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

Abstract

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 SrSO₄ 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.