东营凹陷中央隆起带沉积体系及隐蔽油气藏

Depositional System and Subtle Reservoir in Central Uplift Belt of Dongying Sag

通过对山东东营凹陷中央隆起带主要储集层发育段——沙河街组沉积时期沉积体系的系统研究认为，沙河街 组主要存在三角洲沉积、水下扇沉积、滨浅湖沉积三种沉积体系和八种主要储集层沉积类型，各储集层沉积类型各具特 征。在此基础上，通过油藏的具体分类和特征分析，建立了复杂断块隐蔽油藏的储集层和油藏描述方法；将东营凹陷中 央隆起带中的主要油气藏划分为断块圈闭、构造圈闭和隐蔽圈闭，其中隐蔽圈闭包括砂岩透镜体圈闭、岩性上倾尖灭圈 闭、构造一岩性圈闭、断层一岩性圈闭四类；提出在控油断层自密封的情况下，油藏高度可采用Ｒ．Ｒ．Ｂｅｒｇ的原理进行计算。 对研究同类油藏及其储集层的描述具有借鉴意义。

The studies were systematically made on well-developed major reservoir member, Shahejie formation depositional system in central uplift belt of Dongying sag (Shandong Province). It is shown that in Shahejie formation there mainly exist three types of depositional systems(delta deposit, underwater fan deposit and coastal lake deposit) and eight sorts of reservoir deposits with different features for each one. Based on these and followed by proper reservoir classification and characteristics analysis, this paper established the methods for reservoir description of subtle pool with complex fault blocks, by which the main trap within the belt could be divided into fault block trap, structural trap and subtle trap which includes sand lens trap, lithologic updip thinning out trap, structural-lithologic trap and fault lithologic trap. For self-confined fault controlling oil flow, its height of oil column can be estimated by utilizing R.R.Rerg's principle. These would be of significance for reference to study of similar reservoirs and their characteristics.