Matterhorn Partners Sanction 2.5 Bcf/d Compression Expansion to Ease Permian Gas Glut

The owners of the Matterhorn Express Pipeline sanctioned another big swing at the Permian Basin's gas exit problem on Monday, taking a final investment decision on the Eiger Express Pipeline, a 2.5 Bcf/d, 42-inch line that will run roughly 450 miles from West Texas to the Katy hub near Houston. WhiteWater Development, ONEOK, MPLX and Enbridge said they had locked in enough firm transportation contracts, mostly with investment-grade shippers, to move ahead. Target in-service is mid-2028, subject to permitting.

That is the headline number. The nearer-term relief is smaller and quieter: a compression expansion on the existing Matterhorn line that adds about 0.5 Bcf/d, lifting it from its original 2.0 Bcf/d design toward roughly 2.5 Bcf/d. Together the two moves tell you exactly where the Permian gas market sits right now. Producers are pumping record volumes of associated gas, pipes out of the basin are full, and the price signal at Waha keeps going negative. New steel is coming, but the calendar is the enemy.

What the partners actually approved

Eiger Express is a new-build project, not a debottleneck of the line that started service in November 2024. The FID was taken on August 26, 2025. WhiteWater will build and operate it, drawing supply from multiple Permian connections, including Midland Basin processing plants and Delaware Basin gas via the Agua Blanca Pipeline. ONEOK holds 25.5% of Eiger and MPLX 22%, with WhiteWater carrying the balance as developer.

ONEOK framed the case around demand at the delivery end rather than distress at the wellhead. "This pipeline's strategic location offers connectivity to growing natural gas demand markets, helping to meet the need for increasing electricity generation and international demand for liquefied natural gas exports," said ONEOK president and CEO Pierce H. Norton II. Katy feeds Gulf Coast LNG and the power load that data centers and electrification keep pushing higher. Both ends of the trade matter, but for a Midland producer staring at sub-zero Waha quotes, the wellhead end is the one that stings.

The compression add-on is the part that helps this year

Mid-2028 does nothing for a basin that is oversupplied today. The compression expansion does. Matterhorn was engineered so operators could add horsepower and squeeze more gas through the same 42-inch pipe once the initial ramp settled. That extra roughly 0.5 Bcf/d was slated for the fourth quarter of 2025.

Interstate flow data suggests it arrived early. Samples show Matterhorn deliveries to the Katy market running near 1.65 Bcf/d from June through October, then jumping to as high as 1.95 Bcf/d in November, with flows holding above 1.8 Bcf/d after November 7. That step-change is the compression coming live ahead of schedule. It is real molecules leaving the basin, not a press release. It is also, by itself, not enough.

Why Waha keeps going negative

The math behind negative Waha prices is not complicated. The Permian produces enormous volumes of gas as a byproduct of oil drilling, so output does not fall when gas prices do. Basin production hit a monthly record around 21.5 Bcf/d in July 2025. When the pipes to the coast are full, the marginal molecule has nowhere to go, and sellers will pay someone to take it rather than shut in the oil well that produces it.

The result is a market that spends stretches of the year below zero. Waha ran negative for weeks at a stretch during 2025, and 2024 set the tone, with prices under zero on 46% of trading days and a low near minus 6.41 dollars per MMBtu on August 29, 2024. When gas cannot move and cannot clear at any positive price, some of it gets burned. Flaring in the basin has climbed back toward roughly 500 million cubic feet per day even with Matterhorn running, which is the physical version of a negative price: gas the system cannot absorb.

A wave of pipe, but not until 2026 and beyond

Matterhorn's partners are not alone in reading the same tape. A slate of takeaway projects is lined up behind them:

• Blackcomb - 2.5 Bcf/d to Agua Dulce in South Texas, WhiteWater-operated, targeting 2026.
• Apex - 2.0 Bcf/d to Port Arthur, developed by Targa Resources, targeting 2026.
• Hugh Brinson and other DFW-directed lines - adding intrastate egress toward North Texas demand.
• Saguaro Connector - 2.8 Bcf/d toward the U.S.-Mexico border for export, later this decade.

Add Eiger's 2.5 Bcf/d in 2028 and the basin eventually gets ahead of its own drill bit. The gap is timing. Blackcomb and Apex do not start until 2026. Eiger is a 2028 story. The compression add-on and a handful of smaller expansions are the only meaningful new capacity between now and next year, which is why the Matterhorn ramp-up did not arrest the negative price run. It softened it.

What to watch

Three things will tell you whether the sanction was timed right. First, how quickly Blackcomb and Apex hit their 2026 in-service dates, since a slip pushes real relief deep into next year. Second, whether Permian oil drilling holds up, because associated gas volumes track the rig count and completion pace, not the gas price. Third, LNG and power demand at Katy and along the coast, which is the pull that justifies a 2.5 Bcf/d pipe reaching all the way to Houston in the first place.

The Eiger FID is a bet that Gulf Coast demand keeps growing and that Permian oil keeps flooding the basin with gas that has to go somewhere. Both look like safe bets. The uncomfortable truth for producers is that the fix they most need already exists on paper and mostly does not show up until 2026. Until then, the compression add-on buys a little room, the flares keep burning, and Waha keeps reminding everyone that a full pipe is worth more than the gas inside it.