Technique Of Nitrogen Foam Profile Control In Heavy Oil Reservoir With Edge Water

Heavy oil reservoir is very broad in China，most of that is edge water reservoir.Exploitation of heavy oil itself is very difficult, currently the mainly method is using thesteam, when the edge water emerges, the heat will be used in heating water and be lost, whichaffect the oil production of the entire region significantly.For these problems,injecting thenitrogen foam while steam injection can suppress the edge water, it is significant of oilproduction.From the study of the mechanism of foam fluid, evaluate the property of foam. Study thefactors that nitrogen foam affect the edge water by single-barrelled experiments, the resultsshow that the later injection time, the edge water suppression effect is more obvious; The edgewater suppression effect will increase with the edge water pressure and then decrease thetrend; The higher viscosity of the heavy oil,the later edge water emerge, the worse the edgewater suppression effect. Study the factors that nitrogen foam affect the edge water bydouble-barrelled experiments, the results show that the N2+0.5%foaming agent+N2steamedge water suppression effect is better than the other injection methods.Build the numerical simulation model of Henan Oilfield South three XinQian24blocks.Predict the effect of different injection parameters and method, the results show thatthe later injection time, the cumulative oil production is the highest; Keeping the sameamount of nitrogen and foaming agent injection, increase the number of plug can increase theoil production; Cumulative oil production increase with the gas-liquid ratio and then decreasethe trend, the optimal gas-liquid ratio ranges from1:1to2:1; Nitrogen injection rate canincrease oil production, the optimal gas injection rate is12,000Nm3/d; the optimal injectionmethod:N2+0.5%foaming agent+N2steam. The effect of edge water suppression is obvious,the water cut of the region declines rapidly, it plays the ideal suppression effect of edge water.