渤海湾盆地沧东凹陷孔二段致密储层孔隙结构定量表征

Quantitative characterization of pore structure of the second member of Kongdian Formation tight reservoirs in Cangdong Sag

致密储层孔隙结构评价对致密油勘探开发具有重要意义。利用岩心观察、铸体薄片、扫描电镜(SEM)、氩离子抛光—扫描电镜(Ar-SEM)等多种方法,对比研究了致密砂岩、致密白云岩和泥页岩3类致密储层的孔隙结构特征及差异性。利用ImageJ软件处理和分析SEM图像及Ar-SEM图像。对SEM图像进行伪彩色增强,突出显示其孔隙结构特征,再利用灰度值定量识别了致密储层的孔隙;对Ar-SEM图像进行二值化处理,定量评价了储层中不同孔隙类型的孔隙数目、孔径大小、面孔率、分形维数等参数。

Micro-structure evaluation of tight reservoir is the basis of tight oil exploration and development.Taking the tight reservoir of Ek2 in Cangdong Sag as an example,apply the core observation and description,casting thin sections,scanning electron microscopy （SEM）,argon ion polishing and scanning electron microscopy （Ar-SEM） analysis,to study the pore structure characteristics of tight sandstone,tight dolomite and shale reservoir.On this basis,using ImageJ software to process and analyze the SEM and Ar-SEM image.The SEM image pseudo color enhancement can highlight the characteristics of pore structure,and a comparative research can be done on these three tight reservoirs such as throat shape,size,distribution and connectivity etc.After two value processing of Ar-SEM images,we can quantitatively evaluate the reservoir pore number,pore size,face rate parameters.