The Mechanism And Technical Boundary Values Study Of High Pressure Steam Flooding After Water Flooding In Common Heavy Oil Reservoir

Steam flooding is a kind of methods that can both improve sweep efficiency of water flooded common heavy oil reservoir and enhance oil displacement efficiency.Steam flooding in water flooded common heavy oil reservoir can reduce the oil viscosity and mobility ratio through heating the reservoir.At the same time steam override can effectively use the top remaining oil after water flooding and improve the sweep efficiency,thus greatly improve the oil recovery.In this paper based on the characteristics of buried depth of common heavy oil reservoir in Gudao O ilfield Zhongerzhong N g5 pilot test area,high reservoir pressure caused by long-term water flooding(still at about 7 MPa after steam huff and puff)and high water cut which are not applicable for steam flooding after water flooding,the optimization of well pattern and steam injection parameters for steam flooding is carried out through the technology of reservoir numerical simulation.The feasibility of high pressure steam flooding after water flooding in common heavy oil reservoir is studied and the concept of "the same effect with the same specific volume" is put forward.Besides,the development result of high pressure steam flooding is validated through the field practice in Gudao O ilfield Zhongerzhong N g5 pilot test area.In order to determine the influence of reservoir pressure and steam quality on the steam flooding after water flooding,the mechanisms of high pressure steam flooding in water flooded common heavy oil reservoir are studied through two aspects of reservoir heating and steam expansion.The effects of reservoir pressure,steam quality and the timing of water cut on steam heating reservoir are studied through heat transfer law,temperature front movement,the plane and vertical temperature field distribution and so on.And the effects of reservoir pressure and steam quality on steam expansion in the reservoir are studied through gas saturation front movement,steam chamber volume,the plane and vertical gas saturation field distribution and so on.In the end the effects of different reservoir static parameters and dynamic parameters on reservoir heating and steam expansion are studied.In order to determine the parameters adaptive boundary of high pressure steam flooding after water flooding in common heavy oil reservoir,the effects of different reservoir static parameters and dynamic parameters on the development results of high pressure steam flooding after water flooding are studied through the reservoir numerical simulation technology,and the sensitivity analysis is conducted among the influencing factors.Based on the influencing laws of different reservoir static parameters on the development results of high pressure steam flooding after water flooding in common heavy oil reservoir,combined with dynamic economic evaluation method,the reservoir parameters adaptive boundary and oil price boundary of high pressure steam flooding after water flooding in common heavy oil reservoir is established.