多元隶属函数在致密砂岩储层分类中的应用

不同于常规砂岩储层，致密砂岩储层孔隙结构更为复杂，单靠孔隙度或渗透率等单一参数难以有效划分储层。由于单参数在划分储层方面存在困难，因此引入多个能表征储层特性的参数综合评价致密砂岩气储层。以塔里木盆地克拉苏西部气田为例，压裂后，储层按照气井产能可分为4类，结合储层特点，选用斯通利波时差、斯通利波渗透率、反射系数和孔隙度参数可以较灵敏地反映储层孔隙和裂缝的发育情况，将这4个参数作为致密砂岩气藏储层评价判别集，引入一种基于模糊数学的多元隶属函数的方法来划分致密砂岩气储层，可以明显划分出这4类储层。

Application of multivariate membership function for tight sandstone reservoir classification

Different from the conventional sandstone reservoirs，the pore structure of tight sandstone reservoirs is more complex，and it is difficult to divide the reservoirs by a single parameter such as porosity or permeability.Due to the difficulty of single-parameter in reservoir classification，multi parameters that can describe reservoir characteristics have been integrated to evaluate tight sandstone gas reservoirs.Take western Kelasu Gas Field in Tarim Basin as an example，after fracturing，reservoirs can be divided into four types according to gas well productivity.And combined reservoir characteristics，the stoneley slowness，stoneley permeability，reflection coefficient and porosity can be used to reflect the development of reservoir pores and fractures more sensitively.These four parameters are used as discriminant sets for reservoir evaluation of tight sandstone gas reservoirs.So a method named multivariate membership function which based on fuzzy mathematics is introduced to divide tight sandstone gas reservoirs，which clearly distinguish these four types of reservoirs.