A method for determining the extent of a water body in a continental, arid lake basin sediment

Abstract

The application discloses a kind of about the determination method of continental facies arid lake basin sediment water body distribution range, comprising the following steps: first, the mudstone color of purpose layer is counted by well logging data, and the deep water development range represented by dark mudstone is preliminarily circled out;Then, according to special chemical sedimentary rock such as gypsodum, salt rock or mirabilite etc., shallow water development area of water body is judged;Finally, using the environmental element ratio (Fe / Co) method sensitive to water body, element test is carried out to core near the boundary of ancient lake basin near water body, and calculation is carried out, the application is suitable for oil and gas field geological exploration technical field, the development range of ancient water body is discriminated by the method such as mudstone color, special chemical sedimentary rock and mudstone trace element etc., based on the evidence of water body distribution range, the sand body distribution pattern of arid lake basin sediment type is established, and the means of paleoclimate recovery is further improved, and new research ideas and technical means are provided for the study of paleolake sedimentary evolution process.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field geological exploration technology, specifically a method for determining the distribution range of sedimentary water bodies in terrestrial arid lacustrine basins. Background Technology

[0002] Reconstructing the distribution range of paleowater bodies is a crucial research task in reservoir geology of oil and gas basins, providing significant guidance for understanding basin sedimentary evolution, the genetic types of high-quality reservoirs, and their distribution patterns. Because terrestrial sedimentary lake basins develop different types of sedimentary facies above and below water—such as alluvial fans and fluvial facies above water, and deltaic and beach-bar facies below water—the differences in above-water and below-water environments lead to sedimentary types under different hydrodynamic controls, resulting in significantly different reservoir development patterns and ultimately influencing the distribution of oil and gas reservoirs. In contrast, lake basins in arid environments are more limited in scope, and water bodies exert a more pronounced control over favorable reservoirs. For example, arid sedimentary lake basins develop large-scale tributary river systems above water, representing a reservoir development pattern where these systems are not interconnected. Conversely, in the small-scale water-bearing sedimentary areas at the center of arid lake basins, terrestrial river systems are transformed by water bodies after entering the lake, forming interconnected shallow-water deltas, creating a reservoir development pattern. Therefore, determining the distribution range of paleowater bodies is crucial for understanding the distribution of sand bodies within arid basins. Therefore, determining the distribution range of sedimentary water bodies in terrestrial arid lake basins is of exploratory significance.

[0003] Currently, the commonly used methods for determining the distribution range of paleowater bodies mainly rely on the lithology, color, and typical facies characteristics of sediments for rough identification. For example, red, green, and variegated mudstones are mainly terrestrial sediments, while dark gray or gray mudstones are mainly underwater sediments. In terms of lithology, coarse clastic conglomerate, gravelly sandstone, or medium- to coarse sandstone under oxidized color are generally considered to be terrestrial sediments. If these coarse clastic sediments exhibit massive bedding, parallel bedding, and characteristics of typical terrestrial sedimentary facies such as carbonaceous fragments and red mudstone lacerations, then their representation as terrestrial sediments is more reliable. However, these conventional methods for identifying terrestrial sedimentary facies are subject to uncertainty or inaccuracy. For example, Cao Yingchang et al. (2011) discovered in their study of the sedimentary environment of the Sha-Si-Xia-Kongdian Formation in the Jiyang Depression of the Bohai Bay Basin that the Hao Ke 1 well, located near the center of the basin, developed nearly 1000m of red strata during the Sha-Si-Xia-Kongdian period, mainly consisting of interbedded siltstone and mudstone, and also containing a relatively thick layer of chemical salt gypsum. Judging from the color of the mudstone, this well may have been deposited on land during this period. However, the extensive chemical salt gypsum rock indicates that Hao Ke 1 was largely covered by water during this period. Therefore, the reservoir of this well belongs to underwater deltaic or beach-bar deposits, rather than onshore sediments. Thus, determining whether a well is on land or underwater based solely on sediment color and sedimentary characteristics is not very reliable.

