新型烷基苄基甜菜碱驱油剂的制备与性能评价

Preparation and Performance Evaluation of a New Alkyl Benzyl Betaine Oil Displacement Agent

为获得耐盐性能良好的甜菜碱型两性表面活性剂,以十二烷基苯(直链)、多聚甲醛、二甲胺及3-氯-2-羟基丙磺酸钠为主要原料,通过氯甲基化反应、亲核取代及季铵化反应合成了烷基苄基甜菜碱驱油剂——N-十二烷基苄基-N,N-二甲基羟丙基磺基甜菜碱(DB-17)。用质谱及红外光谱对合成产物的结构进行了表征,测定了DB-17溶液与新疆原油的油水界面张力,并用岩心驱替实验装置评价了DB-17的驱油效果。结果表明,在N,N-二甲基羟丙基磺酸钠与十二烷基苄基氯的投料摩尔比为1.3∶1、反应温度为70℃、反应时间为6 h的条件下合成的DB-17的产率为90.3%。DB-17具有较强的界面活性。随DB-17浓度的增大,油水界面张力降低。DB-17质量浓度为250 mg/L时,可将油水界面张力降至1.3×10^-3m N/m。DB-17的抗盐性较好,15 g/L NaCl溶液对DB-17与原油的界面张力影响较小。250 mg/L的DB-17可使高渗天然岩心在水驱基础上平均提高驱油效率14.7%,DB-17的驱油效果较好。

In order to obtain betaine amphoteric surfactant with good salt tolerance,N-dodecyl benzyl-N,N-dimethyl hydroxypropyl sulfonate betaine(DB-17)was synthesized by using dodecyl benzene(linear chain),polyformaldehyde,dimethylamine and sodium 3-chloro-2-hydroxypropyl sulfonate as main materials through chloromethylation reaction,nucleophilic substitution reaction and quaternary ammonium reaction.The structure of the synthetic compound was characterized by mass spectrometry and infrared spectroscopy.The interfacial tension between DB-17 solution and Xinjiang crude oil was measured.Finally,the oil displacement effect of DB-17 was evaluated by the core displacement device.The results showed that the yield of DB-17 could reach 90.3%when the reaction carried out on the condition of 1.3∶1 mole ratio of N,N-dimethylhydroxypropyl sulfonate sodium and dodecyl benzyl chloride,70℃reaction temperature,and 6 hrs reaction time.DB-17 had strong interface activity.With the increase of DB-17 concentration,the interfacial tension between oil and water decreased.When the mass concentration of DB-17 was 250 mg/L,the interfacial tension between oil and water could be reduced to 1.3×10^-3 mN/m.DB-17 had better salt resistance,and 15 g/L NaCl solution had less effect on the interfacial tension between DB-17 and crude oil.DB-17 had a good flooding effect.250 mg/L DB-17 could increase the oil displacement efficiency of natural rock with high permeability by an average of 14.7%based on water flooding.