抗高温抗复合盐支链型聚合物降滤失剂的合成及其性能

Synthesis and Evaluation of a High Temperature Salt-Resistant Chain Polymer Filter Loss Reducer

针对深井钻探中钻井液处理剂抗温抗复合盐性能不足的问题,以丙烯酰胺(AM)、2-丙烯酰胺-2-甲基丙磺酸(AMPS)、N-乙烯基己内酰胺(NVCL)、二甲基二烯丙基氯化铵(DMDAAC)、烯丙醇聚氧乙烯醚(APEG)为单体,以过硫酸钾和亚硫酸氢钠作为氧化还原体系进行自由基共聚反应,合成了一种支链型聚合物降滤失剂(PAANDA)。通过实验优化确定了最优合成条件为:n(AM)∶n(AMPS)∶n(NVCL)∶n(DMDAAC)∶n(APEG)=50∶20∶5∶10∶15,反应温度为50℃,反应时间为4 h,引发剂用量为0.3%。利用傅里叶红外光谱(FT-IR)和核磁共振氢谱(1H-NMR)确定了聚合产物的分子结构,通过热重分析(TGA)测得PAANDA热分解温度大于300℃,表明其具有良好的热稳定性。同时,应用于水基钻井液中,进一步评价PAANDA对水基钻井液流变和滤失性能的影响。结果显示,当PAANDA加量为2.0%时,180℃老化后API滤失量为4.0 mL,高温高压滤失量为22.6 mL(180℃),同时具有抗复合盐能力,抗盐钙能力优于国外同类产品Driscal D。

A branched polymer filter loss reducer PAANDA has been developed to deal with the problems of poor high-temperature stability and poor salt resistance encountered in deep well drilling.Monomers used for the synthesis include acrylamide(AM),2-acrylamide-2-methyl propane sulfonic acid(AMPS),N-vinyl caprolactam(NVCL),dimethyl diallyl ammonium chloride(DMDAAC)and allyl alcohol polyoxyethylene ether(APEG).Potassium persulphate and sodium bisulphite was used as a redox system for the radical polymerization reaction.Laboratory experiment was conducted to determine the optimum ratio of the raw reaction materials and optimum reaction conditions ad follows:n(AM)∶n(AMPS)∶n(NVCL)∶n(DMDAAC)∶n(APEG)=50:20:5:10:15,reaction temperature=50°C,reaction time=4 hours,concentration of the initiator=0.3%.Using FTIR and 1H-NMR,the molecular structure of the polymerization product was determined.TGA analysis showed that the PAANDA filter loss reducer degrades at above 300°C,indicating that the product has excellent thermal stability.The filtration control property of PAANDA was evaluated in water-based drilling fluids.It was found that at a water-based drilling fluid treated with 2.0%PAANDA has API filter loss of 4.0 mL and HTHP filter loss of 22.6 mL tested at 180°C after aging the fluid at 180°C.The PAANDA also performed better than Driscal D in resisting contamination from compound salts and calcium.