A method for lithological restoration of paleo-geomorphology

Abstract

The present invention provides a method for lithology restoration of paleo-geomorphology, including: differential settlement correction of residual geomorphology; fault restoration; structural-sedimentary unit division; denudation recovery; correction of differential settlement of residual paleo-geomorphology and restoration of denudation, and improvement of paleo-geomorphological framework restoration during the sedimentary period; characterization of bulge parent rock types and residual parent rock distribution; analysis and statistics of drilling cuttings components, statistics of core and cuttings components revealed by drilling in the sedimentary area, and drawing of characteristic distribution map of cuttings components; qualitative restoration of parent rock types and distribution in the source area during the sedimentary period, and on the basis of source-sink unit division, the sink area cuttings are inverted back to the corresponding source area, the parent rock lithology of the source area is corrected, and the distribution range of different parent rocks is corrected according to the relative relationship of cuttings content, and the parent rock lithology and distribution recovery map is obtained. The present invention provides guidance for the study of material distribution in the denudation and sedimentary areas, geomorphic evolution, reservoir characteristics, and favorable reservoir distribution by establishing paleo-geomorphology and prototype basins during the sedimentary period.

Description

Technical Field

[0001] The present invention relates to the technical field of lithology restoration of ancient landforms in geophysics, and in particular to a method for lithology restoration of ancient landforms. Background Art

[0002] The provenance in the extra-basin area has the characteristics of single provenance direction, long geological history, simple provenance evolution and transformation. Compared with the provenance outside the basin, the low uplift covered in the basin later may be the provenance area in the early deposition period. The provenance supply and distribution of dynamic provenance change with time. The size of the provenance area changes at different sequence positions and different stages of lake level changes. At the same time, the lithology of the denuded parent rock in different paleogeomorphic positions will also be different. The paleogeomorphic morphology determines the size of the provenance area and the total amount of sedimentation in the sedimentary area. The lithology of the denuded parent rock determines the original material composition of the reservoir and affects the quality of the reservoir.

[0003] The main methods of paleo-geomorphology restoration include backstripping, original slope angle restoration, fault analysis, etc. Backstripping is one of the most commonly used methods of paleo-geomorphology restoration, and it is also one of the most credible and operable paleo-geomorphology restoration methods.

[0004] Backstripping method: Based on the fact that there is no obvious change in the thickness of the strata in the later period and there is no obvious erosion of the strata, the sedimentary restoration of the original landform is carried out, focusing on the full analysis of the stratum parameters and characteristics.

[0005] Original slope angle restoration method: Based on high-precision sequence stratigraphic theory, it emphasizes the isochronism of sedimentary bodies and the changes in slope angles under the differences in sedimentary patterns of different sedimentary bodies and sedimentary landforms during lowstand, transgression and highstand periods. Under this slope angle change, the original paleo-landform can be restored from new to old. The original slope angle restoration method can restore the original landform pattern of the strata before erosion and transformation.

[0006] Fault analysis method: For the study area with strong tectonic movement, the fault activity and landform pattern of different periods are analyzed differently, and the temporal and spatial evolution differences of faults and paleo-geomorphology in different periods are clarified. It is a full analysis of the fault activity parameters associated with low uplift in the basin. Fault analysis method is one of the most effective methods for studying the paleo-geomorphological restoration related to the development of deltas related to faults in areas with strong fault activity in the basin.

[0007] The main methods for restoring parent rocks are zircon dating and gravel composition tracing. Zircon dating can obtain multiple sets of U-Pb ages through zircon U-Pb dating. By conducting a comprehensive study of the internal structure, trace element characteristics and inclusion composition of different zircon regions, the genetic mechanism of different zircon crystal domains can be given, and a more reasonable geological explanation can be given to these ages.

[0008] The gravel composition tracing method reveals the statistics of gravel composition and content in cores or cuttings from drilling in the sedimentary area, and qualitatively determines the combination pattern of sedimentary parent rocks. The gravel composition content can reflect the lithological characteristics of the parent rock in the source area from a macroscopic perspective.

[0009] Previous research methods mainly focused on the restoration of sedimentary strata erosion and paleo-geomorphology, without considering the impact of the erosion zone. They had certain limitations and did not consider the impact of lithological dimensions on reservoirs. They were unable to effectively restore the ancient sources of the sedimentary period, which greatly affected the judgment of high-quality reservoirs. Summary of the invention

[0010] The present invention provides a lithology restoration method for ancient landforms to solve the technical problem that the prior art lacks consideration of the denudation of parent rocks, landforms and lithology scales during the sedimentation period, resulting in insufficient restoration of ancient sources.

