Boletín de la Sociedad Geológica Mexicana
versão On-line ISSN 1405-3322
GONZALEZ-PARTIDA, Eduardo; CAMPRUBI, Antoni; CANET, Carles e GONZALEZ-SANCHEZ, Francisco. Physicochemical characteristics of brines and hydrocarbons in petroliferous basins and Mississippi Valley type and associated ore deposits. Part I: temperature, pressure, and composition of fluid inclusions. Bol. Soc. Geol. Mex [online]. 2008, vol.60, n.1, pp. 11-22. ISSN 1405-3322.
This paper is a review on the principles for the interpretation of microthermometric data from brine- and hydrocarbon-bearing fluid inclusions. Furthermore, a state-of-the-art analytical methodology is described, that allows to determine the composition of dissolved gas in brines, as well as to determine the type of trapped hydrocarbon, its density and, from such data, to reconstruct its isochore and isoplete. These data cannot be easily obtained to date but allow the crossing ofisochores calculated for two insoluble liquids (brine and oil), and to estimate with precision the initial pressure and temperature during the trapping of fluid inclusions. Such results are necessary (1) to precisely reconstruct the conditions for hydrocarbon migration, (2) to determine the responsible mechanisms for porosity changes in a certain rock type and for the filling of reservoirs, (3) to understand the hydrodynamics ofpaleofluids in basins with associate formation of stratabound deposits, and (4) to better understand diagenetic processes.
Palavras-chave : fluid inclusions; brines; hydrocarbons; petroliferous basins; MVT.