海上高温油田防垢剂的研制及应用

Development and Application of Scale Inhibitor in Offshore High-Temperature Oilfield

针对南海某油田因高温、高矿化度、高二氧化碳造成水处理系统低压段结垢严重的问题,制备了耐高温的防垢剂聚环氧琥珀酸(PESA),并与氨基三亚甲基膦酸(ATMP)、2-膦酸丁烷-1,2,4-三羧酸(PBTCA)进行复配,得到复合防垢剂,分别采用滴定法和纳米粒度及Zeta电位分析仪测定防垢率和水中垢的平均粒径。结果表明,当温度为98℃、PESA∶ATMP∶PBTCA为6∶2∶1、加量为10 mg·L^(-1)时,复合防垢剂的防垢率达到99.8%,水中垢的平均粒径为601.0 nm,PESA、ATMP、PBTCA具有良好的协同作用。现场应用结果表明,加注复合防垢剂后,防垢挂片未发现结垢现象,下游水样中Ca^(2+)浓度与地层水水质分析结果基本一致,防垢效果优于现场用防垢剂。

In view of the serious problem of scale formation in the low pressure section of water treatment system caused by high temperature,high salinity,and high carbon dioxide in an oilfield in the South China Sea,we prepared the high-temperature scale inhibitor polyepoxysuccinic acid(PESA),and then obtained the compound scale inhibitor by combined PESA with amino trimethylene phosphonic acid(ATMP)and 2-phosphonobutane-1,2,4-tricarboxylic acid(PBTCA).Moreover,we measured the scale inhibition rate and average particle size of scale in water sample by titration method and nano-particle size and Zeta potential analyzer,respectively.The results show that when the temperature is 98℃,PESA∶ATMP∶PBTCA is 6∶2∶1,and the dosage is 10 mg·L^(-1),the scale inhibition rate of compound scale inhibitor reaches 99.8%,and the average particle size of scale in water is 601.0 nm,indicating that PESA,ATMP,and PBTCA have good synergistic effect.The field application results show that after adding compound scale inhibitor,no scale phenomenon is found in the scale mounting plate,and Ca^(2+) concentration in the water downstream is basically consistent with the analysis results of formation water quality,indicating that the scale inhibition effect is better than that of the field scale inhibitor.