Method and system for restoring prototype basin of depression basin and compiling structural paleogeographic map

Abstract

The invention discloses a prototype basin recovery and structural paleogeographic map compiling method of a depression basin, and belongs to the technical field of oil exploration, development and research. According to the method, on the basis of a current residual stratum thickness map of a to-be-recovered basin, an original stratum equal-thickness graph after stratum shortening amount expansion is obtained through stratum denudation amount recovery and shortening amount recovery, and the original stratum equal-thickness graph is combined with lithofacies data to supplement a peripheral geodetic structure background; and finally, through paleogeography reconstruction, a prototype basin paleogeography map of the determined geological historical period of the basin to be recovered is compiled. According to the method, the ancient landform in the deposition period can be effectively and reasonably recovered; the method has the advantages that paleo-latitude and paleo-geographic positions can be reflected, the macroscopic pattern of arc-land-mountain-ocean-sea-basin can be embodied, the research of a structure-deposition system and oil and gas accumulation can be effectively supported, and thinking and basis are provided for deep zone field selection and oil and gas exploration.

Description

Technical Field

[0001] The present invention relates to the technical field of petroleum exploration and development research, and in particular to a method and system for restoring a prototype basin of a depression basin and compiling a tectonic paleogeographic map. Background Art

[0002] Restoring basin prototypes is of great significance in petroleum geology. Understanding basin prototypes is essential for reconstructing paleostress fields, paleo-geothermal gradients, and inferred organic matter maturity. Restoring prototype basins can clarify the correspondence between present-day residual basins and prototype basins from a given geological period, the impact of later tectonic deformation on the tectonic sedimentary system of prototype basins from that period, and the control over hydrocarbon accumulation. Due to the longevity and complexity of geological history, early prototype basins have undergone multiple phases of tectonic transformation and superposition. Therefore, the primary task of restoring basin prototypes is to reconstruct the original basin morphology and paleogeography of each stage of tectonic evolution.

[0003] Tectonic paleogeography studies the spatial pattern, tectonic environment, and evolution of tectonic units during a specific geological period. By studying tectonic processes during this period, we can understand the fundamental laws of paleogeographic evolution. Tectonic paleogeographic reconstructions can reveal the past morphology of basins. Tectonic paleogeographic studies of prototype basins from various geological periods help reveal the conditions for oil and gas formation and distribution patterns during these periods, guiding oil and gas exploration.

[0004] Currently, the methods for prototypical basin restoration are:

[0005] 1. Paleogeomorphological restoration method based on source-sink system. Based on the residual landforms of a certain geological period, source-sink units of that period are divided. Combined with tectonic evolution analysis, differential subsidence patterns are clarified and corrected. The paleogeomorphological framework is restored based on the restoration of stratigraphic erosion. On this basis, source-sink units are divided, and the corresponding relationship between different watersheds and overlapping areas is established, ultimately completing the restoration of the prototype basin.

[0006] This method mainly focuses on the amount of erosion of basin strata and the restoration of paleo-geomorphology, without considering the amount of strata shrinkage in the basin during different tectonic activity periods, and cannot effectively and reasonably restore the paleo-geomorphology during the sedimentary period.

[0007] Second, paleo-tectonic restoration methods based on "balanced geological profiles." Using this balanced restoration method, while adhering to the principle that the length or area of ​​rock layers remains unchanged before and after deformation, the current profile is restored to its original form at a certain geological period. Through balanced restoration of multiple geological profiles, the prototype structure of the basin at that geological period is ultimately restored.

[0008] This method mainly restores the shape and range of the prototype basin before deformation through the equilibrium restoration method. It does not place the prototype basin in the plate tectonic pattern map of ancient latitude coordinates. It combines sedimentary phases, sedimentary filling history, tectonic evolution history, residual stratigraphic thickness and other data to restore the prototype basin, reconstruct the paleogeographic environment, and clarify the type of prototype basin in a certain geological history period. Summary of the Invention

[0009] The present invention aims to solve the problem that the prototype basin cannot be restored reasonably and effectively when the prototype basin is restored by using existing technologies without considering the amount of stratum shortening or combining the plate tectonic pattern of ancient latitude coordinates. A method and system for restoring the prototype basin of a depression basin and compiling a tectonic paleogeographic map is provided.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] A method for restoring a prototype basin of a depression basin and compiling a tectonic paleogeographic map comprises the following steps:

[0012] Determine the type and geological history period of the basin to be restored, and draw the isopach map of the residual strata of the geological history period determined for the basin to be restored;

[0013] Based on the residual stratigraphic isopach map, the erosion amount of the stratigraphic layer is restored, and the stratigraphic isopach lines of the eroded area are supplemented to obtain the original stratigraphic isopach map before the stratigraphic erosion in the geological history period determined by the basin to be restored;

[0014] Using the balanced restoration method, on the basis of the original stratigraphic isopach map before stratigraphic erosion, the scope and boundary of the basin to be restored before stratigraphic shortening are restored, and the original stratigraphic isopach map after the stratigraphic shortening amount of the geological history period determined by the basin to be restored is obtained;

[0015] The lithofacies map of the geological history period determined by the basin to be restored is superimposed with the original stratigraphic isopach map after the stratigraphic shortening is expanded, and the surrounding tectonic background is supplemented to obtain the prototype basin and surrounding background map of the geological history period determined by the basin to be restored;

[0016] Based on the prototype basin and surrounding background map, through paleogeographic reconstruction, a paleogeographic map of the prototype basin of the geological history period determined by the basin to be restored is compiled.

