Indexed by:Journal Papers

Date of Publication:2015-06-26

Journal:PHYSICS LETTERS A

Included Journals:SCIE、Scopus

Volume:379

Issue:18-19

Page Number:1197-1201

ISSN No.:0375-9601

Key Words:Nuclear magnetic resonance; Relaxation time; Diffusion coefficient; Mass transfer; n-Hexadecane

Abstract:In this study, we discuss the feasibility in computation of diffusion coefficient (D) using the longitudinal relaxation time T-1. CO2-n-hexadecane in pure solutions and in a porous medium was tested separately by measuring the T-1 of n-hexadecane at varying CO2 concentration (c). The relationship between T-1 and c was correlated. The results show that T-1 exponentially rises with the increase of c. Thus, we proposed the method to estimate D of CO2 using T-1 through the relationship above and Fick's law. We computed D from T-1 and compared this method with the traditional method. The two methods agree well with differences less than 10%. The new method is characterized by simpleness, convenience and flexibility, as it computes D with the only requirement of monitoring T-1. This new method will guide the use of nuclear magnetic resonance logging in in-field testing of CO2 diffusion and migration laws. (C) 2015 Elsevier B.V. All rights reserved.