[0011] In order to solve the above problems, the present invention provides a method for restoring the lithology of paleo-geomorphology, the lithology restoration method comprising:

[0012] S1: differential settlement correction for residual landforms;

[0013] By analyzing the differences in fault activity and the evolution of sedimentary strata thickness in different periods, the differential settlement law and sedimentary base level are clarified, and the differential settlement is corrected;

[0014] S2: fracture recovery;

[0015] Identify and analyze the faults in the study area, restore the fault translation for the later active faults that have a great impact and transformation on the geomorphic framework, and restore the watershed positions of each period;

[0016] S3: tectonic-sedimentary unit division;

[0017] Based on the residual geomorphic characterization after the restoration of faults and watershed positions at each stage, structural-sedimentary units of different key depositional periods are divided;

[0018] S4: restoration of erosion volume;

[0019] By defining the scope of the denudation zone, super-denudation zone and erosion zone, clarifying the scope of denudation in different periods, and completing the restoration of the denudation volume in the denudation zone and super-denudation zone through the principle of total material conservation under the control of the source-sink system and the formation dip recovery method;

[0020] S5: Correct the residual paleo-geomorphological differential settlement and restore the amount of erosion, and improve the paleo-geomorphological framework during the sedimentary period.

[0021] The eroded area is stripped back to the uplift area, and the landforms of the differential sedimentation area are superimposed to complete the restoration of the ancient landform framework during the sedimentary period;

[0022] S6: Characterization of uplift parent rock types and residual parent rock distribution;

[0023] Use rock fragments, gravel, heavy minerals and zircon to determine the lithology and age of the parent rock. Combine well and seismic data to calibrate the seismic phase characteristics of different parent rocks, qualitatively identify the distribution boundaries of different types of parent rocks on the plane, and characterize the distribution of residual parent rocks in the source area.

[0024] S7: Analysis and statistics of drilling cuttings components;

[0025] Conduct petrological analysis on drilling in sedimentary areas, and make detailed classification and statistics of the rock cuttings composition;

[0026] S8: Qualitatively restore the parent rock types and distribution in the source area during the sedimentation period;

[0027] Based on the statistics of rock fragment types and contents, the parent rock types and distribution range of the uplift origin area during the sedimentary period were qualitatively restored, and the main components of sediment gravel were semi-quantitatively predicted.

[0028] Preferably, in step S1, the specific method of the differential settlement correction includes: selecting a planation surface as a deposition reference surface, performing layer flattening processing on the deposition reference surface, and correcting the differential settlement amount in the later stage of deposition.

[0029] Preferably, in step S2, the specific method of fracture recovery includes:

[0030] Step S 21 : Analyze the fault activity period according to the formation attribution of the upper and lower walls of the fault, and perform fault translation restoration on the faults active in the later period;

[0031] Step S 22 : Statistical analysis of the total distance L between the residual landform watershed and the outlet, the total fault distance H, the fault angle α, and the fault distances h1, h2, and h3 of each period, and calculate the position of the watershed in each period, where:

[0032] La=H / tanα (1)

[0033] Le=L-La (2)

[0034] La1=La*h1 / (h1+h2+h3) (3)

[0035] Le1=Le*h1 / (h1+h2+h3) (4)

[0036] L1=La1+Le1 (5)

[0037] Among them: La is the total horizontal uplift distance; Le is the total headward erosion distance; La1 is the horizontal uplift distance of each period; Le1 is the headward erosion distance of each period; L1 is the distance from the watershed to the outlet of each period.

[0038] Preferably, in step S3, the specific method of dividing the structure-sedimentation unit includes:

[0039] Step S 31 : The structural-sedimentary units are divided according to the watersheds, watershed lines and uplift group boundaries;

[0040] Step S 32 : Establish the corresponding relationship between the provenance system and sedimentary system of each uplift group.

[0041] Preferably, in step S4, the specific method of recovering the erosion amount is:

[0042] Step S 41 : Identify the denudation zone, overdenudation zone and overlay zone;

[0043] Step S 42 :The over-stripping area is restored by the formation trend method, and the erosion amount is restored by the formation trend method and volume inversion method in the eroded area.

