川北地区下三叠统飞仙关组优质鲕滩储层成岩演化序列

作    者:侯振学1,王兴志2,宋光建3,李军龙4,胡占群3
单    位:1中海油田服务股份有限公司油田技术事业部资料解释中心; 2西南石油大学资源与环境学院;3中国石油新疆油田公司; 4中国石油川庆钻探工程有限公司井下作业公司
基金项目:
摘    要:
早三叠世飞仙关期,川北地区为台地与海槽相间的沉积格局,在两者的转换地带,发育了大套台地边缘碳酸盐鲕粒滩。该套储层经历的破坏性成岩作用类型主要有压实、压溶作用和胶结作用,建设性成岩作用主要有泥晶化作用、新生变形及重结晶作用、白云石化作用和溶蚀作用。讨论了各种成岩作用的主要特征及对储层的影响。结合成岩阶段划分,建立了该储层的成岩序列。胶结作用可分为三期,对储层的破坏作用非常强,尤其是第二期胶结作用以后,残存下来的孔隙降至5%左右。白云石化作用主要有混合水白云石化和埋藏白云石化,它不仅将岩石孔隙度提高了5%左右,更重要的是在白云岩中形成了较多的晶间孔,为后期埋藏溶蚀作用创造了施展空间。埋藏溶蚀作用使白云岩中的晶间孔溶蚀扩大,形成晶间溶孔,这是优质白云岩储层形成的必要条件,它可将孔隙度再提高5%耀20%左右。
关键词:鲕粒滩相;碳酸盐岩储层;成岩作用;飞仙关组;四川盆地北部

Diagenetic Evolution Sequence of Lower Triassic Feixianguan Excellent Oolitic Beach Reservoir in Northern Sichuan Basin

Author's Name: Hou Zhenxue, Wang Xingzhi, Song Guangjian, Li Junlong, Hu Zhanqun
Institution: Data Interpretation Center, CNOOC Oilfield Services Limited
Abstract:
A platform/trough in-between sedimentary pattern developed in northern Sichuan Basin during Early Triassic Feixianguan age. Thick carbonate oolitic beach reservoirs of platform-marginal facies are developed in the transition zones between platforms and troughs. The reservoirs underwent both destructive and constructive diagenesis. The destructive diagenesis includes compaction, pressolution and cementation and the constructive diagenesis are micritization,neomorphism and recrystallization, dolomitization, dissolution. The main characteristics of these diagenesis and the influence to reservoirs are discoursed. Combined with every diagenetic stage, a diagenetic evolution sequence of reservoirs is set up. Cementation can be divided into three phases, all of which acted as heavy destruction, especially after the second phase of cementation, the porosity in reservoirs decreased to about 5%. Dolomitization includes mixed-water dolomitization and burial dolomitization, which not only increased porosity by about 5 percent but also made a great number of intercrystalline pores form to create favorable rooms for the post-burial dissolution.Burial dolomitization can enlarge intercrystalline pores in dolostone to form intercrystalline dissolution porosity that can increase about 5% to 20% of additional porosity, which is a necessary condition to be high quality dolostone reservoirs.
Keywords: Oolitic beach facies; Carbonate reservoir; Diagenesis; Feixianguan Formation; Northern part of Sichuan Basin
投稿时间: 2011-10-30  
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