Method and device for predicting volume of hydrocarbon source rock in low-exploration-degree basin of rift valley system

Abstract

The invention provides a method and device for predicting the volume of hydrocarbon source rocks in a rift valley system low-exploration-degree basin, and relates to the technical field of oil and gas geology, and the method comprises the steps: selecting a basin with a high rift valley system exploration degree as a scale region according to the spatial-temporal evolution characteristics of the rift valley system and the exploration degree of the basin, and determining an optimal construction condition; analogy is carried out on the dynamic background, the extension mechanism, the fault activity normal form and the structure type of the to-be-predicted basin and the scale area depression to obtain a class ratio K1, and the analogy premise of the to-be-predicted basin and the scale area is determined; performing analogy on the maximum activity rate of the boundary fault of the to-be-predicted basin and the scale area and the maximum thickness of the hydrocarbon source rock stratum system to obtain class ratios K2 and K3; and obtaining an analogy value K according to a formula # imgabs0 #, and calculating the volume of the to-be-predicted basin hydrocarbon source rock through the analogy value K. According to the technical scheme, prediction of the volume of the hydrocarbon source rock in the low-exploration-degree basin of the rift valley system is achieved, and the exploration cost is reduced.

Description

Technical Field

[0001] The present application relates to the field of oil and gas geological technology, and in particular to a method and device for predicting the volume of source rocks in a rift system basin with low degree of exploration. Background Art

[0002] Rift systems are narrow, long fault zones formed by crustal expansion. They can be subdivided into oceanic, continental, and intercontinental rift systems, each formed under distinct geological settings. Rift system basins and shear zones have distinct tectonic positions and strikes, resulting in distinct tectonic evolution processes and sedimentary infill characteristics. Crustal extension and fracturing processes have led to numerous unique sedimentary environments, providing a rich material foundation for the formation of source rocks while also causing the developmental characteristics of source rocks in rift basins to vary from location to location.

[0003] Traditional methods for studying source rock geochemistry often rely on analyzing geological samples. The selection of these samples is influenced by economic factors, making preliminary predictions of oil and gas reserves in rift system basins difficult. Therefore, while comprehensive and detailed geochemical experiments on geological samples can fully reveal the geochemical characteristics and dynamics of source rocks in rift system basins, they are not feasible in areas with low exploration levels. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and device for predicting the volume of hydrocarbon source rocks in rift system low-exploration basins in order to solve the problems of incompleteness and inaccuracy in the current prediction methods of hydrocarbon source rock volume in rift system low-exploration basins.

[0005] The above-mentioned purpose of this application is achieved through the following technical solutions:

[0006] S1: Based on the overall spatiotemporal evolution characteristics of the rift system and the degree of basin exploration, basins with high degree of rift system exploration are identified as scale areas;

[0007] S2: Based on the low-level exploration data of the predicted basin and the high-level exploration data of the scaled area, the structural conditions of the scaled area are analyzed to determine the optimal structural conditions for the development of source rocks. The optimal structural conditions include: depression dynamics mode, depression structure type, maximum activity rate of boundary faults, and maximum thickness of source rock development layer.

[0008] S3: Determine the comparability value between the basin to be predicted and the calibration area by optimizing the structural conditions;

[0009] S4: Based on the thickness and area of ​​favorable source rocks in the scaled area and combined with the comparable value, calculate the volume of favorable source rocks in the basin to be predicted.

[0010] Optionally, step S2 includes:

[0011] High-level exploration data include: existing drilling data and seismic data;

[0012] Based on the high-level exploration data of the scaled area, the structural conditions for the development of source rocks in the scaled area are determined;

[0013] The structural conditions for the development of source rocks in the scale area are screened to determine the preferred structural conditions for the development of source rocks.

