Study On High-temperature Resistant Air Foam System Of Profile Control And Flooding

Reservoir air foam injection technology integrated the merits of both air injection and foam flooding with air as the gas medium and possessing these advantage of rich gas source and low cost.While this technology possesses thermal effect because of LTO.It is a new technology that can effectively improve reservoir recovery,besides it can achieve deep profile control and improve development effect of heterogeneous reservoirs,especially be suitable for high water-cut,serious heterogeneity and these reservoirs with cracks or big channel.Low temperature oxidation reaction(LTO)may occur between a ir and crude oil under reservoir temperature while air is injected and its front-end temperature can significantly increase by 30~50?.Meanwhile LTO is a slow process,so foaming agents used in air foam profile control and flooding should possess well high temperature-resistant and aging-resistant performance that are of great significance for field application of air foam.In this paper,four types of high temperature-resistant air foaming agents have been synthesized with sulfonate surfactants.The foam static evaluation experiment,the blocking ability experiment and the foam high temperature aging experiment have been completed.From six kinds of surfactants including four kinds of synthetic surfactants and common sodium dodecyl benzene sulfonate,sodium dodecyl sulfate,the high temperature-resistant air foam agent is screened as high temperature-resistant air foaming agent with best performance.Through high temperature & high pressure visual air foam meter,the temperature resistance,pressure resistance and salinity resistance performance have been evaluated by static experiment method.The results suggest this foaming agent has well temperature resistance,pressure resistance and salinity resistance performance.Then the effect of different injection factors on the sealing ability of this air foaming agent has been researched and the mechanism of air foam enhanced oil recovery in high temperature reservoir has been revealed.Different injection factors are including temperature,permeability,gas liquid ratio,salinity and injection rate.The thermal effect because of LTO between the air injection and the crude oil testes the aging-resistant performance of foaming agents,so the aging-resistant performance of this air foaming agent has been studied by aging experiment equipment.The results show the thermal effect damage the foaming performance more than the stability performance.Meanwhile it also suggest the aging-resistant performance of this air foaming agent is so well that this foaming agent can be used in air injection.Finally,this paper has carried on the preliminary exploration carbon number(or carbon chain)of high temperature-resistant air foaming agents.The results show that too small or too many carbon number(or carbon chain)is not so well for the performance of foaming agents,so we should design appropriate carbon number(or carbon chain)while synthesizing new high temperature-resistant air foam agents.