文昌A凹陷珠海组储层区域成岩作用特征及定量评价

Regional diagenesis feature and quantitative evaluation from Zhuhai Formation reservoir in Wenchang A Sag

运用砂岩铸体薄片、扫描电镜、图像分析、孔隙定量分析等资料,研究珠海组深部储层砂岩成岩作用,确定成岩作用横、纵向分布规律;计算成岩参数压实损失的孔隙度和压实率、胶结量、视溶蚀率和溶蚀量,分别对压实作用、胶结作用和溶蚀作用进行定量评价,确定区域成岩作用强度.结果表明:珠海组总体为中等—强压实.其中,凹陷西缘为弱胶结、中等溶蚀;凹陷中心以中等胶结、中等溶蚀为主;南断裂东段下降盘为中等—强溶蚀,珠海组一段和二段为中等—强胶结,珠海组三段为弱—中等胶结;南断裂中段下降盘珠海组一段和二段为中等胶结,珠海组三段为弱胶结,珠海组一段为中等近强溶蚀.

Diagenesis of Zhuhai Formation sandstone is studied by cast thin sections,SEM analysis,image analysis and pore quantity analysis et al datum,to recognize the regularities of distribution of diagenesis.Quantity evaluation of compaction,agglutination,dissolution iscarried out respectively by losing porosity of compaction and compaction rate,cementation amount,solution rate and solution amount calculated,to determine the degree of regional diagenesis.Zhuhai formation is totally moderate-strong compaction,in the west edge of depression is weak cementation,moderate solution;in the center of depression is mainly moderate cementation,moderate solution;in north section of downthrow wall of south rapture is moderate-strong solution,the first and second members of Zhuhai formation are moderate-strong cementation,the third member of Zhuhai formation is weak-moderate cementation;in middle section of downthrow wall of south rapture,the first and second members of Zhuhai formation is moderate cementation,the third member of Zhuhai formation is week cementation,the first member is moderate-nearstrong solution.