Operators across the Lower 48 are entering a pivotal new phase of development, where rising marginal costs and declining Tier 1 drilling inventory are set to reshape the economics of U.S. shale. A new report from Enverus Intelligence Research (EIR) lays out a challenging future: one where marginal break-even prices could climb to $95 per barrel by the mid-2030s, up from today’s range around $70.
The Enverus Intelligence Research report, Shale Decline: The Cost Curve Rebuilds, underscores a key reality—America’s most productive and cost-efficient drilling locations are rapidly depleting, forcing operators into lower-tier acreage that is more expensive and less productive.
Permian Still Leading, but Not Exempt
Among U.S. shale basins, the Permian Basin continues to dominate in both remaining inventory and breakeven economics. According to Alex Ljubojevic, Director at EIR and the report’s lead author, operators in the Permian can expect 6,000 economic drilling opportunities per year over the next eight to ten years.
“Compared with other shale plays, the Permian Basin remains above and beyond,” Ljubojevic said. “It comes down to inventory type and location.”
Enverus pegs Permian breakevens below $50 per barrel, making it the last major U.S. play still capable of absorbing price volatility. However, even in the Permian, recent declines in oil prices—hovering in the low $60s—have led to reduced activity.
“With prices between $50 and $60, companies have to make tough decisions,” Ljubojevic added. “Even in the Permian Basin, you still need to generate returns.”
Other plays, such as the Eagle Ford, Bakken, and Haynesville, are not as fortunate. Core inventory in these basins is expected to last only three to five more years, according to EIR. Once that inventory runs out, companies will need to drill in more geologically complex zones—raising costs and reducing returns.
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Structural Cost Curve Shift Underway
The exhaustion of high-quality acreage means that shale producers are facing a structural shift in the U.S. oil cost curve. The Enverus report forecasts that marginal breakevens will rise to $95 per barrel by the early 2030s, as companies turn to more expensive locations to maintain output.
This shift has global implications. Over the past decade, U.S. shale has accounted for more than 100% of net global oil demand growth. But that trend is fading. Enverus now estimates that North America’s share of global demand growth will fall below 50% over the next 10 years.
Other recent analyses support this trajectory:
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Wood Mackenzie reported on September 30 that over 60% of Tier 1 Eagle Ford inventory has already been drilled.
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Rystad Energy forecasts increased drilling in non-core benches of the Delaware Basin and the return of interest in deeper intervals and previously uneconomic zones.
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BTU Analytics data shows a 10–15% year-over-year decline in well productivity among private operators targeting fringe acreage.
Investors have taken note. At the recent EnerCom Dallas 2025 conference, institutional fund managers flagged rising breakevens and dwindling Tier 1 inventory as central risks to the long-term valuation of U.S. E&P companies. In this environment, capital discipline, consolidation, and enhanced subsurface analytics are more important than ever.
Mineral and royalty owners should also adjust expectations. As companies prioritize fewer, higher-return wells, development timelines for non-core tracts could slow, affecting the pace and predictability of royalty income.
U.S. Remains the Swing Producer—For Now
Despite these challenges, the U.S. still holds a key role in global oil markets. Ljubojevic cautioned that without an increase of at least 1 million barrels per day from OPEC+, the U.S. will remain the world’s swing producer. But unlike a decade ago, this swing capacity will come at a higher cost.
The Canadian oil sands may play a larger role in this context. Though more carbon-intensive, they offer a stable, scalable supply with strong economics, thanks to sunk capital and rising Western Canadian Select (WCS) prices. Enverus sees the Permian and the oil sands as North America’s lowest-cost options for sustaining production beyond 2030.
The U.S. shale boom changed global energy markets by unlocking previously untapped resources with speed and scale. But the next chapter will be defined not by rapid growth, but by strategic optimization, complex geology, and a fundamentally higher cost base.
Sources Cited
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Enverus Intelligence Research, Shale Decline: The Cost Curve Rebuilds (October 2025)
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Wood Mackenzie, Eagle Ford Inventory Update (September 2025)
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Rystad Energy, U.S. Shale Outlook (September 2025)
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BTU Analytics, Private Operator Productivity Trends (October 2025)
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