Palaeogeomorphology restoration method in sedimentary period based on seismic reflection amplitude analysis

Abstract

The invention discloses a palaeogeomorphology restoration method in sedimentary period based on seismic reflection amplitude analysis. The method comprises the following steps: basic data collection;rock core calibration; single well synthetic record production and calibration and research of a target stratum; establishment of paleogeomorphology restoration well grid section; finding a lithologicinterface which is obviously related to the ratio of grainstone to stratum; establishment of a wedge forward model; summarizing correlation between thickness and amplitude of the established model; extraction of the amplitude; refitting of a correlation curve; evaluation of single well agreement rate; 3D visualization display of the extracted amplitude attribute diagram; and correction of three-dimensional paleogeomorphology to obtain accurate and quantitative three-dimensional paleogeomorphology. The advantages are that the method solves the problem that a conventional method relies on specific stratigraphic combination and seismic horizon tracking accuracy, and breaks the limitation that if there is no continuous tracking reflection interface above and below the target stratum, the sedimentary paleogeomorphology of the target stratum cannot be accurately restored; and seismic interpretation workload is reduced, and accuracy of paleogeomorphology restoration is improved.

Description

technical field [0001] The invention relates to the technical field of petroleum exploration and development, in particular to a method for restoring sedimentary paleogeomorphology based on seismic reflection amplitude analysis. Background technique [0002] The paleogeomorphological restoration methods currently popular at home and abroad mainly include: impression method, residual thickness method, backstripping method, sedimentological analysis method, error simulation method, sequence stratigraphic paleogeomorphological restoration method (including high-resolution layer Sequence Stratigraphy Paleogeomorphology Restoration Method). Among the above methods, the impression method and the residual thickness method mainly use seismic and well data to restore the paleogeomorphology of the target layer, and their accuracy is relatively high, and the results are relatively reliable. In practical applications, well data with high vertical resolution and seismic data with wide l...

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Problems solved by technology

[0004] Both of the above two classic methods need to find a reflection interface with a relatively stable seismic event phase. If a stable and traceable seismic reflection interface that meets the prerequisites of the above methods cannot be found in practical applications, more reliable paleogeomorphological restoration results cannot be obtained.

Under the condition that the buried depth of the target layer is large, affected by the resolution of seismic data, the phase difference of well-seismic calibration increases, and there is a certain difference between the seismic horizon and the drilling layer, which reduces the accuracy of paleogeomorphology restoration

Therefore, restoration of paleogeomorphology is often limited by geological conditions, resulting in large differences between restoration results and actual drilling.

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