The spill near Fox Creek is about three hectares in size, Trilogy said.
The company said it is unknown how much oil emulsion - a mixture of water and oil - leaked at its Kaybob development in the Alberta Montney.
Executives have travelled to the spill site to meet with clean-up crews and assess the damage, the company said.
Since the leak was detected on 7 October the pipeline has been shut down and purged.
Both
