Fast evaluation of inhibitors for calcium carbonate scale based on pH continuous measurements in jar test at high salinity condition

Abstract Scale formation from calcium carbonate deposition is a major drawback in many industrial facilities, including oil and gas industry, leading to obstruction problems then causing productivity reduction and economic loss. Several anti-scalant formulations, known as inhibitors, are used to control CaCO 3 deposition. The evaluation of inhibitors performance is a time-consuming challenge. In the present work a fast approach for evaluation of inhibitor towards calcium carbonate scale controlling is proposed based on continuous pH measurement under jar test condition. Two commercial inhibitors, phosphino polycarboxylic acid (PPCA), usually regarded as a nucleation inhibitor, and diethylenetriamine pentamethylene phosphonic acid (DETPMP), normally considered a growth inhibitor, were evaluated. It was possible to assess their efficiency at same concentration level (5.0 ppm), and DETPMP was the one presenting a better performance at the investigated conditions. The main mechanism of action of each inhibitor was also recognized by this methodology.