[0004] In addition, some typical underwater sedimentary mineral types, such as mirabilite, salt rock, gypsum, and halides, can prove that there was water during the depositional period. Besides these, some paleowater depth methods can indirectly determine the depth of water bodies and the general outline of their boundaries. For example, the method proposed by Wang Yongshi et al. (ZL201410101705.2) uses the relationship between TOC, stratigraphic thickness, and paleowater depth to reconstruct the depth. However, this method is unreliable for some coarse clastic sediments on the terrestrial margins of basins because, although the stratigraphic thickness is large, the TOC value is very low, making it difficult to accurately identify the extent of the water body and thus establishing an inaccurate model of whether the sand body is above or below water. There are also methods to determine paleowater depth through the wedge-shaped stratigraphic structure of the delta plain and delta front (coastline trajectory) (Kang Bo et al., 2012). However, this method is inaccurate in determining the exact location of 0m water depth in the delta plain because the relatively flat sedimentary structure makes it difficult to calculate paleowater depth using the coastline trajectory method. Furthermore, some scholars have used special paleontological samples (such as microfossils, pollen, ostracods, etc.) and their different types of content (Li Shoujun et al., 2005; Zou Xinqing et al., 2000) to reconstruct the depth of ancient water bodies. These methods require a large amount of paleontological evidence, and it is difficult to collect all such sample data. Moreover, the water depth or surface evidence represented by these data is not accurate, but only a general range of water depth. The uncertainty of these methods indicates that they are not very universal.

[0005] In addition, Zhang Jinliang et al. (2019) (ZL201910936707.6) proposed a method and system for identifying marine-lake environments in nearshore basins. The main approach is to comprehensively utilize four sedimentary results (core sedimentary structures, sea-level curves, geochemical parameters, and biological fossils) to determine whether the nearshore basin marine-lake environment is a marine basin, a continental basin, or a marine trace lake basin. This is a method that comprehensively distinguishes between large marine basins, continental basins, or marine trace lake basins. It cannot accurately determine the distribution location of small water bodies in terrestrial lacustrine basins, thus failing to provide guidance.

[0006] Another method for reconstructing paleowater depth is to utilize the Fe / Co ratio, a sensitive trace element in sediments that reflects changes in water depth. This is a semi-quantitative method for characterizing water depth. Besides paleogeomorphological sedimentology, paleoecology, and organic carbon-stratum thickness, which are mentioned above as methods for quantitatively reconstructing paleowater depth, this is a new trace element proxy indicator that is sensitive to changes in paleowater depth. Related literature indicates that Fe and Co belong to Group VIII elements and have similar physical and chemical properties. Because of these similarities and subtle differences, minute changes in their content in sediments and sedimentary media can be highly indicative. In endogenic deposits, Fe and Co are usually closely coexisting in their divalent state, but they separate according to different aquatic conditions during weathering, erosion, migration, and sedimentation. Under surface conditions, Fe and Co will precipitate or migrate separately according to different pH and Eh values. Under specific pH and Eh values, the relative amounts of each element precipitated are different. Near the shore of a lake, the water is rich in free oxygen, and both Fe and Co precipitate simultaneously, with Fe precipitating in greater proportion than Co. As the water deepens, free oxygen gradually decreases, and the Eh value in the water also gradually decreases. Therefore, under conditions of increasing organic matter and increasing reducing power, the Co content gradually increases, while the Fe content decreases or tends to decrease to a lower level. Thus, the relative amounts of Fe and Co can be used to infer the water depth variation during sediment formation. If the lake water follows the pattern of decreasing free oxygen and increasing reducing power with increasing depth, this distance index becomes an indicator of the relative depth of the paleolake water: a higher Fe / Co value indicates increased oxidation and shallower paleowater; a lower Fe / Co value indicates increased reducing power and deeper paleowater. Due to significant environmental changes both above and below water in arid sedimentary lake basins, the red sandstone and mudstone deposited by a small number of streams in the tributary rivers of the above-water plain have a highly oxygen-rich environment, resulting in a large accumulation of Fe. However, although the underwater environment also has a certain degree of oxidation, the Fe content decreases sharply. The Fe / Co ratio scatter plots above and below water show a certain inflection point, which is helpful for determining the water body extent of the sedimentary area.

