A method, device, computer storage medium and equipment for predicting a sedimentary system of a source-sink system in a terrestrial rift basin

Abstract

The application discloses a kind of prediction methods of continental rift basin source-sink system depositional system, comprising: based on regional tectonic background, restore the paleogeomorphic distribution form of source-sink system source area and sink area;On the basis of sequence stratigraphic framework establishment, the source-sink unit in study area is divided;Based on the paleogeomorphic distribution form of source area and drilling core test data, the effective supply volume of source area, lithology density and average height are obtained, and the supply potential of source area is calculated;Based on the elevation data of source area, the distribution range and characteristics of ancient drainage system are described;The river network density of ancient drainage system is calculated;The width-depth ratio and cross-sectional area of gully are obtained;The optimization index of different source-sink units is calculated;The volume of known depositional system sediments is obtained;The coupling relationship between the optimization index of different source-sink units and the volume of corresponding known depositional system sediments is established;According to the obtained coupling relationship, the unknown depositional system in the source-sink system of study area is predicted.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas exploration and development, and in particular to a method, device, computer storage medium and equipment for predicting a source-sink sedimentary system in a continental fault basin. Background Art

[0002] Guided by the theory of spatiotemporal coupling of source and sink control in continental fault basins, the distribution and prediction of sedimentary systems based on source-sink system analysis is crucial and closely related to offshore exploration in my country. Detrital material produced by weathering and erosion in provenance areas is carried by surface water systems to gullies and other sand transport channels, then into sedimentary areas within the depressions, where it accumulates and develops sedimentary bodies. The formation of a sedimentary system is influenced and controlled by a complex set of variables. To predict the development zones and extent of sedimentary systems, it is necessary to comprehensively study the supply capacity of the provenance, the transport and drainage capacity of the water system, and the collection capacity of the gullies.

[0003] At present, most studies focus on qualitatively analyzing the supply characteristics of provenance areas, the morphological characteristics of sand transport channels, and the development of catchment units. There is a lack of principled quantitative methods and comprehensive prediction methods that can link these three factors. Summary of the Invention

[0004] 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 predicting the source-sink sedimentary system in a continental fault basin. This method aims to fully consider the supply capacity of the provenance, the carrying and drainage capacity of the water system, and the collection capacity of the gully, providing a principled and quantitative method for predicting the source-sink sedimentary system.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for predicting a source-sink sedimentary system in a continental fault basin, comprising the following steps:

[0007] Based on the regional tectonic background, the paleo-geomorphological distribution of the provenance and convergence areas of the source-sink system was restored;

[0008] Based on the sequence stratigraphic framework, the source-sink units in the study area were divided;

[0009] Based on the paleogeomorphology of the provenance area and drilling core test data, the effective source volume, lithologic density and average height of the provenance of different source-sink units are obtained, and the supply potential energy of the provenance of different source-sink units is calculated;

[0010] Based on the elevation data of the provenance area, the distribution range and characteristics of the paleo-river systems of different source and sink units are described;

[0011] Based on the distribution range and characteristics of the ancient river system, the river network density of the ancient river system in different source and sink units is calculated;

[0012] Based on the paleo-geomorphological distribution of the convergence area, the width-to-depth ratio and cross-sectional area of ​​the gully were obtained;

[0013] Based on the river network density, width-to-depth ratio and cross-sectional area of ​​different paleo-drainage units, the preferred index of different source-sink units was calculated.

[0014] Determine the volume of sediments in a known sedimentary system based on the characteristics of drill cores, thin sections, and seismic facies in the sedimentary area;

[0015] Establish the coupling relationship between the preferred index of different source-sink units and the volume of sediments in their corresponding known sedimentary systems;

[0016] Based on the obtained coupling relationship, predictions are made for the unknown sedimentary systems within the source-sink system of the study area.

[0017] As an example, the supply potential energy of the provenance area is calculated by the following formula:

[0018]

[0019] in, Supply potential energy to the provenance area; is the effective source volume of the provenance area; is the lithologic density of the provenance area; is the acceleration due to gravity; is the average height of the provenance area.

[0020] Preferably, the river network density refers to the ratio of the total river system length to the basin area, reflecting the water system transportation capacity of different source-sink system provenance areas.

[0021] Preferably, the width-to-depth ratio of the valley refers to the ratio of the width to the depth of the valley, and the cross-sectional area of ​​the valley is calculated according to the specific shape of the valley.

