摘要
库车坳陷和喀什凹陷是塔里木盆地南天山山前的东、西两个勘探热点地区 ,已发现以克拉 2气田为代表的多个油气田和含油气构造。两个地区的中生界为河流 湖泊 沼泽相含煤碎屑岩沉积建造 ,是主要的烃源岩 ,煤系源岩以生气为主 ,生气强度大 ,湖泊相烃源岩以生油为主 ,油气源充足。喜马拉雅期 ,在南天山强烈挤压和推覆作用下 ,山前形成一系列成排成带展布的褶皱 逆冲断层带 ,并表现为南北分带、东西分段和上下分层的特征 ,圈闭发育 ,类型以断层相关褶皱为主。库车坳陷和喀什凹陷发育多套优质的储盖组合 ,并以古近系巨厚膏泥岩与白垩系砂岩构成储盖组合为主。南天山山前已发现的油气主要来源于三叠 侏罗系湖相、湖沼相烃源岩和石炭系碳酸盐岩 ,以晚期成藏为主 ,有利于油气的保存。因此 ,南天山山前具有形成大 中型油气田的成藏地质条件 ,勘探潜力巨大 ,既是塔里木盆地天然气勘探的主战场 ,也是石油勘探的重要地区。
The Kuqa and Kashi Depressions were hot spots for oil-gas exploration in the Tarim Basin, both of them being situated in the area south of the Nan-Tianshan Mountains. A series of oil-gas fields and petroliferous structures, for example, the Kela 2 gas field, were reported in the area. The Mesozoic accumulation conditions and potentials were discussed in the paper. The Mesozoic coal-bearing strata, with fluvial-lacustrine-marshy sedimentary facies, were main source rocks, in which the coal-measures produced gas and lacustrine source rocks produced oil, respectively. The violent compression and nappe structuring in the Himalayan orogeny resulted in a complicated fold-and-thrust system in the area south of the Nan-Tianshan Mountains, which was characterized with zonation in S-N direction, segmentation along W-E striking and structurally layered vertically. In addition to abundant oil-gas sources, the trap well developed in the area, with a majority being fault-related folds. Some excellent reservoir-cover associations were discovered, in which the associations composed of the thick Paleogene gypsum-mudstones and Cretaceous sandstones were mostly important. So far, the discovered oil-gas in the area was sourced mainly from the Juro-Triassic lacustrine-marshy clastic sediments and the Carboniferous carbonate rocks, which was accumulated in later periods, so as to be advantageous for preservation. To sum up, the area south of the Nan-Tianshan Mountains had geological conditions for accumulation of large-mesoscopic fields and good potentials, where was both a key region of gas exploration and an important area for oil prospecting in the Tarim Basin.
出处
《地质科学》
CAS
CSCD
北大核心
2004年第4期463-474,共12页
Chinese Journal of Geology(Scientia Geologica Sinica)
关键词
油气源
储盖组合
油气田
库车坳陷
喀什凹陷
成藏条件
Source rocks, Reservoir-cover associations, Accumulation in later periods, Large-mesoscopic oil-gas field, South of the Nan-Tianshan Mountains, The Kuqa Depression, The Kashi Depression