[0017] The clear drawing of the residual stratigraphic isopach map of the geological history period determined for the basin to be restored is specifically as follows:

[0018] Based on the current residual stratigraphic thickness map of the basin to be restored, a clear map is drawn to compile the boundaries, scope and stratigraphic thickness distribution of the residual basin in the geological history period determined by the basin to be restored.

[0019] The method of restoring the erosion amount of the stratum based on the residual stratum isopach map and supplementing the stratum isopach lines in the eroded area to obtain the original stratum isopach map before stratum erosion in the geological history period determined by the basin to be restored is as follows:

[0020] Determine the initial denudation point of the strata in the geological history period determined by the basin to be restored, project the initial denudation point onto the residual strata isopach map, and compile the boundary range of the strata in the geological history period determined by the basin to be restored before denudation;

[0021] Determine the amount of erosion of the strata in the geological history period determined by the basin to be restored, add the erosion amount to the residual strata isopach map, and compile the original strata isopach map of the strata in the geological history period determined by the basin to be restored before erosion.

[0022] The thickness trend method is used to determine the amount of erosion of the strata during the geological history period of the basin to be restored, specifically:

[0023] Based on the seismic reflection characteristics of the sedimentary strata, the initial erosion point is found in the eroded layer section on the regional seismic profile, and the visible layer section that can be continuously tracked and has stable thickness in the entire basin to be restored is determined. The sedimentary thinning rate of the visible layer section is calculated, and the original sedimentary thickness of the stratum is calculated based on the geometric relationship, thereby obtaining the erosion amount of the corresponding stratum.

[0024] The compilation of the pre-erosion boundary range of the basin to be restored during the geological history period, based on the contact relationship between the marginal facies of the basin to be restored and the paleo-uplift, includes the following methods:

[0025] When the marginal facies of the basin to be restored overlaps the paleo-uplift, the location where the marginal facies develops is the boundary of the basin to be restored;

[0026] When the marginal facies of the basin to be restored is truncated at the paleo-uplift, the boundary of the basin to be restored is determined after supplementing the stratum denudation zone;

[0027] When there is no marginal phase in the basin to be restored, the boundary of the basin to be restored is determined after supplementing the stratum erosion zone using the trend analysis of the stratum residual thickness.

[0028] The balanced restoration method is used to restore the scope and boundary of the basin to be restored before the formation shortening based on the original formation isopach map before the formation erosion, and obtain the original formation isopach map after the formation shortening amount of the geological history period determined by the basin to be restored is expanded, specifically:

[0029] The geological structure profiles of different parts of the basin to be restored in the determined geological history period are balanced and restored to determine the amount of stratum shortening in different parts. Through the analysis of the stratum shortening, the positions of the stratum isopach lines at different parts are determined to extend outwards, and the shortening amount is superimposed on the original stratum isopach line map before erosion, and the range and boundary before shortening are restored to obtain the original stratum isopach line map after the stratum shortening amount is expanded in the determined geological history period of the basin to be restored.

[0030] The above method is to superimpose the lithofacies map of the geological history period determined by the basin to be restored and the original stratigraphic isopach map after the stratum shortening is expanded, and supplement the surrounding tectonic background to obtain the prototype basin and surrounding background map of the geological history period determined by the basin to be restored, specifically:

[0031] The lithofacies research results from drilling, outcrop, and regional geological data of the basin to be restored are superimposed on the original stratigraphic isopach map after the expansion of the stratum shortening. The boundary of the basin to be restored is adjusted according to the constraints of outcrop and drilling lithofacies. The range of the basin to be restored is expected when restoring the determined geological history. Then, based on the surrounding tectonic background, a comprehensive peripheral tectonic environment is added to obtain the prototype basin and peripheral background map of the geological history period determined by the basin to be restored.

[0032] The paleogeographic reconstruction is used to compile a paleogeographic map of the prototype basin of the geological history period determined by the basin to be restored, specifically:

[0033] Based on the global plate tectonic pattern map of the geological history period, the longitude and latitude range centered on the basin to be restored is selected as the scope of the tectonic paleogeographic map compilation;

[0034] Connect the lithofacies paleogeography of the geological history period determined in the basin to be restored with the lithofacies paleogeography of the surrounding background;

[0035] Based on the lithofacies paleogeographic data of other plates around the basin to be restored during the determined geological history period, the scope and lithofacies paleogeographic environment of each peripheral plate are supplemented and improved;

[0036] Prepare a prototype basin paleogeographic map of the basin to be restored in the determined geological history period.

[0037] The range of longitude and latitude centered on the basin to be restored is selected as the range for compiling the tectonic paleogeographic map, specifically:

[0038] Determine the latitude and longitude of the paleo-tectonic plate position of the basin to be restored during the determined geological history period based on the high-confidence selected paleomagnetic data of the basin to be restored;

[0039] According to the paleolatitude and long axis orientation of the basin to be restored, the prototype basin and the surrounding background map are rotated and embedded into the tectonic paleogeographic map of the paleolatitude coordinates.

