利用毛管压力曲线分形分维方法研究流动单元

利用取心井铸体薄片获得的图像资料和毛管压力曲线,通过图像分形几何学方法以分维数的形式定量地表征出了复杂的微观孔隙喉道结构特征,发现能够很好地划分和评价孔隙岩石中油、气、水的渗流差异,可以用于储层微观流动单元表征。文中阐述了岩石微观孔隙喉道结构分形的理论基础、计算方法和应用于表征流动单元的依据。建立了中国西部砾岩低渗透油藏微观孔隙喉道分维数与孔隙度、渗透率之间计算图版,据此在油藏中利用常规测井资料获得的孔隙度、渗透率参数计算微观孔隙喉道分维数,开展全油藏流动单元划分与评价,取得了良好的效果。研究结果表明,利用毛管压力曲线分形分维方法研究储层微观流动单元是一种很有效的途径。

The study of flow units using fractal and fractal dimension methods of capillary pressure curve

Using the image files and capillary pressure curves obtained by studying casting-body slices of core from coring wells,we have quantitatively demonstrated the complex structural characteristics of micro-pore-throat by applying the method of image fractal geometry and expressing in the form of fractal dimension.The results show that this method can be used to differentiate and evaluate the infiltration flow of oil,gas and water through porous rocks,and to study the microflow units of reservoirs.In this paper,we describe the fractal theory,calculation methods and the relevant bases used for demonstrating flow units of rock microstructures.We established the templates for the conversion calculation between micro-pore-throat's fractal dimension,porosity and permeability for conglomerate hyposmosis reservoirs in west China.By this method,we can calculate micro fractal dimensions using the porosity and the parameters obtained from common log files in reservoirs,in order to classify the flow units of the whole reservoir and to make an evaluation of the flow units.We have obtained good practical results using this method.The conclusion is that the capillary pressure curve fractal and fractal dimension method is an effective methodology for studying micro flow units of oil reservoirs.