车西洼陷缓坡带下第三系低位扇勘探

对车西洼陷缓坡带下第三系进行了层序地层学研究，建立了缓坡带层序地层模式，并着重对沙四段上亚段低位扇进行了分析。该低位扇为扇三角洲沉积，其展布受控于车西缓坡发育的断裂坡折带。成藏控制因素的分析表明，低位扇的成藏主要受烃源岩、储集层、油气运移路径(同沉积断层和不整合面)及同沉积断层、储层展布控制，油藏类型为岩性-构造油藏。利用该分析成果指导该区低位扇油藏的勘探，取得了良好的效果。

Exploration of Eogene low-stand fans at the gentle slope of Chexi depression

Sequence stratigraphy in the Eogene system at the gentle slope belt of Chexi depression is researched, and its sequence stratigraphic pattern is built. The low-stand fan of the upper part of the fourth Member of the Sha-hejie Formation(Es4)is mainly analyzed in this paper. The low-stand fan of the upper Es4 is fan-delta deposit and the faulted slope fold belt developed on the gentle slope of Chexi depression controls its spread and distribution. The analysis of reservoir-forming controlling factors shows that oil accumulation in the low-stand fan is mainly controlled by source rocks, reservoirs, migration paths of oil and gas (syndepositional faults and unconformity surfaces) and the distribution of syndepositional faults and reservoirs, and it is lithologic-structural oil reservoir. The result is applied to the exploration of the low-stand fan oil reservoirs in this area a-chieving good results.