Changing Southern Louisiana Flow Dynamics Raise Concerns for Future LNG

In late 2024, the U.S. saw its first greenfield LNG export facility start-up in several years. Plaquemines LNG, now one of the largest LNG export facilities in the U.S., has ramped substantially in 2025 and saw feedgas flows average 2.3 Bcf/d this past May. However, all of this added demand has significantly altered southern Louisiana natural gas flow dynamics. Two major interstate pipelines that carry key natural gas supply from the Northeast, TGP and TETCO, have put large projects into service in the last six months to feed Plaquemines LNG. The resulting change in flow dynamics, specifically around the Gillis area, raises concerns for how these existing pipes may be able to supply future LNG demand, which is set to double by the end of the decade.

Flows on TGP

Before Plaquemines came online, TGP was flowing gas towards Gillis through Station 823 at an average utilization rate of 69%. However, TGP is now redirecting volumes towards Plaquemines via its 1.1-Bcf/d Evangeline Pass project, which entered service in December 2024. As a result, Station 823 is running at a 54% utilization rate thus far in 2025, resulting in less gas that is flowing towards Gillis. This is meaningful because Gillis is where various pipelines interconnect to flow south to feed LNG demand along the Louisiana Gulf Coast. The dynamic at Station 823 is also seen further upstream at Station 834, which ran at a 72% utilization rate in 2024 and has since dropped to 61% in 2025.

While there is available space to flow towards Gillis on TGP’s 800 line, TGP is constrained upstream at Station 860 North in Tennessee, as illustrated in the chart below. As a result, TGP cannot get incremental volumes from the Northeast to serve additional LNG demand in Louisiana without an expansion upstream. However, as there is available capacity at Station 823, TGP could potentially pick up additional volumes elsewhere on the 800 line via other pipeline interconnects to feed additional LNG demand.

Flows on TETCO

Flow patterns on TETCO reveal a similar dynamic. Historically, TETCO has moved gas from east to west into Gillis, starting from the St. Francisville compressor and flowing through the Opelousas compressor east of Gillis. However, TETCO recently put the 1.26-Bcf/d Venice Extension project into service, which allows volumes on TETCO to move south from the New Roads compressor, near the St. Francisville compressor, to feed Plaquemines LNG. Since that project was put into service, the Opelousas compressor, which previously flowed at an average utilization of 65% in 2023, has only flowed at an average utilization of 21% in 2025. Furthermore, the St. Francisville compressor was not expanded as part of the Venice Extension, leaving just 195 MMcf/d of open capacity on average. All of this means significant incremental volumes on TETCO cannot come from the Northeast. TETCO would instead need to pick up additional volumes between St. Francisville and Gillis to fill the open capacity and feed additional LNG demand.

What this means for future LNG

These changing flow dynamics in southern Louisiana, brought about by the introduction of Plaquemines LNG, ultimately reduce the amount of gas heading into Gillis and, therefore, the amount of supply available for future LNG facilities planned along the Louisiana Gulf Coast. This will undoubtedly have impacts on how these future LNG facilities, including Woodside's Louisiana LNG that achieved FID on April 29^th, are supplied. For more info on BTU Analytics’ LNG, midstream, and natural gas supply coverage, check out our comprehensive energy offering: the Premium Energy Workstation.

This blog post is for informational purposes only. The information contained in this blog post is not legal, tax, or investment advice. FactSet does not endorse or recommend any investments and assumes no liability for any consequence relating directly or indirectly to any action or inaction taken based on the information contained in this article.