An even temperature conformance along the length of the horizontal well is key in maximizing steam-assisted-gravity-drainage (SAGD) production rates. When temperature logs are run in SAGD producers, temperature variations of greater than 50°C between the hottest and coldest spots are commonly observed. The authors theorize that this temperature distribution is related to an inflow distribution and that production rates could be improved if this temperature variance was narrowed.
Introduction
The Firebag project in northeastern Alberta uses SAGD to recover bitumen from the McMurray formation. SAGD uses stacked horizontal-well pairs, with the top well (injector) located 4 to 6 m above the bottom well (producer). Steam is injected into the top well, warming the bitumen and decreasing its viscosity to a point at which it will flow by gravity to the bottom well.
