蠡县斜坡沙三上亚段与沙一下亚段沉积特征及有利储层分布

Sedimentary characteristics and favorable reservoir distribution of the upper submember of the third member and the lower submember of the first member of Shahejie Formation in Lixian Slope

近年来,针对蠡县斜坡提出了以岩性-地层油藏为主的精细勘探目标,这对沉积相的精细划分和重新认识提出了更高的要求。利用岩心、录井及测井资料,精细刻画了蠡县斜坡沙三上亚段和沙一下亚段的沉积特征,并确定了有利储层的分布范围。结果表明:在沙三上亚段沉积期,辫状河道和辫状河泛滥平原较发育;在沙一下亚段沉积期,辫状河三角洲前缘水下分流河道和滨浅湖滩坝较发育。对研究区有利储集砂体物性的统计表明,储集性能由好到差依次为:辫状河三角洲前缘水下分流河道砂体、辫状河河道砂体、滨浅湖滩坝砂体、辫状河三角洲前缘河口坝砂体。在沙三上亚段沉积期,研究区中部的同口镇和辛桥村—旧城村一带发育紧邻泛滥平原泥质烃源岩的辫状河河道沉积,为寻找岩性-地层油气藏的有利地区;在沙一下亚段沉积期,研究区旧城村—西柳村一带发育辫状河三角洲前缘水下分流河道和滨浅湖滩坝沉积,为寻找岩性-地层油气藏的勘探潜力区。

In recent years, fine exploration target of lithologic-stratigraphic reservoirs has been proposed for Lixian Slope, which needs to divide and re-understand the sedimentary facies more clearly. Through core and logging data,the sedimentary characteristics of the upper submember of the third member and the lower submember of the first member of Shahejie Formation were studied, and the distribution of favorable reservoir was determined. Braided channel facies and braided river flood plain facies are developed in the upper submember of the third member of Shahejie Formation, while braided river delta front subaqueous distributary channel and shallow-shore lake beach bar are developed in the lower submember of the first memeber of Shahejie Formation. Based on the distribution characteristic of favorable reservoirs, the sand bodies with reservoir properties from good to poor are as following：braided river delta front subaqueous distributary channel, braided river channel, shallow-shore lake beach bar,braided river delta front mouth bar. During the sedimentary period of the upper submember of the third member of Shahejie Formation, braided channel next to flood plain argillaceous source rocks are developed in Tongkou area and Xinqiao-Jiuchen area, and these areas are favorable for lithologic-stratigraphic reservoirs exploration. During the sedimentary period of the lower submember of the first member of Shahejie Formation, braided river delta front subaqueous distributary channel and shallow-shore lake beach bar are developed in Jiucheng-Xiliu areas, and these areas are favorable for looking for exploration potential area.