[0040] A system for prototypical basin restoration and tectonic paleogeographic map compilation of depression basins, including the following modules:

[0041] The module for drawing the residual stratum isopach map is used to determine the type and geological history period of the basin to be restored, and to draw the residual stratum isopach map of the geological history period determined for the basin to be restored;

[0042] A module for drawing the original stratigraphic isopach map before stratigraphic erosion is used to restore the stratigraphic erosion amount based on the residual stratigraphic isopach map, supplement the stratigraphic isopach lines in the eroded area, and obtain the original stratigraphic isopach map before stratigraphic erosion in the geological history period determined by the basin to be restored;

[0043] A module for drawing the original stratigraphic isopach map after the amount of stratigraphic shortening is expanded is used to restore the scope and boundary of the basin to be restored before the stratigraphic shortening based on the original stratigraphic isopach map before the stratigraphic erosion using the balanced restoration method, and obtain the original stratigraphic isopach map after the amount of stratigraphic shortening is expanded in the geological history period determined by the basin to be restored;

[0044] A module for drawing a prototype basin and surrounding background map is used to superimpose the lithofacies map of the geological history period determined by the basin to be restored with the original stratigraphic isopach map after the stratum shortening is expanded, and to supplement the surrounding tectonic background to obtain a prototype basin and surrounding background map of the geological history period determined by the basin to be restored;

[0045] The module for drawing paleogeographic maps of prototype basins is used to compile paleogeographic maps of prototype basins in the geological history period determined by the basin to be restored through paleogeographic reconstruction based on the prototype basin and surrounding background maps.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The present invention is based on the isopach map of the residual stratigraphic period determined by the basin to be restored. By restoring the amount of stratigraphic erosion and the amount of stratigraphic shortening, it can effectively and reasonably restore the paleo-geomorphology of the sedimentary period. It is also based on the background of the paleo-plate tectonic pattern, can reflect the paleolatitude and paleo-geographic location, and taking into account the paleo-geographic structure and paleo-geographic restoration of the surrounding areas, it reflects the macro-pattern of arc-continent-mountain-ocean-sea-basin, can effectively support the study of structural-sedimentary systems and oil and gas accumulation, and provides ideas and basis for deep zone field selection and oil and gas exploration. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments:

[0049] Figure 1A flow chart of the method for restoring the prototype basin and compiling a tectonic paleogeographic map of a depression basin according to the present invention;

[0050] Figure 2 This is a residual isopach map of the basin during the Sinian Period according to a preferred embodiment of the present invention;

[0051] Figure 3 The original isopach map of the basin before erosion during the Sinian Period in a preferred embodiment of the present invention;

[0052] Figure 4 This is a distribution diagram of shortening amounts at different locations in the basin during the Sinian Period according to a preferred embodiment of the present invention;

[0053] Figure 5 This is the original stratigraphic isopach map after the stratigraphic shortening amount of the basin during the Sinian Period was expanded according to a preferred embodiment of the present invention;

[0054] Figure 6 This is a background map of the prototype basin and its surroundings during the Sinian Period of the preferred embodiment of the present invention;

[0055] Figure 7 A paleogeographic map of the prototype basin during the Sinian Period of the preferred embodiment of the present invention;

[0056] Figure 8 A schematic diagram showing the principle of the thickness trend method for determining the amount of erosion of a stratum according to the present invention;

[0057] Figure 9 A schematic diagram of the structure of the prototype basin restoration and tectonic paleogeographic map compilation system of the depression basin of the present invention;

[0058] Figure 10 This is a schematic diagram of the structure of an electronic device according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0059] The present invention will be further described below with reference to the accompanying drawings:

[0060] In order to have a clearer understanding of the technical process and effects of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0061] like Figure 1 FIG. 1 is a flow chart of a method for restoring a prototype basin of a depression basin and compiling a tectonic paleogeographic map according to an embodiment of the present invention. The method includes the following steps:

[0062] Step 1: Determine the type of basin to be restored and the geological history period in which the prototype basin restoration is required.

[0063] The type of basin A to be restored is a depression basin. The geological history periods experienced by basin A include the Nanhua Period, Sinian Period, Cambrian Period, Ordovician Period, Silurian Period, Devonian Period, Carboniferous Period, Permian Period, Triassic Period, Jurassic Period, Cretaceous Period, Paleogene Period, Neogene Period and Quaternary Period. In this embodiment, the geological history period selected for restoration is the Sinian Period.

[0064] It is understandable that the selected basin to be restored and the geological history period for the restoration of the prototype basin depend on the specific needs of scientific research, oil and gas exploration practice, etc.

[0065] Step 2: Clear the thickness contour map of the residual strata of the geological history period determined for the basin to be restored. Clear the thickness map of the residual strata of the present basin of the geological history period determined for the basin to be restored as the basic map for the restoration of the prototype basin.

[0066] like Figure 2 As shown in the figure, based on the selected basin A, the residual stratigraphic thickness map of the present basin in the Sinian period was cleared and drawn using the Shuanghu software, and the residual stratigraphic isopach map of the boundary, range and stratigraphic thickness distribution of the residual basin in the Sinian period of basin A was compiled as the basic map for the restoration of the prototype basin.

