Patent ID: 8606523

Claim:
A method for determining current condensate saturation in a near-wellbore zone of a wellbore in a gas condensate formation, the method comprising: measuring formation parameters and formation fluid parameters before starting production of the wellbore, wherein (i) the formation parameters and the formation fluid parameters are measured by at least one of a logging tool, core testing, and fluid testing and (ii) the formation parameters and the formation fluid parameters are selected from a group consisting of formation porosity, rock mineral composition, water saturation, water composition, formation gas PVT-data, formation gas composition, and bubble point, determining an expected condensate saturation value and a composition of a gas-condensate mixture in a near-wellbore zone by hydro-dynamic modeling the gas condensate mixture using the measured formation parameters, the formation fluid parameters, and phase permeability functions, creating a numerical model to simulate neutron logging signal change during production using the measured formation parameters, the formation fluid parameters, the expected condensate saturation value, and the determined gas-condensate mixture composition, starting production of the wellbore, performing neutron logging using a neutron logging tool and measuring neutron logging signals after a decrease in well productivity, comparing the measured neutron logging signals with the simulated neutron logging signals, and determining the current condensate saturation by adjusting the phase permeability functions so that a match is obtained between the measured neutron logging signals and the simulated neutron logging signals.