塔里木盆地巴楚—麦盖提地区奥陶系碳酸盐岩沉积特征及模式

Ordovician carbonate sedimentary characteristics and models of Bachu—Maigaiti region in Tarim Basin

通过露头、新钻井岩芯、薄片、测(录)井及地震资料的综合分析,开展奥陶系碳酸盐岩沉积相研究,识别出5种相、11种亚相和20多种微相类型,建立碳酸盐岩台-棚相间沉积相发育模式。以此为指导,结合地震层位解释及反射特征研究,刻画奥陶纪不同时期沉积相平面展布特征。研究结果表明:早奥陶世麦盖提斜坡南部发育欠补偿陆棚相沉积,东部发育开阔台地高能粒屑滩,西部发育中低能藻丘沉积。晚奥陶世早期盆地南部台缘斜坡带应沿玛4井—玉北7井一线向南延伸,且为无镶边缓斜坡沉积。

By comprehensive analysis of outcrop, new drilling core, thin sections, well logging and seismic data, the sedimentary facies of Ordovician carbonate were researched, 5 kinds of facies, 11 kinds of subfacies and more than 20 types of sedimentary microfacies were identified, and the development model of Carbonate platform tent and white sedimentary facies was established. Based on this, in combination with the study of seismic horizon interpretation and reflection character, the plane distribution characteristics of the Ordovician sedimentary facies in different periods were depicted. The results show that the southern part of Maigaiti slope developes under-compensation shelf facies during Early Ordovician, the eastern part develops high-energy particle crumbs beach of open platform, and the western part develops low and medium-energy algal mound deposits. In the earlier period of Late Ordovician, platform-margin slope belt of the southern part of basin should extend south along the Ma4 well-Yubei7 well, and it belongs to the no edge slow slope sedimentary.