[0067] Step 3: Based on the residual stratigraphic isopach map, restore the erosion amount of the stratigraphic isopach, supplement the stratigraphic isopach lines in the eroded area, and obtain the original stratigraphic isopach map before the stratigraphic erosion in the geological history period determined by the basin to be restored.

[0068] The zero-thickness line within the basin represents the stratigraphic pinch-out line of the prototype basin within the continental interior, while the zero-thickness line at the basin margin represents the outer edge of the prototype basin extending outward. Based on the properties of the prototype basin determined in the first step, the stratigraphic isopach lines of the erosion zone are restored.

[0069] like Figure 3 Specifically, based on the residual stratigraphic isopach map of the boundary, range and stratigraphic thickness distribution of the residual basin in Basin A during the Sinian Period obtained in the second step, the erosion amount of the Upper Sinian strata in various areas of Basin A was restored.

[0070] (1) Determine the initial denudation points of the Sinian strata in each area of ​​Basin A. Project the determined initial denudation points of the Sinian strata onto the Sinian residual strata isopach map of Basin A obtained in the second step, and compile the boundary range of the Sinian strata in Basin A before denudation.

[0071] (2) Determine the amount of erosion of the Sinian Period strata in each area of ​​Basin A, add the erosion amount to the residual stratigraphic isopach map of Basin A during the Sinian Period obtained in the second step, and compile the original stratigraphic isopach map of Basin A before the erosion of the Sinian Period strata.

[0072] After the above steps, the original stratigraphic isopach map of the Sinian strata in Basin A before erosion was obtained.

[0073] Among them, the present invention mainly adopts the thickness trend method to determine the amount of erosion of the stratum. Under the condition that the thickness of the stratum before erosion is uniform or changes uniformly, according to the seismic reflection characteristics of the sedimentary stratum, the initial erosion point is found in the eroded layer section on the regional seismic profile, and the "apparent layer section" with stable thickness that is easier to track in the entire basin to be restored is determined. The sedimentary thinning rate of the "apparent layer section" is calculated, and the original sedimentary thickness of the stratum is calculated based on the geometric relationship, and then the erosion amount of the corresponding stratum can be obtained.

[0074] like Figure 8 As shown in the figure, the stratum erosion amount is restored. First, the stratum erosion origin A′ is found, and the stratum thinning rate is determined according to formula ①.

[0075]

[0076] Where K is the formation thinning rate, H0 is the thickness of the apparent interval, H0′ is the thickness of the apparent interval at the origin of formation erosion, L is the horizontal distance between the selected point of the apparent interval and the origin of formation erosion, and θ is the formation dip. When the lower part of the formation is onlapped, the original thickness should not include the onlapped portion.

[0077] The original thickness of the eroded section is calculated using formula ②.

[0078] ②H 0i =H0-k×L i cosθ

[0079] Among them, H 0i is the original stratum thickness in the denuded area,

[0080] The theoretical stratum erosion thickness is calculated using formula ③

[0081] ③h T-ei =H 0i -h ri

[0082] Among them, h T-ei is the stratum denudation thickness corresponding to each point, H 0i is the original stratum thickness of the eroded area, h ri is the residual stratum thickness at each point,

[0083] It should be noted that when the overlying strata are thick and compaction is strong, the amount of stratum erosion calculated using current data is usually very different from the actual stratum erosion amount. Formula ④ is needed to perform stratum compaction correction to obtain the true stratum thickness of the eroded stratum.

[0084] ④H A-ei =h T-ei ×C p

[0085] Among them, H A-ei is the true thickness of the eroded stratum, h T-ei is the stratum denudation thickness corresponding to each point, C p is the formation compaction correction factor.

[0086] Among them, the "visual layer segment" has the characteristics of having an uneroded upper boundary, clear upper and lower interfaces, and can be continuously tracked within a certain range on the seismic profile.

[0087] The restoration of erosion varies for different basin types. This paper mainly restores erosion in depression-type basins. Depression basins are basically symmetrical in cross-section, but it is important to note that the isopach lines of marginal phases such as alluvial fans and fan deltas are only half, and the isopach lines of marginal phases are half-isovalue lines and do not need to be completed. From the inside to the outside of a depression basin, it is the basin phase, the delta basin margin phase, and then the plain phase. If there is a basin-controlling fault that cuts off the isopach line, it does not need to be completed.

[0088] Among them, there are different contact relationships between the marginal facies of the basin to be restored and the paleo-uplift. Therefore, the boundary of the basin to be restored is determined in different ways. There are three ways:

[0089] (1) When the marginal facies of the basin to be restored overlaps the paleo-uplift, the location where the marginal facies develops is the boundary of the basin to be restored;

[0090] (2) When the marginal facies of the basin to be restored is truncated at the paleo-uplift, it is necessary to expand and supplement the denuded zone to determine the boundary of the basin to be restored;

[0091] (3) When there is no marginal phase in the basin to be restored, even if there is stratigraphic overlap or truncation near the paleo-uplift, the boundary of the prototype basin cannot be directly determined. It is necessary to use the residual stratigraphic thickness trend analysis to supplement the stratigraphic thickness of the eroded area and determine the boundary of the basin to be restored.

