During the last two months of 2018, the U.S. exported more Gulf Coast crude oil than it imported, the Energy Information Administration reported March 18, as shipments into the region slumped to a near 33-year low in December 2018.

In the last month of 2018, gross oil exports from the Gulf Coast hit a record 2.3 million barrels per day, while imports came in at 1.9 million bbl/d, the lowest level since March 1986, the agency said.

This was partly due to a reduction in imports from OPEC, which declined in the last two months of 2018, from an average of 1.5 million bbl/d in the first six months of the year to 1.1 million bbl/d in December 2018.

In early December 2018, OPEC members and other major oil producers including Russia agreed to cut oil production by 1.2 million bbl/d, with members trimming output by 800,000 bbl/d and non-OPEC members reducing production by 400,000 bbl/d. The OPEC cut agreement expires in June.

The net trade of crude oil in the Gulf Coast, or the difference between gross exports and imports, dropped from a peak at 6.6 million bbl/d in early 2007 of imports to 0.4 million bbl/d of exports in December 2018.

The increase in oil exports was attributed in part to a sharp ramp up in crude production in recent years, especially in the Gulf Coast, where output hit a record of 7.7 million bbl/d in November 2018.

"The increased production is mostly of light, sweet crude oils, but U.S. Gulf Coast refineries are configured mostly to process heavy, sour crude oils. This increasing production and mismatch between crude oil type and refinery configuration allows for more of the increasing U.S. crude oil production to be exported," the EIA wrote.

During each of the last three months of 2018, the U.S. Gulf Coast exported more than 2 million bbl/d.

Amid the ongoing shale revolution, total U.S. oil production is projected to grow through 2030 and should hold atop 14.0 million bbl/d through 2040, according to the reference case scenario of the EIA's Annual Energy outlook released at the end of January.

As U.S. crude oil production has increased, imports into the Gulf Coast and the country as a whole have declined.

"In the mid-2000s, when both U.S. total and Gulf Coast region crude oil imports were at their highest, the Gulf Coast accounted for nearly two-thirds of the national total. More recently, as Gulf Coast crude oil imports have declined and other regions such as the Midwest and West Coast (PADDs 2 and 5, respectively) have increased their crude oil imports, the Gulf Coast's share of total imports has decreased, most recently averaging 32% in 2018," the EIA said.