The Analysis Of The Oil-water Distribution Difference And The Study Of Development Adjustment On The Donghe4Carboniferous Oil Reservoir

The Donghe4Carboniferous oil reservoir was found in Donghetang oilfield No.4anticline.In1992,DH4well had formation test in6068～6085m which obtained highyield of oil and gas.The formation test found the Donghe4Carboniferous oilreservoir.By analyzing the geological information of the reservoir, sedimentarymodels of reservoir section is no barrier wave controlled shore.The properties of thisreservoir is medium-low porosity and medium-low permeability.The reservoirheterogeneity which is in the flat surface and interlayer heterogeneity are weak.Thereservoir internal anisotropic is strong.Until June2013,the cumulative production ofthe Donghe4Carboniferous oil reservoir fluid43.8904×104t, where the cumulativeoil production43.5694×104t, cumulative water production0.3058×104t, daily oilproduction of31t/d, the degree of recovery of16.5%, oil production rate0.39%water cut rate of3.94%.The current main problems of reservoir is the east block noproductivity, west block formation energy falling too fast.The well pattern of thereservoir needs to be improved to enhance oil recovery and achieve the goal ofmining.After twenty years of mining, geological data and production data constantlyupdated, found some existing problems of Geology understanding.According toreinterpret the testing data and logs, the single well reservoir at the oil-water interfacelevel was determined,and found that there are differences of reservoir oil-waterinterface in blocks.Analysis of that is due to a problem with the determination oflateral sealing ability of fault.Therefore, adopted qualitative and quantitative methods,including: lithology opposed, the earth physical and chemical analysis, dynamic dataanalysis, the fault sealing coefficient method, studied the lateral sealing ability of fault.The preliminary conclusions is that fault slip is small, not completely disconnect theupper1-0layers, two fault block is connected in the process of production.For thelower layer, due to poor permeability, fault formed certain sealing, caused thedifference on both sides of the fault.The fault sealed part of oil in the block which DH4well was located.The oil and water interface is relatively low(-5110m) in thewest block.East block sealing was poor.During the destruction of reservoirs,the oilwas lost and kept some residual oil zones with different thickness.The1-0layer ofeast block is a stratified reservoir.From the point of view of the theory of petroleumgeology,the1-0layer of east block and the west block have the same oil-waterinterface.Oil and water distribution characteristics were analyzed.On the basis of the geological understanding,3D geological mode of the reservoiris established, including the structure model and property model.Geological reservesof the reservoir was calculated.The reserves of Geological modeling is230.83×104t.The reserves which used volume method is233.98×104t.The calculationof the gap is3.15×104t.The calculation error is1.35%.Geological model is reasonableand reliable.After that, the numerical simulation model is setted up, and to deal withfaults and interlayer.The history matching of the reservoir and single well had bedone.The remaining oil distribution of the reservoir was got in June2013.Accordingto the design principles of reservoir development, demonstration of the way for thereservoir will be waterflooding.According to the distribution of the remaining oil,designed three schemes.The injection volume of the schemes and the well spacingwill be preferred.Schemes can predict the production of the next15years.Injectionvolume is determined80m3/d of the preferred embodiment. The scheme predictedcumulative oil production95.75×104m3, the degree of recovery of34.8%.Comparedto the original plan, there is a significant improvement.