Characterization of fractured permeable porous media using relaxation-weighted imaging techniques.

The inversion time (TI) weighted inversion-recovery spin-echo (IRSE) imaging technique was used for laboratory characterization of fractures and porous matrix in permeable media. The method is based on the fact that relaxation rates in fractures and those in surrounding porous matrix are substantially different. Thus, by selectively suppressing imaging signals from either fractures or porous matrix, one can highlight fluid distributions in either of these regions so that fractures can be unambiguously identified and surrounding porous structures can be characterized. The advantages over conventional NMR spin-echo imaging are demonstrated with various fractured porous rock types. A technique to speed acquisitions of images of fluid distributions in porous matrix is also demonstrated.