title: Superstatistics model for T₂ distribution in NMR experiments on porous media.
abstract: We propose analytical functions for T2 distribution to describe transverse relaxation in high- and low-fields NMR experiments on porous media. The method is based on a superstatistics theory, and allows to find the mean and standard deviation of T2, directly from measurements. It is an alternative to multiexponential models for data decay inversion in NMR experiments. We exemplify the method with q-exponential functions and χ(2)-distributions to describe, respectively, data decay and T2 distribution on high-field experiments of fully water saturated glass microspheres bed packs, sedimentary rocks from outcrop and noisy low-field experiment on rocks. The method is general and can also be applied to biological systems.
authors.affiliation: Petróleo Brasileiro S.A., PETROBRAS, Centro de Pesquisas Leopoldo Miguez de Mello, CENPES, Av. Horácio Macedo, 950, Cidade Universitária, Rio de Janeiro, RJ CEP: 21.941-915, Brazil; Centro Brasileiro de Pesquisas Físicas, CBPF, Rua Dr. Xavier Sigaud, 150, Urca, Rio de Janeiro, RJ CEP: 22290-180, Brazil. Electronic address: maury.duarte@petrobras.br.
authors.forename: M D
authors.initials: MD
authors.lastname: Correia
authors.affiliation: Centro Brasileiro de Pesquisas Físicas, CBPF, Rua Dr. Xavier Sigaud, 150, Urca, Rio de Janeiro, RJ CEP: 22290-180, Brazil.
authors.forename: A M
authors.initials: AM
authors.lastname: Souza
authors.affiliation: Centro Brasileiro de Pesquisas Físicas, CBPF, Rua Dr. Xavier Sigaud, 150, Urca, Rio de Janeiro, RJ CEP: 22290-180, Brazil.
authors.forename: J P
authors.initials: JP
authors.lastname: Sinnecker
authors.affiliation: Centro Brasileiro de Pesquisas Físicas, CBPF, Rua Dr. Xavier Sigaud, 150, Urca, Rio de Janeiro, RJ CEP: 22290-180, Brazil.
authors.forename: R S
authors.initials: RS
authors.lastname: Sarthour
authors.affiliation: Petróleo Brasileiro S.A., PETROBRAS, Centro de Pesquisas Leopoldo Miguez de Mello, CENPES, Av. Horácio Macedo, 950, Cidade Universitária, Rio de Janeiro, RJ CEP: 21.941-915, Brazil.
authors.forename: B C C
authors.initials: BC
authors.lastname: Santos
authors.affiliation: Petróleo Brasileiro S.A., PETROBRAS, Centro de Pesquisas Leopoldo Miguez de Mello, CENPES, Av. Horácio Macedo, 950, Cidade Universitária, Rio de Janeiro, RJ CEP: 21.941-915, Brazil.
authors.forename: W
authors.initials: W
authors.lastname: Trevizan
authors.affiliation: Centro Brasileiro de Pesquisas Físicas, CBPF, Rua Dr. Xavier Sigaud, 150, Urca, Rio de Janeiro, RJ CEP: 22290-180, Brazil.
authors.forename: I S
authors.initials: IS
authors.lastname: Oliveira
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D019015:Geologic Sediments / Q000032:analysis / Q000737:chemistry*; D016018:Least-Squares Analysis; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical; D015233:Models, Statistical; D017711:Nonlinear Dynamics; D016062:Porosity; D016008:Statistical Distributions
keywords: NMR relaxation; Porous media; Superstatistics; distribution; q-Statistics