MODELS OF HYDROCARBON GENERATION AND EXPULSION FROM VARIOUS MARINE SOURCE ROCKS

The 17 models of original and secondary hydrocarbon generation and expulsion from marine source rocks have been established. The work has been done on the basis of the thermal-pressure simulated experiment on ten samples selected from Mesozoic marine source rocks in the Qinghai-Xizang Plateau, and the Proterozoic marine source rocks in Jibei. The total hydrocarbon quantity, as well as the ratio of hydrocarbon generation, generated from kerogen in marine source rocks decreases gradually from type Ⅰ to Ⅱ₁, Ⅱ₂ kerogen and solid bitumen. At the same time, the oil quality becomes lighter and lighter, and the gas drier and drier. The efficiency of oil expulsion increases gradually from hydrocarbon-rich shale to marlite, limestone and solid bitumen. Both the total quantity and the ratio of hydrocarbon generation from them show a downward trend. The oil-gas ratio in total hydrocarbon increases gradually from solid bitumen to hydrocarbon-rich shale, marlite and limestone. The quantity of oil-gas generation and expulsion, the total quantity and the ratio of hydrocarbon generation decrease gradually, but the oil-gas ratio in total hydrocarbon increases with the reduction of the content of organic matter in the marine source rock(TOC=0.2%-1.0%).