Investigation of barium sulfate scale inhibitor to improve the squeeze performance in South China Sea Oilfield

In this study, the scale inhibitor PEPB (mixture of polyepoxysuccinic acid (PESA) and 2-phosphonobutane-1, 2, 4-tricarboxylic acid (PBTCA)) was selected to investigate the squeeze performance to solve the barium sulfate scaling problem in South China Sea Oilfield. The squeeze performance of scale inhibitor PEPB was evaluated using static inhibition efficiency test and static adsorption experiment. In addition, the adsorption/desorption characteristics of the inhibitor was investigated by core flooding experiment. The results of static inhibition efficiency tests show that the scale inhibition efficiency of the inhibitor PEPB is greater than 90% at a low concentration of 5 mg/L. The static adsorption capacity of the inhibitor PEPB increases by 171% when the pH value varied from 12.7 to 4.0. In addition, the desorption results evaluated by core flooding experiments show that PEPB has a better desorption performance at low pH value of 4.0. This study provides an effective guidance for optimizing scale inhibitor adsorption performance to extend squeeze lifetime in South China Sea Oilfield.