利用核磁共振T_2谱计算相对渗透率曲线方法研究

Calculation of Relative Permeability Curve by NMR T_2 Distribution

根据岩石毛细管束模型和磁场物理理论研究,推导出核磁共振T2谱与渗透率之间理论关系表达式。给出核磁共振T2谱计算储层渗透率中各参数的物理意义,并得出核磁共振T2谱计算储层相对渗透率计算公式。该公式与压汞曲线推导出的储层润湿相相对渗透率计算公式有一定的相似性,利用实验数据进行验证后取得良好效果,实现了储层动静态参数之间相互转换,进一步拓展核磁共振T2谱资料的应用范围,为储层特征评价、测井产能预测等提供一定的依据。

According to the capillary bundle model and magnetic field of the rock physical theory,obtained is a theoretical relationship between the NMR and permeability,derived is the physical meaning of the parameters in the expression which calculates the reservoir permeability using NMR T2 Distribution,and deduced is the formula which obtains relative permeability of the reservoir using NMR spectrum in wetting phase.This formula is similar with the formula that capillary pressure curves calculate the relative permeability in the wetting phase of the reservoir.It is validated and achieved good results by using the experimental data.The method can achieve the exchange between the reservoir static parameters and dynamic parameters,and further expand the range of applications for the reservoir characteristics using the NMR T2 distribution,so providing some references of evaluating the reservoirs and forecasting the capacity.