Abstract:Proven, Fulaerji oilfield, Jiangqiao oilfield, Erzhan-Alaxin oil-gas field, Baiyinnuole oil-gas field and Pingyang oil-gas field have been found in west slope area, north Songliao Basin. They are located in outside of source area, distance source sag 30~100km. Hydrocarbon accumulation factor is the core issue of oil and gas exploration in west slope area. Based on the structural geology, sedimentary geology and petroleum geology theories, we study on structural characteristics, sedimentary characteristics and typical reservoir anatomy. The main controlling factors of hydrocarbon accumulation show that discovered oil and gas enrich in four nose structural belts and overlap belt, distributary channel sand body, mouth bar, far sand dam and sheet sand are oil and gas reservoir, the hydrocarbon accumulation and enrichment degree are controlled by structural and sedimentary sand body type. Typical reservoir anatomy shows that the reservoir types are various, include micro-amplitude structural reservoir, lithological- structural reservoir, structural-lithological reservoir and lithological updip pinchout reservoir type, etc. Combining with structure, fracture, sediment and hydrocarbon migration factors, we establish oil and gas accumulation model of west slope area, demonstrate that unconformity surface, fault and sand body are hydrocarbon migration channel. We point out oil and gas exploration direction of west slope area for future.