塔里木盆地库车凹陷克拉苏构造带典型构造样式与变形机理分析

ANALYSIS ON THE TYPICAL STRUCTURAL STYLES AND DEFORMATION MECHANISM OF THE KELASU TECTONIC ZONE IN THE KUQA DEPRESSION OF THE TARIM BASIN

孙家振 李兰斌 周新源 皮学军

SUN Jiazhen LI Lanbin ZHOU Xinyuan PI Xuejun

中国地质大学, 石油系, 湖北, 武汉, 430074 2. 中国石油, 新疆塔里木油田股份公司, 新疆, 库尔勒, 841000

Petroleum Department, China University of Geosciences, Wuhan, Hubei 430074, China 2. Tarim Petroleum Exploration and Development Bureau, CNPC, Kuerle, Xinjiang 841000, China

克拉苏构造带是库车坳陷天然气最富集的区带之一.受发育含盐层系的影响,表现为盐上层与盐下层构造变形上下不协调,具双重逆冲构造特征.盐上层发育有低缓倾角的逆冲推覆型牵引构造、陡倾角的逆冲推覆型牵引构造和陡倾角的块体上冲型构造;盐下层以发育叠置的冲断构造为主要特征.根据岩石力学性质分析,逆冲断裂的产状和盐上层构造样式的变化与塑性盐岩层发育的厚度和分布范围等因素有关;同时,由于盐岩层为高质量的天然气盖层,其厚度和连续性的变化也是造成克拉2、克拉3构造天然气差异性聚集的关键因素.

The Kelasu tectonic zone located in the Kuqa Depression of the Tarim Basin is rich in natural gas.Affected by salt-bearing measures,the structural deformation of salt-above layers is not consistent with that of salt-under layers,and it has the features of dual thrust structures.The thrust-nappe-typed drag structre with gentle or deep dipping angles,and the mass-upthrusting structure with deep dipping angles were developed in salt-above layers.And salt under layers are characterized by developing superimposed thrust structures.According to the analysis of lithomechanical properties,the occurrence of thrust faults and the change of structural patterns in salt-above layers are related to the developing thickness and distributive range of plastic saltrock layers.Meanwhile,as saltrock layers are high quality caprocks for natural gas,their thickness and continuous changes are also key factors to result in the differential accumulation of natural gas in the Kela 2 and Kela 3 structures.

https://doi.org/10.11781/sysydz200303247