Goldman Sachs commodity strategist Jeff Currie said May 10 if the U.S. government were to introduce a border tax adjustment on crude oil imports, the spread between Brent and West Texas Intermediate (WTI) futures would widen dramatically.

The principal impact of a border tax adjustment would be to raise the price of domestic crude compared with international grades such as Brent.

"It would blow out the Brent/WTI spread. You could see WTI trade $15 above Brent," Currie told the S&P Global Platts Crude conference.

The premium of Brent crude futures over WTI futures is currently around $2.81 a barrel.

The government of President Donald Trump has considered a Republican proposal for a border tax adjustment system that would levy a 20% tax on all imports while exempting exports.

Domestic U.S. crude prices would automatically rise, pushing up the cost of anything from gasoline to plastics.

Border tax advocates claim the impact of higher import costs and perceived subsidy for exports would be a rise in the real exchange rate of the U.S. dollar.

"For every non-commodity, the dollar does all the work so that the consumer does not pay the price ... oil does not have that leverage," Currie said.