[0092] Step 4: Using the balanced restoration method, on the basis of the original stratigraphic isopach map before stratigraphic erosion, determine the amount of stratigraphic shortening in different parts of the basin to be restored during the determined geological history period. Through the analysis of the stratigraphic shortening, determine the position of the stratigraphic isopach lines in different parts that extend outward, restore the range and boundary before shortening, and obtain the original stratigraphic isopach map after the expansion of the stratigraphic shortening in the determined geological history period of the basin to be restored.

[0093] like Figure 4 and Figure 5 As shown in the figure, specifically, 3Dmove software was used to balance the geological structure profiles of different parts of Basin A during the Sinian Period, and the amount of stratum shortening in different parts of Basin A during the Sinian Period was determined. Through the analysis of the stratum shortening, the positions of the stratum isopach lines of different parts of the basin to be restored were determined, and the shortening amount was superimposed on the original stratum isopach line map before erosion, and the range and boundary before shortening were restored, thus obtaining the original stratum isopach line map of Basin A after the stratum shortening amount was expanded during the Sinian Period.

[0094] The following principles should be followed when restoring balance: (1) conservation of length; (2) conservation of area; and (3) consistency of length of each marker layer in the profile.

[0095] (1) Length conservation: The thickness of the rock layer remains unchanged before and after deformation. A folded rock layer can be unfolded along its centerline to represent its original length. If it is displaced by a fault, it can simply be restored along the fault. The core of this principle is a length balance method.

[0096] (2) Area conservation: the area occupied by the stratum remains unchanged before and after deformation. Considering that most tectonic folds occur after deposition (such as push structures), the stratum has been subjected to diagenetic compaction before deformation, so the area loss caused by diagenetic compaction can be ignored when balancing the profile. Comparing the same rock in the undeformed and deformed areas, if the density (or porosity) remains basically unchanged, the tectonic compaction effect can also be ignored in the calculation. If the profile direction is consistent with the direction of movement, it can be assumed that the stratum deformation along the profile is plane strain. At this time, the volume invariance in three-dimensional space can be converted into the area invariance principle of the (two-dimensional) profile, that is, the area of ​​the profile above the slip layer remains unchanged before and after deformation.

[0097] (3) The lengths of the marker layers in the profile are consistent. If there are no discontinuities between the layers, their original lengths after restoration should be consistent within the same profile. Otherwise, there must be a discontinuity between the long and short layers (e.g., a fault-bend fold).

[0098] The specific method is to first select a pair of reference lines at both ends of the section. The reference lines should be selected where there is no interlayer sliding, such as the axial plane of the main fold, or on the plane perpendicular to the total inclination of the rock layer in the undeformed area. Then measure the length of each layer between the two reference lines. They should be equal, and the section is considered balanced. Otherwise, there must be sufficient reason to explain.

[0099] Step 5: Superimpose the lithofacies map of the geological history period determined by the basin to be restored with the original stratigraphic isopach map after the stratum shortening is expanded, and supplement the surrounding tectonic background to obtain the prototype basin and surrounding background map of the geological history period determined by the basin to be restored.

[0100] like Figure 5 As shown in Figure 1, the lithofacies map of Basin A during the Sinian Period was superimposed with the original stratigraphic isopach map after the stratum shortening was expanded, and the surrounding tectonic background was supplemented to compile the prototype basin and surrounding background map of Basin A during the Sinian Period, as shown in Figure 1. Figure 6 shown.

[0101] Specifically, the lithofacies research results from drilling, outcrop, and regional geological data of Basin A are superimposed on the original stratigraphic isopach map after the stratigraphic shortening amount is expanded in the fourth step. Based on the constraints of the outcrops and drilling lithofacies of Basin A, the boundaries of the basin to be restored are fine-tuned to restore the scope of Basin A during the Sinian Period. Then, based on the surrounding tectonic background, a more comprehensive peripheral tectonic environment is added to restore the prototype basin and peripheral background of Basin A during the Sinian Period.

[0102] Here we need to investigate the tectonic background and surrounding tectonic environment of Basin A:

[0103] (1) During the Sinian Period, the Rodinia supercontinent finally broke apart, and the A Basin completely separated from the Gondwana supercontinent. The continental rifting effect on the A Basin weakened. By the late Sinian Period, the rift valley of the A Basin was in a depression stage, and the sedimentation centers became Kuruktag in the northeast of the A Basin and Aksu in the northwest of the Tarim Basin.

[0104] (2) The subduction of the southern margin of Basin A during the Sinian Period had a stronger impact on the southern part of Basin A than on the northern part, resulting in differential uplift of a large area in the southern part of Basin A. Also, due to the influence of glacial melting, marine transgression caused the northern part of Basin A to become an underwater low-rise, leaving only the paleo-uplift area in the southern part of Basin A.

[0105] (3) The extent of the A Basin ice sea during the Sinian was concentrated in the eastern part of the A Basin. This is because the polarity of the A Basin was different during the Sinian. The polarity of the A Basin differed by 100° during the Late Precambrian. Therefore, the eastern part of the A Basin today was facing north at that time.

