Transcripción del resumen del autor: Thermodynamic steam-trap control, or subcool control, in a typicalsteam-assisted gravity-drainage (SAGD) production is essential to the stabilityand longevity of the operation. It is achieved commonly through the control offluid production. The goal of such control is to maintain a steady and healthyliquid production without allowing steam from the injector to bypass to theproducer. Therefore, it is effectively a control of the liquid level above theproducer. Unfortunately, it is not practical to monitor this liquid level. Arule-of-thumb subcool-per-metre estimation of 10°C/m of liquid level is popularin the industry; however it does not prove to hold in many situations. Thispaper presents a study of the dynamics of SAGD-production control with aresulting algebraic equation that relates subcool, fluid productivity, andwellbore drawdown to the liquid level above a producer. The main conclusions ofthis study include There is no minimum subcool value for a pure-gravity-drainage scenario;however, as the wellbore drawdown is considered, there is a minimum subcoolvalue in order to maintain the stability of fluid flow. For a given productivity, the liquid level increases as subcool increasesor as wellbore drawdown decreases. For each given set of operating parameters, there exists a criticalproductivity below which SAGD operation would halt. Before the steam chamber reaches the top of the reservoir, the fluidproductivity is limited by the vertical distance between the injector and theproducer; the larger the distance, the higher the fluid production rate canbe. A verification of this analysis was conducted by a series of numericalreservoir simulations. Although limited to two dimensions, we expect that thisanalysis captures the main physics amid the dynamic complexity ofSAGD-production control. The resulting algebraic equation can be used forbetter understanding of the dynamics of subcool control and for determiningoperation strategies.

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