[0007] While the aforementioned methods have some applicability, they still have some limitations. First, they are not suitable for the unique sedimentary environment of arid lake basins. Second, it is difficult to collect complete data from different individual methods, and the cross-verification of paleodepths between individual methods is insufficient. Therefore, a new method for accurately identifying the extent of sedimentary water bodies in arid lake basins is urgently needed. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for determining the distribution range of sedimentary water bodies in terrestrial arid lake basins.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A method for determining the distribution range of sedimentary water bodies in terrestrial arid lacustrine basins includes the following steps:

[0011] (1) Based on seismic drilling data, clarify the isochronous stratigraphic framework and sedimentary characteristics of arid lake basins;

[0012] (2) Conduct a statistical analysis of the proportion of mudstone color in the target stratum to determine its planar distribution characteristics;

[0013] (3) Compile chemical rock thickness distribution maps of the target strata and preliminarily determine the distribution range of paleowater bodies in the well area;

[0014] (4) Conduct paleogeographic earthquake reconstruction of the target stratum and preliminarily determine the distribution range of paleowater bodies in the wellless area;

[0015] (5) Conduct Fe and Co trace element tests on mudstone in the lake periphery of the study area;

[0016] (6) Accurately determine the location of ancient water bodies based on the scatter plot of transport distance and the ratio of Fe / Co elements;

[0017] (7) Draw a map showing the distribution of paleowater bodies and sedimentary systems in the target stratigraphic section.

[0018] Preferably, step (1) specifically includes: using regional seismic and drilling core sedimentary analysis data of the basin area, based on the stratigraphic division results of a certain historical period, identifying the main source areas and sedimentary areas of the terrestrial lacustrine basin, and determining the development location of the lacustrine basin sedimentary center.

[0019] Preferably, step (1) specifically includes: starting from the regional seismic interpretation and well calibration of the arid lake basin, establishing an isochronous division scheme for the study area, and then conducting sedimentary characteristic studies within the isochronous framework to clarify the main source areas and sedimentary areas of the terrestrial lake basin and to determine the development location of the lake basin sedimentary center.

[0020] Preferably, step (2) specifically includes: statistically analyzing the percentage of oxidized or reduced mudstone in the target stratum to determine the main surface sedimentary area and deep-water sedimentary area of ​​the arid lake basin.

[0021] Preferably, in step (2), the percentage of mudstone content in the surface sedimentary area is mainly oxidized, while the percentage of mudstone content in the deep-water sedimentary area is mainly reduced.

[0022] Preferably, step (3) specifically includes: conducting a statistical analysis of the thickness of chemical sedimentary rocks in the surrounding drilling cores and cuttings, drawing a contour map of the chemical rock thickness, and clarifying the distribution area of ​​chemical rocks revealed by the drilling, wherein the chemical rocks represent a rough distribution area of ​​water bodies.

[0023] Preferably, step (4) specifically includes: combining the results of compiling mudstone color percentage values ​​and chemical thickness contour lines, and combining the results of the restoration of paleogeography of a certain period of earthquake in the lake basin, identifying the distribution area of ​​water bodies encountered in the wellless area, and roughly determining the distribution range of paleowater bodies based on the above results.

[0024] Preferably, step (5) specifically includes: taking mudstone samples and conducting trace element tests, and using the test results to calculate the Fe / Co ratio.

[0025] Preferably, step (6) specifically includes: drawing a scatter plot of the transport distance and the ratio of Fe to Co elements, combining the results of the water body distribution range from step (2) to step (4), determining the Fe to Co data inflection point representing the boundary between the surface and underwater areas, and finding the accurate location of the water body distribution range.

[0026] Preferably, step (7) specifically includes: taking into account the proportion of mudstone color, thickness of chemical rock and paleogeographic results to preliminarily determine the outline of the paleowater body in the basin, and using the inflection point characteristics of the Fe / Co element ratio scatter points to clarify the boundary between the water surface and the underwater area, and to determine the distribution range of the paleowater body in the study area.

