中文摘要：

在常规岩心测量和核磁共振（NMR）试验的基础上,分析顺磁性矿物对火山岩NMR测量的影响,并对部分样品进行2D NMR测量,探测到基于内部磁场梯度-横向弛豫时间的信号分布、视内部磁场梯度分布和视T2弛豫时间谱。结果表明：顺磁性矿物会在火山岩样品中产生很强的内部磁场;在磁旋动力和分子扩散的作用下,NMR测得的信号信噪比很低,计算到的孔隙度偏低,对于磁铁矿、黄铁矿含量较多的岩心差别最大;用T2-G 2D NMR方法可探测这种内部磁场梯度的分布,并用于流体的扩散分析。

英文摘要：

Some volcanic core samples were measured by conventional petrophysics method and nuclear magnetic resonance （NMR） core analysis method. Through the two dimensional NMR core analysis experiments, the signal distributions based on internal field gradients and transverse relaxation time, apparent intemal field gradients and apparent transverse relaxation distribution were probed. The results show that there is an internal gradient field caused by some paramagnetic minerals （magnetite, pyrite or chlorite） in core matrix. The signal-to-noise ratio of NMR single is very low because of the effects of fluid diffusion and spin dynamic. The porosity measured by NMR is much lower than that by conventional measurement, especially for the core which contains magnetite or pyrite. The T2-G 2D NMR method can be used to detect internal magnetic field gradient distribution and for fluid diffusion analysis.