis and important basis for the deployment of oil and gas exploration wells. In recent years, the exploration and development of my country's offshore oil and gas basins has gradually expanded to new depressions and new zones. The depression formation process often undergoes multiple stages of tectonic uplift and magmatic activity. The depression structure is highly transformed, the stratum erosion is serious, and the unclear understanding of the depression structure and the unclear understanding of the distribution range of high-quality source rocks seriously restrict the exploration prospects of new depressions.

[0003] The traditional prototype basin restoration method is mainly based on the paleogeomorphological research method of balanced profiles. However, it is not very applicable to the situation where the strata are severely eroded, that is, the restoration method under the background of strong transformation. In this case, predecessors mostly used the acoustic time difference method, porosity method and paleogeothermal method, but the above methods are all based on separate drilling data, and are greatly affected by accuracy and human subjectivity, have limited applicability, and are not highly operable, and cannot accurately restore the prototype basin morphology.

[0004] There is currently no good solution in the industry for the restoration of prototype basins that have been severely eroded and transformed by tectonic activities. Existing methods are unlikely to achieve ideal prototype basin restoration effects, and the accuracy and precision of the restoration of the basin prototype structure and eroded strata are difficult to guarantee. Therefore, a quantitative restoration and reconstruction method with high operability and accurate restoration effects is urgently needed. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for restoring and reconstructing the prototype of a modified depression based on high-precision sedimentary boundary constraints, which aims to make full use of the residual stratigraphic sedimentation and structural information of the basin, and accurately and conveniently restore and reconstruct the prototype of the modified depression by finely characterizing and constraining the sedimentary boundary.

[0006] To achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a method for restoring and reconstructing a modified depression prototype, comprising the following steps: Dissect and analyze the depression structure in the study area to identify the structural characteristics of the depression in the study area; Identify the substratigraphic framework of the main depositional periods in the study area; Identify and count the fault points and fault distances within the depression structure, and restore the vertical fault distances of the faults; Identify the vertical uplift of the depression structure and restore the vertical uplift amount; Identify the horizontal extension of the depression structure and restore the horizontal extension; Track and characterize the sedimentary boundaries of the residual strata in the study area, and extract key occurrence information of the residual strata; Based on the extracted key occurrence information of the residual strata, the original distribution morphology of the target strata in the depression structure is restored and reconstructed.

[0007] As a preferred embodiment, the “dissecting and analyzing the depression structure in the study area to identify the characteristics of the depression structure in the study area” is specifically: Based on the seismic data and geological stratification data of the study area, the depression structure was dissected and analyzed, and the main controlling faults, secondary associated faults and angular unconformity surfaces within the depression structure were identified.

[0008] As a preferred embodiment, the “identification of the stratigraphic framework of the main sedimentary periods in the study area” is specifically: Based on the seismic data and geological stratification data of the study area, the stratigraphic framework of the main sedimentary periods in the study area was identified, and the distribution range of the main stratigraphic interfaces and the stratigraphic distribution morphology in the entire area were delineated through seismic reflection characteristics and interface reflection characteristics.

[0009] As a preferred embodiment: the “based on the identified depression structure characteristics and the delineated stratum interface distribution range and stratum distribution morphology, the breakpoints and fault distances of the main controlling fault and the secondary associated fault in the depression structure are identified and counted, and the vertical fault distance of the fault is restored.

[0010] As a preferred embodiment, the “identifying the vertical uplift of the depression structure and restoring the vertical uplift amount” is specifically: For depression structures with vertical uplift due to faults, appropriate reference surfaces are selected, and the vertical uplift is calculated through the elevation difference between the flat area and the uplifted area of ​​the same set of continuously traceable strata, and then vertical restoration is performed.

[0011] As a preferred embodiment, the “identifying the horizontal extension of the depressed structure and restoring the horizontal extension amount” is specifically: For depression structures with horizontal extension of faults, the horizontal extension is calculated through the horizontal displacement of the same set of continuously traceable strata, and then horizontal restoration is performed.

