The United States turned into a net natural gas exporter for a day after the first liquefied natural gas export from Cheniere Energy Inc's Sabine Pass terminal in Louisiana left for Brazil on Wednesday.
The United States however is not expected to become a net exporter of gas on an annual basis until 2017 after more pipelines to Mexico and LNG export terminals enter service, according to federal energy estimates.
The United States was last a net exporter of gas on an annual basis in 1957.
On Wednesday, the United States imported a net 4.8 billion cubic feet of gas per day from Canada and 0.2 bcfd from various LNG import terminals for a total of about 5 bcfd in imports.
Exports however surpassed 6 bcfd on Wednesday, with about 3.3 bcfd going to Mexico and some 3 bcfd going to Brazil on the Asia Vision LNG tanker from Sabine Pass.
Since no LNG ships left Sabine Pass on Thursday, the United States returned to being a net importer that day.
Just over a decade ago, the United States was expected to become a major importer of LNG. Firms that were spending billions to build facilities to import gas from overseas are now spending billions to build LNG export terminals.
The switch was sparked by the shale gas revolution, which unlocked cheap, abundant U.S. supplies especially in the Marcellus and Utica formations in Pennsylvania, West Virginia and Ohio.
To deal with the rapid increase in Northeast U.S. shale gas, pipeline companies reversed the flow of some pipelines built to move gas from Texas and the Gulf Coast to major population centers in the Northeast.
Those pipelines now move Northeast gas south to fuel industrial facilities and LNG export terminals being build along the Gulf Coast.
At the same time, U.S. utilities in the Midwest and Northeast with easy access to cheap Marcellus and Utica gas are buying less from Texas and from Canada, leaving producers in Texas with more fuel to sell to Mexico to feed that country's growing power demand.
There are 5 LNG export terminals under construction in the United States expected to enter service by 2020, including ones by Cheniere at Corpus Christie in Texas, Dominion Resources Inc at Cove Point in Maryland, Sempra Energy (SRE) at Cameron in Louisiana, and Freeport in Texas.
If all of the liquefaction trains under construction at those terminals enter service as planned by 2020, the United States will be able to export about 9 bcfd, about 11 percent of forecast total U.S. gas production at that time.
(Reporting by Scott DiSavino in New York)