The Study of Western Siberia Complex Reservoirs Saturation with Petrophysical and Geophysical Techniques

Ivan Deshenenkov
Gubkin Russian State University of Oil and Gas, Faculty of Petroleum Geology and Geophysics, Moscow, Russian Federation
[email protected]

The integration of petrophysical and seismic data is a key technology for reservoir characterization and subsurface fluids monitoring. Rock physics as a link between seismic and logging data, it’s applied to predict reservoir parameters, such as lithologies and pore fluids, from seismically derived attributes. Fluid substitution procedure is the rock physics technique for understanding how seismic velocity and impedance depend on pore fluids. The conventional fluid substitution model (Gassmann’s model, 1951) assumes homogeneous water saturation without dividing on free and residual water shares.

On the base of petrophysical model of effective porosity it was established a new way of Gassmann's relation application for fluid effect on elastic properties simulation. This fluid substitution model takes free and residual water volumes and properties separately and cement swelling. The model was proved with core samples measurements results.

Developed model was applied for Western Siberia sandstones and Eastern Siberia carbonates investigations. In the studied regions the reservoir saturation identification from seismic data is traditionally complicated task due to their heterogeneity on mineral composition and fluid properties. Seismic responses on oil and gas reservoirs characteristics were modeled with presented approach. Reservoir parameters such as saturation type, residual water features, reservoir properties were studied in seismic field with AVO modeling and simultaneous inversion of synthetic seismograms.

The results of stated work are the petrophysical base of the technique for reservoir saturation type prediction from seismic data, which provides identification of pay-zones, reservoir saturation mapping and three-dimensional modeling in order to drill for oil and gas.

AAPG Search and Discovery Article #90157©2012 AAPG Foundation 2012 Grants-in-Aid Projects