Even as West Texas Intermediate crude oil briefly traded at parity to European Brent, some anticipate the spread to widen again, which would boost energy sector exchange traded funds with international exposure.

Last Friday, WTI reached parity to Brent crude oil, the first time in almost three year, reports Matthew Robinson for Reuters.

Currently, WTI crude is trading around $106.7 per barrel, whereas Brent crude is at $108.1 per barrel. So far this year, the United States Oil Fund (NYSEArca: USO) has gained 15.2%, compared to the 1.2% rise in the United States Brent Oil Fund (NYSEArca: BNO). [iShares: Why Oil Has Proven Resilient]

WTI represents prices that U.S. producers receive while Brent represents prices received internationally, writes Ingrid Pan, Senior Energy analyst at Market Realist.

WTI and Brent have traded on equal ground in the past, but prices have recently diverged due to the recent boost in production in the U.S. and the buildup of crude oil inventories at Cushing, Oklahoma.

Recently, the spread has narrowed as more midstream pipeline infrastructure came online. Additionally, greater pipeline capacity and crude transportation by railway has helped move oil to the East and West coast.