Hydrocarbon accumulation and distribution in lower Paleozoic carbonates inTarim Basin

Carbonates are the main exploratory layers in Tarim Paleozoic cratonic basi n. With abundant oil and gas sources, the lower Paleozoic carbonate in whic h traps develop over a large area and at a high amplitude, has the basic co ndition to form large oil and (or) gas fields. Three types of petroleum acc umulation models, which consist of buried-hill petroleum accumulation in th e high part of the uplift, inner structure petroleum accumulation in the pi tching part of the uplift and fault horst petroleum accumulation on the bor der of the uplift, are found in the lower Paleozoic carbonates. Petroleum o ccurrence is mainly controlled by paleo-uplift, fault, unconformity and fra cture system. The pitching part of the paleo-uplift and the fault belts on the paleo-uplift are the favorable exploratory areas.