The study on multifunctional aminoalkylenephosphonate-based antiscalant for industrial water systems under harsh conditions

Abstract

Mineral scale deposit is one of the major problems incessantly faced in the oil and gas producing wells and surface facilities, and if not well-handled can cause an unsuccessful petroleum production. To eradicate scale deposits, scale inhibitors (SIs) are commonly deployed into industrial water systems. Because of effectiveness and long squeeze lifetimes, organic phosphonate SIs are extensively used for preventing mineral scale formation in industrial water systems. However, they usually exhibit lower Ca2+ and Mg2+ tolerances that restrict their applications in harsh conditions where high inhibitory dosages are needed. In this paper, a multifunctional aminoalkylenephosphonate-based antiscalant having higher Ca2+ and Mg2+ tolerances is studied. The antiscalant was synthesized, characterized (FTIR and NMR spectroscopies), and evaluated in accordance with the NACE Standard Method (TM0374) for preventing CaSO4 and CaCO3 formation in the petroleum industry. The effects of inhibitory dosages, water hardness, temperature, incubation period, and pH were studied. We further tested the performance of the antiscalant in simulated field waters. Experimental results show that the multifunctional aminoalkylenephosphonate-based antiscalant has better inhibitory properties as compared to conventional aminoalkylenephosphonate-based SIs. The incorporation of the sulfonate group into the molecule significantly improved the solubility of the antiscalant and hence its tolerances to Ca2+ and Mg2+ ions. Also, it bolstered thermal stability of the inhibitor. The results from simulated field conditions are promising. The synthesized antiscalant performed superbly than the conventionally aminomethylenephosphonate antiscalants where Ca2+ and Mg2+ concentrations are challenging.