[0012] As a preferred embodiment, the “tracing and depicting the sedimentary boundaries of the residual strata in the study area and extracting the key occurrence information of the residual strata” is specifically: The residual strata distribution range of the target strata in the depression structure within the study area after the vertical fault throw, vertical uplift and horizontal extension are restored is tracked in detail, with an emphasis on the detailed characterization of its sedimentary boundaries to extract the key occurrence information of the residual strata.

[0013] As a preferred embodiment, the “restoring and reconstructing the original distribution morphology of the target stratum in the depression structure” is specifically: A deep learning model based on knowledge enhancement is used, and the key occurrence information of the extracted residual strata is used as the constraints and test conditions of the deep learning model. At the same time, based on the vertical restoration of the depression structure and the horizontal restoration of the depression structure, the original distribution morphology of the source rock sedimentary strata before the depression structure transformation is restored and reconstructed, and the stratigraphic distribution morphology of the prototype basin during the source rock deposition period in the study area is obtained.

[0014] As a preferred embodiment, it also includes the step of obtaining key characteristic parameters of the prototype basin during the deposition period of the source rock in the study area, specifically: According to the stratigraphic distribution morphology of the prototype basin during the source rock deposition period in the study area, the key characteristic parameters of the prototype basin during the source rock deposition period in the study area are obtained, including the area, volume and maximum erosion thickness of the prototype basin provenance.

[0015] In a second aspect, the present invention provides a modified depression prototype restoration and reconstruction device, comprising: The first processing unit is used to dissect and analyze the depression structure in the study area and identify the characteristics of the depression structure in the study area; The second processing unit is used to identify the substratigraphic framework of the main sedimentary periods in the study area; The third processing unit is used to identify and count the breakpoints and fault distances of the faults in the depression structure, and to restore the vertical fault distances of the faults; A fourth processing unit is used to identify the vertical uplift of the depression structure and restore the vertical uplift amount; A fifth processing unit, used for identifying the horizontal extension of the depression structure and restoring the horizontal extension amount; The sixth processing unit is used to track and characterize the sedimentary boundaries of the residual strata in the study area and extract key occurrence information of the residual strata; The seventh processing unit is used to restore and reconstruct the original distribution morphology of the target stratum in the depression structure based on the extracted key occurrence information of the residual stratum.

[0016] The present invention adopts the above technical solution, which has the following advantages: The present invention uses high-precision sedimentary boundaries and sedimentary thickness as constraints, comprehensively considers structural styles and sedimentary systems, restores and reconstructs the structural style and sedimentary filling characteristics of the transformed depression to the greatest extent, correctly understands the depression structure and resource potential, and lays a foundation for analyzing the sedimentary system in the basin, clarifying the distribution range of high-quality source rocks, and predicting favorable reservoirs. It provides an important basis for oil and gas exploration deployment and improves the success rate of oil and gas exploration in transformed depressions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Throughout the accompanying drawings, the same reference numerals are used to represent the same components. In the accompanying drawings: Figure 1 A flow chart of a method for restoring and reconstructing a modified depression prototype provided by an embodiment of the present invention; Figure 2 This is a basement structure map after restoration of the prototype basin in the study area in the embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the present invention clearer, the specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0019] The method for restoring and reconstructing the prototype of a reformed depression provided by the present invention comprises the following steps: dissecting and analyzing the depression structure in the study area, identifying the structural characteristics of the depression in the study area; identifying the stratigraphic framework of the main sedimentary period in the study area; identifying and counting the breakpoints and fault throws of the faults in the depression structure, and restoring the vertical fault throws of the faults; identifying the vertical uplift of the depression structure and restoring the vertical uplift amount; identifying the horizontal extension of the depression structure and restoring the horizontal extension amount; tracking and depicting the sedimentary boundary of the residual strata in the study area, and extracting the key occurrence information of the residual strata; restoring and reconstructing the original distribution morphology of the target strata in the depression structure based on the extracted key occurrence information of the residual strata. The present invention can make full use of the sedimentary and structural information of the residual strata in the basin, and accurately and conveniently restore and reconstruct the prototype of the reformed depression by finely depicting and constraining the sedimentary boundary.