[0022] As an example, the preferred index of the source-sink unit is calculated by the following formula:

[0023]

[0024] Where Y is the preferred index of the source-sink unit; is the river network density; is the width of the valley; is the depth of the gully; is the cross-sectional area of ​​the valley.

[0025] As an example, the “establishment of a coupling relationship between the preferred indexes of different source-sink units and the volumes of sediments in their corresponding known sedimentary systems” is specifically as follows:

[0026] Calculate the volume S of sediments in a known sedimentary system using the preferred index Y of the source-sink unit as the independent variable YZ As the fitting formula of the dependent variable, the coupling relationship between the two is obtained.

[0027] As a preferred embodiment, the “prediction of unknown sedimentary systems within the source-sink system of the study area based on the obtained coupling relationship” is specifically:

[0028] According to the obtained coupling relationship, the unknown sedimentary system is predicted using the preferred index Y of the unknown sediment volume source-sink unit in the source-sink system of the study area.

[0029] In a second aspect, the present invention provides a device for predicting a source-sink sedimentary system in a continental fault basin, comprising:

[0030] The first processing unit is used to restore the paleo-geomorphological distribution of the provenance and convergence areas of the source-sink system based on the regional tectonic background;

[0031] The second processing unit is used to divide the source-sink units in the study area based on the sequence stratigraphic framework;

[0032] The third processing unit is used to obtain the effective source volume, lithologic density, and average height of the provenance of different source-sink units based on the paleo-geomorphological distribution of the provenance area and the drilling core test data, and calculate the supply potential energy of the provenance of different source-sink units;

[0033] The fourth processing unit is used to characterize the distribution range and characteristics of the paleo-river systems of different source-sink units based on the elevation data of the provenance area;

[0034] The fifth processing unit is used to calculate the river network density of the ancient river system in different source and sink units based on the distribution range and characteristics of the ancient river system;

[0035] The sixth processing unit is used to obtain the width-to-depth ratio and cross-sectional area of ​​the gully based on the paleo-geomorphological distribution of the convergence area;

[0036] The seventh processing unit is used to calculate the optimal index of different source-sink units based on the river network density of different paleo-drainage units, as well as the width-to-depth ratio and cross-sectional area of ​​the valley;

[0037] An eighth processing unit is used to obtain the volume of sediments in a known sedimentary system based on the drilling cores, thin sections and seismic facies characteristics of the sedimentary area;

[0038] The ninth processing unit is used to establish a coupling relationship between the preferred indexes of different source and sink units and the volumes of sediments in their corresponding known sedimentary systems;

[0039] The tenth processing unit is used to predict the unknown sedimentary system in the source-sink system of the study area based on the obtained coupling relationship.

[0040] In a third aspect, the present invention provides a computer-readable storage medium storing a computer program, which is executed by a processor to control the device where the processor is located to implement the steps of the method for predicting the source-sink system sedimentary system of a terrestrial fault basin as described in the first aspect of the present invention.

[0041] 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. When the processor executes the computer program, the steps of the method for predicting the source-sink sedimentary system of a terrestrial fault basin as described in the first aspect of the present invention are implemented.

[0042] The present invention has the following advantages due to the adoption of the above technical solution:

[0043] This invention innovatively introduces the concept of "supply potential energy", fully considering the supply capacity of the provenance area, the carrying and drainage capacity of the water system, and the gathering capacity of the valley, and provides a principled and quantitative source-sink system sedimentary system prediction method, which provides an important basis for the deployment of deep-water oil and gas exploration in my country's offshore areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] 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:

[0045] Figure 1 A flow chart of a method for predicting a source-sink sedimentary system in a continental fault basin provided by an embodiment of the present invention;

[0046] Figure 2 This is a table showing the sedimentary system prediction results of different source-sink units in the study area in the embodiment of the present invention;

[0047] Figure 3 This is a diagram showing the predicted results of the sedimentary systems of different source-sink units in the study area in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] To make the objectives, technical solutions, and advantages of the present invention more apparent, specific embodiments of the present invention are further described below with reference to the accompanying drawings. Although 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. Rather, these embodiments are provided 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.

