By Shale Markets · Sunday, September 20, 2026 · 4 min read

Associated Gas Keeps Rising in U.S. Shale Even as Crude Output Stalls

Original illustration created for Shale Markets.

Associated Gas Keeps Rising in U.S. Shale Even as Crude Output Stalls

Permian marketed natural gas production grew 60% between 2021 and 2025, climbing from 17.2 Bcf/d to 27.6 Bcf/d, while Permian crude oil output rose only 39%, from 4.7 million b/d to 6.6 million b/d, according to the U.S. Energy Information Administration on June 18, 2026. The gap is not a story about new drilling. It is a story about what existing wells are doing as they age.

The EIA attributes the divergence to rising gas-oil ratios. The agency's June 18, 2026 release put the 2025 Permian GOR at nearly 4,200 cubic feet per barrel, a 16% increase from 2021 — a figure the EIA reported directly, not one derived by dividing the rounded volume totals elsewhere in the same release, which work out closer to 14% because of rounding in the underlying Bcf/d and million-barrel figures. As reservoir pressure declines in maturing wells, gas moves more freely than oil, and the ratio climbs over a well's life.

How much gas the GOR shift alone produced

Gas Compression Magazine quantified the counterfactual on June 19, 2026: if the Permian's gas-oil ratio had stayed flat at 2021 levels, the region's 2025 gas output would have been 23.8 Bcf/d instead of the roughly 27.6 Bcf/d actually produced — 14% lower. The rising ratio by itself accounts for an extra 3.8 Bcf/d of gas that would not exist if wells behaved the way they did five years earlier.

RBN Energy, publishing on June 25, 2026, put the year-over-year change at 11%, or 2.7 Bcf/d, with 2025 output averaging 27.7 Bcf/d and the gas-to-oil ratio reaching 4.2 Mcf/bbl. RBN's framing was blunt: as the basin matures, GOR is expected to keep climbing, pushing gas and oil trends further apart.

A separate EIA update on March 17, 2026, revised play designations to fold in the Avalon, Barnett, Dean and Woodford intervals, adding 0.2 million b/d to 2025 tight oil estimates and 0.8 Bcf/d to shale gas. With that revision in place, the geographic Permian region produced 6.7 million b/d of crude and 29.1 Bcf/d of marketed gas by December 2025 — a point-in-time figure, not the annual average cited elsewhere, and higher than the full-year numbers because production was still climbing through the back half of the year.

Crude has nearly stopped growing

U.S. crude production is forecast to average 13.8 million b/d in 2026, per the EIA's September Short-Term Energy Outlook, as reported by Energies Media on September 16, 2026 — a step up from the 13.7 million b/d record set in 2025. First-half 2026 output averaged 13.7 million b/d, up 2% from the same period a year earlier. Permian Basin Oil and Gas Magazine, citing the same EIA outlook on September 11, 2026, put the basin's 2026 volume at 6.8 million b/d, a 3% increase from 2025. The magazine attributed part of that growth to WTI averaging $84 per barrel through August, a figure that appears only in that one trade report; whether it reflects realized prices or an EIA forecast assumption is not stated, and Shale Markets could not confirm it against the underlying STEO table. Both trade outlets are summarizing the same federal forecast, not offering independent confirmation of it.

Takeaway is running close to full

East Daley Analytics reported on October 1, 2025 — the most recent egress utilization figure available — that Permian residue gas production averaged 18.6 Bcf/d in 2024 and was expected to rise to 20.9 Bcf/d in 2025, a 12% year-over-year increase, with eastbound egress running at approximately 83% of capacity at the time. The firm's outlook called for residue volumes to climb another 4 Bcf/d on average between 2025 and 2030 as associated gas continues to expand alongside oil production. No utilization figure newer than East Daley's October 2025 estimate is available, even though the crude and GOR data cited elsewhere in this piece run through September 2026.

The Matterhorn Express Pipeline illustrates how quickly that room can close. S&P Global Commodity Insights reported on December 31, 2024, that the pipeline's 2.5 Bcf/d design capacity had begun normalizing West Texas gas prices after a stretch of negative pricing, with Permian associated gas at 20.7 Bcf/d in November 2024, up 1.9 Bcf/d year-over-year. S&P Global projected in the same report that Permian output would rise by 1.1 Bcf/d in 2025 as shippers filled the new capacity. East Daley's December 12, 2025 update found interstate flow samples showing Matterhorn deliveries as high as 1.95 Bcf/d in November 2025, consistent with the pipeline's initial 2.0 Bcf/d in-service capacity from late 2024 plus a 0.5 Bcf/d compression expansion that had come online, bringing the line up toward the 2.5 Bcf/d design capacity S&P Global cited a year earlier.

What the mismatch means for infrastructure planning

Pipeline and processing capacity in the Permian was sized around historical GOR assumptions that no longer hold. A basin producing 6.6 million b/d of oil at a 4,200 cf/bbl ratio generates meaningfully more gas than the same oil volume did at 2021's ratio,