Synthetic saline-aqueous and hydrocarbon fluid inclusions trapped in calcite at temperatures and pressures relevant to hydrocarbon basins: A reconnaissance study

摘要

We conducted reconnaissance experiments to synthesize aqueous and hydrocarbon inclusions trapped in calcite at conditions relevant to petroleum basins, and characterize the microthermometric properties of such inclusions. Fluid inclusions (FIs) were synthesized in a system of saline aqueous solution (5 or 20 wt % NaCl) coexisting with either heavy crude oil or gasoline under gas-undersaturated conditions, from 90 to 210 degrees C and 200-550 bar. The synthetic inclusions are not representative of gas-bearing systems, and methane (CH4) was not detected in any aqueous inclusions. The FIs are mainly distributed along planar healed, cracks, indicating that the inclusions formed by fracture healing in the calcite crystal. Micro thermometric measurements were conducted on coeval aqueous and hydrocarbon inclusions, and Raman spectroscopic analyses were done on aqueous inclusions, to determine the properties of FIs trapped at these conditions.