结合NMR和毛管压力资料计算储层渗透率的方法

基于核磁共振(NMR)测井驰豫时间分布和毛管压力曲线均反应储层孔隙结构的事实,提出了将NMR测井和毛管压力资料相结合计算储层渗透率的新方法。通过对大量压汞和核磁共振测井实验岩心样品的分析,建立了Swanson参数与岩石渗透率的关系模型。为解决压汞数据受岩心样品数量限制的问题,提出了利用核磁共振横向弛豫时间几何平均值求取Swanson参数,可以连续地计算储层的渗透率。对某油田A井低孔隙度、低渗透率储层实际资料的处理表明,用新方法计算得到的渗透率与岩心分析的空气渗透率吻合较好,验证了该方法的准确性和广泛适用性。

A computation method for reservoir permeability by combining NMR log and capillary pressure data

Based on the fact that NMR T₂ distribution and capillary pressure curves can reflect the reservoir pore structure, a novel method was presented to calculate reservoir permeability by combining NMR log and capillary pressure data. A correlation model between Swanson parameter and rock permeability was established by analyzing plenty of core samples with mercury-injection and NMR log data. Considering the problem that capillary pressure data are limited by their quantity, the novel method was presented to acquire Swanson parameter from NMR T₂ geometric mean value and to calculate reservoir permeability consecutively. The permeability data in low-porosity and low-permeability reservoir of Well A calculated by the method are close to the result of air permeability obtained from core analysis, which indicates the accuracy and applicability of this method.