Research On Comprehensive Treatment And Technical Countermeasures Of Low Permeability Reservoir Well Area

At present,low permeability reservoirs in China are facing two major problems.One is that the water saturation of the old developed areas in the oilfield keeps rising while the productivity drops rapidly.The other is that the reservoirs in the new developed areas have poor physical properties and severe geological conditions,which demands higher technical schemes put forward by oilfield workers.From the current development situation,the potential of measures in developed old blocks is decreasing year by year,and the physical properties of reservoirs are deteriorating year by year,which leads to more and more Low-yield and low-efficiency wells.Therefore,it is necessary to put forward a comprehensive treatment plan for the development of low permeability reservoirs.Taking the low permeability reservoir of Y oilfield as the research object,the development characteristics and existing problems of Y oilfield are analyzed.It is found that Y oilfield belongs to fluvial facies deposit and mainly distributes in East-West direction.Water flooding can be divided into three types: bottom water coning,bottom water communication and water flooded wells.By using reservoir numerical simulation technology,the effects of geology,fluid and development are analyzed and evaluated.On the basis of historical fitting,a comprehensive treatment scheme for low permeability reservoirs is put forward.The main understandings are as follows:(1)Through the analysis of development dynamics,it is concluded that the reduction of liquid production is the most important factor causing the reduction of oil production,followed by water content.Therefore,the direction of later treatment should focus on maintaining the stability of liquid production and water control on this basis.(2)According to the distribution of remaining oil,the corresponding measures are put forward,and the key control areas and measures wells are selected.The potential of remaining oil can be tapped by such technical means as angle well oil injection,improving injection-production relationship,potential formation evaluation and hole filling.(3)On the basis of Geology and reservoir,optimizing injection-production parameters can effectively prevent the occurrence of bottom water coning and bottom water coning.