Preparation Of Salt And Oil Resistant Foaming System And Evaluation On Oil-Displacement Ability

Foam flooding has been used in tertiary recovery for three decades and taken some effects.But the research on foam system featured by temperature tolerance,salt resistance and oil displacement is still in its infancy.This article aims at developing a new type of compound foam system under the reservoir conditions of high salinity and oil saturation to ensure they still possess high oil displacement efficiency after polymer flooding.This article mainly describes following processes: through a large number of experiments. firstly,create DAHSB as foaming agent.Secondly,analyze infrared spectrum with Avater370 Fourier transform infrared spectrometer,and then test it’s foaming performance with ROSS-Miles.Thirdly,measure it’s critical micelle concentration with JMP2000 surface tension meter, and then screen the types of several foam stabilizers like fluorocarbon surfactant,n-butyl alcohol and high-molecular polymer and their concentration of co-compounding by evaluating foaming volume and half-life period.DAHSB:FC=900:1(0.3 wt%)+1% n-butyl alcohol+0.1% HPAM(10 million molecular weigh).And experimental results show that this formula has good salt and oil resistance.The static evaluation on identified compound foam system formula:study the changes of foam’s volume and half-life period from three factors including temperature,salinity,oil saturation in the experiment, and conclude the applicable scope of compound foam system.The dynamic assessment on compound foam system formula:simulate“huan 55”block reservoir conditions under the condition that the basic parameters,saturated oil of the core,water drive recovery factor of three simulation cores are same,and create foam flooding with compound foam formula and other three single surface active agent formula.By comparison with the results,conclusion can be drawed that at the same injection,compound foam formula has the highest oil recovery of 72.34%.To sum up,the foam studied in this paper possess a superior performance which has remarkable oil-displacement effects under the condition that the temperature is 70℃,salinity is lower than 7×104 ppm, and oil saturation is below 30%.