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 determinedaccording toan equation of the form (see above equation) where T is the temperature of theheavy oil, T2LM is the logarithmic mean of the T2 distribution of the sampleobtainablefrom nuclear magnetic resonance (NMR) measurements, c' = 1.0 ~ .05, c" = 1.0~.04, .eta.gis the glass transition temperature viscosity of the heavy oil and a functionof T2LM, andC1 is a variable which is a constant for the heavy oil and is a function ofT2LM. Both C1and .eta.g are considered functions of certain NMR values associated with theheavy oilsample, with r7g and C1 preferably estimated by empirically fitting data tothe equationslnT2LM = a' + b' ln .eta.g and lnT2LM = a" + b"C1, where a', b', a" and b" areconstants.