[0020] The following is a detailed description of the method and device for restoring and reconstructing the prototype of a modified depression provided by an embodiment of the present invention in conjunction with the accompanying drawings.

[0021] Embodiment 1: In this embodiment, a small residual depression in a depression in the Pearl River Mouth Basin is selected as the study area. The strata in the key depositional period were severely eroded above the uplift area, the exploration potential of the depression is unclear, and the distribution range and effective volume of the source rock are unknown. The method of the present invention is used to restore the prototype basin of the specific depositional period of the source rock, and calculate the key information of the provenance area of ​​this period.

[0022] See also Figure 1 The present embodiment provides a method for restoring and reconstructing a modified depression prototype, comprising the following steps: S1. Dissect and analyze the depression structure in the study area and identify the characteristics of the depression structure in the study area: Based on the seismic data and geological stratification data of the study area, the depression structure was dissected and analyzed, and the depression structure characteristics such as the main controlling fault, secondary associated fault and angular unconformity surface in the depression structure were identified; S2. Identify the stratigraphic framework of the main sedimentary periods in the study area: Based on the seismic data and geological stratification data of the study area, the stratigraphic framework of the main sedimentary periods in the study area was identified, and the distribution range and stratigraphic distribution morphology of the main stratigraphic interfaces in the whole area were delineated through the seismic reflection characteristics and interface reflection characteristics, such as seismic reflection layers T4, T5, T6 and T7; S3. Identify and count the breakpoints and fault distances of the faults in the depression structure, and restore the vertical fault distances of the faults: Based on the depression structure characteristics identified in step S1 and the distribution range and stratum distribution morphology of the stratum interface delineated in step S2, the breakpoints and fault distances of the main controlling fault and the secondary associated fault in the depression structure are identified and counted, and the vertical fault distance of the fault is restored; S4. Identify the vertical uplift of the depression structure and restore the vertical uplift amount: For depression structures with vertical uplift due to faults, appropriate reference surfaces are selected, and the vertical uplift is calculated through the elevation difference between the flat and uplifted areas of the same set of continuously traceable strata, and then vertical restoration is performed; S5. Identify the horizontal extension of the depression structure and restore the horizontal extension: For depression structures with horizontal extension of faults, the horizontal extension is calculated through the displacement of the same set of continuously traceable strata in the horizontal direction, and then horizontal restoration is performed; S6. Track and characterize the residual stratigraphic sedimentary boundaries in the study area: After the vertical throw, vertical uplift and horizontal extension of the fault are restored, the distribution range of the target strata (i.e. the source rock sedimentary strata) in the depression structure in the study area is carefully tracked, with a focus on the detailed characterization of its sedimentary boundaries, and the key occurrence information of the residual strata is extracted, including the dip and inclination of the residual strata; S7. Restore and reconstruct the original distribution of the target strata in the depression structure: Using the deep learning model based on knowledge enhancement, the key occurrence information of the residual strata extracted in step S6 is used as the constraint and test condition of the deep learning model to restore and reconstruct the original distribution morphology of the target strata before the depression structure transformation, and obtain the stratum distribution morphology of the prototype basin during the source rock deposition period in the study area (such as Figure 2 as shown).

[0023] In the above embodiments, preferably, the method for restoring and reconstructing the modified depression prototype provided by the present invention further comprises the following steps: S8. Calculate the key characteristic parameters of the prototype basin during the period of source rock deposition in the study area: According to the restoration and reconstruction results of step S7, the key characteristic parameters of the prototype basin during the source rock deposition period of the study area are obtained, including the area, volume and maximum erosion thickness of the prototype basin provenance area. The restoration and reconstruction results show that the provenance area of ​​the prototype basin during the source rock deposition period exceeds 300 square kilometers, the maximum erosion thickness reaches 275 meters, and the comprehensive calculation of the depression resource volume exceeds 100 million cubic meters, which can provide an important basis for oil and gas exploration deployment.