[0014] Optionally, step S3 includes:

[0015] The low-level exploration data is seismic data; the optimal structural conditions of the basin to be predicted are obtained through the low-level exploration data of the basin to be predicted;

[0016] Compare the preferred structural conditions of the scaled area with those of the basin to be predicted to determine the comparability value between the basin to be predicted and the scaled area. The specific steps are as follows:

[0017] S31: Determine the analog value K1 between the basin to be predicted and the scale area through the sag dynamics model and sag structure type;

[0018] S32: Determine the analog value K2 between the basin to be predicted and the scale area through the maximum activity rate of the boundary fault;

[0019] The calculation formula of the analog value K2 is as follows:

[0020] Where V1 is the maximum activity rate of the boundary fault of the basin to be predicted, and V2 is the maximum activity rate of the boundary fault of the scale area;

[0021] S33: Determine the analog value K3 between the basin to be predicted and the scale area based on the maximum thickness of the source rock development layer;

[0022] The calculation formula of the analog value K3 is as follows:

[0023] Where H1 is the maximum thickness of the source rock development layer in the basin to be predicted, and H2 is the maximum thickness of the source rock development layer in the scale area;

[0024] The formula for calculating the comparability value is as follows:

[0025] Optionally, step S31 includes:

[0026] The depression dynamics model includes: dynamic background, evolution of extensional mechanism and fault activity paradigm;

[0027] The dynamic background includes: mantle plume migration and plate movement; the evolution of extensional mechanisms includes: simple shear and pure shear; the fault activity paradigm includes: fault activity characteristics and fault activity intensity;

[0028] Depression structure types include grabens and half grabens; grabens include typical grabens, asymmetric grabens, and parallel-transform grabens; half grabens include typical half grabens and single-break migration half grabens;

[0029] Determine A1 by analogy between the dynamic background of the scaled area and the dynamic background of the basin to be predicted;

[0030] Determine A2 by analogy between the evolution of the extensional mechanism of the scaled area and that of the basin to be predicted;

[0031] Determine A3 by analogy between the fault activity of the scaled area and the fault activity paradigm of the basin to be predicted;

[0032] Determine A4 by analogy between the depression structure type of the scaled area and the depression structure type of the basin to be predicted;

[0033]

[0034] Optionally, step S32 includes:

[0035] Through the high-level exploration data of the scaled area, the sedimentary time of source rock development and the characteristics of boundary fault activity are obtained;

[0036] The maximum activity rate of the boundary fault is determined by the sedimentation time of the source rock formation and the activity characteristics of the boundary fault. The calculation formula for the maximum activity rate of the boundary fault is:

[0037]

[0038] Where V f is the maximum activity rate of the boundary fault; T is the sedimentation time of the formation; H d is the thickness of the fault downthrown wall; H i is the thickness of the fault uplift wall.

[0039] Optionally, step S4 includes:

[0040] S41: Based on the thickness and area of ​​favorable source rocks in the scaled area and combined with the analogy, calculate the thickness and area of ​​source rocks in the basin to be predicted;

[0041] S42: Calculate the volume of favorable source rocks in the basin to be predicted based on the thickness and area of ​​the source rocks in the basin to be predicted.

[0042] Optionally, step S4 further includes:

[0043] The thickness and area of ​​the source rock in the basin to be predicted are determined by the following formula:

[0044] H 类 =K×H 刻 , where H类 is the thickness of the source rock in the basin to be predicted, H 刻 is the thickness of source rocks in the scale area;

[0045] S 类 =K×S 刻 , where S 类 is the area of ​​source rock in the basin to be predicted, S 刻 is the area of ​​source rocks in the scale area;

[0046] The volume of source rock in the basin to be predicted is determined by the following formula:

[0047] V 类 =H 类 ×S 类 .

[0048] A device for predicting the volume of source rocks in a rift system basin with low degree of exploration, comprising:

[0049] Division module, data calculation module, comparison module and volume calculation module;

[0050] The division module, data calculation module, comparison module and volume calculation module are connected in sequence;

[0051] The division module is used to determine basins with high exploration degree of the rift system as calibration areas and basins with low exploration degree of the rift system as basins to be predicted based on the overall spatiotemporal evolution characteristics of the rift system and the exploration degree of the basins;

[0052] The data calculation module is used to analyze the structural conditions of the scale area based on the low-level exploration data of the basin to be predicted and the high-level exploration data of the scale area, and to clarify the preferred structural conditions for the development of source rocks; the preferred structural conditions include: depression dynamics mode, depression structure type, maximum activity rate of boundary faults, and maximum thickness of source rock development layer;

[0053] The comparison module is used to determine the comparability value between the basin to be predicted and the scale area by optimizing the structural conditions;

[0054] The volume calculation module is used to calculate the volume of favorable source rocks in the basin to be predicted based on the thickness and area of ​​favorable source rocks in the scale area and in combination with the comparability value.

