The Synthesis And Application Of Quaternary Ammonium Sulphonate Amphoteric Gemini Surfactants

Compare to the traditional surfactant, Gemini Surfactant not only has a high surface activity, low critical micelle concentration value, but also combines the performance of polymer and traditional displacement agents, which has an immense potential in Enhanced Oil Recovery in Oilfield. However, it still has some problems such as abundant promoter should be added when using cationic Gemini surfactant, chromatographic separation may occur in the formation when using multicomponent Gemini surfactant, anionic or nonionic Gemini surfactant is not only difficult to synthesis, but also has a lower oil-water interfacial tension.This research design and synthesize a series of Quaternary Ammonium Sulphonate Amphoteric Gemini Surfactants with special structure, aiming to be applied to the Oilfield in North Shaanxi. The solvent volume ratio of acetone,1,4-dopxane and water to rapidly synthesize the Gemini Surfactants is 1:3:6, this method shifts the two phase reaction to homogeneous reaction without using the phase transfer catalyst, also improving the reaction rate and product yield, the reaction time is shorten to 4-8h, and the product yield reach 88%-96%.This article studies on the oil-water interfacial tension, wettability, salt resistance, Temperature resistance of Gemini surfactant. The result shows when mass fraction of surfactant is 10-6, the oil-water interfacial tension is lower to 10-2-10-3 mN/m, which can be stably exist in 10 mg/L saline solution, and the oil-water interfacial tension is stable under 30?-90? in 105mg/L saline solution.This article studies on the oil displacement performance of Gemini surfactant. The result of oil displacement test on core from Chang 2 and Chang 6 reservoirs at Jingbian Oilfield in North Shaanxi shows that compare to the water flooding, oil displacement efficiency improves 9.2%-18.1% and 8.7%-15.7%, respectively. The water phase permeability is improved to 60.8% and 42.8%, respectively.The field test of Gemini surfactant has been designed and performed in oilfield in North Shaanxi. The result shows when applied for enhanced oil recovery, the oil output increase significantly; the application of Gemini surfactant in clean fracturing fluid system have better carrying capacity of sand, reduce the damage to the formation with completely gel-breaking performance, when used as a cleanup addictive, it improves the fracturing fluid flowback rate, when used asmain ingredientsof crude oil demulsifier, it can reduce the moisture content of purified crude.