渤中地区蓬莱19-3油田油源分析及其成藏与勘探意义

Oil Origin Analysis of PL19-3 Oil Field,Bozhong Area and its significance to oil accumulation and exploration

通过烃源岩的分布与成熟演化进行油源对比,认为PL19-3原油是来自古近系东营组下段(东下段)和沙河街组烃源岩的混源油.沙河街组烃源岩的原油主要来自庙西凹陷、黄河口凹陷,以及渤中凹陷东部区域;东下段烃源岩主要来源于渤东凹陷.多层系源岩、多个生烃凹陷供油为PL19-3晚期构造圈闭快速成藏提供了充足的油气来源.该地区小型凹陷,即渤东、庙西和黄河口凹陷具有重要的勘探前景.

Penglai(PL)19-3 oilfield,in reserve,is the biggest one of the oilfields whose reserves are more than a hundred million tones discovered up to date in Bozhong area.Its oil source is a research focus for a long time.The study on the distribution and maturation of the hydrocarbon source rock and the correlation analysis of oil with source rock show that the crude oil of PL19-3 oilfield is the mixed oil of the oil from lower member of Dongying Formation(Oligocene)source rock with the oil from Shahejie Formation(Eocene)source rock.The oil of Shahejie Formation source rock is mainly from Miaoxi Sag,Huanghekou Sag and the eastern area of Bozhong Sag;the oil of lower member of Dongying Formation is mainly from Bodong Sag.The source rock of several strata and several sags provide rich oil source for the quick accumulation of the structural traps in PL19-3 oilfield in late stage.Bodong Sag,Miaoxi Sag and Huanghekou Sag has important exploration prospects.