METHOD OF PROSPECTING FOR HYDROCARBON DEPOSITS ASSOCIATED WITH FRACTURED-CAVERNOUS RESERVOIRS

摘要

The present method of prospecting for hydrocarbon deposits associated with fractured-cavernous reservoirs, involving special processing of standard CDP seismic survey data (2D and 3D) to produce a complete wavefield containing reflected and diffracted waves, is characterized in that with the aid of special prestack Fresnel migration methods, two seismic data volumes are obtained: a migrated volume for reflected waves (reflectors) and a volume for diffracted waves (diffractors), the diffractor volume being obtained by subtracting the reflected waves and subsequently focusing the scattered waves, the amplitude and spectral attributes of the seismic field are calculated on the basis of the diffractor volume, then a three-dimensional model of the scattering objects in a geological environment (acoustic discontinuity index volume) is obtained on the basis of integral amplitude characteristics, and combined interpretation of the migrated reflector volume and the acoustic discontinuity index volume is used to obtain the distribution of the instantaneous amplitudes of the scattered waves along the cross-section of a volume at intervals corresponding to the producing levels under investigation of a geological section, said distribution being subsequently classified on the basis of the amplitude values in accordance with commercial geophysical data.