The Good Performance of The Mixture of Sulfamic, Acetic, and Citric Acid as an Alternative Carbonate Scale Dissolution at Laboratory Scale

Calcium carbonate scale is one of the challenges faced by the oil and gas industry, as it can disrupt production activities. Acidification using hydrochloric acid is widely applied as a scale remover; however, this reagent is highly corrosive.Hence, this study aims to investigate the effect of combining sulfamic acid, citric acid, and acetic acid in ratios of 9:3:3, 6:6:3, and 3:9:3 at temperatures of 35°, 45°, and 50 °C on an environmentally friendly scale dissolution. The percentage of scale dissolution from the three acids was then compared with 5, 10, and 15% hydrochloric acid at temperatures of 35°, 45°, and 50°C using the gravimetric method. The results of the study on a laboratory scale showed that the largest % scale solubility was obtained with a ratio of sulfamic acid: citric acid: acetic acid of 9:3:3 of 65.79% at a temperature of 50°C. When compared with 5% HCl at 50°C as a control, scale dissolution was 63.49%. This result is supported by scanning electron microscope data, which show that the surface of the scale on the pipe after treatment with three acid combinations has a smoother surface morphology compared to using commercial scale removal (HCl). The use of three acid combinations in this study can serve as an alternative to commercial-scale removal.