磁性流体を用いた岩石中の孔隙ネットワーク定量分析

―岩石磁気データの石油探鉱への応用―

抄録

A unique method for quantifying anisotropic fabric in rocks is reviewed and its value for reconstruction of the preferred direction of pore fluid flow is reassessed. Magnetic techniques that use anisotropy of magnetic susceptibility act as a proxy of permeability anisotropy of reservoir, when it is applied on samples impregnated with liquid containing suspension of magnetic powder. The authors also present preliminary results of their experiments, which evaluated fracture networks developed in tight turbidite sandstones in central Hokkaido. Rock magnetic analyses and micro-focus density imaging have shown a substantial change in pore fabric reflecting inhomogeneous impregnation of magnetic fluid within sample rocks.