[0055] An electronic device includes a processor, a memory, a user interface, and a network interface. The memory is used to store instructions, the user interface and the network interface are used to communicate with other devices, and the processor is used to execute the instructions stored in the memory so that the electronic device performs a method for predicting the volume of hydrocarbon source rocks in a rift system basin with a low degree of exploration.

[0056] A computer-readable storage medium stores instructions, which, when executed, implement a method for predicting the volume of source rocks in a rift system low-exploration basin.

[0057] The beneficial effects of the technical solution provided by this application are:

[0058] Traditional geochemical research on source rocks relies heavily on analytical test data from a certain number of geological samples, which has low practical effectiveness in areas with low exploration levels. This method, which integrates the development characteristics of rift systems and fully utilizes relevant data such as structure and sedimentation, compares the similarities in the structural history of source rock development in various rift basins within the same rift system. By selecting highly explored depressions as calibration areas and basins as calibration areas, and by selecting the optimal depression dynamics model and depression structure type, a preliminary prediction of the source rock volume in areas with low exploration levels is made. This method is suitable for predicting source rocks in rift basins with extremely low exploration levels, and has extremely low economic costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The present application will be further described below with reference to the accompanying drawings and embodiments, in which:

[0060] Figure 1 is a step diagram in an embodiment of the present application;

[0061] Figure 2 is a flow chart in an embodiment of the present application;

[0062] Figure 3 is a calculation diagram of analog values ​​A1, A2, and A3 in the embodiment of the present application;

[0063] Figure 4 It is a calculation diagram of the analog value A4 in the embodiment of the present application;

[0064] Figure 5 is a schematic diagram of the structure of an electronic device in an embodiment of the present application;

[0065] Figure 6 It is a module connection diagram in the embodiment of the present application;

[0066] Figure 7 It is a comparison diagram in the embodiment of this application. DETAILED DESCRIPTION

[0067] In order to have a clearer understanding of the technical features, purposes and effects of this application, the specific implementation methods of this application are now described in detail with reference to the accompanying drawings.

[0068] The embodiments of the present application provide a method and apparatus for predicting the volume of source rocks in a rift system basin with low degree of exploration.

[0069] Please refer to Figure 1 , Figure 1 This is a step diagram of a method for predicting the volume of source rocks in a rift system low-exploration basin in an embodiment of the present application, comprising:

[0070] S1: Based on the overall spatiotemporal evolution characteristics of the rift system and the degree of basin exploration, basins with high degree of rift system exploration are identified as scale areas;

[0071] S2: Based on the low-level exploration data of the predicted basin and the high-level exploration data of the scaled area, the structural conditions of the scaled area are analyzed to determine the optimal structural conditions for the development of source rocks. The optimal structural conditions include: depression dynamics mode, depression structure type, maximum activity rate of boundary faults, and maximum thickness of source rock development layer.

[0072] S3: Determine the comparability value between the basin to be predicted and the calibration area by optimizing the structural conditions;

[0073] In one embodiment, the process of determining the comparability between the basin to be predicted and the calibration area is carried out by constructing geological background data, such as Figure 2 shown.

[0074] S4: Based on the thickness and area of ​​favorable source rocks in the scaled area and combined with the comparable value, calculate the volume of favorable source rocks in the basin to be predicted.

[0075] In one embodiment, a method provides a basis for calculating the resource volume of a basin to be predicted. This method has the advantage of being able to predict the volume of source rocks in rift system basins with low exploration levels, thereby reducing exploration risks and costs.

[0076] Step S2 includes:

[0077] High-level exploration data include: existing drilling data and seismic data;

[0078] Based on the high-level exploration data of the scaled area, the structural conditions for the development of source rocks in the scaled area are determined;

[0079] The structural conditions for the development of source rocks in the scale area are screened to determine the preferred structural conditions for the development of source rocks.

[0080] In one embodiment of the present application, the depression dynamics model and depression structure type determined by combining the regional geological background of the rift system and seismic data are all available data from the early exploration of the low-exploration area, which can clearly define the analogy premise K1 between the basin to be predicted and the scale area, and are therefore preferred.

