Study On Weak-alkali Compound Flooding For No.3 Oilfield Factory's In Daqing

The conditions that synthesized surfactant of ultralow interfacial tension in technic were determined through synthesizing surfactant of soyabean oil acid alkanoamide SA. This paper analyed the characteristic functional groups of raw materials and products by infrared absorption spectroscopy and studied the interfacial tension characteristics of the surfactant of alkanoamide with different carbonchains. Thus it forming mechanism of ultralow interfacial tension was ascerntained.We discussed interfacial tension, static adsorption effect and displacement characteristics of the combined two-component mixture of polymer with SA and Na2CO3/petroleum sulfonate surfactant/polymer ASP system.and studied the influence of polymer concentration, salinity and temperature on the interfacial tension of ASP combinnation. The results indicated that polymer concentration and salinity had more influence on the interfacial tension, and the order of the interfacial tension of SA system (changing thickness of weak alkali) can reach 10-3 mN/m when the salinity is between 1400 to 11000 mg/L. It indicated adsorbance of the two-component (polymer with SA) mixture is less than 1 mg per gram sand by mensuring the absorption isotherm of the SA two-component mixture onto Daqing oil sand(SA concentration is for flooding). In the test room, chemical flooding recovery efficiency of SA surfactant-weak alkali ASP combination can reach more than 20% when the concentration of polymer is 1950 mg/L, Na2CO3 is 0.6% and that of SA surfactant is 0.3%.When the test of interfacial tension, adsorption and flooding effect with petroleum surfonate surfactant made by Petrochina Daqing Refining&Petrochemical company by changed the concentration of surfactant (petroleum sulfonate)/NaCl/Na2CO3 and temperature, the result suggests the best concentrationscope of surfactant /NaCl/Na2CO3. The interfacial tension may achieve 10-3 mN/m. Have determined weak-allkali ASP combination dynamic tension and adsorance is less than 1 mg/g sand by measuring the adsorption isotherm of petroleum sulfonare surfactant onto Daqing oil sand. For petroleum sulfonate surfactant weak-alkali ASP system,the testroom chemical recovery efficiency is also above 20% when the polymer density is 1400 mg/L,petroleum sulfonate surfactant is 0.3%and Na2CO3 density is 1.2%.