[0024] Embodiment 2: The above-mentioned embodiment 1 provides a method for restoring and reconstructing a prototype of a modified depression. Correspondingly, this embodiment provides a device for restoring and reconstructing a prototype of a modified depression. The device for restoring and reconstructing a prototype of a modified depression provided in this embodiment can implement the method for restoring and reconstructing a prototype of a modified depression in embodiment 1. The device for restoring and reconstructing a prototype of a modified depression can be implemented by software, hardware, or a combination of software and hardware. For example, the device for restoring and reconstructing a prototype of a modified depression can include integrated or separate functional modules or functional units to execute the corresponding steps in each method of embodiment 1. Since the device for restoring and reconstructing a prototype of a modified depression in 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 device for restoring and reconstructing a prototype of a modified depression in this embodiment is merely schematic.

[0025] The modified depression prototype restoration and reconstruction device provided in this embodiment includes: The first processing unit is used to dissect and analyze the depression structure in the study area and identify the characteristics of the depression structure in the study area; The second processing unit is used to identify the substratigraphic framework of the main sedimentary periods in the study area; The third processing unit is used to identify and count the breakpoints and fault distances of the faults in the depression structure, and to restore the vertical fault distances of the faults; A fourth processing unit is used to identify the vertical uplift of the depression structure and restore the vertical uplift amount; A fifth processing unit, used for identifying the horizontal extension of the depression structure and restoring the horizontal extension amount; The sixth processing unit is used to track and characterize the sedimentary boundaries of the residual strata in the study area and extract key occurrence information of the residual strata; The seventh processing unit is used to restore and reconstruct the original distribution morphology of the target stratum in the depression structure based on the extracted key occurrence information of the residual stratum.

[0026] Embodiment 3: This embodiment provides a processing device for implementing the modified depression prototype recovery and reconstruction method provided in this embodiment 1. The processing device can be a processing device for a client, such as a mobile phone, a laptop computer, a tablet computer, a desktop computer, etc., to execute the method of embodiment 1.

[0027] The processing device includes a processor, a memory, a communication interface and a bus, and the processor, the memory and the communication interface are connected through the bus to complete mutual communication. The memory stores a computer program that can be run on the processor, and the processor executes the modified depression prototype restoration and reconstruction method provided in this embodiment 1 when running the computer program.

[0028] Preferably, the memory may be a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory.

[0029] 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.

[0030] Embodiment 4: The modified depression prototype restoration and reconstruction method of the present embodiment 1 may be specifically implemented as a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for executing the method described in the present embodiment 1.

[0031] 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.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application 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 replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A method for restoring and reconstructing a modified depression prototype, characterized in that: The following steps are involved: Dissect and analyze the depression structure in the study area to identify the structural characteristics of the depression in the study area; Identify the substratigraphic framework of the main depositional periods in the study area; Identify and count the fault points and fault distances within the depression structure, and restore the vertical fault distances of the faults; Identify the vertical uplift of the depression structure and restore the vertical uplift amount; Identify the horizontal extension of the depression structure and restore the horizontal extension; Track and characterize the sedimentary boundaries of the residual strata in the study area, and extract key occurrence information of the residual strata; Based on the extracted key occurrence information of the residual strata, the original distribution morphology of the target strata in the depression structure is restored and reconstructed.

2. The method for restoring and reconstructing a modified depression prototype according to claim 1, characterized in that: The "anatomy and analysis of the depression structure in the study area and identification of the characteristics of the depression structure in the study area" is specifically: Based on the seismic data and geological stratification data of the study area, the depression structure was dissected and analyzed, and the main controlling faults, secondary associated faults and angular unconformity surfaces within the depression structure were identified.

