沧东凹陷孔东斜坡孔二段沉积特征与油气成藏

Sedimentary characteristics and hydrocarbon accumulation of the 2nd Member of the Kongdian Formation in the Kongdong Slope,the Cangdong Sag

基于沧东凹陷孔东斜坡构造特征、沉积储层特征及区域控砂控藏机制的分析,对孔东斜坡沉积特征与油气成藏模式进行了探讨。研究表明,孔东斜坡孔二段砂岩来自孔店凸起、徐黑凸起两大物源;砂体属三角洲沉积环境,储层物性好,砂岩与烃源岩互层式沉积,源储一体,生储盖组合配置关系好,是岩性油气藏勘探的重点领域。通过对斜坡控砂控藏机制的研究,认为孔东斜坡区孔二段为多物源、多期砂体与反转斜坡构造叠置,具有斜坡中低部位富砂、高部位富泥、砂体上倾尖灭的特征。根据研究成果实施钻探,多口井获工业油流,形成了规模增储新领域。

Based on analyzing the structural characteristics,sedimentary reservoir characteristics and regional sand-control and reservoir-control mechanism of the Kongdong Slope in Cangdong Sag,the study obtained a new understanding of sedimentary characteristics and hydrocarbon accumulation model of this slope.The study shows that the sandstone of the second Member of Kongdian Formation in the Kongdong Slope was derived from two provenances of the Kongdian uplift and Xuhei uplift.The sandstone is delta facies with good reservoir physical properties.It is interbedded with the source rock in this area,showing an integrated source-reservoir feature and a good source-reservoir-cap assemblage,making this slope a key area for prospecting lithologicoil-gas reservoirs.Through studying the sand-control and reservoir-control mechanism,it is considered that the Kong-2 Member in the Kongdong Slope is the superposition of multi-source,multi-stage sand bodies and inverted slope structure,which is sand-rich in the middle and low parts of the slope,mudrich in the high parts and pinch-out of upward inclination of sand bodies.According to the research results,many wells have been drilled and have obtained industrial oil flow,forming a new field of large-scale energy storage.