高含硫气藏硫沉积预测及实施除硫作业时机选择

Sulfur Deposition Prediction and Eliminating Sulfur Deposition in Sour Gas Reservoirs

高含硫气藏在开发过程中,随着气藏压力和温度的降低,元素硫将从气体中析出,从而堵塞天然气的渗流通道,当硫沉积严重降低地层有效孔隙空间及渗透率时,需要实施除硫作业。在考虑气体高速非达西不稳定流动、硫沉积、水动力对硫沉积冲刷与运移、硫沉积对储层危害(孔隙度、渗透率)的基础上,建立了预测硫沉积分布的气固耦合渗流模型。该模型与除硫工艺(溶硫剂)相结合,能够确定实施除硫工艺的时间,以及除硫后近井地带含硫饱和度随生产时间的变化。通过该研究可为高含硫气藏硫沉积预测提供有效方法。

During the production in sulfur gas reservoirs,with the decrease of gas reservoir pressure and temperature,elemental sulfur was separated to block the gas flow channel,the removal of sulfur deposition was needed when formation permeability and effective pore space became a serious decline.On the basis of considering non-Darcy and high-speed instability gas flow,the formation damage induced by sulfur deposition,hydrodynamic erosion and migration of sulfur deposition and sulfur deposition(porosity,permeability),a gas-solid coupling model was established to predict the distribution of sulfur deposition.The model was combined with the sulfur deposition removal(sulfur solvent),it could determine the acting time of sulfur deposition removal,and predict the change of sulfur saturation in the near wellbore area.Through the study above,it can provide an effective method to forecast sulfur deposition in sour gas reservoirs.