含蜡原油蜡晶形态和结构的定量表征

QUANTITATIVE CHARACTERIZATION OF WAX CRYSTAL MORPHOLOGY IN WAXY CRUDES

为了建立含蜡原油流变性的机理模型 ,必须对蜡晶形态和结构的特征进行量化描述。首先 ,采用分块二维熵图像阈值法进行蜡晶图像的自动阈值分割 ;然后 ,采用统计学方法分别对蜡晶的粒度、形状和连续相原油的形态进行特征提取。考虑到蜡晶形状分析中的离散误差 ,提出采用改进的离散圆度算法进行蜡晶形状统计 ,采用计算蜡晶生长区域的数学形态学方法对连续相原油区域进行统计描述 ,从而实现了对蜡晶形态和结构的定量描述。

Wax crystal morphology is one of the prime inner factors influencing the rheological property of waxy crude at a low temperature. The normal way to identify the wax crystal morphology is to qualitatively compare the wax crystal images from video microscopy. In order to develop a mechanistic rheological model of the waxy crude, the quantitative characterization of wax crystal morphology is necessary. The 2D entropy threshold method was used to segment the wax crystal images. Then the size, shape characters of wax crystals and the continuous liquid phase were extracted with a statistic method. An improved discrete algorithm was proposed to calculate the circularity of wax crystals. In addition, a morphology method for calculating the growing region of wax crystal was applied to describe the distribution of the continuous phase in the crude. The processing results of the different wax crystal images testified the effectiveness of this quantitative method for wax crystal characterization.