Experimental Study On Physical Simulation Of Water Flooding Front In Low Permeability Reservoir

Many reservoirs use water injection development technology and achieve good results,However,for low-permeability reservoirs,due to the complex distribution of sedimentary bodies,strong physical changes and non-homogeneous characteristics of reservoirs,therefore,the existence of low-permeability oil reservoirs in the development process,there is uneven absorption between the layers,the water absorption of each water injection layer and the injection capacity does not match,the recovery efficiency is low,the difficult todevelop and the low economy?In order to solve these problems,this paper takes X oilfield block A,block B,block C,block D,these four low-permeable reservoirs as the research object,conducted indoor core experiments?To determine the effect of injection speed,pressure and different permeability differential conditions on the law of change of the leading edge of the water drive.Distribution of the leading edge of the water drive takes the detection of the effect degree of the well and the direction of the well drive as the core,comprehensively uses all kinds of dynamic and static data,gives full play to the advantages of multidisciplinary integration and geology as the main body,carries out the quantitative evaluation of reservoir and reservoir layer,and deeply studies the reservoir parameters.Through the resistance real-time monitoring in the course of the experiment,the monitoring method of the leading edge of the water drive is expounded,and the specific position and movement of the leading edge of the water drive are determined.By analyzing the development history of reservoir and reservoir seepage characteristics,the dynamic characteristics of reservoir development and the effect characteristics of oil wells are expounded.Based on experiments,mathematical models of the water-driven leading edge,and the water-driven leading edge layout,we can draw the following conclusions:1?As the number of PV injected into the water-drive front is negatively related to the viscosity of crude oil,and the water-drive velocity should not exceed the critical velocity of reservoir,it is strictly forbidden to destroy reservoir and cause water channeling.2?For the same block,with different permeability,the PV number of the leading edge of the constant speed flooding is inversely proportional to the permeability,but the final recovery rate of the constant pressure water flooding is proportional to the permeability,and the recovery rate of the constant pressure water flooding is generally higher than that of the constant speed water flooding.3?The difference of displacement leading edge of maximum and minimum permeability increases,which is negatively correlated with the difference of permeability.When the difference is greater than 6,the degree of water flooding increases.4?Water flooding front injection is proportional to flow ratio and extraction degree.the smaller the difference between the injected water viscosity and the crude oil viscosity,the better the water flooding effect and the higher the extraction degree.Compared with the reservoir with high flow ratio,the reverse five-point displacement is insufficient and the remaining oil is more,and the reverse nine-point method can effectively expand the ripple volume,so the reverse nine-point method is superior to the reverse five-point method.At present,the field detection method of water drive leading edge mainly includes tracer method and micro-seismic test method,but it is not possible to monitor the non-homogeneous low permeable reservoir of the mine in real time,and the physical simulation experiment of the movement law of the water drive leading edge is relatively imperfect.Therefore,it is urgent to establish the calculation method of the leading edge of the low-permeable reservoir water drive through reasonable physical simulation experiments,and provide the basis and guidance for the understanding of the law of water drive oil,the analysis of influencing factors,the optimization of the injection well network,and the determination of the distribution of residual oil.