METHOD FOR DETERMINING THE VISCOSITY OF FLUIDS BY NUCLEAR MAGNETIC RESONANCE

摘要

Method for determining the viscosity of a fluid from nuclear magnetic resonance measurements. A curve for correlation between viscosity and logarithmic mean of the transverse relaxation time distribution is defined. To do this, a transverse relaxation time type distribution T2, according to the fluid studied, is taken into account. This distribution is complete. From it a viscosity value is deduced and then this distribution is modified according to characteristics of the measuring apparatus in order to determine a distribution equivalent to a distribution that would be obtained by NMR measurement carried out with this apparatus. The logarithmic mean of this equivalent distribution is calculated. Next, several lowerings of the viscosity are simulated by translating the type distribution in order to obtain several pairs of viscosity/logarithmic mean values, from which the correlation curve is deduced. This curve then makes it possible to determine the viscosity of the fluid from nuclear magnetic resonance measurements. Application to oil exploration.