Net U.S. natural gas exports through the first six months of 2019 more than doubled year-ago levels, according to data from the Energy Information Administration (EIA), showing the rapid transformation underway for a country that only became a net exporter in 2017.

From January through June, net exports averaged 4.1 Bcf/d, up from 2.0 Bcf/d in the first half of 2018. Driven by liquefied natural gas (LNG) exports and pipeline exports to Mexico, the United States exported more than it imported on annualized basis in 2017, marking the first time this had happened in nearly 60 years, according to EIA.

EIA expects net U.S. exports to continue to grow, averaging 4.6 Bcf/d in 2019 before rising to 7.2 Bcf/d in 2020. That growth is to be driven by more LNG export capacity and pipeline infrastructure buildout in Mexico, according to projections.

“Much of the recent increase in total exports is a result of more LNG facilities coming online,” EIA said in a research note Tuesday. “Total U.S. exports of LNG through the first half of 2019 were 37% higher compared with the same period in 2018. Total U.S. LNG export capacity as of June 2019 was 5.4 Bcf/d across four facilities and nine liquefaction trains.”

The list of exporting facilities from January to June included Sabine Pass LNG and Cameron LNG, both in Louisiana; Corpus Christi LNG in Texas; and Cove Point LNG in Maryland. Thus far in the back half of 2019, that list has grown to include Freeport LNG in Texas and Elba Island LNG in Georgia.

In total, EIA expects U.S. LNG export capacity to reach 8.9 Bcf/d by the end of 2019, up from 4.9 Bcf/d at the end of 2018.

Even with the growth in LNG, volumes transported via pipeline across the borders with Mexico and Canada continue to make up most of the U.S. natural gas trade, according to the agency. Net exports to Mexico via pipeline grew 5% in the first six months of 2019, while net exports to Canada remained roughly flat.

“In every month from April through August, U.S. natural gas exports by pipeline have exceeded natural gas imports by pipeline, the longest consecutive stretch of exporting more natural gas by pipeline than importing by pipeline on record,” EIA said.

For January through June, net pipeline exports to Mexico averaged 4.9 Bcf/d, up 0.4 Bcf/d from the year-ago period. Net U.S. pipeline exports across the southern border set all-time highs this summer, hitting 5.2 Bcf/d in June and 5.3 Bcf/d in July.

Pipeline natural gas exports to Mexico averaged 5.534 Bcf/d in August 2019, an 11.2% increase from the same month a year ago, according to energy ministry Sener.

Imports accounted for 70% of Mexico’s total gas supply during the month, up from 68% a year ago.

Excluding demand from national oil company Petróleos Mexicanos (Pemex), imports comprised 91% of total supply, up from 88%.

Mexico’s natural gas import capacity rose by 40% in late August after the commercial startup of the 2.6 Bcf/d Sur de Texas-Tuxpan natural gas pipeline.

The milestone had been delayed by a contractual dispute between developer Infraestructura Marina del Golfo (IMG) and anchor customer Comisión Federal de Electricidad (CFE), Mexico’s state-owned power company.

The government announced on August 27 that CFE had renegotiated the terms of its firm transport capacity agreement with IMG, a joint venture between TC Energy Corp. and Infraestructura ENergética Nova (IEnova).

On Sept. 11, CFE announced a corresponding agreement with Mexican company Fermaca on the final two sections of the informally named Wahalajara pipeline system.

The sections comprise La Laguna-Aguascalientes and Villa de Reyes-Aguascalientes-Guadalajara, which will have the capacity to transport 1.189 Bcf/d and 886 MMcf/d, respectively, and will mean Mexico’s industrial heartland will have access to gas from West Texas. The pipelines should be online by 1Q2020.

Meanwhile, because of additional capacity out of the Appalachian Basin from the Rover and Nexus pipelines, U.S. pipeline export capacity to Canada increased in late 2018, with total exports across the northern border reaching a peak of 3.3 Bcf/d in February 2019, according to EIA.