[0081] In one embodiment, a rift system with low exploration degree contains multiple basins, and its tectonic evolution is extremely complex. Therefore, starting from the regional geological background of the rift system and the tectonic evolution process it has experienced, the multiple tectonic movements experienced by the rift system are analyzed to clarify the overall spatiotemporal evolution characteristics of the rift. Based on the overall spatiotemporal evolution characteristics of the rift system basin, depressions with similar tectonic development backgrounds are selected for analogy, where depressions with high exploration degree are set as scale areas, and depressions with low exploration degree are basins to be predicted. The scale areas and the tectonic evolution stages of the basins to be predicted are divided, and the main periods of their rift activity are determined to determine the source rock development layers. Further, the source rocks of the basins to be predicted are predicted based on the development of the source rocks determined by the scale areas.

[0082] In one embodiment, since there are few actual drillings in the basin to be predicted, four factors, namely, depression dynamics mode, depression structure type, maximum activity rate of boundary faults, and maximum thickness of source rock development layer, are preferably used to predict the source rock in the basin to be predicted, and a comparable prediction formula is established.

[0083] Step S3 includes:

[0084] The low-level exploration data is seismic data; the optimal structural conditions of the basin to be predicted are obtained through the low-level exploration data of the basin to be predicted;

[0085] Compare the preferred structural conditions of the scaled area with those of the basin to be predicted to determine the comparability value between the basin to be predicted and the scaled area. The specific steps are as follows:

[0086] S31: Determine the analog value K1 between the basin to be predicted and the scale area through the sag dynamics model and sag structure type;

[0087] S32: Determine the analog value K2 between the basin to be predicted and the scale area through the maximum activity rate of the boundary fault;

[0088] The calculation formula of the analog value K2 is as follows:

[0089] Where V1 is the maximum activity rate of the boundary fault of the basin to be predicted, and V2 is the maximum activity rate of the boundary fault of the scale area;

[0090] S33: Determine the analog value K3 between the basin to be predicted and the scale area based on the maximum thickness of the source rock development layer;

[0091] The calculation formula of the analog value K3 is as follows:

[0092] Where H1 is the maximum thickness of the source rock development layer in the basin to be predicted, and H2 is the maximum thickness of the source rock development layer in the scale area;

[0093] The formula for calculating the comparability value is as follows:

[0094] In one embodiment, the K value quantitatively determines the similarity between the predicted basin and the calibration area. The first two factors control the comparability of the structural and sedimentary backgrounds of the source rock development in the calibration area and the predicted basin, determining K1. The second two factors, combined with the characteristics of low-exploration areas, select parameters with low economic cost and high research level, and quantitatively constrain them to determine K2 and K3.

[0095] In one embodiment, since there are few actual drillings in the basin to be predicted, it is a rift system basin with low exploration degree. The depression dynamics model determined by combining the geological background of the rift system region and the depression structure type determined by combining the seismic data are all data available from the early exploration of the low-exploration area. Therefore, the depression dynamics model and the depression structure type are selected to determine the analog value between the basin to be predicted and the scale area.

[0096] Step S31 includes:

[0097] The depression dynamics model includes: dynamic background, evolution of extensional mechanism and fault activity paradigm;

[0098] The dynamic background includes: mantle plume migration and plate movement; the evolution of extensional mechanisms includes: simple shear and pure shear; the fault activity paradigm includes: fault activity characteristics and fault activity intensity;

[0099] Depression structure types include grabens and half grabens; grabens include typical grabens, asymmetric grabens, and parallel-transform grabens; half grabens include typical half grabens and single-break migration half grabens;

[0100] Determine A1 by analogy between the dynamic background of the scaled area and the dynamic background of the basin to be predicted;

[0101] Determine A2 by analogy between the evolution of the extensional mechanism of the scaled area and that of the basin to be predicted;

[0102] Determine A3 by analogy between the fault activity of the scaled area and the fault activity paradigm of the basin to be predicted;

[0103] Determine A4 by analogy between the depression structure type of the scaled area and the depression structure type of the basin to be predicted;

[0104]

[0105] In one embodiment, the analog values ​​A1, A2, and A3 of the basin to be predicted and the scale area are determined by the dynamic background, such as Figure 3 According to the depression structure type, the analog value A4 between the basin to be predicted and the scale area is determined, as shown in Figure 4 shown.

[0106] In one example, differences in the growth mechanisms and activity of boundary faults control sag evolution, spatial distribution, and the distribution of sedimentary centers, thereby influencing the development and evolution of source rocks. Combining boundary fault geometry with sag dynamics can determine sag structural types and confirm the comparability of source rock development between the predicted basin and the calibration area.

