Patent ID: 8013601
Filing Date: 2011-09-06
Classification: G01N

Abstract:
1. A method for determining the viscosity of a heavy oil located in a formation traversed by a borehole, comprising: a) locating a nuclear magnetic resonance (NMR) logging tool in the borehole; b) making T c) without bringing said heavy oil uphole, determining the viscosity η of the heavy oil according to where T is the temperature of the heavy oil, T 2LM is the logarithmic mean of the T 2 distribution of the heavy oil obtainable from said T 2 measurements, c′ is a constant between 0.95 and 1.05, c″ is a constant between 0.96 and 1.04, η g is the glass transition temperature viscosity of the heavy oil and a function of T 2LM , and C1 is a variable which is a constant for the heavy oil and is a function of T 2LM .