The subtext inference is that Oil & Gas have a disproportionate impact on the loonie. Most of our hydrocarbon production is sold extraterritorially. This means the foreign buyer needs to exchange their currency for ours for payment. This drives up demand for our currency.

A side note. With the last interest rate hike, the yield differential between Canadian and US equivalent debt instrument yields have narrowed.

5 year Canadian Bond Yield: 1.64
5 year US Treasury Yield: 1.83
10 Year Canadian Bond Yield: 1.99
10 year US Treasury Yield: 2.32