天然气水合物气液分离方案设计与样机试制

Gas-liquid Separation Scheme Design and Prototype Manufacturing for Natural Gas Hydrate

针对海域天然气水合物降压开采过程中气相含液严重影响水合物采收率的问题,结合我国南海神狐海域天然气水合物的实际工况,提出了一种天然气水合物气液螺旋分离装置设计方案,基于压缩因子校正的理想气体状态方程和Dean-Stiel黏度模型,计算了开采地层温压条件下天然气的物性参数,结合计算的关键零部件的结构参数,完成了气液螺旋分离装置的结构设计,同时开展了天然气水合物气液螺旋分离装置的样机试制与试验测试。研究结果表明:天然气实际开采过程中,气体流量较小,液相含量较低,适宜采用螺旋分离装置;在实际开采地层中天然气的密度为130.785 kg/m^(3),动力黏度为0.0182 mPa·s,确定天然气水合物气液螺旋分离装置的螺距为70 mm,圈数为7,螺旋体管外径为105.0 mm;在液相体积分数10%以下,样机分离效率整体在90%以上。研究结果可为高效安全地开发天然气水合物资源提供技术支持。

During depressurization production of natural gas hydrate in the sea area,serious gas-liquid mixing affects the recovery ratio of gas hydrate.Considering the actual working conditions of natural gas hydrate production in Shenhu sea area of South China Sea,a design scheme of gas-liquid spiral separator for natural gas hydrate was presented.Based on the ideal gas state equation corrected by compression factor and Dean-Stiel viscosity model,the physical parameters of natural gas under the conditions of formation temperature and pressure were calculated.Combined with the calculated structural parameters of key components,the detailed structural design of the gas-liquid spiral separator was completed,and the prototype manufacturing and experimental test of the gas-liquid spiral separator for natural gas hydrate were carried out.The results show that in the actual natural gas exploitation process,both gas flow rate and liquid content are low,so it is suitable to use spiral separator.The density of natural gas in the actual produced formation is 130.785 kg/m^(3),and the dynamic viscosity is 0.0182 mPa·s.So it is determined that the screw pitch of the gas-liquid spiral separator for natural gas hydrate is 70.0 mm,the number of spiral turns is 7,and the outer diameter of spiral tube is 105.0 mm.When the liquid content is below 10%,the separation efficiency of the prototype is over 90%.This study provides technical support for the efficient and safe development of natural gas hydrate resources.