摘要
在西湖凹陷花港组低渗储层背景下,优质储层的发育伴随绿泥石和硅质胶结的同时富集,这与绿泥石抑制硅质胶结的观点存在矛盾.综合利用X衍射、铸体薄片、包裹体测试和扫描电镜及能谱分析等资料,以绿泥石分类及其成因分析为基础,通过对比不同粒度储层绿泥石和硅质胶结分布规律,结合地层条件和储层质量演化,分析绿泥石对硅质胶结的影响.研究结果表明:绿泥石发育孔隙衬里和孔隙充填两种产状,孔隙衬里绿泥石由早期黏土薄膜重结晶或直接由孔隙流体结晶而成,孔隙充填绿泥石受控于火山碎屑和长石溶蚀;绿泥石和硅质胶结均在物性较好的粗粒储层中富集;浅埋低地温阶段,孔隙衬里绿泥石有效抑制硅质胶结,仅在绿泥石不连续或颗粒破裂处发育孤立柱状石英晶体,深埋高地温阶段,难以有效抑制硅质胶结,多发育石英加大边;粗粒储层比细粒和砂质砾岩及泥砾岩储层孔隙发育,为石英加大边提供必要的生长空间,导致绿泥石相对含量更高的粗粒储层中硅质胶结也更发育.
In the background of low-permeability reservoir in Huagang Formation,Xihu depression,high-quality reservoir is often associated with the enrichment of chlorite and siliceous cement,which is inconsistent with the view that chlorite can restrain siliceous cement.The classification and formation of chlorite were analyzed by X-ray,casting thin section,fluid inclusion test and scanning electron microscopy with spectrum.And the influence of chlorite on siliceous cement was studied through the comparison of the distribution of chlorite and siliceous cement in different reservoirs and the evolution of formation condition and reservoir quality.The results show that chlorite presents as pore-linking and pore-filling occurrences.Pore-linking chlorite is formed by the recrystallization of early clay coating or crystallization of pore fluid,and pore-filling chlorite is closely related to the dissolution of volcanic debris and feldspar.Chlorite and siliceous cement are both abundant in coarse reservoir(except sandy conglomerate and muddy gravel reservoir).Chlorite can hinder siliceous cement effectively during shallow burial and low geotemperature,and siliceous cement only grows above discontinuity chlorite or broken particle as isolated columnar quartz.Siliceous cement cannot be prevented during deeply buried and high geotemperature,and it develops as quartz overgrowth.The pores of coarse reservoir are more abundant than fine reservoir and conglomerate and muddy gravel reservoir,and the pores provide necessary space for quartz overgrowth,which is the main reason why chlorite and siliceous cement are both plentiful in high-quality coarse reservoir.
作者
孙小龙
林承焰
董春梅
张宪国
马存飞
林建力
谢晶晶
Sun Xiaolong Lin Chengyan Dong Chunmei Zhang Xianguo Ma Cunfei Lin Jianli Xie Jingjing(School of Geosciences, China University of Petroleum, Qingdao 266580, China Reservoir Geology Key Laboratory of Shandong Province, Qingdao 266580, China Shanghai Branch of CNOOC Ltd., Shanghai 200335, China)
出处
《地球科学(中国地质大学学报)》
EI
CSCD
北大核心
2017年第9期1599-1607,共9页
Earth Science-Journal of China University of Geosciences
基金
国家科技重大专项(No.2016ZX05027-004)
国家自然科学基金面上项目(No.41672129)
关键词
西湖凹陷
花港组
绿泥石
孔隙衬里
成因机制
硅质胶结
沉积学
Xihu depression
Huagang Formation
chlorite
pore-linking
formation mechanism
siliceous cement
sedimentology