Patent ID: 7343275
Filing Date: 2008-03-11
Classification: E21B

Abstract:
1. A method for forming a model providing simulation of production by an underground reservoir, under an effect of depletion, comprising: a) measuring respective volumes of oil and gas produced by rock samples from the reservoir subjected to the depletion, as well as relative permeabilities of rock samples to hydrocarbons; b) determining, by a gas fraction flow model, a volume transfer coefficient by means of a pressure dependent empirical function that is calibrated with reference to the measurements of respective volumes of oil and gas, from which a distribution of nuclei that can be activated at a pressure is deduced; c) determining a volume transfer coefficient in the reservoir at selected depletion rates, by means of the gas fraction flow model and by considering that distribution of microbubbles deduced from the measurements is identical to a distribution of nuclei in the reservoir rocks that corresponds to the volume transfer coefficient determined by the gas fraction flow model; and d) predicting the relative permeabilities in the reservoir and reservoir production by means of the volume transfer coefficient.