综合指数法在神木气田储层非均质性应用

Application of the composite index method to the heterogeneity of reservoirs in Shenmu gas field

神木气田是典型的致密气藏,储层受成岩期后期作用被致密化,渗透率值普遍较低,用传统的非均质性研究方法来表征有所局限.为定量探讨研究区域储层的非均质性程度,本文采用了综合指数法来进行表征.综合指数法选取的非均质性参数有:渗透率、孔隙度、含气饱和度、泥质含量、含砂量、夹层密度、孔喉半径等.考虑到该区域储层较为致密,故针对开发效果选取了上述前四个参数作为主要参考指标.通过借鉴前人的两种计算各参数权重值的方法来相互印证.结果显示:两种权重计算方法均显示各小层非均质性很强,且太1段最强,符合对该区域太1段地质背景的认识,也反映出沉积背景对储层非均质性起到了控制作用.

Shenmu gas field is the typical tight gas reservoirs.The reservoir is densified in the later diagenesis,leading to the general lower value of permeability.So there would be some limitation to use the traditional heterogeneity methods for characterization.In order to quantitatively investigate the reservoir heterogeneity degree of the study area,this method of comprehensive index is used to characterize.The parameters using in this method are many,such as permeability,porosity,gas saturation,clay content,sand content,mezzanine density,pore throat radius.Considering the reservoir densified in this area,the first four main parameters are selected for the development efforts.Two methods of weight are used for reference to confirm mutually.Conclusions is that the two methods showed that the heterogeneity of the small layer is very strong,and small layer of Tai 1is the strongest,fitting the cognition of the Tai 1layer geological background.Also reflecting the controlling of deposition background on reservoir heterogeneity.