[0044] Preferably, in step S5, the specific method for correcting the differential settlement of the residual paleo-geomorphology and restoring the erosion amount to improve the restoration of the paleo-geomorphology framework during the depositional period is as follows: after clarifying the watershed position and the total amount of erosion, the erosion amount is stripped back to the residual geomorphology uplift area restored by the fault according to the corresponding erosion-deposition corresponding unit and superimposed on the sedimentary area corrected for differential settlement to complete the restoration of the paleo-geomorphology framework during the depositional period.

[0045] Preferably, in step S6, the specific method for describing the type of raised parent rock and the distribution of residual parent rock is:

[0046] Step S 61 :Carry out well seismic calibration on the through-well seismic profile in the study area.

[0047] Step S 62 : Statistical analysis of the differences in seismic phases of different parent rocks,

[0048] Step S 63 : Establish a seismic phase identification chart for basement parent rock types,

[0049] Step S 64 :Trace the distribution boundaries of different parent rocks in a plane and complete the characterization of parent rock distribution in the source area.

[0050] Preferably, in step S7, the specific method for analyzing and counting the components of drilling cuttings is: based on the source-sink unit division, petrological analysis is performed on the drilling cuttings in different unit sink areas, the cuttings composition is finely divided, and the relative content of each component is counted.

[0051] Preferably, in step S8, the specific method for qualitatively restoring the source area parent rock type and distribution during the sedimentation period is:

[0052] Step S 81 :According to the proportion of different gravel contents, the corresponding proportion of the parent rock source area is inferred;

[0053] Step S 82 : Semi-quantitative restoration of the distribution range of parent rocks in the uplift origin area during the deposition period;

[0054] Step S 83 : According to the sand-forming index formula SGIA(A+B)=[SA+SB] / SA(SGIA(A+B) is used to semi-quantitatively predict the main components of sedimentary gravel in the source area composed of lithology A and B;

[0055] Among them, SGIA(A+B) is the sand-forming index of lithology A; SA+SB is the total source area; SA is the source area of ​​lithology A.

[0056] Compared with the prior art, the present invention has significant advantages and beneficial effects, which are specifically embodied in the following aspects:

[0057] 1. When restoring ancient landforms, the present invention takes into account the changes in landform morphology caused by tectonic movements, supplements the restoration of tectonic movements, and makes landform restoration more scientific and accurate; the activity of later faults changes the source-sink unit structure, and the quantitative restoration of such faults can more truly reflect the landform pattern after source area erosion, and the division of structural units based on it is more scientific and accurate.

[0058] 2. Geomorphology-lithology restoration based on the source-sink system framework creates a good framework for studying the source and material basis of each structural-sedimentary unit. The amount of denudation and the denuded parent rock are linked to the sedimentary material to provide a new basis for the development of favorable reservoirs. The parent rock type, source strength, sedimentary system distribution and their temporal and spatial evolution laws of each structural-sedimentary unit can be clearly and intuitively displayed on the restored prototype basin, which can directly guide and predict favorable reservoirs in oil exploration, and provide a highly operational and intuitive method for geomorphology-lithology restoration using well seismic data, solving the problem of restoring the source of material and the sequencing of favorable reservoirs in sedimentary areas based on well seismic data involved in oil and gas exploration, which has a wide range of uses and broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a flowchart of the steps of the paleo-geomorphology lithology restoration method in an embodiment of the present invention;

[0060] Figure 2 It is a residual paleo-geomorphology differential settlement correction map in an embodiment of the present invention;

[0061] Figure 3 This is a schematic diagram of restoration of a fractured grid section in an embodiment of the present invention;

[0062] Figure 4 This is a diagram showing the plane recovery result of the fracture system in an embodiment of the present invention;

[0063] Figure 5 It is a diagram for quantitative verification of the structural-sedimentary unit division and fault system in the embodiment of the present invention;

[0064] Figure 6 It is a schematic diagram of the identification of the denudation zone, the overdenudation zone and the overlying zone and the restoration of the denudation amount in an embodiment of the present invention;

[0065] Figure 7 This is a plane restoration diagram of the erosion amount in an embodiment of the present invention;

[0066] Figure 8 This is a paleo-geomorphological restoration map during the sedimentation period in an embodiment of the present invention;

