Oil accumulation related to migration of source kitchens in the Lukeqin structural belt,Turpan-Hami

The Lukeqin structural belt is the main heavy oil accumulation zone in the Turpan-Hami Basin.The recent discovery of light oil in the Triassic indicates that there may be multiple source kitchens contributing to the oil accumulation.According to oil geochemical analysis and oil-source correlation,the oil in deep and shallow reservoirs of the Lukeqin Oilfield presents different physical and saturated hydrocarbon mass spectrum characteristics.The Triassic heavy oil is from the northern Upper Permian lacustrine source rocks,and the light oil represented by the Yudong-9 Well is from the northwestern Lower Jurassic coal-measure source rocks.The timing of oil charging was determined by K/At isotope dating,reservoir fluid inclusion analysis and the evolution history of different source rocks.In summary,the accumulation process consists of two stages.From the end of Triassic to early Jurassic,the northern Permian source kitchen generated a considerable amount of oil,which was finally degraded to heavy oil,migrated to the south and then accumulated.The northwestern Jurassic coal-measure source kitchen began to generate oil at the end of Cretaceous,while the northern source kitchen could only generate a little hydrocarbon.The heavy oil and the light oil have different source rock locations,migration directions and accumulation times.The migration of hydrocarbon source kitchens affects the distribution of heavy oil and light oil reservoirs at the present time.