川东北飞仙关组优质储层形成研究  

DIAGENESIS OF EXCELLENT RESERVOIRS IN FEIXIANGUAN FORMATION IN NORTHEASTERN SICHUAN BASIN

作　　者：何莹[1] 郭旭升[2] 张克银[1] 赵勋[3] 边树涛[4] 周文英[1] 

机构地区：[1]中国石化西南分公司勘探开发研究院 [2]中国石化南方勘探开发分公司 [3]中国石油新疆油田公司彩南油田作业区 [4]中国地质大学

出　　处：《天然气工业》2007年第1期12-16,共5页Natural Gas Industry

基　　金：中石化西南分公司先导开发项目(编号:KF-22)的部分研究成果

摘　　要：四川盆地东北部飞仙关组经历了3个成岩演化阶段:准同生—早期成岩阶段、浅埋—中埋成岩阶段、深埋成岩阶段。主要成岩作用有:泥晶化、胶结、压实压溶、重结晶、白云石化、溶蚀和破裂等。其中,溶蚀作用和白云石化作用是改善储集性能的主要有利因素。溶蚀作用发生在成岩作用的各个阶段,以早期大气淡水渗滤作用形成选择性溶蚀和深埋藏阶段含CO2和H2S流体对全岩的溶蚀作用为主。白云石化作用,以早成岩阶段混合水白云石化作用为主,埋藏白云石化作用次之。与复杂的成岩作用对应,飞仙关组鲕滩储层的孔隙大体也经历了4次重要的演变:沉积时原始孔隙度为35%、准同生—早期成岩阶段后的25%、浅埋—中埋成岩阶段后的5.5%、深埋成岩阶段的10%。由此认为,川东北飞仙关组鲕滩相储层储集性能的改善主要依赖于白云石化作用和深埋成岩阶段的非选择性溶蚀作用。The Feixianguan Formation in northeastern Sichuan Basin has experienced 3 evolutionary stages, namely penecontemporaneous-early diagenetic stage, shallow-moderate burial diagenetic stage, and deep burial diagenetic stage. The major types of diagenesis include micritization, cementation, compaction & pressolution, recrystallization, dolomitization, dissolution and fracture, in which the dolomitization and dissolution are the major contributors to the improvement of poroperm characteristics of the oolitic beach reservoirs. Dissolution, which can occur in every diagenetic stage, is dominated by selective dissolution resulted from percolation of meteoric water in the early diagenetic stage and the whole rock dissolution resulted from CO2 and H2S fluids in the deep burial diagenetic stage. The dolomitization is dominated by mixed water dolomitization in the early diagenetic stage, followed by burial dolomitization. In correspondence with the complicated diagenesis, the pores of oolitic beach reservoir also experienced 4 major evolutionary stages: original porosity of 35% in the stage of sedimentation, 25% after the penecontemporaneous-early diagenetic stage, about 5.5% after the shallow-moderate burial diagenetic stage, and 10% in the deep burial diagenetic stage. Therefore, the high quality oolitic beach reservoirs in the Feixianguan Formation are mainly resulted from dolomitization and non-selective dissolution in deep burial diagenetic stage.

关 键 词：四川盆地 东北 早三叠世 鲕粒滩 储集层 成岩作用 “甜点”储集层 

分 类 号：P618.130.1[天文地球—矿床学]