Том: 193 , Уear of publication: 2018

Computer simulation of physicochemical equilibria and evasion-invasion processes in the water-gas system enables modeling gas saturation degree variability and the physical nature of gaseous diffusion redistribution at the hydrocarbon accumulation - formation waters interface and in the transition zone from hydrocarbon accumulation to the peripheral waters. Aquifers with waters characterized by low (< 0.2) to maximum saturation (0.8-1.0) with gases have been established within Cretaceous, Jurassic and Paleozoic deposits of the West Siberian sedimentary basin (WSSB), along with an increase in the saturation degree of formation waters with gases as the occurrence depth of reservoir intervals increases, and a relationship between gas saturation of formation waters and their total gas saturation value. All waters with total gas saturation exceeding 1.8 L/L become ultimately saturated with gases (Kg = 1.0), providing thereby theoretical prerequisites for the formation of hydrocarbon accumulations. The zone of Kg values spanning from 0.8 to 1.0 is associated with major gas condensate accumulations, while less saturated waters - with oil accumulations.