[0106] (4) At the end of the Sinian Period, the glaciers melted and the ice sheet retreated, leaving sea ice only in the northern part of Basin A, far from the equator at that time (which is now the eastern part of Basin A).

[0107] (5) Around the Sinian A Basin, the Kudun Ocean in the southwest continued to open, and the southeast was completely separated from the Gondwana supercontinent, forming the initial limited Altun Ocean, which was connected to the Kudun Ocean.

[0108] (6) At the northern margin of Basin A, the Southern Tianshan Ocean continued to open, and the entire basin was in a back-arc expansion environment, resulting in the emergence of a continental limited ocean basin.

[0109] Based on the above-mentioned tectonic background of the periphery of Basin A and adding a more comprehensive peripheral tectonic environment, we can compile the prototype basin and peripheral background map of Basin A during the Sinian Period.

[0110] Step 6: Through paleogeographic reconstruction, compile a paleogeographic map of the prototype basin of the geological history period determined by the basin to be restored.

[0111] like Figure 6 and Figure 7 As shown in the figure, through paleogeographic reconstruction, the prototype basin paleogeographic map of Basin A in the Sinian Period was compiled.

[0112] Based on the global plate tectonic pattern map of the Sinian Period, the range centered on Basin A, spanning 30° latitude and 40° longitude, was selected as the scope for compiling the tectonic paleogeographic map.

[0113] Among them, based on the paleomagnetic data of Basin A that have been selected with high confidence, it is determined that the position of the ancient tectonic plate of Basin A during the Sinian Period was 30° latitude and 40° longitude.

[0114] According to the paleolatitude and long axis orientation of Basin A, the prototype basin and surrounding background map of Basin A during the Sinian Period compiled in the fifth step was rotated and embedded into the tectonic paleogeographic map of paleolatitude coordinates (centered on Basin A, spanning 30° latitude and 40° longitude).

[0115] During the embedding process, the scale of the fusion map needs to be adjusted according to the scale difference between the Sinian prototype basin map of Basin A and the global plate pattern map.

[0116] When the prototype basin and surrounding background map of Basin A during the Sinian Period are embedded in the tectonic paleogeography map of paleolatitude coordinates (centered on Basin A, spanning 30° latitude and 40° longitude), it is necessary to first connect the lithofacies paleogeography of Basin A during the Sinian Period with the lithofacies paleogeography of the surrounding background. Then, based on the lithofacies paleogeography data of other plates surrounding Basin A during the Sinian Period, the scope and lithofacies paleogeographic environment of the plates surrounding Basin A during the Sinian Period are supplemented and improved, and finally the prototype basin paleogeography map of Basin A during the Sinian Period is compiled.

[0117] like Figure 9As shown, the present invention also proposes a prototype basin restoration and tectonic paleogeographic map compilation system for a depression basin, comprising:

[0118] The module for drawing the residual stratum isopach map is used to determine the type and geological history period of the basin to be restored, and to draw the residual stratum isopach map of the geological history period determined for the basin to be restored;

[0119] A module for drawing the original stratigraphic isopach map before stratigraphic erosion is used to restore the stratigraphic erosion amount based on the residual stratigraphic isopach map, supplement the stratigraphic isopach lines in the eroded area, and obtain the original stratigraphic isopach map before stratigraphic erosion in the geological history period determined by the basin to be restored;

[0120] A module for drawing the original stratigraphic isopach map after the amount of stratigraphic shortening is expanded is used to restore the scope and boundary of the basin to be restored before the stratigraphic shortening based on the original stratigraphic isopach map before the stratigraphic erosion using the balanced restoration method, and obtain the original stratigraphic isopach map after the amount of stratigraphic shortening is expanded in the geological history period determined by the basin to be restored;

[0121] A module for drawing a prototype basin and surrounding background map is used to superimpose the lithofacies map of the geological history period determined by the basin to be restored with the original stratigraphic isopach map after the stratum shortening is expanded, and to supplement the surrounding tectonic background to obtain a prototype basin and surrounding background map of the geological history period determined by the basin to be restored;

[0122] The module for drawing paleogeographic maps of prototype basins is used to compile paleogeographic maps of prototype basins in the geological history period determined by the basin to be restored through paleogeographic reconstruction based on the prototype basin and surrounding background maps.

[0123] like Figure 10 As shown, the present invention also provides an electronic device 100 for restoring a prototype basin of a depression basin and compiling a structural paleogeographic map; the electronic device 100 includes a memory 101, at least one processor 102, a computer program 103 stored in the memory 101 and executable on the at least one processor 102, and at least one communication bus 104.

[0124] The memory 101 can be used to store the computer program 103. The processor 102 implements the steps of the method for restoring the prototype basin of a depression basin and compiling a tectonic paleogeographic map described in Example 1 by running or executing the computer program stored in the memory 101 and calling the data stored in the memory 101. The memory 101 can mainly include a program storage area and a data storage area. The program storage area can store an operating system and at least one application required for a function (such as a sound playback function, an image playback function, etc.); the data storage area can store data (such as audio data) generated by the use of the electronic device 100. In addition, the memory 101 can include non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device.

