埕岛东斜坡东营组层序地层特征及油气勘探方向

Sequence stratigraphic characteristics and hydrocarbon exploration targets of Dongying Formation in Eastern Slope Area of Chengdao Oilfield

通过岩心、钻井、测井、地震等资料的分析,对埕岛东斜坡东营组进行了层序地层划分,分析了东营组沉积相的构成、演化和分布规律,明确了油藏类型及控制因素。研究表明:东营组分为4个四级层序;发育辫状河三角洲、滑塌浊积扇、低位浊积扇、湖泊及曲流河5种沉积相类型;形成了岩性类和岩性-构造类2个油气富集区,油层主要集中在SQ2上升半旋回和下降半旋回下部及SQ3,油气成藏受控于侵蚀沟谷、断层和坡折带。在此基础上,优选有利勘探层位和区带,进行探井部署,取得了良好的勘探效果,对下步区带勘探工作具有指导意义。

According to the detailed analysis of cores, drilling, well logging data and the interpretation of seismic section, the sequence stratigraphy of Dongying Formation in Eastern Slope Area of Chengdao Oilfield is divided. At the same time, the distribution, evolution and composition of sedimentary facies are analyzed. The main controlling factor of hydrocarbon accumulation and reservoir types are determined. The result indicates that the Dongying formation is divided into four fourth-order sequence. Five kinds of sedimentary systems are identified in this area, which are braided-delta, slumping turbidite fan, low turbidite fan, lacustrine and meandering stream. Two oil and gas regions for lithologic reservoir and lithologic structure reservoir are formed. The hydrocarbons are mainly concentrated in SQ2 rising hemicycle and the lower part of declining hemicycle and SQ3. Hydrocarbon accumulation is controlled by erosion gullies, fault and slope break belt. Based on the above analyses, the favorable exploration horizons and zones are optimized. The deployment of exploration wells produces good exploration results, which can provide reliable evidence for the next exploration.