A model for predicting elemental sulfur solubility and deposition in high sulfur gas wells
To evaluate accurately the extent of sulfur plugging damage in high sulfur gas wells,this paper presents a model for predicting the solubility of elemental sulfur.The model takes into account the solute pressure characteristics under typical high sulfur gas reservoir conditions,and was based on a comprehensive analysis of a significant volume of experimental data on sulfur solubility in acidic gases.Based on the above,a mathematical model for the quantitative characterization of elemental sulfur deposition is theoretically derived according to gas-water percolation theory and the sulfur solubility-pressure function.Finally,we used basic static and dynamic data from a high sulfur edge-water gas reservoir in Sichuan Basin,including a typical sulfur-plugged gas well,to analyze quantitatively the factors affecting the sulfur plugging saturation of the gas countermeasures for alleviating reservoir sulfur plugging.We discussed the variational patterns of reservoir sulfur saturation and strategies for mitigating this issue,and we explored some technical ideas.The results showed that:(1)through validation,it was demonstrated that the sulfur solubility prediction model established in this paper had better predictive performance and the predicted results compared to previous models.(2)The degree of sulfur blockage in gas wellswas influenced by a combination of factors.Under the same production time,a larger daily gas production,initial reservoir water saturation,non-Darcy flow constant,smaller effective reservoir thickness,initial reservoir porosity and permeability,and bottom-hole flowing pressure caused more severe sulfur deposition blockages in gas wells.(3)As the gas well production time increased,the gas well sulfur plugging area gradually expanded into the periphery of the wellbore.Different strategies for sulfur deposition management should be adopted at different stages of gas reservoir development.In the early stage of gas reservoir development,it is recommended to adopt a"rate control first,treatment second"approach to sulfur control;in the middle stage of development,a"control and treat together"approach should be adopted;and in the late stage of development,economic benefits should be given priority,and maintaining gas well production with liquids should be the focus of work in this stage.These research results provided theoretical guidance and technical support for the efficient development of high sulfur gas reservoirs.
high sulfur gas reservoirshigh sulfur gas wellssulfur solubilitysulfur depositionpredictive models
万方数据
维普
