Heat recovery optimization in a steam-assisted gravity drainage (SAGD) plant

Pinch Analysis was used to improve the energy performance of a typical steam-assisted gravity drainage (SAGD) process. The objective of this work was to reduce the amount of natural gas used for steam generation in the plant and the associated greenhouse gas emissions. The INTEGRATION software was used to analyze how heat is being used in the existing design and identify inefficient heat exchanges causing excessive use of energy. Several modifications to improve the base case heat exchanger network (HEN) were identified. The proposed retrofit projects reduced the process heating demands by improving the existing heat recovery system and by recovering waste heat and decreased natural gas consumption in the steam production unit by approximately 40 MW, representing approximately 8% of total consumption. As a result, the amount of glycol used to transfer energy across the facility was also reduced, as well as the electricity consumption related to glycol pumping. It was shown that the proposed heat recovery projects reduced natural gas costs by C$3.8 million/y and greenhouse gas emissions by 61,700 t/y of CO2.