Single horizontal wellbore gravity drainage assisted steam flooding process

摘要: Disclosed is a gravity-drainage assisted steam flooding process for the recovery of all from thin viscous heavy oil reservoirs using single horizontal wellbore. Steam injected through fully or partially insulated tubing to exit at near toe long well penetrating reservoir. Initially, low (10-30%) quality circulated along condition wellbore and increase heated radius about 1 2 meters. Oil reservoir fluids immediately adjacent are produced annular space between string slotted liner that surrounds it. After period circulation, production outlet shut in constrained injection continued initiate an active chamber zone portion Subsequently, fluid withdrawal resumed outlet, while liquid level vertical section controlled maintain nearly constant pressure outlet. The higher (50-70% more) rate similar than initial cause expansion propagation volume vertically towards top formation, longitudinally its heel, laterally away inter-well boundary with next row well. As flows into under both gravitational counter current flow drive, oil, condensate conductively convectively drain annulus then pumped surface.