A Quantitative Study of the Petroleum Generation and Migration Development in The Tarim Basin, Northwest of China: ABSTRACT

The Tarim Basin is the largest undeveloped petroliferous basin in China. Sediments in the basin range from Precambrian to Tertiary in age and from marine carbonate to non-marine clastic in depositional environment. Investigations indicate that there are potential structural, stratigraphic and unconformity traps for oil and gas in the basin. Applying one and two dimensional basin modelling systems to the well data and cross section, a number of different geologic scenarios such as sedimentary compactions, diagenesis, unconformities, faults, thermal maturation, hydrocarbon generation, expulsion, migration and accumulation are modeled. The modelling results in the basin reveal: (1) there is a vast amount of source rock which is thermally mature or overmatured, (2) there are multiple peaks of hydrocarbon generation and a continuous expulsion process in the basin's history, (3) the Carboniferous rocks which have undergone severe diagenesis are the major oil-producing rocks in both structural and lithological reservoirs in the Paleozoic strata; while the isolated clastic sediments are the major traps in the younger strata, (4) oil in the stratigraphic reservoirs comes mainly from the adjacent source rocks, and, (5) diagenesis and faulting are the major controlling factors for the hydrocarbon accumulations in the Paleozoic reservoirs.