Method for determining fluid characteristics of subterranean formations

Abstract

Core samples are obtained from a plurality of differing depths in a subterranean formation. The samples are dried to effect an evaporation of the water content, leaving behind a salt precipitate. The dried samples are weighed. The salt precipitate is then leached out of the samples and the samples are again weighed, the difference in such weighings identifying the amount of salt precipitate. Alternatively, the salt content can be more accurately determined by chemical analysis of the leached solution. A measurement is made of the pore volume of the samples. From the measured weights of salt precipitates and sample pore volumes, the salt content in mass per unit volume is determined for each sample. Such salt content is plotted versus formation depth from which the core samples were taken. Trends in such plotted salt content are used to identify fluid characteristics of the formations at the in-situ reservoir conditions of pressure and temperature and at the in-situ wettability state of the reservoir.

Dependencies are inferred from the claim text.