title: Analytic theory of two-dimensional NMR in systems with coupled macro- and micropores.
abstract: Two-dimensional (2D) nuclear magnetic resonance (NMR) experiments involve a sequence of longitudinal (T(1)) and transverse (T(2)) measurements. When such experiments are applied to porous media, they are believed to provide new and important information regarding diffusive coupling between distinct pore subpopulations. However, we show in this paper that, in many cases of interest, this is simply not true. One often encounters systems in which the one-dimensional (1D) T(1) and T(2) processes are each controlled by just two distinct decay modes. If these modes form a complete set, then one can derive analytic formulas that describe, exactly, the 2D NMR measurements. Therefore, for such systems, the 2D measurements bring no additional information over that which is already present in the 1D results. Our predictions agree quite well with numerical results based on the microporous grain-consolidation (μ-GC) model.
authors.affiliation: Schlumberger Doll Research, One Hampshire Street, Cambridge, Massachusetts 02139, USA.
authors.forename: David Linton
authors.initials: DL
authors.lastname: Johnson
authors.affiliation: Schlumberger Doll Research, One Hampshire Street, Cambridge, Massachusetts 02139, USA.
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: Schwartz
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D008962:Models, Theoretical; D016062:Porosity