Generation Of Heavy Oil And Biodegraded Gas

Since the methane fermentation bacterium first selects 12CO2, the methane of heavy oil degration gas contains more light and 13C is still in the residual CO2. So the methane carbon isotope in heavy oil degration gas shows the characterics of high negative values(-100‰~-45‰). While CO2 demonstrated the extraordinarily heavy carbon isotope values(~+15‰).Trough the petroleum geology analysis of the heavy oil area in the northwest of Junger Basin, we think the heavy oil is mainly comes from Fengcheng group and has the characteristics of multilayer containing oil and gas, multi-tectogenesis lead to multiple conservation and the shallow of bury depth of crude oil lead to the dense of microorganism degradation.The shallow gas in the studied area is in characteristics of light carbon isotope, dry, rich in N2 and related with heavy oil. But because of shallow bury, fracture and unconformity developed widely, the shallow gas in the northwest dense oil is mainly composed of heavy oil degration gas, also mixed of thermogenic gas. Through the geology geochemistry condition analysis, the heavy oil degration gas area is got and the has great potential esploring prospect.