Numerical Study of the SAGD Process in the Burnt Lake Oil Sands Lease

Abstract

Abstract A numerical study was conducted to predict recovery performance for the steam-assisted gravity-drainage (SAGD) process in the Burnt Lake oil sands lease. A geological and petrophysical description of the lease and a base case numerical model were prepared. Experience gained at the very successful Alberta Department of Energy Underground Test Facility (UTF) SAGD pilot was utilized in the numerical modelling. The base case predicted favorable performance for a 1000 m long horizontal well pair, with a calendar day oil rate over 15 years of 70.1 m3/d, and an oil-steam ratio of 0.34. Optimisation of SAGD operations and factors such as spacing between well pairs will enhance the predicted performance. Sensitivity studies showed that the SAGD process at the Burnt Lake site is expected to be robust, with a low to moderate sensitivity of recovery performance to reservoir properties within the range of uncertainty of these properties. The reservoir properties investigated include permeability, relative permeability, wettability changes, oil viscosity, thermal conductivity, flow barriers, and solution gas effects. Other factors investigated include operating pressure and placement of the production well. The only factor with a large effect on overall performance was placing the production well in a low permeability zone.