[0067] Fig. 9 This is a well-seismic parent rock lithology calibration diagram in an embodiment of the present invention;

[0068] Fig.10 It is a superimposed diagram of residual parent rock type and landform distribution in an embodiment of the present invention;

[0069] Fig.11 It is a characteristic plane distribution diagram of rock cuttings components in an embodiment of the present invention;

[0070] Fig.12 This is the paleo-geomorphology-lithology information of the inner provenance area and the key well verification diagram in the sand-forming index restoration of the embodiment of the present invention. DETAILED DESCRIPTION

[0071] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0072] like Figure 1 As shown, an embodiment of the present invention provides a method for restoring the lithology of paleo-geomorphology, and the method for restoring the lithology of paleo-geomorphology comprises the following steps:

[0073] S1: differential settlement correction for residual landforms;

[0074] By analyzing the differences in fault activity in different periods and the evolution of sedimentary strata thickness, the differential settlement law and sedimentary base level are clarified, and the differential settlement is corrected.

[0075] like Figure 2 As shown, in this embodiment, the base surface leveling method is used to correct the differential settlement of the underlying residual landforms during the critical period, and the differential settlement correction results are shown in the figure.

[0076] S2: fracture recovery;

[0077] The faults in the study area were identified and analyzed, and the fault translation restoration was carried out for the later active faults that had a great impact and transformation on the geomorphic framework, and the watershed positions of each period were restored.

[0078] like Figure 3 As shown in the figure, the fault translation recovery is performed on the seismic workstation, and the restored seismic interpretation data is exported as a graph to obtain the following Figure 4 The fracture recovery results are shown in Figure 2.

[0079] S3: tectonic-sedimentary unit division;

[0080] Based on the residual landform characterization after the restoration of faults and watershed positions at each stage, structural-sedimentary units of different key depositional periods are divided.

[0081] Specifically in this embodiment, Figure 4 In the fault restoration result map shown, the watershed, watershed, ridge line and erosion boundary line in the study area are picked up. Within the erosion area, the ancient landform after fault restoration is further divided into primary, secondary and tertiary source-sink units based on the watershed and watershed, completing the division of structural-sedimentary units, and then quantitatively verifying the rotation and tilting landforms for the active fault blocks.

[0082] S4: restoration of erosion volume;

[0083] The eroded area is stripped back to the uplifted area and the landforms of the differential sedimentation areas are superimposed to complete the restoration of the ancient landform framework during the sedimentary period.

[0084] Specifically in this embodiment, Figure 6 , 7 As shown in the figure, the denudation zone (no sedimentary strata), overdenudation zone (early sedimentation, late denudation, overlap and denudation phenomena occur simultaneously) and overlay zone (strata receiving sedimentation, no denudation phenomenon) are identified. Different methods are selected for restoration according to the amount of denudation in the denudation zone and overdenudation zone. For the overdenudation zone, according to Figure 6 As shown in the figure, the formation extension method is used to restore the erosion amount; for the eroded area, under the premise of ensuring that the watershed, watershed and ridge line remain stable, the total amount of material is restored by the trend extension method and the volume inversion method with constant total amount of material. After restoring the erosion amount of the eroded area and the super-stripped area, the following is obtained: Figure 7 The erosion recovery diagram is shown.

[0085] S5: Correct the differential settlement of residual paleo-geomorphology and restore the amount of denudation to improve the paleo-geomorphological framework during the sedimentary period;

[0086] Specifically in this embodiment, Figure 8As shown, based on the paleo-geomorphology corrected by differential sedimentation in step S1, the total amount of erosion in the erosion zone and the super-erosion zone in step S4 is respectively superimposed in the respective regions, and the interface superposition operation is performed to finally complete the restoration of the paleo-geomorphology framework of the deposition period.

[0087] S6: Characterization of uplift parent rock types and residual parent rock distribution:

[0088] The lithology and age of the parent rock are determined using rock cuttings, gravel, heavy minerals and zircon. Well-to-seismic data are combined and through-well seismic data are used to calibrate the seismic phase characteristics of different parent rocks. The distribution boundaries of different types of parent rocks are qualitatively identified on the plane, and the distribution of residual parent rocks in the source area is characterized.

[0089] Specifically in this embodiment, Fig. 9 , 10 As shown, according to regional surveys and drilling lithology revelations, and in Fig. 9 After the well-seismic calibration shown in the figure, the boundaries of different parent rocks are tracked in the seismic workstation to obtain Fig.10 The residual parent rock types and geomorphic distribution characteristics are shown.

