沾化凹陷孤岛凸起西缘地区古近系沉积储层特征及成藏条件分析

Sedimentary Reservoir Characteristics and Hydrocabon Pooling Conditions of Paleogene in the West Area of Gudao Uplift of Zhanhua Depression

沾化凹陷孤岛凸起西缘地区尚有较大面积的储量空白区以及多个孤立出油点,具有良好的勘探潜力,但一直以来缺乏系统完整的研究阻碍了进一步油气勘探的开展。本文系统分析孤岛凸起西缘地区古近系的烃源岩、储层、盖层、圈闭、运移、保存等油气成藏的六要素特征,探讨了研究区的油气成藏条件,认为孤岛凸起西缘地区古近系具有良好的油气成藏条件。研究区处于渤南洼陷和孤岛凸起之间的坡折带,在两边正负向构造强烈活动的双重影响下,有利于来自渤南洼陷沙四、沙三段烃源岩生成的油气沿断层、不整合面及砂体等优势运移通道通过侧向和垂向两种方式运移,并在研究区发育的扇三角洲、浊积扇等储集层内形成地层岩性油气藏和构造–岩性复合油气藏。

Although there are several isolated oil yielding points in the west area of Gudao uplift of Paleo-gene,a large area of no reserve is still remained.It showed a good exploration potential of Paleogene in the west area of Gudao uplift in Zhanhua Depression.However,lacking of systematic geological research hampers further oil and gas exploration.Based on the systematic research of structure,strata and sedimentary characteristics of Paleogene in the west area of Gudao uplift,source rock,reservoir,cap rock,trap,migration and reservation characteristics were researched.It is concluded that oil and gas accumulation conditions of Paleogene in the west area of Gudao uplift of Zhanhua Depression are advantageous.The study area is located in the slope break belt which is located between Bonan Sag and Gudao uplift.Under the influence of positive and negative structure activity,the oil and gas that generated from the source rock in the 4th and 3rd member of Shahejie Formation in Bonan Sag were migrated along the fault,unconformity and sandbody,and then accumulated into lithologic oil reservoirs and structural-lithologic reservoirs which were formed in the fan-delta and turbidite fan.