Method and device for acquiring erosion thickness of sedimentary basin

Abstract

The invention relates to a method and device for acquiring erosion thickness of a sedimentary basin. The method comprises the following steps: acquiring information of different stratums in a researched area, wherein the information includes top-to-bottom depth of each stratum, sampling depth of each sample point of each stratum, lithology and porosity; building a fitting relationship between the corresponding porosity, depth and lithology of each stratum according to the stratum information; comparing the fitting relationships of the corresponding porosity, depth and lithology of upper and lower adjacent stratums to determine the erosion of the lower one of the two upper and lower adjacent layers; adding a stratum of which the thickness is shown as delta H and the lithology is similar to the that of the residual part to the top part of the determined erosion stratum, in order to compensate porosity difference between the upper and lower stratum interfaces; acquiring the erosion thickness H0 of the basin under initial deposition according to the compensated erosion stratum. According to the technical scheme, the method shows high applicability and effectiveness in complex geological conditions.

Description

technical field [0001] The invention relates to the technical field of geological exploration, in particular to a method and device for obtaining the denudation thickness of a sedimentary basin. Background technique [0002] Stratum denudation is a common phenomenon in the development process of sedimentary basins. During the process of stratum uplift and denudation, the diagenetic evolution, drainage and geothermal field of sediments will all change, and the degree of change is closely related to the magnitude of denudation. In the analysis of basin evolution history, the accurate recovery of stratum denudation thickness is the focus and difficulty of reconstructing burial history, and it is the prerequisite for inversion of basin thermal history, oil and gas generation and expulsion history, and accumulation history. [0003] There are many methods for estimating the thickness of formation denudation at home and abroad, and the following are summarized: [0004] (1) Stra...

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Problems solved by technology

Then the denuded thickness can be obtained by the graphical method. The disadvantage of this method is that when the thickness of the stratum deposited above the denuded surface exceeds the thickness of the denuded layer, this method cannot be used to recover the denuded amount.

[0010] It can be seen from the introduction of the above denuded thickness methods that the current methods for recovering stratum denuded thickness have certain limitations. For example, the stratigraphic correlation method and the deposition rate method are suitable for areas with a high degree of stratigraphic research, and the logging curve method is suitable for denuded thickness. In larger areas, the applicable condition of the vitrinite reflectance method is that the thickness of the strata deposited above the denuded surface does not exceed the thickness of the denuded layer. The seismic stratigraphy method is greatly affected by human factors, and the natural gas equilibrium concentration method can only be used in areas where natural gas is generated. area

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