In March imports to the Gulf Coast averaged 1.8 million barrels a day, a more than 70 percent decline since 2007, according to a report from the Energy Information Administration. That has resulted in the Gulf Coast effectively operating as a net exporter for the past five months.

EIA attributed the shift to declining production in Venezuela due to political turmoil and the decision by the Organization of Petroleum Exporting Countries to cut exports in a bid to raise global oil prices.

"Imports are being replaced by increased production of domestic crude oil," the report read. "Together, these trends have fundamentally changed how the Gulf Coast region is supplied with crude oil."

While still preliminary, early reports show imports rising slightly in April and May of this year to an average of 1.9 million barrels per day.