鄂尔多斯盆地中央古隆起与天然气聚集

鄂尔多斯盆地中央古隆起可以划分为中部凸起剥蚀区、西翼陡坡区、东翼缓坡区、北翼平缓北倾区、南翼陡缓变化区.经历了前加里东期、加里东期、海西期、燕山期几个发育阶段.古隆起的构造发育与烃源岩热演化配置良好.其东翼靖边-志丹-富县区为 Ⅰ 类远景区;北翼定边-天池区次之;西翼陡坡区较差.主要储集层是奥陶系顶部风化淋滤带.

THE CENTRAL UPLIFT OF ORDOS BASIN AND ITS GAS ACCUMULATION

The central uplift of Ordos Basin is located in Wuqi-Qingyang-Fuxian region and could be divided into steep slope area in the west flank,eroded area in central uplift,gen-tle slope area in the east flank,gentle slope in the north flank and steep-gentle changing area in the south flank.The uplift underwent Pre-Caledonian,Caledonian,Hercynian,Yenshan and etc.evolution periods.The uplift is close to two gas generation centers of Or-dovician,Permo-Carboniferous Systems,which provide rich gas-sources for the east flank slope area,thus the uplift is favourable in seeking for weathered-crust and other subtle traps.The bauxite of Middle Carboniferous Benxi Formation can be direct seal,and Per-mian argillaceous rocks may act as regional seals.Hence Jingbian-Zhidan-Fuxian area in the east flank of the uplift is most favorable for gas exploration,then Dingbian-Tianchi,the west steep slope is the reserve area.