Research On Compound Foam Profile Control Of Heavy Oil Thermal Recovery

In the middle and later parts of the heavy oil thermal recovery,the reservoir exhibits salient features: strong heterogeneity,permeability differences,different oil properties,well spacing and reservoir tilt,gravity separation.These characteristics result in high temperature steam moving to the upper reservoir,steam channeling in large pores,lower volumetric sweep efficiency and steam utilization,heterogeneous steam absorption profile.The ultimate recovery will be decreased.Most heavy oil reservoirs have entered the multi-round cycle steam stimulation,production effect is deteriorating year by year.And there are big gap in utilization between high-permeability layer and low-permeability layer.In the formation gas or water channeling phenomenon is more severe.There are low steam injection pressure,poor production effect,invalid huff and puff,and water flooding.Therefore,according to the current condition,it's necessary to research foam profiling control technology of heavy oil thermal production wells.The steam absorption profile and steam injection efficiency of injection well must be improved.In this paper,because of the above reasons,research on compound foam profiling control is proposed,which can effectively solve the problem of high formation water storage rate,big gap in vertical utilization,and low efficiency of steam and hot water flooding.The main research contents in this field include: mechanism of compound foam system profiling control,optimization of nitrogen initiators and high temperature foaming agents,optimization of injection parameters and injection method and field test research on compound foam profiling control.Compound foam profiling control technology is a new technology suited for assistant cycle steam simulation,which has some features of gas flooding,surfactant flooding and foam flooding.The technology has the characteristics of less input,simple construction,and outstanding effect.The effect of cycle steam simulation is improved,and the well water cut is decreased.The well production and the recovery is increased.