METHODS FOR DETERMINING IN SITU THE VISCOSITY OF HEAVY OIL USING NUCLEAR MAGNETIC RESONANCE RELAXATION TIME MEASUREMENTS.

摘要

The viscosity .eta. (in centipoise) of a heavy oil sample is determined according to an equation of the form (see above equation) where T is the temperature of the heavy oil, T2LM is the logarithmic mean of the T2 distribution of the sample obtainable from nuclear magnetic resonance (NMR) measurements, c' = 1.0 ~ .05, c" = 1.0~ .04, .eta.g is the glass transition temperature viscosity of the heavy oil and a function of T2LM, and C1 is a variable which is a constant for the heavy oil and is a function of T2LM. Both C1 and .eta.g are considered functions of certain NMR values associated with the heavy oil sample, with r7g and C1 preferably estimated by empirically fitting data to the equations lnT2LM = a' + b' ln .eta.g and lnT2LM = a" + b"C1, where a', b', a" and b" are constants.