Oil and gas accumulation and exploration potential in the Biyang sag north slope

By summarizing distributional characteristics of oil and gas of the northern slope belt in Biyang sag,on the basis of the oil sources, nose-like structure, sand body extension direction and size, fault system characteristic and their configuration relationships, northern slope belt can be divided three types of accumulation models:migration-accumulation of convergent type, migration and accumulation along the fault-adjusting hydrocarbon migration along the northeast of sag, controlling accumulation model and slope selfsource and self-reservoir accumulation models along the northwest of sag. This paper analyzed and summarized the regularities and characteristics of hydrocarbon enrichment that are ①inheritance deposition-tectonic slope is directing zone of hydrocarbon large-scale migration, and nose shaped uplift is hydrocarbon enrichment belt;②slope belt and the center of sag are favorable areas of shaping low-stand fan lithologic reservoirs and fault-lithologic reservoirs. And it pointed out that the main potential goals of the further exploration are old oilfield potential tapping, H3 lower section, fault-lithologic reservoirs in the slope belt, non-structural principal part lithology and fault-lithologic reservoirs, unconformity reservoirs in slope border shallow layer and so on.