基于核磁共振刻度流动单元复杂砂岩储层渗透率建模方法

针对复杂砂岩储层基于流动单元指数的渗透率建模时存在流动单元指数计算精度低且物理意义不明确的问题,提出基于核磁共振刻度流动单元的渗透率建模方法。在深入分析渗透率影响因素的基础上,应用流动单元指数对储层类型进行分类,建立碳酸盐岩级别约束的不同流动单元类型的渗透率计算模型。将SDR模型和Kozeny-Carman等方程相结合,建立流动单元指数与T2几何平均值的关系,实现了流动单元指数的准确计算。该方法综合考虑了骨架矿物与孔隙结构的双重影响,将核磁共振测井和常规测井有机结合,具有常规多元拟合、SDR、Timur-Coates等方法无可比拟的优越性,极大地改善了渗透率计算效果。

Permeability Calculation of Complex Sandstone Reservoir Based on Flow Unit Calibrated by NMR Logging

The problems of low calculating precision of flow unit index and unclear physical meaning exist when calculating permeability based on flow unit index for the complex sandstone reservoirs,so the new permeability calculation method based on flow unit calibrated by NMR logging is established.On the basis of analyzing the influence factor of permeability,the reservoir types are determined by flow unit index,permeability of different flow units is calculated restrained by carbonate content.Combining the SDR model and Kozeny-Carman model,the relationship between flow unit index and NMR T2 geometric average is established and the flow unit index is calculated precisely.This method considers the dual influence of matrix mineral and pore structure,combines NMR logging and conventional logging and has the incomparable superiority over conventional multivariate fitting method,SDR model and Timur-Coates model.