鄂尔多斯盆地西峰地区特低渗砂岩储层属性建模

Properties Modeling of Extra-low Permeability Sandstone Reservoir in Xifeng Area,Ordos Basin

针对鄂尔多斯盆地西峰地区低渗砂岩储层物性极差、非均质性强的特点,从储层低渗的成因机制研究入手,建立了"分选性砂岩含量"模型来约束孔隙度建模;并将"序贯指示模拟思想"引入到渗透率建模当中。通过贝叶斯指示模拟与协变量参数的有机结合,最终形成了一套适合于低渗-特低渗储层属性建模的方法。研究结果表明,砂质含量与颗粒分选程度、成岩作用类型及强度是低渗砂岩储集空间发育分布的控制因素,而有效的建模方法精确刻画了次生孔隙发育带与相对高渗区。建模结果客观反映了低渗储层的严重非均质性,改善了低渗储层随机建模方案,能为油藏数值模拟、开发方案的制定提供合理的地质模型。

According to the characteristics of bad physical property and strong heterogeneity of low permeability sandstone reservoir in the Xifeng area,Ordos Basin,a set of targeted property modeling method was developed,starting from the formation mechanism of low permeability. Based on porosity modelling controlled by the ＂F-sand model＂,the traditional ＂Sequential Indicator Simulation＂concept was applied into the permeability modeling,by means of Bayes Indicator simulation combined with covariant parameters. The result shows that the effective modeling methods presicely characterized the zones of secondary pore and relatively high permeability,controlled by the separated sand content as well as types and intensity of diagenesis. The modeling result objectively reflected the severe heterogeneity of low permeability reservoir and improved the random modeling scheme. The accomplishment and output of this research can provide reasonable geological model for reservoir numerical simulation and development planning in a field with this type of reservoirs.