3. The method for restoring and reconstructing a modified depression prototype according to claim 2, characterized in that: The "identification of the sub-stratigraphic framework of the main sedimentary periods in the study area" is specifically: Based on the seismic data and geological stratification data of the study area, the stratigraphic framework of the main sedimentary periods in the study area was identified, and the distribution range of the main stratigraphic interfaces and the stratigraphic distribution morphology in the entire area were delineated through seismic reflection characteristics and interface reflection characteristics.

4. The method for restoring and reconstructing a modified depression prototype according to claim 3 is characterized in that: The method "identifies and counts the breakpoints and fault distances of the main controlling fault and secondary associated fault in the depression structure based on the identified depression structure characteristics and the delineated stratum interface distribution range and stratum distribution morphology, and restores the vertical fault distance of the fault.

5. The method for restoring and reconstructing a modified depression prototype according to claim 4 is characterized in that: The aforementioned “identifying the vertical uplift of the depression structure and restoring the vertical uplift amount” is specifically: For depression structures with vertical uplift due to faults, appropriate reference surfaces are selected, and the vertical uplift is calculated through the elevation difference between the flat area and the uplifted area of ​​the same set of continuously traceable strata, and then vertical restoration is performed.

6. The method for restoring and reconstructing a modified depression prototype according to claim 5, characterized in that: The “identifying the horizontal extension of the depression structure and restoring the horizontal extension amount” is specifically: For depression structures with horizontal extension of faults, the horizontal extension is calculated through the horizontal displacement of the same set of continuously traceable strata, and then horizontal restoration is performed.

7. The method for restoring and reconstructing a modified depression prototype according to claim 6, characterized in that: The "tracing and depicting the sedimentary boundaries of the residual strata in the study area and extracting key occurrence information of the residual strata" is specifically: The residual strata distribution range of the target strata in the depression structure within the study area after the vertical fault throw, vertical uplift and horizontal extension are restored is tracked in detail, with an emphasis on the detailed characterization of its sedimentary boundaries to extract the key occurrence information of the residual strata.

8. The method for restoring and reconstructing a modified depression prototype according to claim 7, characterized in that: The "restoring and reconstructing the original distribution morphology of the target stratum in the depression structure" is specifically: A deep learning model based on knowledge enhancement is used, and the key occurrence information of the extracted residual strata is used as the constraints and test conditions of the deep learning model. At the same time, based on the vertical restoration of the depression structure and the horizontal restoration of the depression structure, the original distribution morphology of the source rock sedimentary strata before the depression structure transformation is restored and reconstructed, and the stratigraphic distribution morphology of the prototype basin during the source rock deposition period in the study area is obtained.

9. The method for restoring and reconstructing a modified depression prototype according to claim 8, characterized in that: It also includes the steps of obtaining the key characteristic parameters of the prototype basin during the source rock deposition period in the study area, specifically: According to the stratigraphic distribution morphology of the prototype basin during the source rock deposition period in the study area, the key characteristic parameters of the prototype basin during the source rock deposition period in the study area are obtained, including the area, volume and maximum erosion thickness of the prototype basin provenance.

10. A modified depression prototype restoration and reconstruction device, characterized in that: include: The first processing unit is used to dissect and analyze the depression structure in the study area and identify the characteristics of the depression structure in the study area; The second processing unit is used to identify the substratigraphic framework of the main sedimentary periods in the study area; The third processing unit is used to identify and count the breakpoints and fault distances of the faults in the depression structure, and to restore the vertical fault distances of the faults; A fourth processing unit is used to identify the vertical uplift of the depression structure and restore the vertical uplift amount; A fifth processing unit, used for identifying the horizontal extension of the depression structure and restoring the horizontal extension amount; The sixth processing unit is used to track and characterize the sedimentary boundaries of the residual strata in the study area and extract key occurrence information of the residual strata; The seventh processing unit is used to restore and reconstruct the original distribution morphology of the target stratum in the depression structure based on the extracted key occurrence information of the residual stratum.

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