sub pore-scale investigation of wettability alteration during low salinity water flooding

Scale deposition due to the injection of incompatible fluids has been a challengeable issue in the oilfield operations# deposition process generally associated with the porosity and permeability reduction of the reservoir rock# in current study, a series of experiments conducted to investigate the effect of ion concentration and salinity of the injected brine on the total amount of caso4 precipitation# the water compatibility tests were performed to evaluate two different mechanisms of inorganic scaling; mixing of incompatible water and the rate of injection# therefore, contact angle measurement was utlized to examin the effect of scaling process on the wettability# based on the results obtained here, the amount of caso4 precipitation increases as the concentration of so42- ions in the injected brine was increased from ½ to 1 times of its original concentration# even though, the increasing of ca2+ ions in sea water increases the caso4 scaling, the presence of mg2+ ions in sea water increases the solubility of caso4, inhibiting the scale deposition this study also showed that, the rate change is the dominant parameter in scaling formation# by increasing the rate of sw, the amount of solubility of caso4 was increased#