METHOD OF EVALUATING CURRENT GAS SATURATION IN BOTTOMHOLE ZONE OF WELL IN DEPOSIT OF VOLATILE OIL Russian patent published in 2010 - IPC E21B47/00 

FIELD: oil and gas industry.

SUBSTANCE: before well operation there are measured parametres of reservoir-collector and reservoir fluid by traditional logging methods including neutron, and by analysis of core and fluid samples. There is created a numerical model of change of neutron logging signals for measured parametres of reservoir, reservoir fluid and assumed gas saturation at the production well. Assumed gas saturation is determined by means of hydro-dynamic modelling of composition of gas-oil mixture for measured parametres of the reservoir, reservoir fluid and functions of phase permeability. Neutron logging is carried out during operation at reduced well yield. Signals of neutron logging and signals of created numerical model are compared. Current gas saturation is determined by results of compliance of measured and modelled signals of neutron logging.

EFFECT: upgraded accuracy of evaluating gas saturation in bottomhole zone both in cased and not cased well.

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