Filtration anisotropy in terrigenous collectors and its influence on oil field development (Western Siberia deposits)

The paper deals with the oil recovery problem, research methods for heterogeneity parameter determination in oil-bearing horizons and its influence on the reservoir porosity and permeability. The article describes the author's lithologic-and-petrophysic anisotropy detection method. This method allows quantifying the directions, quantities, the lateral heterogeneity influence probability in the reservoir and takes into account its possible manifestation in the field development process. For measuring magnetic susceptibility of rocks paleomagnetic oriented core samples were used. Preferred orientation directions of elongated quartz grains in sandstones were defined by microscope using oriented thin sections. The magnetic anisotropy ellipsoids have high correlation with the preferred orientation directions of the elongated grains in the reservoir rocks. The spatial relationship between the grain orientation and the terrigenous reservoirs hydrodynamic formation features was identified; it predetermines the pore matrix structure and the filtration parameter anisotropy. The anisotropy factor was determined by comparing actual and estimated water cut indices. Based on the horizontal anisotropy parameters, field model was constructed. This model gives an elliptical waterflooding front - the closest to the real geological and hydrostatic field model.