渤海湾盆地沾化凹陷沙河街组页岩油微观储集特征

页岩油储层微观孔隙储集特征是勘探开发的重要基础资料。采集渤海湾盆地沾化凹陷罗69井沙河街组三段页岩油层段18块岩心样品，利用氩离子抛光-场发射扫描电镜实验，研究页岩油储层孔隙发育特征。沾化凹陷沙三段页岩油层段为泥岩和灰岩的过渡岩性，以灰质泥岩、泥质灰岩和含泥灰岩为主，夹少量灰岩薄层。页岩油层段主要孔隙类型包括泥质碎片间微孔和碳酸盐矿物的溶蚀孔、晶间孔和晶内孔。页岩油层段的储层孔隙主要由泥质部分提供，泥质粒间孔提供的面孔率贡献最大，方解石溶蚀孔对面孔率有一定贡献，晶间孔和晶内孔的面孔率贡献最低。页岩油储层孔隙的孔径属于纳米级和微米级，纳米级孔隙数量占绝对优势，然而储层孔隙面积主要由数量较少的微米级孔隙提供，即页岩油开发的储集空间应该以微米级孔隙为主要对象。 

Microscopic characteristics of shale oil reservoirs in Shahejie Formation in Zhanhua Sag,Bohai Bay Basin

The microscopic pore characteristics of shale oil reservoirs are important basic data for exploration and development. Eighteen core samples were collected from the third member of Shahejie Formation (Es₃) in well Luo 69 in the Zhanhua Sag, Bohai Bay Basin, and were analyzed using argon-ion polishing Scanning Electron Microscopy (SEM) to discuss the pore development characteristics of shale oil reservoirs. The shale oil layer in Es₃ showed a transitional lithology of mudstone and limestone, dominated by limy mudstone, argillaceous limestone and mud bearing limestone, with minor thin layers of limestone. Argillaceous inter-particle pores, carbonate dissolved pores, inter-crystal pores and intra-crystal pores are the main pore types of the shale oil layer. Argillaceous pores provided most of reservoir pores of the shale oil layer. Most of the plane porosity was argillaceous inter-particle pores, while calcite dissolved pores made a smaller contribution and inter-crystal pores and intra-crystal pores were less important. The pore diameters of shale oil reservoirs were classed as nano scale and micron scale, and the nano scale pores have an absolute dominance quantitatively. The reservoir pore area was mainly provided by non-dominant micro-scale pores, which should be focused on in shale oil exploration.