Each sample taken is identified with the total volume of oil produced when the sample is taken. These two field measured data are combined in this production profile to show tracer arrival at the surface. Each point on the profile represents the analytical results of one sample. The ester tracer predictably arrives after 750 bbls of production. Dispersion, or mixing in the pore space smoothes out the square edges of each profile. The alcohol arrival volume relative to the ester arrival volume combined with the alcohol’s K value is the source of Swc. The material balance tracer (MIBK) returns at the injected concentration, 1800 ppm and has a total area of 1,800,000 bbl-ppm showing a 100% material balance.