[0107] In one embodiment, the depression dynamics model directly affects the tectonic activity and sedimentary environment of the depression and controls the development of source rocks. Therefore, this patent predicts the development possibility of source rocks in the basin to be predicted by comparing the depression dynamics models of two depressions.

[0108] Step S32 includes:

[0109] Through the high-level exploration data of the scaled area, the sedimentary time of source rock development and the characteristics of boundary fault activity are obtained;

[0110] The maximum activity rate of the boundary fault is determined by the sedimentation time of the source rock formation and the activity characteristics of the boundary fault. The calculation formula for the maximum activity rate of the boundary fault is:

[0111]

[0112] Where V f is the maximum activity rate of the boundary fault; T is the sedimentation time of the formation; H d is the thickness of the fault downthrown wall; H u is the thickness of the fault uplift wall.

[0113] In one embodiment, seismic and drilling data from the calibration area are further combined to determine the stratigraphic thickness of the source rock development strata and the activity rate of the boundary faults. Ultimately, the thickness and area of ​​the source rock development in the calibration area are determined. The maximum stratigraphic thickness of the source rock development strata is a key parameter for assessing hydrocarbon generation potential. The activity rate of the boundary faults directly affects the basin's accommodation capacity, provenance supply, and paleogeomorphology, thereby controlling the development of reservoirs and source rocks.

[0114] Step S4 includes:

[0115] S41: Based on the thickness and area of ​​favorable source rocks in the scaled area and combined with the analogy, calculate the thickness and area of ​​source rocks in the basin to be predicted;

[0116] S42: Calculate the volume of favorable source rocks in the basin to be predicted based on the thickness and area of ​​the source rocks in the basin to be predicted.

[0117] Step S4 further includes:

[0118] The thickness and area of ​​the source rock in the basin to be predicted are determined by the following formula:

[0119] H类 =K×H 刻 , where H 类 is the thickness of the source rock in the basin to be predicted, H 刻 is the thickness of source rocks in the scale area;

[0120] S 类 =K×S 刻 , where S 类 is the area of ​​source rock in the basin to be predicted, S 刻 is the area of ​​source rocks in the scale area;

[0121] The volume of source rock in the basin to be predicted is determined by the following formula:

[0122] V 类 =H 类 ×S 类 .

[0123] In one embodiment:

[0124] 1. Rift systems developed within five Archean cratons. Basin sedimentation was controlled by the surrounding orogenic belts. Under the control of early tectonic activity, weak tectonic zones formed large-scale rift structures with a near north-south trend. The overall evolution of the rifts is characterized by early expansion in the south and late expansion in the north, initially widening and then narrowing, and migrating eastward.

[0125] 2. The rift system comprises 26 rift basins, divided into the eastern and western branches. During the Early Miocene, rifting primarily occurred in the eastern branch. Under the dynamic influence of deep mantle plumes, active rifting, dominated by simple shear extension, developed, leading to the development of many half-grabens in the eastern branch. Furthermore, the varying strength, multi-stage nature, and spatial migration of mantle plumes further control the diversity of tectonic styles in the eastern branch half-grabens. The migration of mantle plume hotspots also contributes to the multi-stage evolution of half-grabens, characterized by simple shear in the early stages and pure shear extension in the later stages.

[0126] The scaled area is located in the northern part of the eastern branch of the rift system in the example. The Oligocene entered the initial stage of rifting and began to receive sediment infill. The Miocene was the main rifting stage, with rapid sedimentation and high rates of fault activity. Rifting activity was relatively continuous and stable from the Oligocene to the Middle Miocene, with little change in sedimentation rates. Rifting activity almost stagnated after the Middle Miocene. The predicted basin is located in the southern part of the scaled area. Because the rift system develops earlier in the south and later in the north, it is believed that the predicted basin developed in the Oligocene. However, due to weak seismic reflections in the lower part, it is difficult to accurately infer. Therefore, it is believed that the predicted basin began to develop a rift environment in the Early Miocene, and the source rocks mainly developed in the Miocene strata. Both are early active rifts.