[0090] S7: Analysis and statistics of drilling cuttings components;

[0091] Petrological analysis is carried out on the wells drilled in the sedimentary area, and the composition of the rock cuttings is finely divided and counted.

[0092] Specifically in this embodiment, Fig.11 As shown, drilling in the sedimentary area is statistically analyzed to reveal the core and cuttings components, and a characteristic distribution map of the cuttings components is drawn, which is the characteristic distribution map of the cuttings components.

[0093] S8: Qualitatively restore the parent rock types and distribution in the source area during the sedimentation period;

[0094] Based on the statistics of rock fragment types and contents, the parent rock types and distribution range of the uplift origin area during the sedimentary period were qualitatively restored, and the main components of sediment gravel were semi-quantitatively predicted.

[0095] Specifically in this embodiment, Fig.12 As shown in the figure, based on the source-sink unit division, the rock cuttings in the sink area are inverted back to the corresponding source area, the lithology of the source area parent rock is corrected, and the distribution range of different parent rocks is corrected according to the relative relationship of the rock cuttings content, and the following is obtained: Fig.12 The parent rock lithology and distribution recovery map is shown. According to the sand-forming index formula, the gravel content of Well BZ26-5-1 is mainly carbonate rock, which is consistent with the drilling revelation.

[0096] It should be noted that the source-sink system is a hot topic in the field of sedimentology that has developed in recent years. It mainly studies the mutual coupling relationship between provenance areas, transportation areas, and depositional areas. The source-sink system of continental basins analyzes the provenance system and depositional system from a geomorphological perspective, and can intuitively find the direct correspondence between the erosion zone and the depositional zone, as well as the response differences under different boundary conditions. The core of the study of the source-sink system of continental basins is to study the quantitative-semi-quantitative characterization of the relationship between the source of materials and the response of sedimentary materials, which is also the basis for the dual restoration of paleo-geomorphology-lithology during the sedimentary period.

[0097] This invention uses the latest core idea of ​​quantitative research on source-sink system to complete the restoration of landform and lithology. First, the sedimentary datum is selected to correct the differential settlement, the fractures in the residual landform are analyzed and restored, and the structural-sedimentary unit division is carried out on the residual paleo-landform after the fracture restoration, the source of the material and the total amount of the material are clarified, and the total amount of the material in the erosion area and the source of the material are restored by calibrating the erosion range and sedimentary volume, so as to complete the restoration of the paleo-landform in the key period; secondly, the source area parent rock type needs to be statistically analyzed and drilled, the seismic phase characteristics of different parent rocks are calibrated by drilling, the plane parent rock distribution boundary is delineated, the drilling cuttings components in the sink area are finely analyzed and statistically analyzed, and the source area parent rock type and distribution range are corrected according to the corresponding relationship with the source area, and finally the landform-lithology restoration results are improved on the basis of landform restoration.

[0098] Specifically, in step S1, the specific method of the differential settlement correction includes: selecting a planation surface as a deposition reference surface, performing layer flattening processing on the deposition reference surface, and correcting the differential settlement amount in the later stage of deposition.

[0099] Specifically, in step S2, the specific method of fracture recovery includes:

[0100] Step S 21 : Analyze the fault activity period according to the formation attribution of the upper and lower walls of the fault, and perform fault translation restoration on the faults active in the later period;

[0101] Step S 22 : Statistical analysis of the total distance L between the residual landform watershed and the outlet, the total fault distance H, the fault angle α, and the fault distances h1, h2, and h3 of each period, and calculate the position of the watershed in each period, where:

[0102] La=H / tanα (1)

[0103] Le=L-La (2)

[0104] La1=La*h1 / (h1+h2+h3) (3)

[0105] Le1=Le*h1 / (h1+h2+h3) (4)

[0106] L1=La1+Le1 (5)

[0107] Among them: La is the total horizontal uplift distance; Le is the total headward erosion distance; La1 is the horizontal uplift distance of each period; Le1 is the headward erosion distance of each period; L1 is the distance from the watershed to the outlet of each period.

[0108] Specifically, in step S3, the specific method of dividing the structure-sedimentation unit includes:

[0109] Step S 31 : The structural-sedimentary units are divided according to the watersheds, watershed lines and uplift group boundaries;

[0110] Step S 32 : Establish the corresponding relationship between the provenance system and sedimentary system of each uplift group.

