鄂尔多斯盆地晚古生代以来构造-沉积演化与致密砂岩气成藏  

The relationship between tectonic-sedimentary evolution and tight sandstone gas reservoir since the late Paleozoic in Ordos Basin

作　　者：杨华[1,2] 刘新社[1,2] 闫小雄[1] 

机构地区：[1]中国石油长庆油田分公司,陕西西安710018 [2]低渗透油气田勘探开发国家工程实验室,陕西西安710018

出　　处：《地学前缘》2015年第3期174-183,共10页Earth Science Frontiers

基　　金：国家大型油气田及煤层气开发重大专项(2011ZX05007-004;2011ZX05044)

摘　　要：鄂尔多斯盆地上古生界主要发育致密砂岩气藏,已发现地质储量超过5万亿m3,勘探潜力大。文中通过盆地构造演化史分析,结合包裹体测温、锆石U-Pb定年、自生伊利石K-Ar测年等分析方法,明确了晚古生代以来构造演化对上古生界致密砂岩气藏的控制作用。研究表明:石炭纪—二叠纪沉积古地形平缓,构造沉降缓慢,形成了大面积分布的煤系烃源岩和砂岩储层;三叠纪—中侏罗世快速沉降,压实作用及硅质胶结作用明显,水岩作用强,致密砂岩储层形成;晚侏罗世—早白垩世构造活动强烈,伴随构造-热事件的发生,天然气大量生成并运聚成藏,致密气藏形成;早白垩世末—现今地层抬升剥蚀,天然气散失,低压气藏形成。Ordos Basin dominantly developed tight sandstone gas reservoirs in the Upper Paleozoic, with great exploration potential as large geological reserve, more than 5 trillion m3. By analyzing the tectonic evolution history of the basin, combined with inclusion thermometry, zircon U-PB dating and authigenic illite K-Ar dating etc. , it is defined that the controlling role on Upper Paleozoie tight sandstone gas reservoir is the tectonic evolution since the Late Paleozoic. Studies have shown that sedimentary palaeotopography was gentle and tectonic subsidence was slow during the Carboni{erous-Permian, which formed source rocks and sandstone reservoir with great extent. During the Triassic - Middle Jurassic, sedimentation became rapid with significant compaction and siliceous cementation. Along with strong water-rock interaction, tight sandstone reservoir began to occur. Intensive tectonic activities with the occurrence of thermal tectonic events made a large number of natural gas generated and migrated to accumulate during the Late Jurassic- Early Cretaceous, which resulted in forming tight gas reservoir. From the Early Cretaceous to present, some natural gas was lost, ~nd lots of low-pressure gas reservoirs have formed due to stratum uplift and denudation.

关 键 词：鄂尔多斯盆地 上古生界 构造演化 致密气 低压气藏 

分 类 号：P618.130.2[天文地球—矿床学]