一种新型核磁原理分析和弛豫方法研究

A new type of NMR principle analysis and relaxation method study

核磁共振测井是能同时提供渗透率、孔隙度、束缚水饱和度等地层参数的一种测井手段,利用储层中氢核的核磁共振性质来判断地层中各种孔隙度情况,受核磁共振元素影响导致不同地层中氢核元素分布会发生改变,来判断储层孔隙中的流体性质,并结合不同流体的弛豫谱时间差异来判断储层中不同流体性质的T2谱分布,区分出孔隙中油、气和水的T 2分布谱,从而分析算出地层含水饱和度。从其基本原理入手,分析了核磁矩算法原理、原子核的自旋量子数和磁矩关系、核磁矩的取向和能量分析等方面,并通过实验来测定硫酸铜水溶液中氢原子核的核磁共振弛豫时间T1、T2随CuSO4浓度的变化关系,同时对本次结论进行理论方面阐述和合理性分析。

The NMR logging provides parameters of reservoirs,such as porosity,permeability,bound water,etc.The NMR technology measures the Hydrogen nuclear response from the formation pore fluid,combined with the time difference of relaxation of different fluids,the different T2 spectrum distribution can be used to distinguish gas,oil and water,and to calculate the water saturation.The article explains that the basic principle of nuclear magnetic moment algorithm,nuclear spin quantum number and magnetic moment relations,the orientation of nuclear magnetic moment and the energy analysis,etc.The experiment measures the NMR relaxation times T1 and T2 of hydrogen nuclei in a solution of copper sulfate in water.The inverse relationship between T1 and the concentration of solution is experimentally demonstrated and theoretically explained in the scale of the experiment.