Maturity of coal-derived hydrocarbon in pvrolvsis experiments.

Hydrocarbon generation and expulsion experiment in account of pressure and expulsion effects is an important approach in resource assessment and petroleum formation mechanism.lt is necessary to integrate hydrocarbon generation process in pyrolysis experiments with geological maturity. An immature coal is pyrolyzed in three experiment models.The first two are in confined gold reactors at temperatures from 300°C to 650°C with heating rates of 2°C. h and 20°C/h and under a pressure of 30MPa.The third is in hydrocarbon generation and expulsion simulation rig at temperatures from 250°C to 650°C with rapid healing rates and holding lime of 72 hour and under a pressure of 30Mpa. The relationship between hydrogen carbon atomic ratio and vitrinite reflectance is confirmed by the mathematical statistics of 139 geological samples. In view of indicative feature of hydrogen-carbon atomic ratio for organic maturation and hydrocarbon generation, the curves between experimental thermal parameters and geological maturity are graphed for these three series of experiments. Compared with geological maturity R_o the value of solid residue in confined gold reactors is higher by 0-0.9%, and the value at higher maturity stage in hydrocarbon generation and expulsion simulation rig is lower by 0-0.2%. The values of Easy%R_o in the three series of experiments are 0-0.8% lower than the values of geological maturity. Obviously, the vitrinite reflectance of solid residue in hydrocarbon generation and expulsion simulation rig is nearer to geological maturity than in con fined gold reactor. The conclusion reflects that pressure and hydrocarbon expulsion play an important role in thernial maturity and hydrocarbon generation process of organic mailer. Krror analysis shows thai the corrected maturity of experimental samples with hydrogen carbon atomic ratio relationship are 0.25% lower in oil window,0.5% lower in gas stage than the real geological maturity. These curves can be applied to resource assessment in coal measures regions by pyrolysis experiments. [ABSTRACT FROM AUTHOR]