渤海湾盆地东营凹陷八面河地区潜山油气藏

Buried hill reservoirs in Bamianhe area of Dongying depression,Bohai Bay basin

于红枫 王英民 李雪

Yu Hongfeng Wang Yingmin Li Xue

渤海湾盆地东营凹陷南部斜坡带八面河地区寒武—奥陶系碳酸盐岩长期出露地表遭受淋滤剥蚀,使碳酸盐岩中溶蚀孔洞发育,加之构造活动产生的裂缝与溶蚀孔洞互相连通,形成了良好的风化壳储层。牛庄和博兴生油洼陷的沙河街组上亚段及沙河街组三段棕褐色油页岩和暗色泥岩具较强的生烃能力,是主要的烃源岩;孔店组二段灰、深灰色泥岩具良好的生烃能力,也是较为可靠的烃源岩。它们生成的油气经过由南部斜坡带的断层、新近系与古近系和古近系与中生界之间的不整合面以及古近系孔店组和沙河街组的砂体输导层组成的运移通道沿斜坡向上运移,到达八面河地区寒武—奥陶系潜山碳酸盐岩风化壳储层后,受到馆陶组、沙河街组四段及孔店组的泥岩封盖而聚集成藏。

Cambrian and Ordovician carbonates in Bamianhe area on the southern slope of Dongying depression in Bohai Bay basin have experienced leaching and denudation during the long period of outcropping,resulting in well developed dissolution rugs.Moreover,fractures resulting from tectonic activities communicate with the dissolution vugs lead to the formation of good weathered-crust reservoirs.The brown oil shales and dark-colored mudstones in the 4th and 3rd members of Shahejie Fm in Niuzhuang and Boxing sags have large hydrocarbon-generating potentials,thus they are the major source rocks.The grey and dark-grey mudstones in the 2nd member of Kongdian Fm have relatively good hydrocarbon-generating capacity,thus they are also relatively good source rocks.The hydrocarbons generated from these source rocks might have migrated through the pathways,composed of faults in the southern slope zone,the unconformities between Neogene and Paleogene and between Paleogene and Mesozoic,as well as the sandbodies or cartier beds in Paleogene Kongdian and Shahejie Formations,and upward along the slope.When they migrated into the Cambrian-Ordovician carbonate weathered-crust reservoirs in Bamianhe area,they might have accumulated and become pools,due to the sealing of mudstones in Guantao Fm,the 4th member of Shahejie Fm and Kongdian Fm.

10.11743/ogg20050310