(Portland, OR) -- Gas prices are up after the crude oil production cut announced by OPEC-plus. Triple-A reports the national average increased seven cents to three-51 a gallon and Oregon's average increased four cents to three-93. The OPEC-plus announcement caused the price of crude oil to top the 80 dollar per barrel mark. Prices are also up, because refineries are switching to more expensive summer blends of fuel, along with higher demand and tighter supplies.