摘要
根据模拟实验结果分析了塔里木盆地库车坳陷北部第三系膏盐质盖层岩石力学特征。膏岩、盐岩和泥岩为塑性材料,变形过程为典型的塑性形变,蠕变表明第三系膏盐质盖层具有较强的流动性。构造挤压使膏盐质盖层塑性流动,受断裂改造作用往往在构造圈闭上方形成巨厚的膏泥岩层。膏泥岩岩性致密,排替压力高,普遍具有异常高的孔隙流体压力,是一套优质盖层。盖层段内的穿盐断裂和盐内滑脱断裂多为膏泥岩蠕变形成的塑性断层,断裂带内部结构主要为软泥充填的大裂缝组合,伴生裂缝不发育,断裂静止期封闭性好,有效阻止天然气散失。
Rock mechanic characteristics of the Tertiary gypsum cover in the north of Kuche depression is analyzed based on simulation experiment. Plaster rock, salt rock and mudstone are plastic material and have the ability of plastic deformation. Creeping shows that the Tertiary gypsum cover has strong fluidity. Plastic flow appears if the gypsum cover suffers tectonic stress. Under the influence of fault, the gypsum cover usually forms huge gypsum mud cover tectonic trap, which is compact with high expulsion and pore fluid pressure so as to be good cover. Most of fractures and detachment fractures are formed by gypsummud rock creeping. And there are huge fracture groups filled with ooze in fracture zone, which have excellent enclosing function and hold gas back effectively.
出处
《石油实验地质》
CAS
CSCD
北大核心
2006年第1期25-29,共5页
Petroleum Geology & Experiment
基金
国家重大基础研究(973)项目(2001CB20914)
关键词
封闭
塑性断层
岩石力学
膏盐质盖层
库车坳陷
塔里木盆地
sealing
plastic fault
rock mechanics
gypsum cover
the Kuche Depression
the Tarim Basin
