高含硫气藏硫溶解度及硫沉积预测新模型

为了更加准确地预测近井地带硫沉积的影响,在改进元素硫溶解度预测模型的基础上,提出了一个基于非达西流推导,考虑气体参数及dc/dp随压力的变化,并考虑应力敏感影响的硫的饱和度预测模型。结合实例分析了非达西流、应力敏感等参数对硫的饱和度的影响,得到以下结论:改进的硫沉积预测模型考虑了非达西流,并考虑了和压力相关的参数的变化,使计算的结果更科学准确;较强的应力敏感会导致硫沉积的速度加快,气井的极限生产时间也会相应缩短;硫沉积引起的含硫饱和度的变化和地层初始渗透率有着密切的关系,地层初始渗透率越小,硫堵的可能性就越大,废井的时间也越早。

Study on New Evaluation Modle for the Solubility of Element Sulfur And Deposition Prediction in High Sulfur Gas Reservoir

In order to more accurately predict the influence of sulfur deposition near wellbore area,we build a new sulfur saturation prediction model ,which is on the basis of the improvement of elemental sulfur solubility prediction model, considering the gas parameters and dc/dp along with the change of pressure and the influence of stress sensitivity. With the analysis of non-darcy flow and stress sensitivity and other parameters on the influence of the sulfur saturation in a example, we can get the following conclusions: Improved sulfur deposition prediction model in consideration of non-Darcy flow and the variation of parameters related to pressure makes results more scientifically and accurately.Strong stress sensitivity can lead to the acceleration of sulfur deposition and the reduction of limit time of the gas well. What is more,sulfur deposition has a close relationship with the initial formation permeability. The lower initial formation permeability is,the more possible the formation damage caused by the sulfur deposition is,and the earlier the time of abounded well is.