Method for operating a hydrocarbon deposit by injection of a gas in foam form

Method for operating an underground formation comprising hydrocarbons, by means of an injection of an aqueous solution comprising a gas in foam form and a flow simulator relying on a displacement model of said gas in foam form, said displacement model being a function of an optimal mobility reduction factor of said gas and of at least one interpolation function of said optimal mobility reduction factor, said interpolation function being a function of at least one parameter relating to at least one characteristic of the foam and of at least one constant, characterized in that, from at least one sample of said formation, measurements of conventional relative permeabilities to said gas in non-foaming form and measurements of conventional relative permeabilities to said aqueous phase:

• A. said displacement model of said simulator is determined according to at least the following steps:
• i. a plurality of values of said parameter is defined relative to at least one of said interpolation functions, an injection is performed into said sample of said gas in non-foaming form and of said gas in foam form according to said values of said parameter relative to said function, and a headloss with foam and a headloss without foam are measured respectively for each of said values of said parameter relative to said function;
• ii. from said measurements of headloss relative to said interpolation function, an optimal value of said parameter relative to said function is determined, said optimal value making it possible to maximize a ratio between said headlosses without foam and said headlosses with foam measured for said function;
• iii. from said measurements of headloss performed with said optimal value determined for at least said interpolation function, from said measurements of conventional relative permeabilities to said gas in non-foaming form and from said measurements of conventional relative permeabilities to said aqueous phase, said optimal mobility reduction factor is determined;
• iv. for at least said interpolation function, from said optimal mobility reduction factor, from said measurements of headloss relative to said interpolation function, from said measurements of conventional relative permeabilities to said gas in non-foaming form and from said measurements of conventional relative permeabilities to said aqueous phase, said constants of said interpolation function are calibrated;
• B—from said displacement model and from said flow simulator, an optimal operation scheme for said deposit is determined and said hydrocarbons are exploited.