柴达木盆地马海气田地质特征及运聚成藏机理模式

GEOLOGIC FEATURE AND MIGRATION-ACCUMULATION MECHANISM OF THE MAHAI GAS FIELD, THE QAIDAM BASIN

刘元 罗群 庞雄奇 李自龙

Liu Yuan Luo Qun Pang Xiongqi Li Zilong

浙江大学, 地球科学系, 浙江, 杭州, 310017 2. 北京展谱石油技术开发有限公司, 北京, 102249 3. 石油大学, 盆地与油藏研究中心, 北京, 102249

Department of Earth Sciences, Zhejiang University, Hangzhou, Zhejiang 310017, China 2. Beijing Zhanpu Petroleum Technology Development Co. Ltd, Beijing 102249, China 3. Research Center of Basin and Accumulation, University of Petroleum, Beijing 102249, China

马海气田包括马海构造顶部浅层构造气藏和其西南翼深层地层超覆气藏2个不同层位、不同特征、不同类型、不同形成时期、不同成藏主控因素的气藏。气源均来自40~50km以外的伊北凹陷。断裂和不整合面是天然气长距离垂向、横向运移的重要通道。它们经历了不同的气藏形成与演化阶段,具有不同的油气成藏动力学特征,从而形成了马海浅层构造气藏的“构造力驱动、断裂-输导层输导、次生型油气运聚成藏”机理模式和马海深层地层超覆气藏的“浮力驱动、断裂-不整合输导、原生型油气运聚成藏”机理模式。最后运用这2种机理模式预测了柴达木盆地有利的天然气聚集区带。

The Mahai gas field includes Mahai shallow layer tectonic gas accumulation and Mahai deep layer stratigraphic overlap gas accumulation with different accumulation types, forming periods, as well as main controlling forces. Gas of the two accumulations both come from the Yibei depression 40-50 km to the Mahai gas field. Fault and unconformity are the most important paths for vertical and lateral migration. The formation and evolution as well as dynamic features are different, resulting in two kinds of gas migration-accumulation mechanism models: 1)"tectonic stress drives gas to migrate along fault-conduction and forms secondary gas accumulation" for the Mahai shallow layer tectonic gas accumulation; 2)"buoyancy drives gas to migrate along fault-unconformity and forms primary gas accumulation" for the Mahai deep layer stratigraphic overlap gas accumulation. Favorable gas accumulation regions of the Qaidam basin are forecasted according to the two mechanism models.

国家重大基础研究(973)项目(G19990433)

https://doi.org/10.11781/sysydz200502158