陕北气田含醇污水综合治理室内实验研究

陕北气田生产中大多采用甲醇抑制水合物的形成,一部分甲醇溶于水相形成了含醇污水。含醇污水中的甲醇需回收循环使用,以降低天然气的生产成本。该含醇污水水质特点是矿化度非常高,油分和机械杂质含量也较高,pH值较低,同时溶解有一定量的CO2及O2,因此在甲醇回收装置运行中经常出现管线、设备腐蚀穿孔、精馏塔结垢堵塞等现象,严重影响装置的安全运行。针对以上问题在此提出用絮凝/缓蚀阻垢技术综合治理陕北气田含醇污水,含醇污水经处理后,总铁、H2S、机杂、油分含量大为降低;含醇污水对碳钢腐蚀速率可控制在0.15 mm/a以下,阻垢率达到100%,可以完全解决陕北气田含醇污水甲醇回收处理过程中存在的结垢、腐蚀、堵塞等问题。

Experimental Research of Comprehensive Disposing Sewage Containing Methanol in ShanBei Gasfield

Methyl alcohol has been used for controlling the formation of hydrate in gas production field in Shanbei gasfield, so a part of methyl alcohol dissolved in water to form sewage containinn methanol. The methyl alcohol in the wewage must be recovered and cyclically utilized, so as to reduce cost. The gasfield sewage containinn methanol is of high salinity, of high mechanical impurity, of high oil, of low pH, of a certain amount of dissolved gases（ CO2 and H＂2S）. So that there existed the phenomena of the pipeline equipment＇s being punched by corrosion and the rectification tower＇s being plugged by scalinn in the course of operation of methyl alcohol recovery installation, thus influencing severely the safety in production of the installation. For this reason, an floeculation -/corrosion control - scale prevention technique of disposing the sewane containinn methanol in Shanbei gas field is put forward in the paper. After the sewage＇s being disposed, the H2S, mechanical impurity, oil, and total Fe content in it might be reduced greatly,and its corrosion rate less than 0. 15 mm/a, and its scale prevention rate was up to 100%. Therefore the problems of scaling, plunning and corroding existinn in the course of the methyl alcohol recovery and disposal of the sewage containing methanol in Shanbei gas field may be fully solved by use of such a technique.