ALKALINE FLOODING IN LOW ACID NUMBER CRUDE OIL

Alkaline flooding is the earliest chemical flooding method reported. Its usage
was in the beginning limited to reservoirs with high acid numbers because of the
assumption that recovery is due to in situ surfactant that is formed from alkali-acidic
components reactions. Alkaline flooding while succeeded in increasing microscopic
sweep did not reduce the mobility ratio. Consequently, the macroscopic sweep was
not improved. Later work proved that improvement in recovery was not dependent
on high acid number. This work aims to relate the increase in recovery by alkaline
flooding due to end-points relative permeability changes and formation of IFT
reducing components that do not depend on acids.