An Experimental Study on Permeability Reduction Resulting from Mixed BaSO4, CaSO4, and SrSO4 Scale Deposition in Porous Media during Water Injection

Sulfate scale deposition (BaSO4, CaSO4, and SrSO4) is a common problem in oilfield operations around the world, which causes significant formation damage during production and injection activities. This paper presents the results of an experimental study on the permeability reduction of porous media due to sulfate scale deposition. A set of experiments were conducted to investigate the effects of cation (Ba2, Ca2, and Sr2 ions) concentration and the number of cation species on the permeability reduction resulting from single sulfate scales (single BaSO4, CaSO4, and SrSO scales) and mixed BaSO4, CaSO4, and SrSO4 scale deposition in porous media during water injection. The experiments were performed at a constant temperature of 70 °C and a constant anion (SO4 2- ion) concentration of 3968 ppm in the pack of glass beads as the porous media. The results show that the intensity of permeability reduction increases with increasing cation concentration. These results also declare that the permeability reduction of porous media due to mixed BaSO4, CaSO4, and SrSO4 is clearly severer than single scales.