[0049] The method for predicting the sedimentary system of the source-sink system of a continental fault basin provided by the present invention comprises: restoring the paleo-geomorphological distribution morphology of the provenance and convergence areas of the source-sink system based on the regional tectonic background; dividing the source-sink units in the study area based on the establishment of a sequence stratigraphic framework; obtaining the effective source supply volume, lithologic density and average height of the provenance area based on the paleo-geomorphological distribution morphology of the provenance area and drilling core test data, and calculating the supply potential energy of the provenance area; characterizing the distribution range and characteristics of the paleo-water system based on the elevation data of the provenance area; calculating the river network density of the paleo-water system; obtaining the width-to-depth ratio and cross-sectional area of ​​the valley; calculating the preferred index of different source-sink units; obtaining the volume of sediments in a known sedimentary system; establishing a coupling relationship between the preferred index of different source-sink units and the volume of sediments in their corresponding known sedimentary systems; and making a prediction of the unknown sedimentary system in the source-sink system of the study area based on the obtained coupling relationship.

[0050] The following describes in detail the method for predicting the source-sink system sedimentary system of a continental fault basin provided by an embodiment of the present invention with reference to the accompanying drawings.

[0051] Example 1:

[0052] This example selects a sedimentary area beneath a certain uplift and fault terrace in the Bohai Bay Basin as a study area for a continental fault basin source-sink system. Multiple source-sink units with distinct characteristics are developed in the study area, with the sedimentary bodies of source-sink units 2-6 having known developmental characteristics and volumes. Using the method presented in this paper, a comprehensive study of provenance drainage systems and gully characteristics across the different source-sink units in the study area was conducted, and a prediction of the sedimentary system for source-sink unit 1 was made.

[0053] See also Figure 1 This embodiment provides a method for predicting the source-sink sedimentary system of a continental fault basin, comprising the following steps:

[0054] S1. Paleogeomorphological restoration:

[0055] Based on the regional tectonic background, the paleo-geomorphological distribution of the provenance and convergence areas of the source-sink system is restored.

[0056] S2. Division of source and sink units:

[0057] Based on the sequence stratigraphic framework, the study area is divided into source-sink units 1-6 (seeFigure 3 ).

[0058] S3. Supply potential energy calculation:

[0059] Based on the paleo-geomorphological distribution of the provenance area and experimental data such as drilling cores, important parameters such as the effective source volume, lithologic density, and average height of the provenance area were read, and the supply potential energy of the provenance of source-sink units 1-6 was calculated using the following formula:

[0060]

[0061] in, Supply potential energy to the provenance area; is the effective source volume of the provenance area; is the lithologic density of the provenance area; is the acceleration due to gravity; is the average height of the provenance area.

[0062] S4. Description of ancient river systems:

[0063] Based on the elevation data of the provenance area, the distribution range and characteristics of the paleo-river systems of the six source-sink units are depicted respectively.

[0064] S5. Calculation of river network density:

[0065] Based on the characterization results of the ancient river system, the river network density of the ancient river systems of the six source-sink units was calculated respectively. The river network density refers to the ratio of the total river system length to the basin area, reflecting the river system transportation capacity of the provenance areas of different source-sink systems.

[0066] S6. Calculation of valley characterization parameters:

[0067] Based on the paleo-geomorphological distribution of the convergence zone, the width-to-depth ratio and cross-sectional area of ​​the valleys corresponding to the six source-sink units were obtained respectively. The width-to-depth ratio of the valley refers to the ratio of the width to the depth of the valley, and the cross-sectional area of ​​the valley is calculated according to the specific shape of the valley. For example, the V-shaped valley is calculated as a triangular area and the U-shaped valley is calculated as a rectangular area.

[0068] S7. Calculation of the preferred index:

[0069] Based on the above parameter calculation results, the optimization indexes of the six source and sink units are calculated respectively by the following formula:

[0070]

[0071] Where Y is the preferred index of the source-sink unit; is the river network density; is the width of the valley; is the depth of the gully; is the cross-sectional area of ​​the valley.

[0072] S8. Given a sedimentary system, find:

[0073] Based on the characteristics of the drilling core, thin sections and seismic facies in the sedimentary area, the volume of sediments in the known sedimentary systems in the source-sink units 2-6 was calculated (see Figure 2 ).

[0074] S9. Coupling of the relationship between the preferred index and the sedimentary system:

[0075] Establish a coupling relationship between the sedimentary system and the optimal index within source-sink units 2-6.

[0076] S10. Prediction of unknown sedimentary systems:

[0077] Based on the coupling relationship obtained by S9, a prediction is made for the sedimentary system within the No. 1 source-sink system.

