石油工学における硫酸カルシウムおよび硫酸バリウムのスケーリングとその阻害のシミュレーションおよび実験的研究

Petroleum engineering could engage numerous challenges caused by sulfate mineral precipitation and deposition. This severe critical issue which could directly lead to production reduction, was investigated in this study. Accordingly, the precipitation, deposition, and inhibition of calcium and barium sulfate were scrutinized from the simulation and experimental perspectives. The simulation tools, PHREEQC and Aspen Plus, were first used to corroborate the results of the high-temperature (90 °C) standard static experimental tests conducted for calcium and barium sulfate precipitation and deposition phenomena. In the experimental phase of the inhibition study, folic acid was evaluated as a green scale inhibitor (SI) and compared to a phosphonate-based commercial SI regarding inhibition efficiency (IE%) and inhibition mechanisms. The findings indicated that folic acid reduced calcium and barium sulfate precipitation as much as 50.8% and 44.8% respectively at the specific critical mixing ratios through the crystal modification inhibition mechanism provided by scanning electron microscopy (SEM) analysis. Moreover, folic acid could perform effectively in the mitigation of calcium and barium deposition by 53.7% and 47.2% in the presence of 5 g of dolomite rock. However, a comparison of a commercial SI and folic acid showed that the commercial SI was weaker than folic acid for mitigation of sulfate deposition through the threshold inhibition mechanism.