达县—宣汉地区长兴组礁滩白云岩成岩作用与成岩环境研究

Diagenetic processes and environments of the reef shoal dolostones from the Changxing Formation in the Daxian-Xuanhan region,northeastern Sichuan

摘要: 达县—宣汉长兴组礁滩白云岩主要成岩作用类型有压实作用、压溶作用、胶结作用、白云石化作用、新生变形作用、溶蚀作用、破裂作用和充填胶结作用等,对研究区储层贡献最大的成岩作用主要是溶蚀作用、新生变形作用和破裂作用。根据岩石中所形成的大量溶蚀孔隙、晶间溶孔和晶间孔以及裂缝的特征,该套礁滩白云岩储层的良好物性主要形成于中—深埋藏环境。

Abstract: The diagenesis of the reef shoal dolostones from the Changxing Formation in the Daxian-Xuanhan region includes compression,pressure solution,cementation,dolomitization,neomorphism,dissolution,fracturing and infilling-cementation,of which dissolution,neomorphism and fracturing serve as most important ones in the study area.Judged from abundant solution openings,intercrystal solution openings,intercrystal pores and fissures and cracks in the reservoir rocks,the good physical properties of the reef shoal dolostone reservoirs should be formed in the moderately and deeply buried environments.