东营凹陷胜坨地区沙三—沙四段扇体特征与岩性油气藏

FAN DEPOSIT CHARACTERISTICS OF SHAHEJIE FORMATION IN SHENGTUO AREA OF DONGYING DEPRESSION

东营凹陷胜坨地区沙四段、沙三段沉积时期 ,发育了洪积扇、近岸水下扇和浊积扇 3种扇体沉积 ,根据其沉积、成藏特征分析了 3种扇体的成藏规律和分布特点。研究结果表明 ,沙四段沉积期主要发育洪积扇 ,岩性以砾岩、含砾砂岩为主 ,断层附近砂体的储集性能好 ,多形成背斜和断块油气藏 ;沙三段下部沉积期发育近岸水下扇 ,岩性以砾岩、含砾砂岩为主 ,扇中储集物性最好 ,多形成构造岩性油气藏 ;沙三段中部沉积期发育浊积扇 ,岩性以砂岩为主 ,储集性能好 ,但砂体薄 。

Various fan deposits such as fluvial fans, coastal subaquatic fans and turbidity fans were developed in Es\-3 and Es\-4 deposition periods in Shengtuo area of Dongying Depression. The reservoir forming and distribution rules of above mentioned fans were analyzed comprehensively, according to the sedimentation and reservoir features. Fluvial fans developed in Es\-4 deposition period were characterized by conglomerate and gravel bearing sandstone formation. These fans often developed anticlinal and block reservoirs, and sandstones near faults have good reservoir properties. Coastal sub aquatic fans often developed in early period of Es\-3 deposition were characterized by conglomerate and gravel bearing sandstone formation. The mid fan often developed structural lithologic hydrogen pool with the best reservoir property. Turbidity fans developed in the middle period of Es\-3 deposition were characterized by sandstone formation showing good reservoir property and thin sand bodies, and the lenticular body and updip wedge out reservoirs were often developed.