[0078] Example 2:

[0079] The above-mentioned embodiment 1 provides a method for predicting the sedimentary system of a continental fault basin source-sink system. Correspondingly, this embodiment provides a device for predicting the sedimentary system of a continental fault basin source-sink system. The device for predicting the sedimentary system of a continental fault basin source-sink system provided in this embodiment can implement the method for predicting the sedimentary system of a continental fault basin source-sink system of embodiment 1. The device for predicting the sedimentary system of a continental fault basin source-sink system can be implemented by software, hardware, or a combination of software and hardware. For example, the device for predicting the sedimentary system of a continental fault basin source-sink system 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 predicting the sedimentary system of a continental fault basin source-sink system 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 device for predicting the sedimentary system of a continental fault basin source-sink system of this embodiment is merely schematic.

[0080] The device for predicting the source-sink sedimentary system of a continental fault basin provided in this embodiment includes:

[0081] The first processing unit is used to restore the paleo-geomorphological distribution of the provenance and convergence areas of the source-sink system based on the regional tectonic background;

[0082] The second processing unit is used to divide the source-sink units in the study area based on the sequence stratigraphic framework;

[0083] The third processing unit is used to obtain the effective source volume, lithologic density, and average height of the provenance of different source-sink units based on the paleo-geomorphological distribution of the provenance and drilling core test data, and calculate the supply potential energy of the provenance of different source-sink units;

[0084] The fourth processing unit is configured to delineate distribution ranges and characteristics of the paleo-drainage systems of different source-sink units based on the elevation data of the source area;

[0085] The fifth processing unit is configured to calculate the river network density of the paleo-drainage systems of different source-sink units based on the distribution ranges and characteristics of the paleo-drainage systems;

[0086] The sixth processing unit is configured to obtain the width-depth ratio and cross-sectional area of the gully based on the paleo-geomorphology distribution pattern of the sink area;

[0087] The seventh processing unit is configured to calculate the preferred index of different source-sink units based on the river network density of different paleo-drainage system units and the width-depth ratio and cross-sectional area of the gully;

[0088] The eighth processing unit is configured to obtain the volume of the sediment of the known depositional system based on the drilling core, thin section and seismic facies characteristics of the sedimentary area;

[0089] The ninth processing unit is configured to establish the coupling relationship between the preferred index of different source-sink units and the volume of the sediment of the corresponding known depositional system;

[0090] The tenth processing unit is configured to make a prediction on the unknown depositional system in the source-sink system of the study area according to the obtained coupling relationship.

[0091] Embodiment 3:

[0092] The embodiment provides a processing device for implementing the method for predicting the depositional system of the source-sink system of the continental rift basin provided in Embodiment 1. The processing device can be a processing device for a client, such as a mobile phone, a notebook computer, a tablet computer, a desktop computer, etc., to execute the method of Embodiment 1.

[0093] The processing device includes a processor, a memory, a communication interface and a bus. The processor, the memory and the communication interface are connected through the bus to complete the communication among each other. The memory stores a computer program that can run on the processor. When the processor runs the computer program, the method for predicting the depositional system of the source-sink system of the continental rift basin provided in Embodiment 1 is executed.

[0094] Preferably, the memory can be a high-speed random access memory (RAM: Random Access Memory) and can also include a non-volatile memory, such as at least one disk memory.

[0095] Preferably, the processor can be a central processing unit (CPU), a digital signal processor (DSP) or various types of general-purpose processors, which are not limited here.

[0096] Embodiment 4:

[0097] The method for predicting the sedimentary system of the source-sink system of the continental fault basin of this embodiment 1 can 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 this embodiment 1.

[0098] 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.

[0099] 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 make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions 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 predicting the source-sink sedimentary system of a continental fault basin, characterized in that: The following steps are involved: Based on the regional tectonic background, the paleo-geomorphological distribution of the provenance and convergence areas of the source-sink system was restored; Based on the sequence stratigraphic framework, the source-sink units in the study area were divided; Based on the paleogeomorphology of the provenance area and drilling core test data, the effective source volume, lithologic density and average height of the provenance of different source-sink units are obtained, and the supply potential energy of the provenance of different source-sink units is calculated; Based on the elevation data of the provenance area, the distribution range and characteristics of the paleo-river systems of different source and sink units are described; Based on the distribution range and characteristics of the ancient river system, the river network density of the ancient river system in different source and sink units is calculated; Based on the paleo-geomorphological distribution of the convergence area, the width-to-depth ratio and cross-sectional area of ​​the gully were obtained; Based on the river network density, width-to-depth ratio and cross-sectional area of ​​different paleo-drainage units, the preferred index of different source-sink units was calculated. Determine the volume of sediments in a known sedimentary system based on the characteristics of drill cores, thin sections, and seismic facies in the sedimentary area; Establish the coupling relationship between the preferred index of different source-sink units and the volume of sediments in their corresponding known sedimentary systems; Based on the obtained coupling relationship, the unknown sedimentary system in the source-sink system of the study area is predicted; The supply potential energy of the provenance area is calculated by the following formula: in, Supply potential energy to the provenance area; is the effective source volume of the provenance area; is the lithologic density of the provenance area; is the acceleration due to gravity; is the average height of the provenance area; The preferred index of the source-sink unit is calculated by the following formula: Where Y is the preferred index of the source-sink unit; is the river network density; is the width of the valley; is the depth of the gully; is the cross-sectional area of ​​the valley.

