析出硫为液态的高含硫气藏数值模拟方法  

A numerical simulation method for high-sulfur gas reservoirs with liquid released sulfur

作　　者：李继强[1] 戚志林[1] 胡世莱 袁迎中[1] 严文德[1] 向祖平[1] 

机构地区：[1]复杂油气田勘探开发重庆市重点实验室.重庆科技学院

出　　处：《天然气工业》2015年第11期40-44,共5页Natural Gas Industry

基　　金：国家科技重大专项"高含硫气藏安全高效开发技术"(编号:2011ZX05017);国家自然科学基金项目"裂缝性底水凝析气藏水侵机理研究"(编号:51374296)

摘　　要：为实现对高含硫气藏开发过程中析出硫的定量预测,提出了析出硫为液态的高含硫气藏数值模拟方法。首先以硫溶解度随压力变化实验为基础,建立硫溶解度数学模型和析出硫液相体积分数计算模型,计算不同压力下析出硫的液相体积分数,创建CVD实验;其次通过气体组成的归一化处理,确定高含硫气藏的真实气体组成;最后综合真实气体组成、CVD实验和CCE实验结果,创建反映硫析出的PVT样品,采用组分模型进行析出硫为液态的高含硫气藏数值模拟研究。采用该方法对四川盆地普光气田主体气藏开发过程中析出硫进行了定量预测,结果表明:硫饱和度随以井筒为中心的径向距离的增大而减小,越接近井筒,硫析出量越大,硫饱和度越高;随生产时间的延长,天然气采出程度越高,气藏压力越低,硫析出区域增大,相同半径处的硫饱和度增大。该方法实现了对高含硫气藏析出硫的定量预测,提高了开发动态预测的准确性,为科学开发该类气藏提供了更可靠的决策依据。In order to predict quantitatively the released sulfur during the development of high sulfur gas reservoirs, a numerical sim- ulation method was proposed for high sulfur gas reservoirs with liquid released sulfur. Firstly, two models （the mathematical model for sulfur solubility and the calculation model for liquid volume fraction of released sulfur） were established on the basis of variation experiments of sulfur solubility with pressure to calculate the liquid volume fraction of released sulfur under different pressures and carry out CVD experiment. Secondly, the real gas compositions of high-sulfur gas reservoirs were determined after gas composition was normalized. And finally, PVT samples which could reflect the released sulfur were provided by combining real gas compositions with CVD and CCE experiment results. And the numerical simulation was conducted on high-sulfur gas reservoirs with liquid re- leased sulfur by using compositional models. This method was applied in the Puguang Gasfield,Sichuan Basin, for quantitative pre diction of released sulfur during the development of the main gas reservoirs, It is shown that sulfur saturation decreases with the in- crease of radial distance to the borehole, i.e. the closer to the borehole, the more released sulfur and the higher sulfur saturation. And with the development, the degree of gas reserve recovery increases, gas reservoir pressure decreases, sulfur release area enlar ges and sulfur saturation at the same radius increases. Based on this method, the released sulfur of high-sulfur gas reservoirs can be predicted quantitatively and the accuracy of development performance prediction can be improved. This paper provides reliable deci- sion basis for the development of this type of reservoirs.

关 键 词：高含硫气藏 液态硫 数值模拟 硫溶解度 液相体积分数 硫饱和度 四川盆地 普光气田 

分 类 号：TE37[石油与天然气工程—油气田开发工程]