Journal of Canadian Petroleum Technology, Vol.49, No.11, 22-29, 2010
Lloydminster, Saskatchewan Vertical Well SAGD Field Test Results
Husky Energy's Pikes Peak steam project has been highly successful using CSS and follow-up steam drive for vertical and directional wells located on the bottomwater-free structural high inside the oil/water contact of the Waseca channel sand reservoir(1). In some areas, recoveries of up to 90% have been achieved with a cumulative steam/oil ratio (SOR) of less than 3.0. Use of CSS with follow-up drive has not been successful where bottomwater is present outside the oil/water contact. Some improvement in performance was achieved using large CSS slugs and high-steam injection rates, but in some locations CSS performances were still poor and conversion from CSS to drive has not been successful in any location. In 2008 Husky initiated a field test of a single vertical well SAGD configuration in an area outside the oil/water contact to evaluate an alternate process in which the "conventional" CSS performance of 10 wells was poor from the second or third stimulation onward. The results from the first single vertical SAGD well pilot demonstrated that a single vertical well SAGD configuration could be successfully completed and operated. The field data are being evaluated using empirical and numerical modelling methods to develop completion and operating strategies that optimize future produced oil rates and SORs. Another benefit of the field test was its demonstration of a low-cost and rapid method to help determine if a reservoir has sufficient vertical permeability for horizontal well SAGD to work.