基于孔隙几何形态导电理论的低孔隙度低渗透率储层饱和度解释模型

A Saturation Interpretation Model for Low Porosity and Permeability Reservoirs Based on the Pore Geometric Conduction Theory

在Herrick和Kennedy孔隙几何形态导电理论的基础上,结合低孔隙度低渗透率储集层的孔隙结构特征,将低孔隙度低渗透率储层岩石电导率看成黏土束缚水导电相、微孔隙水导电相和可动水导电相的等效电导率之和,考虑黏土束缚水孔隙、微孔隙、自由流体孔隙的孔隙几何形态以及自由流体孔隙中可动水的几何分布特征对岩石导电性影响,建立一种新的基于孔隙几何形态导电理论的低孔隙度低渗透率储层通用饱和度解释模型。利用大庆C地区F油层岩样的岩电实验数据,对提出的模型进行了实验精度分析,并确定出该地区低孔隙度低渗透率储层通用饱和度模型中的参数值。利用建立的模型及确定的模型参数值处理了大庆C地区F油层实际井资料,将处理结果与密闭取心分析饱和度和试油结果进行了对比。结果表明,该模型适用于低孔隙度低渗透率储层饱和度评价。

Due to the effect of complex pore structures in low porosity and permeability reservoirs, it is necessary to build a saturation model that can give a better description of effects of the pore structures on conductance characteristics of the rocks in low porosity and permeability reservoirs. Pore geometric con- duction theory, proposed by Herriek and Kennedy, is suitable for interpreting effects of the pore struc- tures on the conductance rules of the rocks. In the theory, several variables are introduced to reflect in- fluence of pore geometry and geometrical distribution of formation water on conductivity of the rocks. Based on pore geometric conduction theory and characteristics of pore structures in low porosity and per- meability reservoirs, a general saturation interpretation model for low porosity and permeability reser- voirs is established in this paper. In the model, conductivity of the rocks is considered to be the sum of e- quivalent conductivity of clay bound water, microscopic capillary pore water and free water, and the effects of clay bound water pore geometry, microscopic capillary pore geometry, free fluid pore geometry and geometrical distribution of free water on rock conductivity are also considered. The precision of the model is verified, and the determination of the parameters in the model is also given with core experimen- tal data in F formation of Daqing C area. Then, some log data are processed with the model and parame- ters, and the results are compared with core analysis water saturation in sealed coring well and well test results. The results show that the new saturation equation can be applied in saturation evaluation of low porosity and permeability reservoirs