Experimental study of Iron-Control Chemicals for High Temperature Sour Gas Wells

Iron control agent is an important additive of acidizing. Iron compounds that precipitate during acidizing can reduce reservoir permeability in the critical near-wellbore area. In this study, the applicability of reduction for several ferric ion reducing agents is investigated Reduction strengths and time duration for complete reduction are determined for all presented ferric ion reducers. Mixtures include ferric ion reducer and various catalysts are prepared and compared with each other. Thioglycolic acid is determined as the best ferric reducing agent and also potassium iodide as the best catalyst. Therefore, mixture of thioglycolic acid and potassium iodide is more effective among all mixtures. This mixture is compared with commercial reducing agents obtained from BJ service at high temperature and in the presence of hydrogen sulfide. Performance of the proposed mixture is better than the commercial reducing agent. This proposed iron control additive is appropriate for acidizing at high temperature in sour gas wells.