Unstoppable Momentum – What Williams Gains From Its Acquisition of Momentum Midstream

The Haynesville Shale is the nation’s third-largest natural gas producer, and the onshore play closest to most of the U.S.’s existing and planned LNG export capacity. Those facts make the gas pipelines between the Haynesville and the Gulf Coast critically important — and valuable — assets, a reality Williams Cos. just affirmed with its newly announced agreement to acquire Momentum Midstream for $5.5 billion. In today’s RBN blog, we’ll examine the transaction, two simultaneously unveiled pipeline expansion projects, and what it all means for Williams, Haynesville gas producers and LNG exporters. We’ll also discuss the unusual history of Momentum, a private equity-backed entity now in its sixth iteration in 22 years.

As we said earlier this year in Southbound, the Haynesville Shale in North Louisiana and East Texas is one of the most consequential gas basins in the U.S., especially as LNG exports along the Gulf Coast continue to grow. While the Appalachian Basin is the largest gas producer, and the Permian the fastest-growing, the Haynesville stands out for three significant reasons:

• Its location puts it in a sweet spot, nestled close to Gulf Coast LNG export facilities and well positioned to serve rising power demand across the Southeast.
• Unlike the Permian and Appalachian basins, the Haynesville isn’t boxed in by infrastructure and pipeline constraints. It has spare pipeline capacity (though that does not mean that all the gas can get to the most ideal markets), which means producers can ramp up output in the near term without waiting for new infrastructure.
• The basin is extremely responsive to Henry Hub prices, perhaps more so than any other basin in the U.S. When prices are high, production climbs; when prices are low, it pulls back. That makes the Haynesville one of the country’s most effective swing producers.

Williams already was a leading midstream player in the region before the August 3 announcement that it is acquiring Momentum Midstream (aka M6 Midstream LLC — more on that below) from primary private-equity backer EnCap Flatrock Midstream, Momentum’s management team and other investors for about $3.5 billion of cash and debt considerations and $2 billion of Williams equity. The deal is expected to close later this year.

As shown in Figure 1 below, Williams owns and operates the 174-mile, 1.8-Bcf/d Louisiana Energy Gateway (LEG; yellow line), which runs from northwestern Louisiana to the gas hub in Gillis, LA. LEG finally came online in Q3 2025 after an extended legal battle with Energy Transfer — a scuffle worth a blog in itself. Williams also owns the 10,000-mile Transco system (red lines), which moves vast amounts of gas through coastal Texas and Louisiana, home to a long list of existing, under-construction and planned LNG export terminals (solid, striped and checked blue diamonds, respectively).