C_(16)格尔伯特醇聚氧烷烯醚硫酸盐的制备及其界面性能研究

Study on the preparation of C_(16) Guerbet alcohol polyoxyalkylene ether sulfate and its interfacial properties

用C_(16)格尔伯特醇经共聚加成环氧丙烷(PO)和环氧乙烷(EO),再经氨基磺酸硫酸化合成了一种支链烷基醇醚硫酸盐(C_(16)GA-PES)。这种新型阴-非复合型表面活性剂具有优良的水溶性、耐盐性和表面活性。45℃下溶于大庆地层水,单独即可将大庆轻质原油/地层水界面张力降至超低;对稍重质的大庆三类油层油,使用该表面活性剂与少量亲油性更强的表面活性剂混合,亦可将界面张力降至超低。这种新型结构表面活性剂吸附在油/水界面形成的单分子层具有从强亲油到弱亲油-弱亲水再到强亲水的过渡结构,而双烷基链又赋予单分子层较高的烷基链密度,从而增强了单分子层与油分子的相互作用,易于将原油/水界面张力降至超低。与相应的嵌段中间体相比,共聚所得非离子中间体黏度显著降低,便于管道输送并且有利于采用SO3气体降膜式硫酸化工艺制备硫酸盐。

A new anionic-nonionic surfactant with branched hydrophobic group was prepared using C_(16) Guerbet alcohol by co-polymerization of propylene oxide(PO)and ethylene oxide(EO)followed by sulfation with aminosulfonic acid.This surfactant(C_(16)GA-PES)shows excellent aqueous solubility,good tolerance to inorganic electrolytes such as sodium chloride(NaCl)and calcium chloride(CaCl_(2)),and good surface activity(cmc=1.15×10^(-6) mol/L).When dissolved in Daqing formation water(pH=8-9)with a total salinity of 6788 mg/L,including 23 mg/L Ca^(2+)and 31 mg/L Mg^(2+)at 45℃,the C_(16)GA-PES solely can reduce the interfacial tension(IFT)between Daqing light crude oil and formation water to ultralow(<0.01 mN/m);for the slightly heavy crude oil from the third type of reservoir in Daqing oilfield,ultralow IFT can be achieved by mixing the C_(16)GA-PES with a small fraction of more hydrophobic surfactant,1,3-didecyl glyceryl ether hydroxypropyl sulfobetaine(diC_(10)GE-HSB).The new surfactant adsorbs at the oil/water interface constituting a monolayer which has high alkyl chain density and a transition structure from strongly hydrophobic to weak hydrophobic-weak hydrophilic and to strong hydrophilic,resulting in strong interactions between the monolayer and oil molecules and making ultralow IFT easily achievable.It is also noticed that,the nonionic intermediate produced by co-polymerization of PO and EO has low viscosity,which is beneficial to pipeline transport and sulfation with SO_(3)/air mixture.