2. The method for predicting the source-sink sedimentary system of a continental fault basin according to claim 1, characterized in that: The river network density refers to the ratio of the total river system length to the basin area, reflecting the river system transportation capacity of different source-sink system provenance areas.

3. The method for predicting the source-sink sedimentary system of a continental fault basin according to claim 2, characterized in that: The width-to-depth ratio of the valley refers to the ratio of the width to the depth of the valley, and the cross-sectional area of ​​the valley is calculated according to the specific shape of the valley.

4. The method for predicting the source-sink sedimentary system of a continental fault basin according to claim 1, characterized in that: The specific method of "establishing a coupling relationship between the preferred indexes of different source-sink units and the volume of sediments in their corresponding known sedimentary systems" is as follows: Calculate the volume S of sediments in a known sedimentary system using the preferred index Y of the source-sink unit as the independent variable YZ As the fitting formula of the dependent variable, the coupling relationship between the two is obtained.

5. The method for predicting the source-sink sedimentary system of a continental fault basin according to claim 4, characterized in that: The aforementioned "prediction of unknown sedimentary systems within the source-sink system of the study area based on the obtained coupling relationship" is specifically: According to the obtained coupling relationship, the unknown sedimentary system is predicted using the preferred index Y of the unknown sediment volume source-sink unit in the source-sink system of the study area.

6. A device for predicting the source-sink sedimentary system of a continental fault basin, characterized in that: include: The first processing unit is used to restore the paleo-geomorphological distribution of the provenance and convergence areas of the source-sink system based on the regional tectonic background; The second processing unit is used to divide the source-sink units in the study area based on the sequence stratigraphic framework; The third processing unit is used to obtain the effective source volume, lithologic density, and average height of the provenance of different source-sink units based on the paleo-geomorphological distribution of the provenance and drilling core test data, and calculate the supply potential energy of the provenance of different source-sink units; The fourth processing unit is used to characterize the distribution range and characteristics of the paleo-river systems of different source-sink units based on the elevation data of the provenance area; The fifth processing unit is used to calculate the river network density of the ancient river system in different source and sink units based on the distribution range and characteristics of the ancient river system; The sixth processing unit is used to obtain the width-to-depth ratio and cross-sectional area of ​​the gully based on the paleo-geomorphological distribution of the convergence area; The seventh processing unit is used to calculate the optimal index of different source-sink units based on the river network density of different paleo-drainage units, as well as the width-to-depth ratio and cross-sectional area of ​​the valley; An eighth processing unit is used to obtain the volume of sediments in a known sedimentary system based on the drilling cores, thin sections and seismic facies characteristics of the sedimentary area; The ninth processing unit is used to establish a coupling relationship between the preferred indexes of different source and sink units and the volumes of sediments in their corresponding known sedimentary systems; The tenth processing unit is used to predict the unknown sedimentary system in the source-sink system of the study area based on the obtained coupling relationship; The supply potential energy of the provenance area is calculated by the following formula: in, Supply potential energy to the provenance area; is the effective source volume of the provenance area; is the lithologic density of the provenance area; is the acceleration due to gravity; is the average height of the provenance area; The preferred index of the source-sink unit is calculated by the following formula: Where Y is the preferred index of the source-sink unit; is the river network density; is the width of the valley; is the depth of the gully; is the cross-sectional area of ​​the valley.

7. A computer-readable storage medium, characterized in that A computer program is stored, and the computer program is executed by a processor to control the device where the processor is located to implement the steps of the method for predicting the source-sink system sedimentary system of a continental fault basin as described in any one of claims 1 to 5.

8. A computer device, characterized in that: The method comprises 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 predicting the source-sink sedimentary system of a continental fault basin described in any one of claims 1 to 5 are implemented.

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