Study On Synthesis And Oil Displacement Property Of Cystine Gemini Surfactants

With the developing of exploration of oil field, main oilfield have entered into high waterand extra-high water period, so production of petroleum decrease faster. In order to enhanceoil recovery, tertiary recovery is imperative. However, chemical flooding is one of mostimportant direction remotely. Therefore, research and development of novel tertiary recoveryagent is a key technique, of which surfactant is important recovery agent. Compared withtraditional single surfactant, gemini surfactant has low critical micelle concentration and highinterfacial activity. But now anionic gemini surfactants have complex synthetic route, lowproductivity and high cost. So it is clear that how to synthetize superior anionic geminisurfactant easily and rapidly still is a key question in applications of gemini surfactant.This thesis used cystine and carboxylic acid chlorides as materials to synthetize cystinegemini surfactant by one step method. At the same time, the target products are characterizedby nuclear magnetic resonance, their surface activity are researched and one of the productsodium dioleoylamino cystine (SDOLC) is researched by TX-500C interface tensiometer.Interfacial tension property and effect factors have been analyzed. The viscoelasticity ofHPAM and gemini surfactant is measured by the rheometer, and then the optimal floodingsystem is determined. Finally the oil displacement performance is evaluated.The experiment results show that acylation reaction synthetic route is right andproduction has proved to be realiable; Solubility of gemini surfactants are nice; SDOLCmatch with Daqing oil well and0.1wt.%SDOLC has10-2order of magnitude interfacialtension at low concentration of alkali; Metal ion can improve interfacial tension between oilphase and water phase, but complexant HEDP.Na4can shield Ca2+and Mg2+and decrease thecontent of alkali; Viscoelasticity of HPAM increase with the higher concentration, decreasewith the higher temperature and decrease with the higher concentration of metal ion; Theoptimal flooding system is determined by measuring viscoelasticity and interfacial tension ofHPAM/Gemini, which is1800mg/LHPAM+0.1%SDOLC+0.15%NaOH+0.06%HEDP.Na4；The results of oil displacement experiment show that recovery efficiency of the compoundsystem contained gemini surfactant is higher than HPAM displacement reaching up to4%-5% and higher than water flood reaching up to about25%both in homogeneous cores andheterogeneous cores.