鄂尔多斯盆地富县地区奥陶系岩溶风化壳储集层类型与形成条件

作    者:马春生,许化政,郑浚茂,宫长红
单    位:中国地质大学(北京)
基金项目:
摘    要:
早奥陶世,庆阳—黄陵古隆起北侧形成蒸发台地斜坡白云岩坪膏质白云岩、含膏白云岩沉积。加里东期,该古隆起随同鄂尔多斯盆地整体抬升,其北坡不同层位的石膏质白云岩、含膏白云岩差异溶蚀形成了膏溶角砾白云岩、蜂窝状膏溶细晶白云岩、针孔状膏溶白云岩、粒间溶孔细晶白云岩和溶蚀孔洞泥粉晶碳酸盐岩等不同类型的岩溶储集层。斜坡宽缓、地下水流梯度小、晶粒或结核状易溶膏盐颗粒分散是斜坡上岩溶储集层发育且类型多样的主因。斜坡北侧陕北坳陷以膏盐岩地层为主的致密岩性为斜坡上风化淋滤储集层的天然气聚集提供了区域圈闭条件,从而使富县斜坡成为天然气勘探的有利场所。
关键词:鄂尔多斯盆地;庆阳要黄陵古隆起;富县斜坡;风化壳储集层;储集层类型;储集层成因

Types and Formation Conditions of Ordovician Karst Weathering-crust Reservoirs in Fuxian Slope Area, Ordos Basin

Author's Name: Ma Chunsheng, Xu Huazheng, Zheng Junmao, Gong Changhong
Institution: China University of Geosciences (Beijing)
Abstract:
During early Ordovician time,a set of tidal flat dolostone deposited in evaporated platform slope in the northern side of Qingyang-Huangling Paleouplift,Ordos Basin. During the period of Caledonian orogeny,the paleouplift was uplifted accompanying with the rising basin while karst weathering-crust reservoirs with many types of anhydrite –dissolved dolostone formed within widespread different layers in the northern slope due to differential dissolution. Development and various types of karst reservoirs are dominantly attributed to these factors, i.e. the wide and gentle inclining slope, the low gradient of waterflow, the spreading crystal or nodular soluble anhydrite and salt grains. As the dense evaporate strata provide regional trapping condition for gas accumulation in weathering-leaching crust reservoirs in Fuxian Slope, it becomes an area favorable for gas exploration.
Keywords: Ordos Basin; Fuxian Slope; Weathering crust reservoir; Karst reservoir; Reservoir type; Origin of reservoir
投稿时间: 2010-05-20  
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