卫81 块沙四段储层沉积微相及剩余油分布研究

The Sedimentare Microfacies of Reservoirs and the Features of Remained Oil Distribution in the Fourth Member of Wei 81 Fault-Block in Weicheng Oilfield

刘永春,李晓平,王　波,刘丽莉,张雪玲

Liu Yongchun , Li Xiaoping, Wang Bo, et al

中原油田分公司勘探开发科学研究院

Research Institute of Petroleum Exploration and Development , Zhongyuan Oilfield Company , SINOPEC, Henan 457001 , P. R. China

针对卫城油田卫81 块沙四段油藏储层非均质性严重、油田处于中高含水开发期,水驱动用程度低的特点,对其储层沉积特征、流动单元沉积微相及剩余油分布的关系进行了研究。该区E_s4 段属于浅水湖泊三角洲沉积,骨架砂体为河道砂、河道间砂、前缘砂(席状砂) 、远砂坝。动态资料及油藏精细描述、数值模拟等项研究表明,流动单元的沉积微相与油层的水淹程度和地下剩余油的分布密切相关:河道砂微相油层水淹严重,剩余油潜力较小,前缘砂和河道间微相油层水淹中等,剩余油潜力较大;远砂坝微相油层水淹程度低,剩余油有一定潜力。根据剩余油分布特点,确定了5 种改善水驱效果的方法,实施后取得了较好的效果。

Aimming at the high heterogeneity of the reservoirs , mid-high water content , low efficiency of water drive , this article studies the relationship arnong the depoSitional features of the reservoirs , the microfacies of flow units and the distribution of remained oil in the fourth Member of 81 fault-block in Weicheng Oilfield. Es4 in this area belongs to shallow lake deltaic deposit , with sandstone mainly of channel sand , interbasin sand , frontal sand and far bar. Performance data , fine reservor description and numerical simulation show : there are close relations among sedimentary micro facie of flow units , the water-out level of reservoirs and the distribution of the remained oil. That is , if the channel sand reservoir are seriously water -out ,the development potential of remained oil is small ; frontal sand reservoir and interbasin sand reservoirare water-out intermediately , the development potential of remained oil is high ; and if the far bar reservoir is oprly water -out , there is certain possibility for remained oil. Thus , 5 plans are made to better water drive on the grollnd of the features of the rernained oil , and have got success in practice.