Optimization of effective sulfur solvents for sour gas reservoir

Abstract Sulfur deposition attracts great attention for the exploration of oil and gas and is considered one of the most important hazardous processes in China, and all over the world. Thus, investigating a sulfur solvent is absolutely necessary and highly desirable in the sour gas reservoir development. In recent years, various sulfur solvents were developed and applied in different oilfields. However, they have disadvantages in their practical applications. In this paper, a solution is proposed to solve the problem and improve the sulfur dissolving ability. Three types of sulfur solvents were prepared, all of which have their own characteristics and advantages in different cases and compared with the existing sulfur solvents under the same conditions. The solubility of Dimethyl disulfide(DMDS)-based sulfur solvent system was up to 202.8 wt% at room temperature and 1020.0 wt% at 90 °C. Amine solvent systems also achieved high sulfur solubility. The solubility of diethylene triamine-ethanolamine solvent system could reach 79.6 wt% at room temperature and 210.0 wt% in 90 °C. It was shown that a more efficient sulfur solvent system can be achieved by remixing with suitable additives. This paper focuses on a preliminary study of optimizing effective sulfur solvents in order to solve the problems caused by sulfur deposition. In the long run, this may revolutionise the process of exploration, transportation and refining of crude oil or natural gas. Microscopic analysis by Scanning Electron Microscope (SEM) was used to facilitate understanding the mechanism of sulfur dissolution in each system and their differences.