Год издания: 2014

The interaction of seismic waves with cavernous/fractured reservoirs is analyzed on the base of finitedifference simulation with grids locally refined in time and space. The necessity to use such grids is caused by significantly differing scale of heterogeneities in the background (coarse grid) and reservoir (fine grid). Computations for each subdomain are carried out in parallel. The data exchange between each subdomain within a group is implemented using nonblocking iSend/iReceive MPI commands in order to guarantee high scalability of the algorithm. The data exchange between the two groups is done simultaneously with coupling the coarse and fine grids by spatial interpolation on the base of Fourier transform. Over the last decade the use of scattered waves won a significant place among the wide range of seismic techniques. But so far the main area of application of scattered waves is narrowed to spatial localization of micro heterogeneities clusters, like cracked and fractured areas, cavities and so on. In other words these waves are using just to say "yes" or "no" to the presence of a microstructure. At the same time more detailed knowledge about fine structure of hydrocarbon reservoirs, like orientation of fracture corridors and fluid saturation of micro heterogeneities (especially cavities) is extremely important in the design phase of deep and horizontal wells. In order to be able to predict this microstructure one must possess a detailed knowledge of the particular features of interaction of seismic waves with cavernous fractured reservoirs, manifestation of fluid saturation especially. We have developed justified, verified and implemented for supercomputers with parallel architecture the reliable instrument for the studying complicated processes of waves' propagation in realistic 3D heterogeneous multiscale models of geological media - the special finite-difference method with local mesh refinement in time and space. On this base is possible to deal with realistic models and acquisitions and take into account both small scale heterogeneities of a reservoir and mesoscale variations in overburden. This software was applied for simulation of seismic waves' propagation through realistic digital model developed on the base of all available data for some East Siberian oil field. We have found that orientation of fracture corridors and fluid saturation of reservoir microstructure has very specific impact in synthetic images of scattered waves which can be used as predictive criteria in real life data processing and interpretation. These criteria are verified by comparison of predictions with well log data (fracture orientation) and permeability (fluid saturation) of a collector by test results.