US refiners have had a tough 25 years, Pioneer Natural Resources Chairman and CEO Scott Sheffield said during a lunch keynote presentation at the Independent Petroleum Association of America Oil & Gas Investment Symposium in New York today.

East Coast refiners face a competitive disadvantage to those located on the Gulf Coast because Eastern plants largely process imported crude oil from countries where crude prices are linked to international benchmark Brent. Brent crude prices tend to be higher than lower quality heavy oil imported and processed by Gulf Coast facilities.

Access to light, sweet Bakken crude oil changed this in recent years, which gave Eastern refiners some breathing room, as they could purchase feedstock priced considerably lower than Brent and export refined products overseas at Brent-linked prices.

See Phillips 66: ‘Everything’s Better with Bakken’

The current debate over exporting US crude oil has producers and refiners in disagreement. US producers want to receive higher prices for their crude oil, but refiners want to purchase crude at the lowest prices achievable because they make their money on the spread between crude and refined products.

The differential between US benchmark WTI and Brent blew out to as much as $30/bbl in recent years, as US production surged and international supply was constrained by events in the Middle East and elsewhere. That price differential is currently around $5/bbl.

Some believe preventing US crude oil exports could cause the Brent/WTI price differential to widen again as US supply builds without adequate market access.

So getting back to Sheffield’s comment, as the chief of a large independent US producer, he would like to sell crude oil for higher prices offered in overseas markets.

“A $10 to $15 per barrel differential is fair,” for refiners. “$30 per barrel is too much, in my opinion.”