Waleed Al-Khamees

Radial-basis-function-based nuclear magnetic resonance heavy oil viscosity prediction model for a Kuwait viscous oil field

AbstractCharacterizing heavy oil viscosity by nuclear magnetic resonance (NMR) relaxation time (T1 and T2) measurements is much more challenging than characterizing light oil viscosities. Crude oils contain a wide range of hydrocarbons, resulting in broad T1 and T2 distributions that vary with the oil composition. Most often, a single geometric mean value T1,gm or T2,gm is correlated with the crude oil viscosity, which cannot accurately account for the inherent complexity of the oil constituent information. Furthermore, as the viscosity increases, some of the protons in the oil relax too quickly to be observable by logging or laboratory NMR instruments. This results in deficiencies of relaxation time and signal amplitude that give rise to apparent T1 and T2 distributions (T1,app and T2,app) and apparent hydrogen index (HIapp). Using T1,app and T2,app distributions in NMR viscosity models could produce erroneous heavy oil viscosity estimations. Several attempts have been made to overcome these challenges b...