岩石孔隙介质小型核磁共振技术研究进展

Research Advances of Compact NMR Technology for Rock Porous Medium

对小型核磁共振技术在岩石孔隙介质中的应用进行论述。岩石通常是由一种或多种矿物组成的多孔介质,孔隙度、孔径分布等参数具有非均质性和复杂性。小型核磁共振技术以仪器小型化为原则,缩小主磁体体积,获得强度高、均匀性好的磁场,实现岩石孔隙特性的准确评价。一维时域测量技术通过测量弛豫时间得到孔隙度和弛豫时间分布,进而利用经验模型确定流体渗透率。二维时域测量技术利用二维Laplace方法将扩散和弛豫分析相结合,形成关联图谱,更有效地划分油气水流体组分和判断油的类型。小型核磁共振技术在可移动性、经济性、成熟性等方面日趋完善,为孔隙介质现场检测和科学研究奠定了技术基础。

Discussed is the application of compact nuclear magnetic resonance(NMR)technology for the rock porous medium.Rock is usually a porous medium composed of one or more minerals,its parameters including porosity and pore size distribution are with heterogeneity and complexity.The principle of the compact NMR technology is the instrument miniaturization.By reducing the volume of main magnet,the magnetic field with high strength and good homogeneity is obtained,as to realize the accurate evaluation of rock porous characteristics.1D time-domain measurement technology obtains the porosity and relaxation time distribution by measuring the relaxation time,and uses empirical model to determine the fluid permeability.2D time-domain measurement technology combines diffusion and relaxation analysis using 2D Laplace method to form a correlation map,which can more effectively divide fluid components including oil,gas and water and judge oil types.The compact NMR technology is becoming more and more perfect in mobility,economy and maturity,which lays a technological foundation for the field detection and scientific research of porous medium.