Abstract
Despite the progress made on the expansion of scale inhibitor (SI) product selection over the years, significant challenges due to mineral scaling persist. Though multiple scale inhibitor chemistries are available for mild to moderately severe conditions, there are limited scale inhibitor options that can effectively manage mineral scaling for harsh production environments. Therefore, the purpose of this study was to develop a novel scale inhibitor for severe production conditions such as those encountered in Pre-Salt formations.
A synthetic strategy was implemented to develop new scale inhibitors based on terpolymers. From the multiple polymers synthesized, the best candidates were pre-selected based on thermal stability, brine compatibility and static bottle tests at 70°C. Standard dynamic scale loop (DSL) tests were then conducted to evaluate the performance of the new polymers and their corresponding blends. Test conditions simulated various production environments for Pre-Salt development.
Our studies indicated that the novel scale inhibitor showed temperature stability for upwards of 60°C for 7 days and 4°C and 40°C for 30 days and compatibility with very high TDS brine (> 200k mg/L) even at elevated temperature (130⁰C). Furthermore, the final synthesized polymer showed the best stability and overall performance under these conditions compared to that of a commercial product and other synthesized products tested. It was also demonstrated that a synergistic effect between the final polymer and phosphonate in the final blend was responsible for further improved performance.