[0027] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0028] This invention uses a combination of mudstone color, special chemical sedimentary rocks, and mudstone trace elements to determine the development range of ancient water bodies, overcoming the difficulty of accurately distinguishing between underwater red mudstone, shallow water, and waterless areas. Based on evidence of water body distribution, it establishes a sand body distribution pattern for arid lake basin sedimentary types. This method further improves paleoclimate reconstruction techniques and provides new research ideas and technical means for the study of ancient lake sedimentary evolution processes. Attached Figure Description

[0029] Figure 1 This is a flowchart illustrating the operation of the present invention;

[0030] Figure 2 This is a diagram showing the color distribution of mudstone and the thickness distribution of salt-gypsum rock in the X group of Depression A in this embodiment of the invention;

[0031] Figure 3 This is a map showing the distribution of paleomorphology and paleowater bodies in the X group of Depression A in this embodiment of the invention.

[0032] Figure 4 This is a scatter plot of the transport distance of segment X in depression A and the Fe / Co element ratio in an embodiment of the present invention.

[0033] Figure 5This is an overlay diagram of the water distribution range and sedimentary system in the X section of Depression A in an embodiment of the present invention. Detailed Implementation

[0034] The following embodiments further illustrate specific implementations of the method for determining the distribution range of sedimentary water bodies in terrestrial arid lacustrine basins according to the present invention. The method for determining the distribution range of sedimentary water bodies in terrestrial arid lacustrine basins according to the present invention is not limited to the descriptions in the following embodiments.

[0035] Example 1:

[0036] A method for determining the distribution range of sedimentary water bodies in terrestrial arid lacustrine basins, such as... Figure 1 As shown, it includes the following steps:

[0037] (1) Using sedimentary analysis data such as earthquakes and well cores in the basin area, based on the stratigraphic division results of a certain historical period, identify the main source areas and sedimentary areas of the terrestrial lacustrine basin, and determine the development location of the lacustrine sedimentary center.

[0038] (2) Statistically determine the percentage of oxidized or reduced mudstone in the target strata to identify the main surface sedimentary areas (mainly oxidized) and deep-water sedimentary areas (mainly reduced).

[0039] (3) Conduct statistics on the thickness of chemical sedimentary rocks in the surrounding well cores and cuttings, draw contour maps of chemical rock thickness, and clarify the distribution area of ​​chemical rocks revealed by the wells. Here, chemical rocks represent the approximate distribution area of ​​water bodies.

[0040] (4) By combining the percentage values ​​of mudstone color and the results of compiling chemical thickness contour lines, and the results of restoring the paleogeography of the lake basin during a certain period of earthquake, the distribution area of ​​water bodies encountered in well-free areas can be effectively identified. By combining the above results, the distribution range of paleowater bodies can be roughly determined.

[0041] (5) Trace element Fe and Co were tested on mudstone cores near the lake shore;

[0042] (6) Draw a scatter plot of transport distance and Fe / Co element ratio. Combine the results of the water body distribution range of the above three methods, and focus on the Fe / Co data inflection point that represents the boundary between the water surface and the underwater area, so as to find the accurate location of the water body distribution range.

[0043] (7) The outline of the ancient water body in the basin was initially determined by combining the mudstone color ratio, chemical rock thickness and paleogeographic results. At the same time, the inflection point characteristics of the Fe / Co element ratio scatter points were used to clarify the boundary between the water surface and the water surface. The distribution range of the ancient water body in the study area was determined by combining the two methods.

[0044] By adopting the above technical solution:

