核磁共振测井判别气层方法研究及在辽河油田的应用

Method of Identifying Gas Reservoirs with NMR and Its Application in Liaohe Oilfield

天然气纵向弛豫时间τ1、横向弛豫时间τ2及扩散系数D与油、水有较大差别,通过分析天然气的弛豫特征和在差谱、移谱测井方法上的响应特征,总结了核磁共振测井识别气层的基本方法和思路。辽河油田测井实例分析和试油结论表明,核磁共振测井识别气层具有很高的准确性和直观性。综合应用标准τ2、差谱、移谱可以有效降低解释误差,提高测井识别储层流体的解释精度。

The relaxation times(τ1 and τ2) and diffusivity(D) of natural gas were quite different from those of water and oil.Through analyzing the relaxation characteristic of gas and the response characteristics of gas in differential spectrum and shifted spectrum.The basic approach and thread of distinguishing gas reservoir has been summarized.Through analyzing the its relaxation characteristics of natural gas and response characteristics of differential spectral and shifted spectral methods,the fundamental methods and ideas of gas reservoir identification with NMR were summed up.The application in Liaohe Oilfield and oil test results indicate that NMR can distinguish gas reservoir with high accuracy and visualization.Application in combination of standard τ2 spectrum,differential spectrum and shifted spectrum can effectively reduce errors and improve the accuracy of interpretation efficiently.