东营凹陷王庄地区沙河街组砂砾岩扇体特征

Properties of Fan Granulite in Shahejie Formation in Wangzhuang Area, Dongying Depression of Shandong Province

随着东营凹陷北部陡坡带王庄—宁海地区亿吨级稠油藏的发现 ,稠油成藏类型的砂砾岩扇体隐蔽油气藏勘探已经成为现阶段的油气勘探的重点目标和储量增长点之一。利用现代沉积学、测井学和地震勘探等手段 ,通过对王庄地区砂砾岩扇体特征研究后认为 :王庄地区在早第三纪以形成沙三、沙四段的较高水动力能砂砾岩扇体 (冲积扇、扇三角洲、近岸水下扇 )沉积体为主 ,其中扇三角洲砂砾岩体是本区最主要的砂砾岩扇体类型 ,并具有较好的储集性能 ,是本区最主要的油气储集体 ;王庄地区砂砾岩扇体沉积 ,强烈地受制于边界构造条件 ;本区的砂砾岩扇体沉积及其形态均受沉积相的控制 ,并具有复杂多变的特征 ,从而直接导致了本区油气藏的聚集和分布具有复杂多变的特点。

When the thick oil deposit of hundred million tons is discovered in Wangzhuang to Ninghai area in the north steep slope zone of Dongying depression, the cover-up oil deposit exploration of granulite fans of thick oil diagenetic type has become a key target and rising point of oil and gas explorations at present. Through the manners of modern sedimentology, well-logging and seismic prospecting, and through the study of Wangzhuang case, the authors point out that, in early Tertiary, the granulite fans (alluvial fan, fan delta, inshore underwater fan) of higher hydrodynamic force are sedimented, of which, fan delta granulite was the most important granulite fan type in the region, of favorable storage character and the predominant storage reservoir of oil and gas. The granulite fan sedimentation in Wangzhuang area is enslaved to the boundary tectonic conditions; the granulite fan sedimentation and its shaping are both controlled by sedimentary facies and provided with complex and changeable characteristics, and the complex and changeable properties of the accumulation and distribution for the oil deposit are resulted from the above characteristics.