Mixing ratios quantitative assessment of source-mixed gas reservoirs by carbon isotope analysis in Dinan Uplift, Junggar Basin, China

The mixing of natural gas is common in petroliferous basin, and the quantitative measurement of mixing ratio is important. A mathematical model based on carbon isotope was established to distinguish the mixed origin in Dinan Uplift, Junggar Basin. Our studies showed that the gas from Kelamary field, the northern part of Dinan Uplift, derived from Carboniferous source rock, while the gas in the southern area is of mixed origins, which involves mixing of gas from Carboniferous and Permian source rocks. The mixing proportion of Permian-derived gas increased with Ro, ranging from 8% to 45% and from 0.5% to 1.2%, respectively.