The role of Triassic source rocks in the formation of oil accumulation in the Fukang Depression (China)
This article presents the results of geological and geochemical studies of the organic matter of source rocks and oil from reservoirs in the Karamay Formation (Anizian-Ladinian stages) in the eastern part of the Fukang Depression in Junggar petroleum basin. The quantity, quality, and degree of maturity of the organic matter in clayey mudstones in upper part of the Karamay Formation (T2k) were considered and the composition of the original organic matter, the conditions of its accumulation and the degree of maturity were reconstructed using pyrolytic parameters and biomarkers. The dark gray and gray mudstone in upper part of the Karamay Formation accumulated in fresh or low salinity lakes with relatively reducing conditions. At present, the organic matter of the Formation within the depression is in the zone of mesocatagenesis MK1-MK3, and therefore has not fully realized its oil-geological potential. It has been previously established that mudstones in upper part of the Karamay Formation provided the hydrocarbon fluids for the Karamay reservoirs located in the submerged part of the Fukang Depression.