Pre-stack low frequency signal recognition method of complex oil pool

Abstract

A pre-stack low frequency signal recognition method of complex oil pool comprises the steps of: obtaining the original seismic data by the artificially excited seismic wave, thereby obtaining the geologic horizon file of the target layer; selecting the optimal time window of the geologic horizon file to determine the target layer; separating the near, middle and far offset distance data for the pre-stack seismic data in the target layer; performing spectrum analysis for the data in the target layer range, so as to respectively obtain the oil and gas sensitive optimal frequency ranges of the seismic data before and after the stacking; extracting seismic wave low and high frequency information in the target layer within the oil and gas sensitive optimal frequency ranges by the frequency division technology; detecting whether oil and gas exist or not by the characteristics that the low frequency range energy is enhanced and the high frequency range energy is weakened; and finally comparing with a known exploratory well, and analyzing and outputting the result. In the invention, based on the two-phase medium model much closer to the underground actual situation, the use of the pre-stack low frequency signal with richer information for recognizing the oil and gas reservoir stratums is realized; and compared with traditional indirect method and direct method, the recognition method has the advantages of low cost and high precision.

Description

technical field [0001] The invention relates to a method for identifying complex oil reservoirs, in particular to a method for identifying pre-stack low-frequency signals of complex oil reservoirs, and belongs to the field of geophysical exploration. Background technique [0002] Traditionally, the main method for detecting oil and gas in reservoirs is the indirect method, that is, looking for structures that may contain oil and gas, and then determining the well location. At present, with the continuous development of oil and gas resources, the exploration of structural oil and gas reservoirs has gradually shifted to the exploration of lithologic oil and gas reservoirs or complex oil and gas reservoirs. The difficulty of exploration is increasing, and it is necessary to find new technologies to solve the problems faced. Since the discovery of bright spot technology, the method of using seismic waves to identify reservoirs has gradually developed from post-stack inversion to...

AI Technical Summary

Problems solved by technology

These new methods have seen good results in some areas, but they are not suitable for the areas where they are used. It is still necessary to find new methods to solve the detection problem of oil and gas reservoirs

On the other hand, most of the previous methods are based on single-phase media models, while oil and gas reservoirs are typical two-phase media, which is one of the main reasons for the low accuracy of previous methods

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