中上扬子区层序样式对盖层封闭性的控制作用  

Control on cap rock seal capacity by sequence style in middle-upper Yangtze region

作　　者：周雁[1] 彭勇民[1] 李双建[1] 

机构地区：[1]中国石油化工股份有限公司石油勘探开发研究院,北京100083

出　　处：《石油实验地质》2011年第1期28-33,共6页Petroleum Geology & Experiment

基　　金：国家科技重大专项项目(2008ZX05005-002);国家自然科学基金项目(40739904)资助

摘　　要：中上扬子区海相沉积主要表现为T型、H型和TH型3种层序样式,不同层序样式对成藏要素的控制作用不同。相对于T型、TH型,盖层沉积及演化主要受H型样式控制。对于泥质岩盖层,H型样式的二级层序海侵体系域(TST)下部的盖层质量较好;对于膏盐岩盖层,它们多出现于快速海侵、缓慢海退的H型样式的二级层序高水位体系域(HST)中。同时,H型样式泥岩在三级层序内的TST也有利于油气封盖;在湖南古丈县罗依溪镇的栖凤隧道剖面上,由HST到TST,突破压力从小变大,比表面积从大变小,页岩中的砂质含量变小、灰质含量增大,显然,H型样式泥质岩类盖层TST明显比HST好。The marine strata in the middle--upper Yangtze region can be divided into 3 types.. T, H and TH. Different sequence style has different effect on accumulation. Cap rock deposition and evolution are mainly controlled by the H style. As to muddy cap formations, the cap rocks in the 2nd grade transgression system tracts （TST） of the H style are good in quality. For gypsum cap formations, the cap rocks in good quality mainly locate in the 2nd grade high-stand system tracts （HST） of the H style, which has experienced fast transgression and slow regression. Meanwhile, the mudstones in the 3rd grade TST of the H style are also favorable for petroleum sealing. On the profile of Qifeng tunnel, Luoyixi Town, Guzhang City, Hunan Province, from HST to TST, breakthrough pressure and calcareousness content increase, while specific surface area and sandy content decrease. It illustrates that the seal capacity of muddy cap rocks in transgression system tracts is better than that in high-stand system tracts.

关 键 词：层序样式 盖层 保存条件 海相沉积 扬子地区 

分 类 号：TE122.25[石油与天然气工程—油气勘探]