A four foot long pipe (ID = 2″) packed with silica sand was used to study the effects of formation damage caused by completion and work-over fluids in a high permeability reservoir. Pressures were recorded at five locations (1 foot apart) across the high permeability sand pack as different fluids at a rate of 5 ft/day were injected into it. Bentonite and salt concentration of the injected fluids were changed and their effects on the single phase permeability of the sand pack at different filtration levels were investigated. Some runs were performed using field water from San Ardo field in California. Finally, effects of formation damage on oil recovery by water-flooding were also studied.
Results show that depending on the composition and the amount of the injected fluids, high permeability sand pack develops irreversible permeability loss which in turn limits the ultimate oil recovery during water-flooding. Results also show that maintaining proper filtration level can minimize the degree of damage to the high permeability sand pack.