[0125] The at least one processor 102 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The processor 102 may be a microprocessor or any conventional processor, etc. The processor 102 is the control center of the electronic device 100 and connects various parts of the entire electronic device 100 using various interfaces and lines.

[0126] The memory 101 in the electronic device 100 stores a plurality of instructions for implementing a method for restoring a prototype basin of a depression basin and compiling a tectonic paleogeographic map. The processor 102 can execute the plurality of instructions to implement:

[0127] Determine the type and geological history period of the basin to be restored, and draw the isopach map of the residual strata of the geological history period determined for the basin to be restored;

[0128] Based on the residual stratigraphic isopach map, the erosion amount of the stratigraphic layer is restored, and the stratigraphic isopach lines of the eroded area are supplemented to obtain the original stratigraphic isopach map before the stratigraphic erosion in the geological history period determined by the basin to be restored;

[0129] Using the balanced restoration method, on the basis of the original stratigraphic isopach map before stratigraphic erosion, the scope and boundary of the basin to be restored before stratigraphic shortening are restored, and the original stratigraphic isopach map after the stratigraphic shortening amount of the geological history period determined by the basin to be restored is obtained;

[0130] The lithofacies map of the geological history period determined by the basin to be restored is superimposed with the original stratigraphic isopach map after the stratigraphic shortening is expanded, and the surrounding tectonic background is supplemented to obtain the prototype basin and surrounding background map of the geological history period determined by the basin to be restored;

[0131] Based on the prototype basin and surrounding background map, through paleogeographic reconstruction, a paleogeographic map of the prototype basin of the geological history period determined by the basin to be restored is compiled.

[0132] If the module / unit integrated in the electronic device 100 is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory and read-only memory (ROM, Read-Only Memory).

[0133] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0134] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0135] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0136] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0137] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the same. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art may still modify or make equivalent substitutions to the specific implementations of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the scope of protection of the claims of the present invention to be approved.

Claims

1. A method for restoring a prototype basin of a depression basin and compiling a tectonic paleogeographic map, characterized in that: The following steps are involved: Determine the type and geological history period of the basin to be restored, and draw the isopach map of the residual strata of the geological history period determined for the basin to be restored; Based on the residual stratigraphic isopach map, the erosion amount of the stratigraphic layer is restored, and the stratigraphic isopach lines of the eroded area are supplemented to obtain the original stratigraphic isopach map before the stratigraphic erosion in the geological history period determined by the basin to be restored; Using the balanced restoration method, on the basis of the original stratigraphic isopach map before stratigraphic erosion, the scope and boundary of the basin to be restored before stratigraphic shortening are restored, and the original stratigraphic isopach map after the stratigraphic shortening amount of the geological history period determined by the basin to be restored is obtained; The lithofacies map of the geological history period determined by the basin to be restored is superimposed with the original stratigraphic isopach map after the stratigraphic shortening is expanded, and the surrounding tectonic background is supplemented to obtain the prototype basin and surrounding background map of the geological history period determined by the basin to be restored; Based on the prototype basin and surrounding background map, through paleogeographic reconstruction, a paleogeographic map of the prototype basin of the geological history period determined by the basin to be restored is compiled.

2. The method for restoring the prototype basin and compiling a tectonic paleogeographic map of a depression basin according to claim 1, characterized in that: The clear drawing of the residual stratigraphic isopach map of the geological history period determined for the basin to be restored is specifically as follows: Based on the current residual stratigraphic thickness map of the basin to be restored, a clear map is drawn to compile the boundaries, scope and stratigraphic thickness distribution of the residual basin in the geological history period determined by the basin to be restored.

3. The method for restoring the prototype basin and compiling a tectonic paleogeographic map of a depression basin according to claim 1, characterized in that: The method of restoring the erosion amount of the stratum based on the residual stratum isopach map and supplementing the stratum isopach lines in the eroded area to obtain the original stratum isopach map before stratum erosion in the geological history period determined by the basin to be restored is as follows: Determine the initial denudation point of the strata in the geological history period determined by the basin to be restored, project the initial denudation point onto the residual strata isopach map, and compile the boundary range of the strata in the geological history period determined by the basin to be restored before denudation; Determine the amount of erosion of the strata in the geological history period determined by the basin to be restored, add the erosion amount to the residual strata isopach map, and compile the original strata isopach map of the strata in the geological history period determined by the basin to be restored before erosion.

4. The method for restoring the prototype basin and compiling a tectonic paleogeographic map of a depression basin according to claim 3, characterized in that: The thickness trend method is used to determine the amount of erosion of the strata during the geological history period of the basin to be restored, specifically: Based on the seismic reflection characteristics of the sedimentary strata, the initial erosion point is found in the eroded layer on the regional seismic profile, and the visible layer segment that can be continuously tracked and has stable thickness in the entire basin to be restored is determined. The sedimentary thinning rate of the visible layer segment is calculated, and the original sedimentary thickness of the stratum is calculated based on the geometric relationship, thereby obtaining the erosion amount of the corresponding stratum.

