中文摘要：

为了研究高温气藏地层水蒸发盐析规律,根据油-气-水三相热力学平衡及盐类溶解/沉淀原理和地层水蒸发盐析实验结果,建立了考虑地层水蒸发、水中Na Cl沉淀和储集层孔渗变化的综合盐析模型,对高温气藏开发过程中地层水蒸发盐析现象及其影响因素进行了分析,并提出了预防和解除储集层盐析伤害的方法。研究结果表明,气藏开发过程中盐析主要发生于生产井区域。含水饱和度小于束缚水饱和度时,生产井区域最终析出盐浓度较小,盐析对储集层的影响可以忽略;含水饱和度高于束缚水饱和度时,流动的地层水不断将Na Cl携带至井筒处,从而造成生产井区域Na Cl大量析出,严重损害甚至完全堵塞储集层,最终缩短气藏开发生命周期。储集层温度、地层水盐度和储集层孔隙度的增加会加剧盐析对储集层的伤害,开采速率和储集层渗透率的增加会降低盐析对储集层的伤害。

英文摘要：

To study the pattern of formation water evaporation and salt precipitation,based on the oil-gas-water three phase thermodynamic equilibrium,the principle of salt dissolution/precipitation,and results of formation water evaporation and salt precipitation experiment,a comprehensive salt precipitation model considering formation water evaporation,precipitation of Na Cl in water,and reservoir porosity and permeability variations was established to analyze the salt precipitation and its influence factors during the development of high temperature gas reservoir,and some methods preventing and removing salt precipitation were proposed.The study results show that salt precipitation usually occurs in production well area during development of gas reservoir.When the initial formation water saturation is less than the irreducible water saturation,the concentration of precipitated salt from production well area will be lower,and the influence of salt precipitation on reservoir can be ignored.When initial formation water saturation is higher than irreducible water saturation,the flowing formation water constantly carries Na Cl to the well bore,leading to massive precipitation of Na Cl in the production well area,damaging or even plugging the reservoir completely,and shortening the development life cycle of gas reservoir at last.The increase of reservoir temperature,formation water salinity and reservoir porosity will intensify reservoir damage caused by salt precipitation.But the increase of production rate and reservoir permeability will reduce reservoir damage caused by salt precipitation.The results of this study can guide the prevention and removal of salt precipitation,enhancement of gas reservoir productive capacity and secondary development of high temperature gas reservoir.