Present situation and development prospect of foam flooding

The development history,oil-displacement mechanism and the newly research direction of foam flooding at home and abroad were briefly introduced in this paper;In addition,the application and effect of foam flooding obtained in the oilfield were presented.Then the advantages and disadvantages of foam flooding were analyzed and the existent problems,especially those that should be paid attention in the popularization of foam flooding were put forward.Furthermore,the effect and the advantages and disadvantages of injecting foam slugs discontinuously to improve the water flooding and other oil-displacement modes were discussed and these constraints of foam flooding were studied.Based on those results,it was considered that the poor stability,bad oil resistance and high gas injection costs of foam system were the key factors that limited its development.Thus,designing new-type foam agents that had low cost,good foaming power,excellent interface property and displacement efficiency,as well as developing foam systems that used cheap gases such as flue gas or air as gas source and improving the injection pattern and process were the important research directions of foam flooding.