The influence on oil and water relative permeabilities is investigated in geological porous media. A simulation network model is used to compute the oil and water relative permeabilities and capillary pressure/ Heterogeneous porous medium is simulated by network as a composition of two pores space with different permeabilities and whose microstructure is determined by experimental histograms received on the samples A, B, C of Samotlor oil fields. The obtained results are compared with analogous curved in homogenous structures. A theoretical explanation is given for obtained results. This research can be used as petrophysical information for a construction effective models, used in solving problems of full wave 3D simulation of seismic field for perspective oil reservoirs.