Refined restoration method for ancient karst landform

Abstract

The invention discloses a refined restoration method for an ancient karst landform. According to the method, spectra inversion is carried out by using original seismic data and logging data of a target stratum, thereby obtaining a seismic reflection coefficient data volume; positions, at the reflection coefficient data volume, of a top boundary and a bottom boundary of the target stratum at the logging position can be calibrated according to the logging data, tracking is carried out automatically by using the calibrated top boundary and bottom boundary as seed points, thereby obtaining the positions of the top boundary and bottom boundary of the whole target stratum at the reflection coefficient data volume; subtraction of the top boundary and the bottom boundary of the whole target stratum is carried out to obtain a residual thickness of the target stratum; and then the ancient karst landform of the target stratum is restored by using the residual thickness method. With the method, the restoration precision of the ancient karst landform can be improved and the exploration economic benefits of the karst reservoir can be improved effectively.

Description

technical field [0001] The invention relates to the technical field of oil and gas field exploration, in particular to a fine karst ancient landform recovery method. Background technique [0002] For a long time, in the field of petroleum exploration technology, paleogeomorphology restoration technology is a commonly used technology in karst reservoirs. Using the recovered paleogeomorphology, the distribution of karst highlands, karst slope areas and karst depressions can be clarified, so as to quickly determine the favorable areas for the development of karst reservoirs. At present, a variety of karst paleogeomorphological restoration methods have been developed at home and abroad. For example, the impression method, the residual thickness method, the sequence stratigraphy method, and the sedimentology method are the most widely used exploration techniques in the restoration of karst paleogeomorphology. [0003] When the above method is applied in practice, due to the imp...

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Problems solved by technology

[0004] 1) The deposition of strata above the denuded surface is unstable, and affected by tectonic movements, there may be structural inversion. Therefore, no standard layer with relatively stable deposition in the entire area can be found on the denuded surface, which leads to the use of, for example, the impression method The error of the recovered karst paleogeomorphology results is too large;

[0005] 2) The thickness of the residual dolomite is relatively thin, and the lateral variation is large. Due to the low resolution of the existing seismic data, it is impossible to accurately identify the top and bottom boundaries of the residual dolomite. One layer is used as the base level, which leads to low accuracy of the karst paleogeomorphology results obtained by using the residual thickness method, for example, due to the influence of structure and compaction.

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