Fluid inclusion: a tracer of hydrocarbon and thermal fluid migration in Yingqiong Basin.

Fluid inclusion is an efficient tracer to understand the subsurface thermal fluid and hydrocarbon migration, however, it has some uncertainties in det ermining maximum paleotemperature and its precise period. In order to estim ate the reliability of homogenization temperatures, a mathematical model fo r laboratory homogenization temperature measurement is set up based on mass conservation theory. The formula indicates that bigger fluid inclusions ar e more precise in determining forming temperatures. The case study of Yingq iong Basin shows that the homogenization temperatures of the inclusions are dominated by thermal fluid from 3000 similar to 4000m near fracture zone, and the forming condition of the fluid inclusions indicates a close relatio n with the overpressure beds, hydrocarbon generation, expulsion and migrati on. This conclusion is agreeable with the observation data of vitrinite ref lection ratio and some borehole temperatures.