[0045] Since the location of paleolake basin water bodies directly controls the importance of sedimentary patterns favorable for reservoir sand bodies, conventional methods such as mudstone color and sedimentary facies are prone to uncertainty in determining the distribution range of paleowater bodies. This invention integrates mudstone color, special chemical sedimentary rocks, and mudstone trace elements to determine the development range of paleowater bodies, overcoming the difficulty in accurately distinguishing between underwater areas with red mudstone and shallow or aquifer zones. First, by statistically analyzing the mudstone color of the target stratigraphic interval using well logging data, the deep-water development range represented by dark mudstone is preliminarily delineated. Then, shallow-water development zones are identified based on special chemical sedimentary rocks such as gypsum, salt, or mirabilite. Finally, using the water-sensitive environmental element ratio (Fe / Co) method, elemental analysis and calculations are performed on core samples near the water body boundary of the paleolake basin. By using empirical inflection points in the data, the formation environment (above or below water) can be accurately determined. Through these steps, the planar distribution range of paleowater bodies can be reliably and accurately depicted. Based on the evidence of water body distribution range, a sand body distribution pattern for arid lake basin sedimentary types is established. This method further improves paleoclimate reconstruction techniques and provides new research ideas and technical means for the study of ancient lake sedimentary evolution processes.

[0046] Example 2:

[0047] like Figure 1 As shown, the comprehensive method for determining the distribution range of paleowater bodies in the arid lake basin includes the following steps:

[0048] The specific steps for implementation are as follows:

[0049] (1) Based on data such as seismic drilling, clarify the isochronous stratigraphic framework and sedimentary characteristics of arid lake basins;

[0050] Starting with regional seismic interpretation and well calibration of terrestrial arid lacustrine basins, an isochronous division scheme for the study area is established. Then, sedimentary characteristics are studied within the isochronous framework to identify the main source areas and sedimentary zones of the terrestrial lacustrine basins and determine the development location of the lacustrine basin sedimentary center.

[0051] (2) Conduct a statistical analysis of the proportion of mudstone color in the target stratum to determine its planar distribution characteristics;

[0052] Based on the thickness statistics of mudstone color from a large number of drilling cores and cuttings, the percentage content of oxidized mudstone thickness (brick red, purplish red, brown, etc.) in the target layer is determined, thereby identifying the main surface sedimentary areas (mainly oxidized colors) and deep-water sedimentary areas (mainly reduced colors) in arid lake basins.

[0053] (3) Compile chemical rock thickness distribution maps of the target strata and preliminarily determine the distribution range of paleowater bodies in the well area;

[0054] In areas dominated by gray and dark-water colored mudstone deposits, we conducted a statistical analysis of the thickness of chemical sedimentary rocks from surrounding well cores and cuttings, and delineated contour maps of chemical rock thickness to clarify the distribution areas of chemical rocks revealed by drilling. These chemical rocks represent the approximate distribution areas of water bodies.

[0055] (4) Conduct paleogeographic earthquake reconstruction of the target stratum and preliminarily determine the distribution range of paleowater bodies in the wellless area;

[0056] By combining the research results of steps (2) and (3), the approximate range of paleowater bodies in the well-controlled area can be determined. For the well-free area, the seismic paleogeography of the target layer can be restored. In this way, the distribution location of water bodies in the well-controlled area can be effectively determined based on the paleogeographic results. By combining the above results, the distribution range of paleowater bodies can be roughly determined.

[0057] (5) Conduct Fe and Co trace element tests on mudstone in the lake periphery of the study area;

[0058] By sampling mudstone and conducting trace element tests, the Fe / Co ratio was calculated using the test results.

[0059] (6) Accurately determine the location of ancient water bodies based on the scatter plot of transport distance and the ratio of Fe / Co elements;

[0060] By calculating the Fe / Co element ratio, a scatter plot of the transport distance and the Fe / Co element ratio is drawn. Combining the results of the water body distribution range from the three methods mentioned above, the focus is on identifying the Fe / Co data inflection point at the boundary between the surface and underwater areas, thereby finding the accurate location of the water body distribution range.

[0061] (7) Draw a map showing the distribution of paleowater bodies and sedimentary systems in the target stratigraphic section;

[0062] By combining the mudstone color proportion, chemical rock thickness, and paleogeomorphological results, the outline of the paleowater body in the basin was initially determined. At the same time, the boundary between the above-water and underwater areas was clarified by using the Fe / Co element ratio scatter plot. Combining the above steps, the distribution range of the paleowater body in the study area was accurately determined. Based on the distribution range of the paleowater body, the development range of different sedimentary systems in the plane was laid.

