Nexen Inc. was a Calgary-based energy company focused on exploration and production of oil and natural gas. Formerly known as Canadian Occidental Petroleum Ltd., Nexen built a diversified portfolio spanning Canada’s oil sands, offshore UK North Sea, and unconventional shale and gas resources. In 2013, the company was acquired by CNOOC Limited; its North American operations now operate under CNOOC Petroleum North America (CNOOC International).
For the chemical industry, Nexen is notable for its historical ownership of Nexen Chemicals, a producer of chlor-alkali and sodium chlorate used in pulp and paper, water treatment, and related industrial applications. That business was spun out in 2005 as Canexus and was later integrated into Chemtrade. Nexen’s upstream activities have also intersected with chemical value chains through supply of natural gas liquids and sulfur derived from hydrocarbons.
