鄂尔多斯延长气田铝土岩分布规律及其地质意义

西安石油大学 地球科学与工程学院,陕西 西安 710065

延长气田; 铝土岩; 风化壳古地貌; 奥陶系气藏

The distribution rule and its geological significance of Bauxite in Yanchang gasfield of Ordos Basin
YUAN Zhen,WU Fu-li,FENG Rong

(School of Earth Sciences and Engineering,Xi'an Shi You University,Xi‘an 710065,China)

Yanchang gas field; bauxite; weathering crust paleogeomorphy; ordovician gas pool

DOI: 10.13800/j.cnki.xakjdxxb.2016.0614

备注

鄂尔多斯盆地延长气田本溪组底部发育一套铝土岩,通过野外调查、岩心观察及测井曲线识别,明确了延长气田本溪组铝土岩物化特征及分布规律,并在此基础上结合区域地质背景探讨了延长气田本溪组铝土岩的出现对资源勘查的意义。研究认为:铝土岩的富集与奥陶系风化壳古地貌的发育有密切关系,通过铝土岩分布规律的认识有助于风化壳古地貌的重建; 伽马能谱测井表明延长气田铝土岩中有明显的铀化矿异常,为盆地铀资源的勘查提供了新的方向; 作为不整合面的重要产物,铝土岩成为下覆奥陶系气藏的区域盖层,通过铝土岩分布规律的研究对下伏气藏勘探起到了指导意义。

A suite of bauxite occurs in the bottom of Benxi formation in Yanchang gasfield of Ordos Basin.Through the open field survey,core observation and well-log recognition,the physical-chemical characteristics and distribution law of bauxite are made clear.And based on the law,the exploration significance for the bauxite in Bnexi formation of Yanchang gasfield is discussed in the paper with the regional geological background.The study considers bauxite accumulation is bound up with the paleogeomorphy of Ordovician Weathering Crust.Through understanding the distribution law of bauxite the paleogeomorphy of Ordovician Weathering Crust will be reconstructed.The spectral logging characteristics of bauxite shows that the obvious abnormal of uranium mineralization.It provides a new direction for exploration of uranium resources.The bauxite becomes the regional cap rock of the downlap gas pool in Ordovician.And the distribution law of bauxite will have a guiding significance for the gas exploration.