[0127] The Early and Middle Miocene were the most active stages of rifting, characterized by the highest rates of sedimentation and the highest proportion of stratigraphic thickness, significantly exceeding the proportions of the other three stages. Existing drilling data in the calibration area also indicate the presence of the Lower Miocene Huxiang mudstone member, with the Oligocene Huxiang mudstone member as a secondary source rock. The Lower Miocene has moderate to high organic matter abundance, with predominantly Types I-II1. Furthermore, a sandstone outcrop has been discovered in the eastern part of the basin, with top and bottom ages of 8.5 and 13.1 Ma, respectively, indicating a Middle to Late Miocene age. The TOC content of the outcrop mudstone samples ranges from 0.74% to 5.38%, with an average of 2.7%. The HI ranges from 131 to 830 mg / gTOC, with an average of 530 mg / gTOC, indicating a high abundance of organic matter in the source rocks, dominated by Type I-II1 kerogen. The Tmax values ​​of the mudstone samples range from 438°C to 445°C, indicating a low-maturity to mature thermal evolution stage for the organic matter. The data show similarities in quality, type, and maturity to the main Miocene source rocks in the calibration area, confirming the potential for the development of high-quality source rocks in the Miocene of the predicted basin.

[0128] The analysis of single well geochemical data refers to the petroleum and natural gas industry standard SY / T5735-2019 "Geochemical Evaluation Methods for Source Rocks".

[0129] This study also conducted corresponding physical simulation and numerical simulation experiments in the scale area, focusing on the influence and control mechanism of the rift extension dynamics model on the specific sag evolution process and structural style, in order to determine the structural conditions for the development of source rocks in the scale area. It is believed that the boundary fault section of the scale area is "shovel-shaped", which is a typical single-fault half-graben. Figure 7 In the context of the vertical center of the mantle plume migrating from west to east, the early stage was mainly a simple shear extension mode. The steep slope zone was more tectonic than the gentle slope zone, the boundary fault activity rate was high, and the sedimentation was rapid, which was conducive to the development of source rocks. In the late stage, the extension mode was converted to a pure shear mode. The fault activity and sedimentation center migrated to the gentle slope zone. The steep slope zone was more conducive to the preservation of source rocks than the gentle slope zone. The sedimentation center migrated due to the conversion of the extension mode. The thickness center developed in the central and southern part of the sag along the boundary fault. The maximum thickness exceeded 2000m. The distribution area of ​​strata exceeding 1000m was large, reaching 940km. 2 .

[0130] Combined with drilling data and seismic data, it is found that this set of source rocks are characterized by low velocity, low density and relatively high gamma value on the well logging curve, and by continuous strong reflection of medium and high frequency on the seismic profile, revealing that the thickness of this set of source rocks in the calibration area can reach 700m, and the effective source rock area can reach 1150km 2 .

[0131] 3. The dynamic mechanism of the basin to be predicted also has the characteristics of the transition from simple shear to pure shear in the migration and extension mode of the mantle plume. For a long time, it has also been a single-fault continuous half-graben controlled by the "shovel-type" normal fault. Figure 7 Its dynamic mechanism and depression structure type are similar to those of the scale area and are comparable.

[0132] Since the basin to be predicted and the calibration area both have the same mantle plume migration and shear mode from simple shear to pure shear, the sag dynamic mode is exactly the same, and both are single-break half-grabens, K1 is determined to be 1.

[0133] The maximum activity rate of the Lower Miocene boundary fault in the predicted basin is 130 m / Ma, and the maximum activity rate of the Lower Miocene fault in the calibration area is 150 m / Ma, so K2 is determined to be 0.87.

[0134] Based on the maximum thickness of the Lower Miocene strata in the predicted basin being 1400m and the maximum thickness of the Lower Miocene strata in the calibration area being 2000m, K3 is determined to be 0.7.

[0135] Finally, the ratio of the thickness and area of ​​the source rock in the predicted basin to the calibration area is calculated: K = 0.785

[0136] The maximum thickness of the Lower Miocene source rock in the calibration area is 700m, and the maximum thickness of the source rock in the basin to be predicted is determined as: H 类 =549.5m.

[0137] The maximum area of ​​favorable source rocks in the Lower Miocene of the scale area is 1150 km 2 , determine the maximum area of ​​favorable source rocks in the basin to be predicted: S 类 =902.75km 2 .

[0138] The prediction results of source rock volume in the basin to be predicted are obtained:

[0139] V 类 =496.06km 3 .

