Method for predicting carbonate rock oil and gas reservoir

Abstract

The invention relates to a method for predicting a carbonate rock oil and gas reservoir through low-frequency information. Firstly, a dispersion-viscosity wave equation is used for forwards modeling of a fluid layer to obtain low-frequency earthquake reflection characters. namely low-frequency energy abnormality of the fluid layer; secondarily, a single-frequency time-frequency domain energy time sequence of earthquake signals is used as a new time signal, a compound filter acts on the new time signal, and then instant maximum time-frequency domain energy is obtained, so that the obtained low-frequency energy is outstanding in abnormality and has high time resolution. All the steps are carried out on a low-frequency band, and the low-frequency band is the frequency band corresponding to 15-35% of the instant spectrum accumulative energy. The dispersion-viscosity wave equation is used for forwards modeling of the fluid layer to obtain low-frequency earthquake reflection characters of the fluid layer. namely low-frequency energy abnormality, compared with the prior art, the extracted low-frequency strong energy is outstanding in abnormality and has high time resolution, and prediction accuracy of the carbonate rock oil and gas reservoir is improved.

Description

technical field [0001] The invention relates to oil and gas geophysical exploration, in particular to a new method for predicting carbonate rock oil and gas reservoirs. Background technique [0002] Carbonate reservoirs contain more than 60% of the world's oil and gas reserves, so it is of great practical value to study the prediction methods of carbonate reservoirs. Carbonate reservoirs are often accompanied by fractures, holes, and well-developed pores. Compared with surrounding rocks, one of the seismic reflection characteristics is strong amplitude. The fluid (oil, gas) in the rock mass will make the spectrum of the seismic signal shift to the low-frequency end and High-frequency attenuation occurs (low-frequency attenuation is slow). These phenomena cause carbonate reservoirs to present low-frequency and strong energy anomalies. If the "low-frequency and strong energy anomalies" can be effectively extracted, the beneficial effects of carbonate reservoirs can be obtained...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the above problems, a method for predicting carbonate oil and gas reservoirs is provided. The purpose is to use the existing low-frequency methods for carbonate reservoir prediction, whether it is to extract single-frequency low-frequency components or use low-frequency associated The problem of low time resolution of low-frequency components cannot be avoided, and the spatial distribution characteristics of fluid reservoirs cannot be described with high precision. This is the inevitable result of the "uncertainty principle".

Images