The spectral-time analysis of a seismic trace shows the position and the number of seismic reflections in a given time interval as a function of filtration frequency. This makes the method appropriate for reservoir properties forcasting. The point is that seismic reflections represent zones with high gradients of the main seismic characteristics (velocity and density). These zones are usually the boundaries of sedimentary cycles of various ranks. Therefore, the sequences, formed in the same conditions and having the same sedimentation history, in theory ought to provide the same spectral-time images. The sequences, differing in the succession of sedimentary cycles, consequently ought to differ in spectral-time images.
The theory does not take into consideration any post-sedimentation changes of reservoir properties.
In the research planned the executant is going to check how the theory stated above conforms with the data of core porosity and permeability as well as inflows and lithology of an oil-bearin layer. For this purpose all the information mentioned will be obtained on one of The Western Siberia's oil-fields.
The goal of the investigation is determination how a spectral-time image can be interpreted for making a forecast of reservoir properties on an oil-field's area. The executant is going to determine the main factors which influence a spectral-time image and how they change the latter.
AAPG Search and Discovery Article #90925©1999 AAPG Foundation Grants-in-Aid