[0063] Example 3:

[0064] The research focuses on the Paleogene X Formation sediments in Depression A. Comprehensive analysis of geological data suggests this sedimentary deposit is a fluvial-lacustrine terrestrial arid basin sedimentary system. A review of existing literature on paleowater depth reconstruction in Depression A's X Formation reveals previous methods such as paleogeomorphological sedimentology, paleoecology, and organic carbon-stratum thickness for paleowater body reconstruction. The Fe / Co ratio of trace elements is also recognized as a semi-quantitative method reflecting water depth. Considering the advantages, disadvantages, and applicability of these methods, this invention proposes a comprehensive approach that integrates mudstone color, specific chemical sedimentary rocks, paleogeomorphology, and mudstone trace elements to determine the extent of paleowater development. This overcomes the difficulty in accurately distinguishing between underwater areas with red mudstone, shallow water, and areas without water.

[0065] First, by analyzing the mudstone color of the target formation using well logging data, the deep-water development range represented by the dark mudstone of the X group in the A depression was preliminarily delineated (e.g., Figure 2 (as shown); then, based on special chemical sedimentary rocks such as gypsum, salt, or mirabilite, the shallow water development zone is determined; for the well-free area, the seismic paleogeography of the target layer is restored. In this way, the distribution location of water bodies in the well-controlled area can be effectively determined based on the paleogeographic results, thus confirming the distribution area of ​​water bodies encountered in the well-free area. Combining the above results, the distribution range of paleowater bodies in the X group of the A depression can be roughly determined (e.g., Figure 3 (As shown); Finally, using the water-sensitive environmental element ratio (Fe / Co) method, elemental analysis and calculations were performed on core samples near the water boundary of the paleocean basin. The results were then analyzed using empirical inflection points (such as...). Figure 4 (As shown) This allows for precise differentiation between above-water and underwater formation environments. Through the above steps, the planar distribution range of paleowater bodies can be reliably and precisely characterized. Based on evidence of the water body distribution range, a sand body distribution pattern of the arid lacustrine basin sedimentary type in Depression X Formation A can be established (e.g., Figure 5 (As shown).

[0066] By adopting the above technical solution:

[0067] This application integrates methods such as mudstone color, special chemical sedimentary rocks, paleogeography, and mudstone trace elements to determine the development range of paleowater bodies, overcoming the problem of not being able to accurately distinguish between underwater areas with red mudstone and shallow or aquatic zones. First, by statistically analyzing the mudstone color of the target stratigraphic interval using well logging data, the deep-water development range represented by dark mudstone is preliminarily delineated. Then, shallow-water development zones are identified based on special chemical sedimentary rocks such as gypsum, salt, or mirabilite. Finally, systematic sampling and trace element testing are conducted on mudstone from the established environment of the lake basin. Empirical numerical summaries are summarized using environmental element ratios (Fe / Co) sensitive to water bodies. Elemental testing and calculations are then performed on core samples near the water body boundary of the paleowater basin. These numerical values ​​are compared with empirical values ​​to accurately determine whether mudstone with different values ​​represents an above-water or underwater formation environment. Through these steps, the planar distribution range of paleowater bodies can be reliably and accurately depicted. Based on evidence of the water body distribution range, a sand body distribution pattern for arid lake basin sedimentary types is established. This method further improves the means of restoring ancient water environments and provides new research ideas and technical means for the study of ancient lake sedimentary evolution processes.

[0068] This method is primarily applicable to the restoration of the distribution range of sedimentary water bodies in arid terrestrial lacustrine basins, and it also has certain reference value for the restoration of sedimentary water bodies in other types of lacustrine basins. The restoration results of accurately identifying paleowater body ranges using this method can provide valuable guidance for the prediction of various types of high-quality reservoirs in arid lacustrine basins.

