Laboratory-Based Prediction of Sulphate Scaling Damage

Abstract

The BaSO4 scaling is a chronicle disaster in water-flood projects with incompatible injected and formation waters. This is usually due to precipitation of barium sulphate from the mixture of both waters and consequent permeability reduction resulting in well productivity decrease. The sulphate scaling damage system contains two governing parameters: the kinetics coefficient characterising the velocity of chemical reaction and the formation damage coefficient reflecting permeability decrease due to salt precipitation. Previous work has derived analytical-model-based method for determination of kinetics coefficient from laboratory coreflood on quasi steady state commingled flow of injected and formation waters. The current study extends the method and derives formulae for calculation of formation damage coefficient from pressure drop measurements during coreflood. The proposed method can be extended for axi-symmetric flow around the well allowing calculation of both sulphate scaling damage coefficients from field data on barium concentration in produced water and well productivity decline. We treat several laboratory test data and field data, and obtain values of two sulphate scaling damage parameters. The values of kinetics and formation damage coefficients as obtained from either laboratory or field data vary in the same range intervals. It validates the proposed mathematical model for sulphate scaling damage and the analytical-model-based method "from lab to wells". Copyright 2006, Society of Petroleum Engineers.