Study On Surfactant Oil-displacement Technology For Wuliwan Area

Jingan oilfield in Wuliwan area is the typical low permeability reservoir, water-flooding development passed through more than ten years, the water cut of oil well rising, injectability falling, recovery rate rely on water-flooding is relatively low. Therefore, this paper aims to study the surfactant system adaptation to the Wuliwan area, in order to increase the oil displacement efficiency, enhance oil recovery.This thesis firstly synthesis of oligomeric diol (α-sodium sulfonate) of lauric acid diester anionic gemini surfactant (GSS) with lauric acid, polyethylene glycol as the main raw material under laboratory conditions, determination of the critical micelle concentration (CMC) is only438mg/L, surface tension under critical micelle concentration for30.9mN/m, and at lower concentrations interfacial tension of crude oil in Wuliwan area to1.4x10-2mN/m; then through interfacial tension test, screened the sulfonate surfactant E and nonionic surfactant H, which can reduce the interfacial tension of oil in Wuliwan area respectively to4.5210-2mN/m and2.27x10-2mN/m in0.4%concentration; then testing the interfacial activity of GSS with E and H mixed system, experimental results show that nonionic surfactant H and GSS has synergistic effect better, and verified in H and GSS when the ratio of3:1to Wuliwan area oil/water interfacial tension fell to a ultralow level (10-3mN/m); finally, performance of the surfactant system of HG3-1were evaluated, experimental results show that HG3-1has excellent interfacial activity, with strong salt resistance, temperature resistance, wetting and low absorption loss, and has good flooding effect, is a suitable oil displacement agent for Wuliwan area of low permeability reservoir.