Method for determining consistent water relative permeability values from dynamic displacement data

摘要

Corrected water relative permeability values for a core sample are determined from dynamic displacement measurements by the steps of plotting a ratio of water rate output (q.sub.w) to calculated water relative permeability values (k.sub.rw) vs. average water saturation (S. sub.w), determining if a straight line segment exists in areas of the plot corresponding to high average oil saturations, and if it does, extrapolating the straight line segment to the end of the plotted data, otherwise plotting a tangent to the plotted ratio from a beginning point of the plot, producing a line in parallel with the extrapolated straight line segment or the tangent line but shifted so as to pass through the irreducible water saturation point S.sub.iw, and correcting the calculated water relative permeability values k.sub.rw by multiplying the calculated values k.sub.rw by a ratio of a value on the q.sub.w /k.sub.rw plot to a value on the constructed straight line. The applied corrections eliminate distortions in the calculated water relative permeability values k.sub.rw due to an end effect at the core sample which causes distortions in the dynamic displacement measurements.