Since 1996, EnCana Corporation has been advancing twin-well steam assisted gravity drainage (SAGD) technology at the Senlac Thermal Project in East Senlac, Saskatchewan, Canada. The latest development phase, Senlac Phase C, consists of two 750 m horizontal well pairs (C1 and C2) drilled in Section 11040-26W3. Start-up steaming operations were initiated in June, 2001, with injector-producer communication established six weeks later. Both pairs were ramping up to full oil production rates by late July, 2001. Oil production from the C1 well pair through the end of October, 2002 averaged 275 m(3)/d, with peak monthly rates exceeding 460 m(3)/d while operating under solvent-aided SAGD (SAP) conditions. Over the same 16-month period, oil production from the C2 well pair averaged 335 m(3)/d, with peak monthly rates exceeding 420 m(3)/d under conventional SAGD conditions. Cumulative steam-oil ratios for the Cl and C2 well pairs are 2.7 m(3)/m(3) and 2.3 m(3)/m(3), respectively.