THERMAL SIMULATION OF HEAVY CRUDE OIL FROM WELL S74 IN THE TARIM BASIN (Ⅱ)——HYDROCARBON GENERATING POTENTIAL OF BITUMEN

The hydrocarbon productive rate of the degradation-oxidant bitumen were discussed based on the geochemical characteristics of the simulation products and the hydrocarbon productive rate at various simulation temperature points of the heavy crude oil from Well S74 in the Tarim Basin.The results indicated that hydrocarbon-generation of the degradation-oxidant bitumen was mainly taken place in the oil-generating window,in other word,oil was mainly generated when R_o was not larger than 1.24%(T=350℃),with its oil productive rate of 245 kg/t.There also was some hydrocarbon-generating potential in the highly-matured bitumen,but almost no hydrocarbon-generating potential in the over-matured bi-tumen.Their products were mainly alkane gas.According to above model,hydrocarbon generation amount of the Silurian bitumen sandstones in the Shaya and the Katake Uplifts was calculated.It showed that the generated hydrocarbon was magnitude and probably was one of important sources for hydrocarbon accumulations since the Late Hercynian in the Tarim Basin.