[0140] Please refer to Figure 6 , Figure 6 This is a module connection diagram of a device for predicting the volume of source rocks in a rift system low-exploration basin in an embodiment of the present application, including:

[0141] Division module, data calculation module, comparison module and volume calculation module;

[0142] The division module, data calculation module, comparison module and volume calculation module are connected in sequence;

[0143] The division module is used to determine basins with high exploration degree of the rift system as calibration areas and basins with low exploration degree of the rift system as basins to be predicted based on the overall spatiotemporal evolution characteristics of the rift system and the exploration degree of the basins;

[0144] The data calculation module is used to analyze the structural conditions of the scale area based on the low-level exploration data of the basin to be predicted and the high-level exploration data of the scale area, and to clarify the preferred structural conditions for the development of source rocks; the preferred structural conditions include: depression dynamics mode, depression structure type, maximum activity rate of boundary faults, and maximum thickness of source rock development layer;

[0145] The comparison module is used to determine the comparability value between the basin to be predicted and the scale area by optimizing the structural conditions;

[0146] The volume calculation module is used to calculate the volume of favorable source rocks in the basin to be predicted based on the thickness and area of ​​favorable source rocks in the scale area and in combination with the comparability value.

[0147] This application also discloses an electronic device. Figure 5 , Figure 5 Schematic diagram of the structure of an electronic device disclosed in an embodiment of the present application. The electronic device 500 may include: at least one processor 501, at least one network interface 504, a user interface 503, a memory 505, and at least one communication bus 502.

[0148] The communication bus 502 is used to implement the connection and communication between these components.

[0149] The user interface 503 may include a display screen, and the optional user interface 503 may also include a standard wired interface or a wireless interface.

[0150] The network interface 504 may optionally include a standard wired interface or a wireless interface (such as a WI-FI interface).

[0151] The present application also discloses a computer-readable storage medium storing a plurality of instructions suitable for loading by a processor to execute the above-mentioned method for predicting the volume of source rocks in a rift system low-exploration basin.

[0152] The above are merely exemplary embodiments of the present disclosure and are not intended to limit the scope of the present disclosure. In other words, any equivalent variations and modifications made in accordance with the teachings of the present disclosure are still within the scope of the present disclosure. Those skilled in the art will readily conceive of other embodiments of the present disclosure after considering the disclosure and the practical implications thereof.

[0153] This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not described herein. The description and examples are to be considered as exemplary only, and the scope and spirit of the present disclosure are to be defined by the claims.

Claims

1. A method for predicting the volume of source rocks in a rift system basin with low exploration degree, characterized by: The method comprises the following steps: S1: Based on the overall spatiotemporal evolution characteristics of the rift system and the degree of basin exploration, basins with high degree of rift system exploration are identified as scale areas; S2: Based on the high-level exploration data of the scaled area, the structural conditions of the scaled area are dissected to identify the optimal structural conditions for the development of source rocks. The optimal structural conditions include: depression dynamics mode, depression structure type, maximum activity rate of boundary faults, and maximum thickness of source rock development layer. S3: Obtain low-level exploration data of the basin to be predicted, and determine the comparability value between the basin to be predicted and the calibration area by optimizing structural conditions and low-level exploration data; S4: Based on the thickness and area of ​​favorable source rocks in the scaled area and combined with the comparable value, calculate the volume of favorable source rocks in the basin to be predicted.

2. The method for predicting the volume of source rocks in a rift system low-exploration basin according to claim 1, wherein: Step S2 includes: High-level exploration data include: existing drilling data and seismic data; Based on the high-level exploration data of the scaled area, the structural conditions for the development of source rocks in the scaled area are determined; The structural conditions for the development of source rocks in the scale area are screened to determine the preferred structural conditions for the development of source rocks.

3. The method for predicting the volume of source rocks in a rift system low-exploration basin according to claim 2, wherein: Step S3 includes: The low-level exploration data is seismic data; the optimal structural conditions of the basin to be predicted are obtained through the low-level exploration data of the basin to be predicted; Compare the preferred structural conditions of the scaled area with those of the basin to be predicted to determine the comparability value between the basin to be predicted and the scaled area. The specific steps are as follows: S31: Determine the analog value K1 between the basin to be predicted and the scale area through the sag dynamics model and sag structure type; S32: Determine the analog value K2 between the basin to be predicted and the scale area through the maximum activity rate of the boundary fault; The calculation formula of the analog value K2 is as follows: Where V1 is the maximum activity rate of the boundary fault of the basin to be predicted, and V2 is the maximum activity rate of the boundary fault of the scale area; S33: Determine the analog value K3 between the basin to be predicted and the scale area based on the maximum thickness of the source rock development layer; The calculation formula of the analog value K3 is as follows: Where H1 is the maximum thickness of the source rock development layer in the basin to be predicted, and H2 is the maximum thickness of the source rock development layer in the scale area; The formula for calculating the comparability value is as follows:

