Barium Sulphate Oilfield Scaling: Mathematical and Laboratory Modelling

Abstract

<jats:title>Abstract</jats:title><jats:p>The formation damage in scaled-up production wells caused by incompatibility of injected and formation waters have long been known. Precipitation of salts results in permeability decline. Among the most onerous of all scaling species is that of sulphates, particularly barium and strontium sulphates.</jats:p><jats:p>We study effects of porous media on the BaSO4 scaling kinetics.</jats:p><jats:p>A new methodology for determination of reaction rate coefficient from coreflood tests consists of the sequence of diffusivity reaction free tests, of transient tests with chemical reaction, and of simultaneous injections of both injected and formation waters with quasi steady state concentration profiles for barium and sulphate ions. The diffusivity tests serve for dispersivity coefficient determination. Quasi steady state tests allow determination of the reaction rate coefficient versus velocity. The transient test data as compared with the mathematical modelling data validate the model and the data of steady state test data treatment.</jats:p><jats:p>An analytical model developed is used for treatment of quasi steady state test data. The transient tests are treated by a numerical model.</jats:p><jats:p>The main result of the work is proportionality between the reaction rate coefficient and flow velocity for the parameter range studied.</jats:p>