Detection of Highly Cavernous Sub-Seismic Zones in Carbonate Reservoirs by Scattered Waves

In the recent study of the Yurubcheno - Tokhomskoye oil field more and more attention is paid to the Riphean intervals with high cavitary. Current estimates forecast about 30% of geological reserves of hydrocarbons within these intervals. Neither the origin nor dissemination of these intervals are clear nowadays. There is general geological knowledge about these layers. In particular, it is worth mentioning that their average width is 0.5 m – 1 m, the average voidage is about 10% and they are located just below the Riphean interface at a depth around 2000 m. To assess the possibility of seismic techniques for imaging these objects we perform full-scale numerical simulation of seismic waves propagation and generate synthetic multishot - multioffset data. The simulation was done by parallel software on the base of finite-difference technique with local grid refinement in time and space. Next, we use multicomponent Gaussian beams to construct scattered waves images of thin cavitary layers.