[0111] Specifically, in step S4, the specific method of recovering the erosion amount is:

[0112] Step S 41 : Identify the denudation zone, overdenudation zone and overlay zone;

[0113] Step S 42 :The over-stripping area is restored by the formation trend method, and the erosion amount is restored by the formation trend method and volume inversion method in the eroded area.

[0114] Specifically, in step S5, the specific method for correcting the differential settlement of the residual paleo-geomorphology and restoring the erosion amount to improve the restoration of the paleo-geomorphology framework during the depositional period is as follows: after clarifying the watershed position and the total amount of erosion, the erosion amount is stripped back to the residual geomorphology uplift area restored by the fault according to the corresponding erosion-deposition corresponding unit and superimposed on the sedimentary area corrected by the differential settlement, so as to complete the restoration of the paleo-geomorphology framework during the depositional period.

[0115] Specifically, in step S6, the specific method for describing the type of raised parent rock and the distribution of residual parent rock is:

[0116] Step S 61 :Carry out well seismic calibration on the through-well seismic profile in the study area.

[0117] Step S 62 : Statistical analysis of the differences in seismic phases of different parent rocks,

[0118] Step S 63 : Establish a seismic phase identification chart for basement parent rock types,

[0119] Step S 64 :Planar tracking of the distribution boundaries of different parent rocks to complete the characterization of the parent rock distribution in the source area.

[0120] Specifically, in step S7, the specific method for analyzing and counting the components of drilling cuttings is: based on the source-sink unit division, petrological analysis is performed on the drilling cuttings in different unit sink areas, the cuttings composition is finely divided, and the relative content of each component is counted.

[0121] Specifically, in step S8, the specific method for qualitatively restoring the source area parent rock type and distribution during the sedimentation period is:

[0122] Step S 81 :According to the proportion of different gravel contents, the corresponding proportion of the parent rock source area is inferred;

[0123] Step S 82 : Semi-quantitative restoration of the distribution range of parent rocks in the uplift origin area during the deposition period;

[0124] Step S 83 : According to the sand-forming index formula SGIA(A+B)=[SA+SB] / SA(SGIA(A+B) is used to semi-quantitatively predict the main components of sedimentary gravel in the source area composed of lithology A and B;

[0125] Among them, SGIA(A+B) is the sand-forming index of lithology A; SA+SB is the total source area; SA is the source area of ​​lithology A.

[0126] Although the disclosure is disclosed as above, the protection scope of the disclosure is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A method for restoring the lithology of ancient landforms, characterized in that: include: S1: differential settlement correction for residual landforms; By analyzing the differences in fault activity and the evolution of sedimentary strata thickness in different periods, the differential settlement law and sedimentary base level are clarified, and the differential settlement is corrected; S2: fracture recovery; Identify and analyze the faults in the study area, restore the fault translation for the later active faults that have a great impact and transformation on the geomorphic framework, and restore the watershed positions of each period; S3: tectonic-sedimentary unit division; Based on the residual geomorphic characterization after the restoration of faults and watershed positions at each stage, structural-sedimentary units of different key depositional periods are divided; S4: restoration of erosion volume; By defining the scope of the denudation zone, super-denudation zone and erosion zone, clarifying the scope of denudation in different periods, and completing the restoration of the denudation volume in the denudation zone and super-denudation zone through the principle of total material conservation under the control of the source-sink system and the formation dip recovery method; S5: Correct the residual paleo-geomorphological differential settlement and restore the amount of erosion, and improve the paleo-geomorphological framework during the sedimentary period. The eroded area is stripped back to the uplift area, and the landforms of the differential sedimentation area are superimposed to complete the restoration of the ancient landform framework during the sedimentary period; S6: Characterization of uplift parent rock types and residual parent rock distribution; Use rock fragments, gravel, heavy minerals and zircon to determine the lithology and age of the parent rock. Combine well and seismic data to calibrate the seismic phase characteristics of different parent rocks, qualitatively identify the distribution boundaries of different types of parent rocks on the plane, and characterize the distribution of residual parent rocks in the source area. S7: Analysis and statistics of drilling cuttings components; Conduct petrological analysis on drilling in sedimentary areas, and make detailed classification and statistics of the rock cuttings composition; S8: Qualitatively restore the parent rock types and distribution in the source area during the sedimentation period; Based on the statistics of rock fragment types and contents, the parent rock types and distribution range of the uplift origin area during the sedimentary period were qualitatively restored, and the main components of sediment gravel were semi-quantitatively predicted.

