Method of determining the relation between fractional flow and saturation of oil

摘要

Disclosed herein is a method for determining the fractional flow and corresponding fluid saturation of fluid phases in a subterranean oil-bearing formation containing more than one mobile fluid phase. A carrier fluid containing a plurality of precursors is injected into the formation by means of a well. The carrier fluid is substantially insoluble in a first fluid phase and miscible with a second fluid phase in the formation. Each of the precursors has a distinct partition coefficient between the carrier fluid and the first fluid phase which differs from the partition coefficients of the other precursors. Each precursor forms at least one tracer product within the formation with each tracer having a partition coefficient between the carrier fluid and the first fluid phase which differs from that of its corresponding precursor. After measurable quantities of tracer are formed by the precursors, the carrier fluid tracer solution is displaced through the formation to a point of detection which is preferably the injection well. The relation between fractional flow and saturation of the fluids in the formation can be determined by applying the principles of chromatography as applied to the movement of the precursors through a porous medium containingtwo mobile fluid phases.