硫酸钡防垢剂的制备与性能评价

Preparation and Performance Evaluation of Barium Sulfate Scale Inhibitor

油田结垢通常会导致地层及管线堵塞,导致开发成本增加,采收率降低。针对这一问题,将低分子量聚丙烯酸钠、水解聚马来酸酐和聚天冬氨酸3种防垢性能较好的螯合剂复配制得硫酸钡防垢剂,评价了防垢剂对硫酸钡垢的防垢性能、悬浮性能和对管线的腐蚀性能等。结果表明,硫酸钡防垢剂中低分子量聚丙烯酸钠、水解聚马来酸酐和聚天冬胺酸的最佳质量比为2∶2∶3。在钡离子质量浓度为300 mg/L、温度为50℃的条件下,防垢剂加量高于12.5 mg/L时即具有优良的防垢效果,防垢剂加量为100 mg/L时的防垢率可达到95%以上。防垢剂的耐温性较好,对管线的腐蚀性较低。防垢剂可影响硫酸钡垢的沉降和垢晶核的正常生长,使所得垢结构规律且更加松散,有利于后续的机械清垢处理,满足油田的正常生产需要。

Scaling in oilfield usually leads to the blockage of formation and pipeline,cost increase of development and reduction of oil recovery.Aiming at this problem,barium sulfate scale inhibitor was prepared by using three kinds of chelating agents with good anti-scaling performance,such as sodium polyacrylate with low molecular weight,hydrolyzed polymaleic anhydride and polyaspartic acid.The anti-scaling performance,suspension performance and corrosion performance to pipeline of barium sulfate scale inhibitor were studied.The results showed that the best mass ratio of sodium polyacrylate with low molecular weight,hydrolyzed polymaleic anhydride and polyaspartic acid in barium sulfate scale inhibitor was 2∶2∶3.When the mass concentration of barium ion was 300 mg/L and the temperature was 50℃,the scale inhibitor had an excellent anti-scaling effect when the dosage was higher than 12.5 mg/L.When the dosage of scale inhibitor was 100 mg/L,the anti-scaling rate could reach more than 95%.The scale inhibitor had good temperature resistance and low corrosion resistance to pipeline.The scale inhibitor could affect the sedimentation of barium sulfate scale and the normal growth of scale nuclei,which made the structure of obtained scale regular and looser.It was conducive to the subsequent mechanical cleaning treatment and met the normal production need of oilfield.