摘要
在高含硫气藏的开发过程中，随着井筒温度、压力的降低，硫会在井筒中析出沉积，严重影响气井的正常生产和管道安全。目前多数硫溶解度模型受使用条件的限制，无法准确预测不同温度、压力条件下的硫溶解度。针对高含硫气井的气体组分特征，在Hu溶解度模型的基础上，结合多相流和传热学理论，建立了高含硫井筒温度、压力分布模型以及硫沉积预测模型。对某高含硫气田进行实例分析，计算得出温度分布、硫溶解度分布规律以及硫沉积量，并研究了气井日产量、硫化氢体积分数对井筒硫沉积的影响规律。研究结果表明：硫溶解度从井口到井底逐渐增大，呈非线性变化；同一时间，气井产量增加，井口温度升高，则硫溶解度增大，硫在井筒的析出位置上升，井筒相同深度的硫沉积量增大。模型计算出的硫析出位置与实例相比，误差小于1%。准确预测井筒中的硫沉积，有助于更好地管理具有潜在硫沉积问题的气井。
Abstract
During the development of high-sulfur gas reservoirs, with the decrease of wellbore temperature and pressure, sulfur will precipitate and deposit in the wellbore, which will seriously affect the normal production of gas wells and the safety of pipelines. At present, most sulfur solubility models are restricted by operating conditions, and cannot accurately predict sulfur solubility under different temperature and pressure conditions. Aiming at the composition characteristics of high-sulfur gas wells, based on the Hu solubility model, combined with multiphase flow and heat transfer theory, a high-sulfur wellbore temperature and pressure distribution model and a sulfur deposition prediction model were established. A case study of a high-sulfur gas field was carried out, the temperature distribution, sulfur solubility distribution and sulfur deposition were calculated, and the influence of gas well daily production and hydrogen sulfide content on it was studied. The research results show that the solubility of sulfur gradually increases from the wellhead to the bottom of the well, showing a non-linear change. In the same time, with the increase of gas well production and wellhead temperature, sulfur solubility increases, sulfur precipitation location in the wellbore increases, and the amount of sulfur deposition at the same wellbore depth increases. Compared with the example, the sulfur precipitation position calculated by the model is less than 1%. Accurately predicting the sulfur deposition in the wellbore will help to better manage the sour gas wells with potential sulfur deposition problems.
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