The Research Of Advanced Water Injection Mechanism Of Fu-yang Reservoirs

Advancing water injection refers to the flood-production method in which injectorsbegin to flood before producers begin to put into production, and the oil saturation within thedrainage area should be no less than the original oil sation when producers are brought intoproduction, and the formation pressure are higher than the original formation pressure, and aneffective flooding system is built. In view of the current situation that there is no analysis andstudy of the factors which affect advancing water injection within reservoirs with lowpermeability at home now,and the fact that there are a lot of factors to be considered toconduct the research,in addition,these factors interact each other,this paper adopts theorthogonal experiment method.Wehave studied the effect of many single factors,includingwell patterns,the distance of wells,the time of water injection,permeabilities, the viscocity ofcrude oil and the gradient of threshold pressure,to advancing water injectionwithin reservoirswith low permeability. We find that the time of advancing water injection, permeabilities, welldistance and the formation pressure factor are the major factors which affect the degree ofreserve recovery and the oil producing capacity of each well by multiple factors rangeanalysis.The good effect of advancing water injection can be achieved by optimizingcontrollable factors such as the time of advancing water injection and the well distance.In thispaper,the research was made about the effect of injection time,permeability,injector producerdistance and pressure coefficient on the leading injection in the low permeabilityreservoir.The result showed that leading injection could enhance the driving pressuredifferential and decrease the adverse effect of pressure sensitivity on the development of thelow permeability reservoir.Leading injection showed a good effect on enhancing oilproduction.Proper injector producer intervals are inportant.Optimum displacement resultcould not be achieved when the distance was too big or too small.Good result of leadinginjection could be achieved in the normal and subnormal pressure reservoir,while in the surerpressure and low permeability reservoir,delayed injection should be adopted.Advanced-water-flooding has become an important method for developing lowpermeability reservoirs.Advanced-water-flooding is to inject water into water wells before oilwells product oil.This will increase formation ressure,avoid permeability decreasing,thresholdpressure ient and iscosity ncreasing.Besides,advanced-water-flooding will raise pressuregradient and make fluids flow faster.What’s more,it will avoid Fingering and improve oilrecovery.