Flaring and Venting

We have significantly reduced flaring in our Western Canada Gas operations. Since 2007, we reduced flaring by 17,385 103m3, or 32 percent. Approximately 34 percent of this reduction is a result of decreased well-test flaring associated with drilling fewer wells. The remaining reduction is due to significant decreases in flaring at eight facilities in Alberta, British Columbia and Saskatchewan. In some locations we reduced our flare stack purge and pilot gas usage, and their related emissions, by converting flare stacks to either vent stacks or by modifying them for maintenance-only flare stack service where safe to do so. This ensures that more natural gas is conserved.

In 2007, we determined that we needed to improve our reporting of vented gas volumes. Since then, we have substantially improved our effort to ensure all vented volumes are reported appropriately, especially at well level. As a result, from 2008 to 2009, 66 more facilities reported venting and our reported venting volumes increased significantly. Despite this increase in our reported vented volumes, our larger decrease in flaring led to a 12 percent reduction in combined flaring and venting emissions.

Reducing Venting

In the last two years, we installed technology to manage the air-to-fuel ratio on fuel-gas at three compressors near Grande Prairie, Alberta. This installation provides optimized combustion and results in significant fuel-gas savings. Our Noel Gas Plant team then took the effort a step further with the installation of technology that captures vented gas and burns it as fuel in the engine. This has the environmental benefit of reducing emissions at the plant as well as the economic benefit of reducing fuel-gas usage and increasing sales gas. The unit was installed as a test case, with a portion of the vents tied-in, and is currently capturing approximately 130 standard cubic feet per hour of previously vented gas. Lessons learned from the Noel plant will help to lower the costs of future technology installations and improve its operation.