[0069] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for determining the distribution range of sedimentary water bodies in terrestrial arid lacustrine basins, characterized in that, Includes the following steps: (1) Based on seismic drilling data, clarify the isochronous stratigraphic framework and sedimentary characteristics of arid lake basins; (2) Conduct a statistical analysis of the proportion of mudstone color in the target stratum to determine its planar distribution characteristics; (3) Compile chemical rock thickness distribution maps of the target strata and preliminarily determine the distribution range of paleowater bodies in the well area; (4) Conduct paleogeographic earthquake reconstruction of the target stratum and preliminarily determine the distribution range of paleowater bodies in the wellless area; (5) Conduct Fe and Co trace element tests on mudstone in the lake periphery of the study area; (6) Accurately determine the location of ancient water bodies based on the scatter plot of transport distance and the ratio of Fe / Co elements; (7) Draw a map showing the distribution of paleowater bodies and sedimentary systems in the target stratigraphic section.

2. The method for determining the distribution range of sedimentary water bodies in terrestrial arid lacustrine basins as described in claim 1, characterized in that, The specific steps (1) include: using regional seismic and drilling core sedimentary analysis data of the basin area, based on the stratigraphic division results of a certain historical period, identifying the main source areas and sedimentary areas of the terrestrial lacustrine basin, and determining the development location of the lacustrine basin sedimentary center.

3. The method for determining the distribution range of sedimentary water bodies in terrestrial arid lacustrine basins as described in claim 1, characterized in that, The specific steps (1) include: starting with the regional seismic interpretation and well calibration of the arid lake basin, establishing an isochronous division scheme for the study area, and then conducting sedimentary characteristic studies within the isochronous framework to clarify the main source areas and sedimentary areas of the terrestrial lake basin and to determine the development location of the lake basin sedimentary center.

4. The method for determining the distribution range of sedimentary water bodies in terrestrial arid lacustrine basins as described in claim 1, characterized in that, Step (2) specifically includes: calculating the percentage of oxidized or reduced mudstone content in the target stratum to determine the main surface sedimentary areas and deep-water sedimentary areas of the arid lake basin.

5. The method for determining the distribution range of sedimentary water bodies in terrestrial arid lacustrine basins as described in claim 4, characterized in that, In step (2), the percentage of mudstone content in the surface sedimentary area is mainly oxidized, while the percentage of mudstone content in the deep-water sedimentary area is mainly reduced.

6. The method for determining the distribution range of sedimentary water bodies in terrestrial arid lacustrine basins as described in claim 1, characterized in that, The specific steps (3) include: conducting a statistical analysis of the thickness of chemical sedimentary rocks in the surrounding drilling cores and cuttings, drawing a contour map of the thickness of chemical rocks, and clarifying the distribution area of ​​chemical rocks revealed by the drilling, wherein the chemical rocks represent the approximate distribution area of ​​water bodies.

7. The method for determining the distribution range of sedimentary water bodies in terrestrial arid lacustrine basins as described in claim 1, characterized in that, The specific steps (4) include: combining the percentage values ​​of mudstone color and the results of compiling chemical thickness contour lines, and combining the results of the restoration of paleogeography of a certain period of earthquake in the lake basin, identifying the distribution area of ​​water bodies encountered in the wellless area, and roughly determining the distribution range of paleowater bodies based on the above results.

8. The method for determining the distribution range of sedimentary water bodies in terrestrial arid lacustrine basins as described in claim 1, characterized in that, Step (5) specifically includes: taking mudstone samples and conducting trace element tests, and using the test results to calculate the Fe / Co ratio.

9. The method for determining the distribution range of sedimentary water bodies in terrestrial arid lacustrine basins as described in claim 1, characterized in that, The specific steps (6) include: drawing a scatter plot of the transport distance and the ratio of Fe to Co elements, combining the results of the water body distribution range from steps (2) to (4), identifying the Fe to Co data inflection point representing the boundary between the surface and underwater areas, and finding the accurate location of the water body distribution range.

10. The method for determining the distribution range of sedimentary water bodies in terrestrial arid lacustrine basins as described in claim 1, characterized in that, The steps (7) include: taking into account the proportion of mudstone color, chemical rock thickness and paleogeographic results to preliminarily determine the outline of the ancient water body in the basin, and using the inflection point characteristics of the Fe / Co element ratio scatter points to clarify the boundary between the water surface and the underwater area, and to determine the distribution range of the ancient water body in the study area.

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