Calculation of sulfur deposition in gas condensate wells in middle east

Sulfur deposition has been one of the major concerns in the sour-gas industry. This is due to the significant reduction in the deliverability of a gas well. To illustrate, in deep sour gas reservoirs, elemental sulfur often exists as a trace element in vapor at reservoir pressure and temperature. Reduction in reservoir pressure and temperature due to production of gas to the surface reduces sulfur solubility in the gas phase so that the dissolved elemental sulfur precipitates in the wellbore region of the sour gas well, thus building up sulfur scale over a period. The compositional simulation model was GEM from CMG and we used WinProp for phase behavior of a generalized deep sour gas well in the Middle East. We observed that the deposition of sulfur is in the tubing and not like salt/scale deposition in the casing which is due to evaporation and super saturation in the brine phase as it produced through the perforations.