4. The method for predicting the volume of source rocks in a rift system low-exploration basin according to claim 3, wherein: Step S31 includes: The depression dynamics model includes: dynamic background, evolution of extensional mechanism and fault activity paradigm; The dynamic background includes: mantle plume migration and plate movement; the evolution of extensional mechanisms includes: simple shear and pure shear; the fault activity paradigm includes: fault activity characteristics and fault activity intensity; Depression structure types include grabens and half grabens; grabens include typical grabens, asymmetric grabens, and parallel-transform grabens; half grabens include typical half grabens and single-break migration half grabens; Determine A1 by analogy between the dynamic background of the scaled area and the dynamic background of the basin to be predicted; Determine A2 by analogy between the evolution of the extensional mechanism of the scaled area and that of the basin to be predicted; Determine A3 by analogy between the fault activity of the scaled area and the fault activity paradigm of the basin to be predicted; Determine A4 by analogy between the depression structure type of the scaled area and the depression structure type of the basin to be predicted; 5. The method for predicting the volume of source rocks in a rift system low-exploration basin according to claim 3, wherein: Step S32 includes: Through the high-level exploration data of the scaled area, the sedimentary time of source rock development and the characteristics of boundary fault activity are obtained; The maximum activity rate of the boundary fault is determined by the sedimentation time of the source rock formation and the activity characteristics of the boundary fault. The calculation formula for the maximum activity rate of the boundary fault is: Where V f is the maximum activity rate of the boundary fault; T is the sedimentation time of the formation; H d is the thickness of the fault downthrown wall; H u is the thickness of the fault uplift wall.

6. The method for predicting the volume of source rocks in a rift system low-exploration basin according to claim 1, wherein: Step S4 includes: S41: Based on the thickness and area of ​​favorable source rocks in the scaled area and combined with the analogy, calculate the thickness and area of ​​source rocks in the basin to be predicted; S42: Calculate the volume of favorable source rocks in the basin to be predicted based on the thickness and area of ​​the source rocks in the basin to be predicted.

7. The method for predicting the volume of source rocks in a rift system low-exploration basin according to claim 6, wherein: Step S4 further includes: The thickness and area of ​​the source rock in the basin to be predicted are determined by the following formula: H 类 =K×H 刻 , where H 类 is the thickness of the source rock in the basin to be predicted, H 刻 is the thickness of source rocks in the scale area; S 类 =K×S 刻 , where S 类 is the area of ​​source rock in the basin to be predicted, S 刻 is the area of ​​source rocks in the scale area; The volume of source rock in the basin to be predicted is determined by the following formula: V 类 =H 类 ×S 类 。 8. A device for predicting the volume of source rocks in a rift system basin with low degree of exploration, used to implement the method for predicting the volume of source rocks in a rift system basin with low degree of exploration as claimed in any one of claims 1 to 7, characterized in that: The device comprises: Division module, data calculation module, comparison module and volume calculation module; The division module, data calculation module, comparison module and volume calculation module are connected in sequence; The division module is used to determine basins with high exploration degree of the rift system as calibration areas and basins with low exploration degree of the rift system as basins to be predicted based on the overall spatiotemporal evolution characteristics of the rift system and the exploration degree of the basins; The data calculation module is used to analyze the structural conditions of the scale area based on the low-level exploration data of the basin to be predicted and the high-level exploration data of the scale area, and to clarify the preferred structural conditions for the development of source rocks; the preferred structural conditions include: depression dynamics mode, depression structure type, maximum activity rate of boundary faults, and maximum thickness of source rock development layer; The comparison module is used to determine the comparability value between the basin to be predicted and the scale area by optimizing the structural conditions; The volume calculation module is used to calculate the volume of favorable source rocks in the basin to be predicted based on the thickness and area of ​​favorable source rocks in the scale area and in combination with the comparability value.

9. An electronic device, characterized in that: The electronic device comprises a processor, a memory, a user interface and a network interface, wherein the memory is used to store instructions, the user interface and the network interface are used to communicate with other devices, and the processor is used to execute the instructions stored in the memory so that the electronic device executes the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores instructions, and when the instructions are executed by a computer, the method according to any one of claims 1 to 7 is executed.

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