A cumulant analysis for non-Gaussian displacement distributions in Newtonian and non-Newtonian flows through porous media

✍ Scribed by Ulrich M. Scheven; John P. Crawshaw; Valerie J. Anderson; Rob Harris; Mike L. Johns; Lynn F. Gladden

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 214 KB
• Volume: 25
• Category: Article
• ISSN: 0730-725X
• DOI: 10.1016/j.mri.2006.11.020

✦ Synopsis

We use displacement encoding pulsed field gradient (PFG) nuclear magnetic resonance to measure Fourier components S(q) of flow displacement distributions P(zeta) with mean displacement (zeta) for Newtonian and non-Newtonian flows through rocks and bead packs. Displacement distributions are non-Gaussian; hence, there are finite terms above second order in the cumulant expansion of ln(S(q)). We describe an algorithm for an optimal self-consistent cumulant analysis of data, which can be used to obtain the first three (central) moments of a non-Gaussian P(zeta), with error bars. The analysis is applied to Newtonian and non-Newtonian flows in rocks and beads. Flow with shear-thinning xanthan solution produces a 15.6+/-2.3% enhancement of the variance sigma(2) of displacement distributions when compared to flow experiments with water.