Sulfur deposition law in gas wells with high sulfur content

In consideration of the difficulties of sulfur release and deposition prediction in wellbores with high content of sulfur, a mathematical model was built for multi-phase fluid flow and heat transfer in gas wells with high content of sulfur, and a discrimination rule and computing method were given for multi-field coupling sulfur release in wellbore and sulfur deposition. The computing results show that the sulfur solubility from hole bottom to wellhead in gas well with high sulfur content decreases gradually, showing non-linear variation; sulfur release occurs in the wellbore, and the precipitation location and amount are mainly affected by temperature gradient, pressure gradient and H2S mass concentration; and sulfur deposition in wellbore is mainly affected by gas carrying capacity and local flow field disturbance. The greater the temperature and pressure decrease, the earlier the sulfur precipitates; under the same flow pressure, the higher the gas production is, the earlier the sulfur precipitates and the greater the precipitation is. This study simulates the production performance of gas wells and gives the distribution law of sulfur release, sulfur deposition, pressure and temperature in gas wells with high sulfur content; the calculation results may be used to provide guidance for field adjustment of development scheme and optimization of production parameters and provide basis for formulating a scheme to prevent sulfur deposition.