2. The method for lithological restoration of ancient landforms according to claim 1, characterized in that: In step S1, the specific method of the differential settlement correction includes: selecting a planation surface as a deposition reference surface, performing layer flattening processing on the deposition reference surface, and correcting the differential settlement amount in the later stage of deposition.

3. The method for lithological restoration of ancient landforms according to claim 1, characterized in that: In step S2, the specific method of fracture recovery includes: Step S 21 : Analyze the fault activity period according to the formation attribution of the upper and lower walls of the fault, and perform fault translation restoration on the faults active in the later period; Step S 22 : Statistical analysis of the total distance L between the residual landform watershed and the outlet, the total fault distance H, the fault angle α, and the fault distances h1, h2, and h3 of each period, and calculate the position of the watershed in each period, where: La=H / tanα (1) Le=L-La (2) La1=La*h1 / (h1+h2+h3) (3) Le1=Le*h1 / (h1+h2+h3) (4) L1=La1+Le1 (5) Among them: La is the total horizontal uplift distance; Le is the total headward erosion distance; La1 is the horizontal uplift distance of each period; Le1 is the headward erosion distance of each period; L1 is the distance from the watershed to the outlet of each period.

4. The lithology restoration method of ancient landform according to claim 1, characterized in that: In step S3, the specific method of dividing the structure-sedimentation unit includes: Step S 31 : The structural-sedimentary units are divided according to the watersheds, watershed lines and uplift group boundaries; Step S 32 : Establish the corresponding relationship between the provenance system and sedimentary system of each uplift group.

5. The method for lithological restoration of ancient landforms according to claim 1, characterized in that: In step S4, the specific method of recovering the erosion amount is: Step S 41 : Identify the denudation zone, overdenudation zone and overlay zone; Step S 42 :The over-stripping area is restored by the formation trend method, and the erosion amount is restored by the formation trend method and volume inversion method in the eroded area.

6. The method for lithological restoration of ancient landforms according to claim 1, characterized in that: In step S5, the specific method for correcting the differential settlement of the residual paleo-geomorphology and restoring the erosion amount to improve the restoration of the paleo-geomorphology framework during the depositional period is as follows: after clarifying the watershed position and the total amount of erosion, the erosion amount is stripped back to the residual geomorphology uplift area restored by the fault according to the corresponding erosion-deposition corresponding unit and superimposed on the sedimentary area corrected by the differential settlement, so as to complete the restoration of the paleo-geomorphology framework during the depositional period.

7. The method for lithological restoration of ancient landforms according to claim 1, characterized in that: In step S6, the specific method for describing the type of raised parent rock and the distribution of residual parent rock is: Step S 61 : Carry out well-seismic calibration on the through-well seismic profile in the study area; Step S 62 :Statistical analysis of the differences in seismic phases of different parent rocks; Step S 63 : Establish a seismic phase identification chart for basement parent rock types; Step S 64 :Trace the distribution boundaries of different parent rocks in a plane and complete the characterization of parent rock distribution in the source area.

8. The method for lithological restoration of ancient landforms according to claim 1, characterized in that: In step S7, the specific method for analyzing and counting the components of drilling cuttings is: based on the source-sink unit division, petrological analysis is performed on the drilling cuttings in different unit sink areas, the cuttings composition is finely divided, and the relative content of each component is counted.

9. The method for lithological restoration of ancient landforms according to claim 1, characterized in that: In step S8, the specific method for qualitatively restoring the source area parent rock type and distribution during the sedimentation period is: Step S 81 :According to the proportion of different gravel contents, the corresponding proportion of the parent rock source area is inferred; Step S 82 : Semi-quantitative restoration of the distribution range of parent rocks in the uplift origin area during the deposition period; Step S 83 : According to the sand-forming index formula SGIA(A+B)=[SA+SB] / SA(SGIA(A+B) is used to semi-quantitatively predict the main components of sedimentary gravel in the source area composed of lithology A and B; Among them, SGIA(A+B) is the sand-forming index of lithology A; SA+SB is the total source area; SA is the source area of ​​lithology A.

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