乌尔逊凹陷苏仁诺尔CO_(2)气藏主控因素分析

Analyse on main controlling factors of Surennuoer CO_(2) gas reservoir in Wuerxun Sag

乌尔逊凹陷苏仁诺尔走滑断裂带西部南屯组发育天然CO_(2)气藏。利用测井、地震、岩心、生产数据等资料,采用序贯高斯模拟方法,建立苏仁诺尔气田南屯组三维地质模型,包括构造模型(地层、断裂带)、岩性模型、物性模型,分析乌尔逊凹陷南屯组的地层格架、断裂分布,以及砂岩储层和物性的三维空间展布特征。结果表明:乌尔逊凹陷苏仁诺尔气田南屯组储层具有低孔隙度、低渗透率的特点,CO_(2)气藏主要分布于断裂活动带构造高点。苏仁诺尔走滑断裂带作为运移通道,对CO_(2)气藏分布起决定性作用;储层岩性和物性在控制CO_(2)气藏聚集和分布中起次要作用。该结果对寻找研究区CO_(2)气藏及后期勘探开发具有指导意义。

Natural CO_(2)gas reservoirs are developed in Nantun Formation in the west of Surennuoer Strike-Slip Fault Zone in Wuerxun Sag.By using logging,seismic,core and production data and adopting facies control method,a three-dimensional(3D)geological model of Nantun Formation in Surennuoer Gas Field is established,including structural model(stratum,fault zone),lithologic model and physical property model,which reflects the stratigraphic framework and fault distribution of Nantun Formation in Wuerxun Depression,as well as the 3D spatial distribution characteristics of sandstone reservoirs and physical properties.The results show that the Nantun Formation of Surennuoer Gas Field in Wuerxun Sag has the characteristics of low permeability and low porosity,and the CO_(2)gas reservoir is mainly distributed in the structural height of fault active zone.As a migration channel,Surennuoer Strike-Slip Fault Zone plays a decisive role in the distribution of CO_(2)gas reservoirs.Reservoir lithology and physical properties play a secondary role in controlling the accumulation and distribution of CO_(2)gas reservoirs.The results have guiding significance for finding CO_(2)gas reservoirs in the study area and later exploration and development.