摘要: |
基于测录井资料对比,结合区域构造演化特征,将草湖凹陷侏罗系划分为两个三级层序J-SQ1与J-SQ2。J-SQ1时期气候温暖潮湿,层序发育完整的上升半旋回和下降半旋回沉积,发育辫状河体系和湖泊体系;J-SQ2时期气候逐渐转为炎热半干旱,层序发育不完整,只发育上升半旋回沉积,主要由氧化型湖泊体系构成,发育滨浅湖砂滩、泥滩互层沉积。其中,J-SQ1早期辫状河河道砂体叠置厚度大,储层物性好,上覆中厚层湖相泥岩沉积,是本区有利的储集层段。 |
关键词: 草湖凹陷 侏罗系 沉积体系 层序地层 |
DOI: |
附件 |
投稿时间:2010-05-28修订日期:2010-08-30 |
基金项目:国家十一五重大科技专项(2008ZX05002) |
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Sequence stratigraphy and depositional systems in the Caohu depression, Tarim Basin, Xinjiang |
LU Jin-bo, WANG Ying-min, ZHANG Lei, WANG Gai-yun, GU Xiu-mei |
(1. School of Resources and Information Technology, China University of Petroleum, Beijing 102249, China; 2. State Key Laboratory of Petroleum Resources and Exploration, China University of Petroleum, Beijing 102249, China; 3. PetroChina Coalbed Methane Co. ltd., Beijing 100028, China; 4. Dagang Oil Field Power Company, Tianjin 300280, China) |
Abstract: |
The Jurassic strata in the Caohu depression, Tarim Basin, Xinjiang are divided, on the basis of well logs and regional tectonic evolution, into two third-order sequences J-SQ1 and J-SQ2. During the deposition of J-SQ1 sequences, the climates were warm and humid. The sequence displays the complete rising-falling semicyclic deposits. Till the deposition of J-SQ2 sequences, the climates turned into hot and semiarid ones. The sequences display only the rising semicyclic deposits, and consists of oxidized lacustrine depositional systems in which the littoral-shallow lacustrine sand-mud beach deposits are developed. The braided channel sandstones in J-SQ1 sequences are believed to be the favourable reservoir rocks in the study area due to tremendous thickness, better physical properties and moderate to thick overlying lacustrine mudstone. |
Key words: Caohu depression Jurassic depositional system sequence stratigraphy |