| An important way of exploiting heavy oil,extra heavy oil is steam huff and puff.The difference of permeability,interlayer agenesis and steam overlapping effects,steam injection can lead to high permeability layer become strong suction vapor layer,low permeability layer into weak steam absorption layer,leading to severe layer steam absorption and low permeability.With the increase of stimulation rounds,slowly inter-well steam channeling interference may occur,so that the effect of cyclic steam stimulation can greatly reduce.Nitrogen foam flooding is a kind of mixture of steam flooding technology is widely used in oil field.N itrogen foam has high viscosity,good performance of a closure,and the foam fluid with large pore plugging,characteristics of water plugging.But at high temperatures the conventional foaming agent foaming ability is weak,and the foam is unstable.Due to the above reasons,this paper puts forward the optimization of nitrogen foam profile control technology,through the indoor experiment from the concentration,temperature performance,temperature tolerance time screening foaming agent performance and showed that DF-2 and GD-2 foaming agent is a foaming agent of high temperature resistant better through the foam comprehensive value.Two kinds of foaming agent SiO 2 nano particles were added in later,respectively to evaluate the performance of four kinds of chemicals,the results showed that adding SiO2 nanoparticles significantly improved the stability of the whole system.Through experiments the addition of nanoparticle foam stability and profile control effect is very good,the bubble interior flooding test system was proved to be effective in enhancing the recovery rate.At the same time will be improved and applied in construction site and injection device of foam,effectively improve the steam huff puff effect,reduce the single well water content,increase single well production,improve the recovery of the oil. |
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