COMBINED PROTON T-1N AND CPMG T-2N STUDIES OF WATER-SATURATED SANDSTONE CORE PLUGS

被引：3

作者：

JEROSCHHEROLD, M ^{[1
]}

THOMANN, H ^{[1
]}

THOMPSON, AH ^{[1
]}

机构：

[1] EXXON RES & ENGN CO,CORP RES LAB,ANNANDALE,NJ 08801

来源：

MAGNETIC RESONANCE IMAGING | 1994年 / 12卷 / 02期

关键词：

STRETCHED EXPONENTIAL; TRANSVERSE RELAXATION; GRADIENT-INDUCED RELAXATION VELOCITY; RESTRICTED DIFFUSION; EFFECTIVE DIFFUSION COEFFICIENT;

D O I：

10.1016/0730-725X(94)91558-X

中图分类号：

R8 [特种医学]; R445 [影像诊断学];

学科分类号：

1002 ; 100207 ; 1009 ;

摘要：

Diffusion dynamics for water in a series of sandstone core plugs with a broad range of permeabilities was studied using both the Carr-Purcell-Meiboom-Gill (CPMG) and inversion recovery experiments. Both the transverse and longitudinal magnetization curves were found to fit well to stretched exponential relaxation kinetics. At short times, the transverse magnetization is well described by an expression for free diffusion averaged over a distribution of pore sizes. The stretch exponents for the transverse and longitudinal magnetization are shown to be simply related to the width of the pore size distribution. A cross over from free to restricted diffusion is evident in the dependence of T-2 with increasing diffusion time set by the interpulse spacing tau in the CPMG experiment. The T-2(tau) data is fit to a model which interpolates between the limits of free and restricted diffusion. A length derived from this model is shown to provide a simple estimate of the absolute fluid flow permeability.

引用

页码：369 / 373

页数：5

共 16 条

[11]

Glasel, Lee, On the interpretation of water nuclear magnetic resonance relaxation times in heterogeneous systems, J. Am. Chem. Soc., 96, (1974)

[12]

LeDoussal, Sen, Decay of nuclear magnetization by diffusion in a parabolic magnetic field An exactly solvable model, Physical Review B, 46, (1992)

[13]

Mitra, Sen, Effects of microgeometry and surface relaxation on NMR pulsed-field-gradient experiments: Simple pore geometries, Phys. Rev. B, 45, (1992)

[14]

Stejskal, Use of spin echoes in a pulsed magnetic-field gradient to study anisotropic restricted diffusion and flow, J. Chem. Phys., 43, (1965)

[15]

Mitra, Sen, Schwartz, LeDoussal, Diffusion propagator as a probe of the structure of porous media, Phys. Rev. Lett., 68, (1992)

[16]

Thompson, Katz, Raschke, Mercury injection in porous media: A resistance devil's staircase with percolation geometry, Phys. Rev. Lett., 58, (1987)

← 1 2 →