Inhibition efficiencies of synthesized anhydride based polymers as scale control additives in petroleum production

Most recently a series of low molecular weight maelic-anhydride based polymers were synthesized in our laboratory which can be used as scale control additives to prevent mineral precipitation from water. Scaling is a serious problem in hydrocarbon production facilities specially when water flooding process has been used. In this paper we report some experiments with these polymers which have been conducted for anti-precipitation tests with CaCO3, CaSO4 and Mg(OH)2 scales and calculating percent inhibition. The Scanning Electron Microscope (SEM) studies have been used to show photographs for these scales with and without the presence of synthesized polymers. The impacts of polymers on the morphological changes of the scales were examined extensively. It was observed that the inhibition ability on the calcium carbonate scale is much higher and even with 0.5 ppm dosage the efficiency is around 90-95% when the pH level is 10.45 at temperature of 70 °C. For calcium sulfate the efficiency was slightly lower and at 2–3 ppm level the efficiency around 70% was observed. Inhibition constant was determined for various synthesized polymers and % inhibition is shown versus inhibition constant for various types of scales.