As Easy Oil Fades, Thermal EOR Steps Back In

With aging reservoirs dominating supply, thermal EOR is reclaiming its role as a practical, disciplined tool for extending field life

22 Jan 2026

Across the oil industry a quiet shift is underway. Production is moving away from new discoveries and towards old fields, many of them well past their prime. That change is forcing companies to look again at enhanced oil recovery (EOR), not as an experiment, but as a means of survival. Among the available tools, thermal EOR is reasserting its value.

The logic is straightforward. Mature reservoirs now account for a growing share of global output. Easy drilling targets are scarcer, costs are higher and investors demand restraint. In such conditions the priority is not expansion, but optimisation, squeezing more oil from reservoirs that are already mapped, connected to pipelines and understood by engineers.

Thermal methods dominate EOR where oil is heavy and reluctant to flow. By injecting steam, operators lower viscosity and mobilise hydrocarbons that would otherwise stay underground. Steam flooding and cyclic steam stimulation have long produced some of the highest recovery rates in such settings. That track record explains why thermal EOR remains central to development plans in North America and other ageing basins.

Capital discipline, however, has sharpened. Projects are now judged as much on energy efficiency and cost control as on headline recovery factors. Steam generation is expensive, and not every field can justify it. Operators increasingly focus on incremental gains, fine-tuning well placement, improving heat management and extending the life of existing assets rather than building new ones.

Alongside these established practices, hybrid approaches are attracting interest, mostly in laboratories and pilot projects. Combining heat with gas or chemical injection may improve sweep efficiency or reduce energy losses. For now such methods are viewed as extensions of thermal EOR, not replacements. Their appeal remains highly reservoir-specific.

Environmental scrutiny adds another layer of complexity. Thermal recovery is energy-hungry and emissions-intensive. That has pushed companies to invest in monitoring, efficiency upgrades and emissions-management strategies, even when these efforts attract little publicity. Such considerations increasingly shape which projects go ahead.

Despite these constraints, market forecasts point to steady growth in EOR through the decade, with thermal techniques retaining a large share, especially in heavy-oil regions. The message is plain enough. As the era of easy barrels fades, oil production will depend less on bold exploration and more on disciplined enhancement. Heat, applied carefully, still has a role to play.