塔里木盆地西部断层的活动性与封闭性

Activity and sealing property of faults in the western part of Tarim basin

研究区位于塔里木盆地西部,主要跨越巴楚断隆和阿瓦提凹陷两个构造单元。自寒武纪以来,本区主要经历了三次挤压作用,形成了第一期北西向、第二期南北向和第三期北西向褶皱和断裂构造。断层活动性是断层封闭性研究的基础和关键。活动断层的主体部分是开启的,但即使是强烈活动的断层,只要在储层或生油层附近发育较多的泥岩层构成与之相接的泥岩剪切带,断层的这些部分仍然具有封闭性。断层的封闭性应该在断层活动性研究的基础上作进一步分析。塔里木盆地西部断层的活动性与封闭性研究表明,第一期北西向断层在中寒武世—泥盆纪和第三纪—第四纪、第二期南北向断层在晚二叠世和第三纪—第四纪、第三期北西向断层自老第三纪形成以来主体部分分别处于开启状态。

The western part of Tarim basin crosses Bachu block uplift and Awati depression, and have experienced three compressian deformations since Cambrian, NW, NS and NW folds and faults are formed sepretely by the three deformation. Plenty research as show the fault activity is the foundation for researches of fault sealing property. Even though the main part of the active fault is opening, some parts of the active fault are sealing when mudstone in the fault form shearing zone which daub the reservoir or oil-generating strata. Based on the activity of the faults, the fault's sealing property is going to be studied by other methods. The main part of the NW faults formed in the first deformation period were opening in medium Cambrian to Devonian, and Tertiary to Quaternary; The main part of the NS faults formed in the second deformation period were opening in late Permian, Tertiary to Quaternary; The main part of the NW faults formed in the third deformation period have been opening since Tertiary in the western part of Tarim basin.