Heavy oil reservoirs of steam-injection development after water-flooding have normally experienced many different production processes,such as cold production,water-flooding, steam buff and puff,and steam flooding.Some complex phenomena and effects may occur in the non-isothermal recovery processes,for example,distillation,decline in in-situ oil viscosity,water gravity segregation,steam overlap,the development of wormholes,forming foaming oil,thermal expansion effect of formation fluid and rock,and reversed wettability.Simultaneously,formation damage induced by clay swelling,external particles invasion,fines generation, migration,sanding and asphaltene precipitation may happen, which can lead to variations in formation permeability and porosity and significantly reduce oil production rate and even lead to its complete loss.Traditional model for simulating heavy oil reservoir production behavior has not allowed for the influence of formation damage on heavy oil reservoir and has neglected dynamic changes in formation porosity and permeability.Thereby,it becomes unreliable to design and
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