Permeability and anisotropy of IODP core samples by mobile NMR

主要目标是：(1)改进和扩展迄今为止开发的核磁共振技术，使用Halbach扫描仪在钻井现场进行现场岩心分析；(2)设计移动核磁共振设备，用于常规无损在线测量ODP和IODP计划中饱和水岩心部分的孔隙率和孔径分布。在前一个项目中生产的设备适用于演示实验室研究的原理和在实验室附近的基础研究中使用。对于常规检查，需要使用滑动台和舒适的操作软件进行改进。方法研究的目的是为实验数据提供孔径分布函数之外的细节。应用于此目的的核磁共振技术有多脉冲弛豫测量、常规脉冲梯度核磁共振、核磁共振成像和新的二维核磁共振实验，这些实验将弛豫时间和扩散系数的分布联系起来。通过结合图像信息、松弛图或扩散图的孔隙尺寸积分分布函数以及扩散-扩散相关图的孔隙各向异性积分信息，可获得一组详细的数据，最终可用于模拟孔隙结构和孔隙连通性，从而获得比现有渗透率更准确的估计。

The main objectives are (1) to refine and extend the NMR techniques developed so far for in¿situ core analysis at the drilling site with a Halbach scanner, and (2) to design mobile NMR equipment for routine nondestructive on-line measurements of porosity and pore size distributions of water saturated drill core sections within the ODP and the IODP program directly after drilling. The equipment produced in the previous project is suitable to demonstrate the principles in laboratory studies and to use in basic investigations near to the laboratory. For routine investigations it needs to be improved with a sliding table and comfortable operating software. The methodical study aims at providing experimental data with details beyond the pore-size distribution function. The NMR techniques applied to this purpose are multi-pulse relaxometry, conventional pulse gradient NMR, NMR imaging, and novel two-dimensional NMR experiments which correlate distributions of relaxation-times and diffusion-coefficients. By combining the image information, the integral pore-size distribution function from relaxation or diffusion maps, and the integral information about pore anisotropy from diffusion-diffusion correlation maps, a set of detailed data is available, which eventually can be used to model the pore structure and pore connectivity to finally obtain estimates of permeability more accurate than currently available.