5. The method for restoring the prototype basin and compiling a tectonic paleogeographic map of a depression basin according to claim 3, characterized in that: The compilation of the pre-erosion boundary range of the basin to be restored during the geological history period, based on the contact relationship between the marginal facies of the basin to be restored and the paleo-uplift, includes the following methods: When the marginal facies of the basin to be restored overlaps the paleo-uplift, the location where the marginal facies develops is the boundary of the basin to be restored; When the marginal facies of the basin to be restored is truncated at the paleo-uplift, the boundary of the basin to be restored is determined after supplementing the stratum denudation zone; When there is no marginal phase in the basin to be restored, the boundary of the basin to be restored is determined after supplementing the stratum erosion zone using the residual stratum thickness trend analysis.

6. The method for restoring the prototype basin and compiling a tectonic paleogeographic map of a depression basin according to claim 1, characterized in that: The balanced restoration method is used to restore the scope and boundary of the basin to be restored before the formation shortening based on the original formation isopach map before the formation erosion, and obtain the original formation isopach map after the formation shortening amount of the geological history period determined by the basin to be restored is expanded, specifically: The geological structure profiles of different parts of the basin to be restored in the determined geological history period are balanced and restored to determine the amount of stratum shortening in different parts. Through the analysis of the stratum shortening, the positions of the stratum isopach lines at different parts are determined to extend outwards, and the shortening amount is superimposed on the original stratum isopach line map before erosion, and the range and boundary before shortening are restored to obtain the original stratum isopach line map after the stratum shortening amount is expanded in the determined geological history period of the basin to be restored.

7. The method for restoring the prototype basin and compiling a tectonic paleogeographic map of a depression basin according to claim 1, characterized in that: The above method is to superimpose the lithofacies map of the geological history period determined by the basin to be restored and the original stratigraphic isopach map after the stratum shortening is expanded, and supplement the surrounding tectonic background to obtain the prototype basin and surrounding background map of the geological history period determined by the basin to be restored, specifically: The lithofacies research results from drilling, outcrop, and regional geological data of the basin to be restored are superimposed on the original stratigraphic isopach map after the expansion of the stratum shortening. The boundary of the basin to be restored is adjusted according to the constraints of outcrop and drilling lithofacies. The range of the basin to be restored is expected when restoring the determined geological history. Then, based on the surrounding tectonic background, a comprehensive peripheral tectonic environment is added to obtain the prototype basin and peripheral background map of the geological history period determined by the basin to be restored.

8. The method for restoring the prototype basin and compiling a tectonic paleogeographic map of a depression basin according to claim 1, characterized in that: The paleogeographic reconstruction is to compile a paleogeographic map of the prototype basin of the geological history period determined by the basin to be restored, specifically: Based on the global plate tectonic pattern map of the geological history period, the longitude and latitude range centered on the basin to be restored is selected as the scope of the tectonic paleogeographic map compilation; Connect the lithofacies paleogeography of the geological history period determined in the basin to be restored with the lithofacies paleogeography of the surrounding background; Based on the lithofacies paleogeographic data of other plates around the basin to be restored during the determined geological history period, the scope and lithofacies paleogeographic environment of each peripheral plate are supplemented and improved; Prepare a prototype basin paleogeographic map of the basin to be restored in the determined geological history period.

9. The method for restoring the prototype basin and compiling a tectonic paleogeographic map of a depression basin according to claim 8, characterized in that: The range of longitude and latitude centered on the basin to be restored is selected as the range for compiling the tectonic paleogeographic map, specifically: Determine the latitude and longitude of the paleo-tectonic plate position of the basin to be restored during the determined geological history period based on the paleomagnetic data selected with high confidence for the basin to be restored; According to the paleolatitude and long axis orientation of the basin to be restored, the prototype basin and the surrounding background map are rotated and embedded into the tectonic paleogeographic map of the paleolatitude coordinates.

10. A system for restoring the prototype basin of a depression basin and compiling a tectonic paleogeographic map, characterized in that: Includes the following modules: The module for drawing the residual stratum isopach map is used to determine the type and geological history period of the basin to be restored, and to draw the residual stratum isopach map of the geological history period determined for the basin to be restored; A module for drawing the original stratigraphic isopach map before stratigraphic erosion is used to restore the stratigraphic erosion amount based on the residual stratigraphic isopach map, supplement the stratigraphic isopach lines in the eroded area, and obtain the original stratigraphic isopach map before stratigraphic erosion in the geological history period determined by the basin to be restored; A module for drawing the original stratigraphic isopach map after the amount of stratigraphic shortening is expanded is used to restore the scope and boundary of the basin to be restored before the stratigraphic shortening based on the original stratigraphic isopach map before the stratigraphic erosion using the balanced restoration method, and obtain the original stratigraphic isopach map after the amount of stratigraphic shortening is expanded in the geological history period determined by the basin to be restored; A module for drawing a prototype basin and surrounding background map is used to superimpose the lithofacies map of the geological history period determined by the basin to be restored with the original stratigraphic isopach map after the stratum shortening is expanded, and to supplement the surrounding tectonic background to obtain a prototype basin and surrounding background map of the geological history period determined by the basin to be restored; The module for drawing paleogeographic maps of prototype basins is used to compile paleogeographic maps of prototype basins in the geological history period determined by the basin to be restored through paleogeographic reconstruction based on the prototype basin and surrounding background maps.

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