苏北高邮凹陷下第三系砂岩中碳酸盐胶结物类型演变及其地质意义

本文根据苏北高邮凹陷下第三系砂岩油层中碳酸盐胶结物的薄片和电镜扫描研究,按碳酸盐胶结物的类型演变特征分为五类;1.泥晶状碳酸盐,2.重结晶状碳酸盐,3.溶性状碳酸盐残留物,4.铁碳酸盐沉淀,5.镶嵌交代状碳酸盐。对各类碳酸盐的成因与成岩阶段的关系及其对储集层的影响进行了探讨,并认为在油田开发期要防止铁碳酸盐在酸化过程中以Fe(OH)₃和H₂S的形式沉淀,造成油层损害。 

EVOLUTION OF THE TYPE OF CARBONATE CEMENTS IN LOWER TERTIARY SANDSTONE OF GAO YOU DEPRESSION IN NORTHERN JIANGSU AND ITS GEOLOGICAL SIGNIFICANCE

The thin section study and electronic scanning microscopy were applied to carbonate cements in sandstones of oil layers in lower Tertiary of Gao You depression in northern Jiangsu.Based on the characteristics of evolution,five types of carbonate cements are determined.1.Micritic carbonate 2.recrystalliz-ed carbonate 3.dissolution carbonate relics 4.ferri-carbonate precipitates 5,Mosaic replaced carbonate.The relationship between the origins of various types of caronates and diagenetic stages and the affects on reservoirs were discussed.The author thought ferri-carbonate is likely to precipitate in the forms of Fe(OH)₃ and H₂S in the process of acidulation during field deve-loment,which would damage oil formation.