The classical SAGD (Steam Assisted Gravity Drainage) involves drilling wells in parallel horizontal pairs. Steam is injected into the upper well (injector) to heat the reservoir and mobilize bitumen/heavy oil so that it drains to the lower well (producer) and can be lifted to the surface. In this process, steam distribution in the injector and a sustainable liquid level above the producer are key to achieve steam chamber conformance. The completion designs of these wells are critical in order to achieve optimal bitumen/heavy oil recovery and steam chamber development1.
Orifice based Flow Control Devices (FCDs) are being used in the SAGD wells. The FCDs in the injector (Steam Splitters) are used to customize steam distribution along the well. The FCDs in the producer (Inflow Control Devices) are used to develop a uniform inflow along the horizontal wellbore.
In this paper, a method will be presented for determining the size and position of Steam Splitters and Inflow Control Devices. This method can be used for both simple and complex reservoirs containing geological heterogeneity, hydraulic barriers and baffles. The validation of the design by field data in a Case Study will also be presented. It is shown that using FCDs in the wellbores helps to improve conformance and performance of SAGD well pairs significantly.