东河1油田退汞毛管压力曲线的分形特征

根据分形理论,以退汞毛管压力为测量尺度,以对应的退汞饱和度分布频率为测量对象,对东河1油田岩样退汞毛管压力曲线进行的分形研究和分形维数计算结果表明,该油田岩样退汞毛管压力曲线(孔隙分布)具有分形特征。在考虑退汞麻痹效应和特低渗透率岩样退汞中止点假定条件下,对退汞量作了必要的修正。退汞曲线分形特征具有完整性,测量尺度范围从最高注入压力到最低退出压力。同时测量尺度与测量对象的数值具有良好的相关性,在双对数图上有良好的直线关系。退汞曲线分形维数D0W与渗透率、孔隙度、退汞效率和均质系数等常规孔隙结构特征参数均有较好的相关性,可以作为一个新的孔隙结构特征参数。

Fractal dimensions of mercury-ejection capillary pressure curves in Donghe-1 Oilfield

The correlativity of mercury-ejection capillary pressure and mercury saturation was analyzed. The mercury-ejection capil- lary pressure curves in Donghe 1 Oilfield were studied with the fracta dimensions theory. The mercury-eiection capillary pressure curve, that is, the distribution of pore structure in sandstone reservoir is characterized by fractals. By assuming the existence of mercury-ejection threshold pressure and mercury ejection ending for extreme low-permeable rock, a necessary correction for mercury-ejection volume was made. The mercury-ejection capillary pressure curve is characterized by integrative fractals and a large range from the highest to lowest injection pressure. The measured scale and objects have a fairly good correlation. The fractal dimension of mercury-ejection capillary pressure curve is taken as a new characteristic parameter of pore structure, because of its good correlation with regular parameters such as permeability, porosity, mercury-eJection efficiency and homogeneous coefficient.