Abstract:

Carboniferous bitumen outcrops were widely exposed in Eastern Qaidam Basin, and previous studies have confirmed that Carboniferous source rocks have undergone a hydrocarbon generation process. So an indepth study of bitumen characteristics and reservoirforming model is important to guiding the petroleum exploration in this area. The paper studied the physics and geochemistry of the bitumen in this area by using the geographical method and the experimental geochemical method, which reveals that the bitumen underwent less extent of biodegradation and oxidation. In addition, the reservoirforming model of bitumen is discussed by studying geological settings and structure movement. The widely distributed Carboniferous and Jurassic source rocks are the material basis of the formation of Carboniferous bitumen, and partial favorable reservoirs provide effective reservoir space. Unconformity surfaces and faults system are wideranging in this area which not only control the oil and gas migration, but also provide an evidence for the structure destruction of oil reservoir. The three master factors above are crucial impacts on bitumen forming in this area.

Key words: bitumen, genesis model, Carboniferous, Delingha depression