Research Of Dynamic Prediction And Control Method Of Steam Flooding In Extra Heavy Oil Reservoir

Gradually increased along with the global demand for resources,especially for heavy oil reservoir,the thermal recovery is the most effective method and mature.The displacement mechanism of steam drive and technology research is relatively perfect,but the study of mathematical model is not completenes,especially for steam flooding front dynamic prediction,heat loss calculation and steam drive performance prediction model is not completenes.At the same time,it is also necessary to study for the dynamic analysis and control technology in the process of steam flooding system.Accounting for the effect of steam override,pseudo mobility ratio,etc.,based on the theory of liquid-steam boundary,and using mathematical integral method,the shape of steam front was investigated,and an evolving model of extra heavy oil vertical well steam flooding was established.Thus,the evolution of steam chamber was described precisely.Then with the model the effects of steam injection velocity,pseudo mobility ratio,steam effective-permeability,etc.,on the evolving process of steam chamber were analyzed.Based on the evolution of the steam chamber,using the theory of heat transfer and transient heat balance theory,deduced the formation of heat loss calculation under the effect of gravity override.Thus,analyzed the parameters what impact of the rate of heat loss under the model.Based on the steam chamber and heat loss and combined the conservation of energy conversion and related theory established the steam drive performance prediction model.Forecasting oil and water production situation and to analysis of sensitivity parameters in the process of steam drive.According to this production data of steam flooding to divide the stage of the steam flooding.injectionproduction dynamic rule and dynamic control technology research in stages.Analyzed the injection-production dynamic rule and researched dynamic control technology in different stages.The study of evolution of the steam chamber showed that steam injection rate and pseudo mobility ratio evolution had a greater influence on the steam chamber shape.Heat loss calculation model was used to analy the influence parameters of the thermal loss rate,and the results show that for the thick oil reservoir,the greater steam injection rate,the smaller oil heat loss efficiency.The steam drive performance prediction,which indicates that the early production rise faster,oil production is reduced after the hot fluid field breakthrough,and production fell sharply to 0 after steam breakthrough.The sensitivity analysis of parameters show that the well spacing,steam injection rate and oil layer conditions have great influence on the development effect in the process of steam drive.By dynamic control technology researching,it shows that start-up phase needs drive at the right time and optimizing injection parameters.The steam injection rate,production factor and dryness of steam injecting should be optimized at the stage of optimizing.And at the break through adjustment stage need to take control,transform steam injection method and optimize the injection-production parameters during the intermittent steam injection.Through a series of macro-control measures the steam drive may achieve a good development effect.In this paper,steam flooding prediction theory and the research of injection-production dynamic and control technology in the process of steam drive to improve the extra heavy oil reservoir steam flooding comprehensive development and management level has important practical significance.