Petroleum science is entering a new era defined not by a single discovery, but by a question: which problems must be solved before the world can safely extract, store, transport, transform, and eventually decarbonize energy at planetary scale? In its August 2026 issue, Petroleum Science presents an ambitious response with “One hundred grand challenges in petroleum science,” an editorial roadmap developed over five years. Inspired in part by David Hilbert’s famous 1900 list of mathematical problems, the initiative identifies the scientific uncertainties most likely to shape petroleum research, energy technology, and subsurface engineering over the coming decades.
The timing is significant. Exploration is moving toward ultra-deep formations more than 8,000 meters beneath the surface and into increasingly complex deepwater environments, while unconventional resources account for much of the growth in reserves and production. At such depths, familiar assumptions begin to fail. Pressures can exceed 140 megapascals and temperatures can rise above 200 degrees Celsius, creating conditions in which rocks deform unpredictably, fluids behave in unfamiliar ways, and conventional seismic imaging loses accuracy. Meanwhile, hydrocarbons must be studied alongside carbon capture, utilization and storage, hydrogen, geothermal energy, artificial intelligence, and the emerging economic value of subsurface data.
The challenge list was launched in 2021 by the journal’s editorial board, which invited contributions from researchers and drew on strategic reports from organizations including the International Energy Agency, the American Association of Petroleum Geologists, and the Society of Petroleum Engineers. Candidate questions were assessed through expert workshops, external review, and screening criteria that included originality, urgency, transformative potential, interdisciplinarity, long-term influence, and balance across the field. Researchers from China University of Petroleum ultimately assembled a portfolio of 100 fundamental questions spanning exploration and development, storage and pipeline networks, refining and petrochemicals, petroleum materials, carbon management and emerging energy systems, and energy economics and digital transformation.
The authors classify the problems into three broad scientific patterns, revealing that petroleum research is no longer focused solely on finding and extracting oil and gas. Sixty-eight challenges are mechanism-oriented, seeking theories that explain why complex processes occur across multiple scales. These include the coupled effects controlling hydrocarbon accumulation in ultra-deep formations and the behavior of gas, liquid, and solid interfaces during multiphase catalysis. Thirteen are technology-oriented, addressing engineering limits such as high-precision geophysical prediction and drilling-fluid rheology under extreme pressure and temperature. The remaining 19 are system-level problems, involving the optimization of entire energy chains, the resilience of global supply networks, and the ownership and pricing of industrial data.
Among the ten challenges highlighted as particularly disruptive is the search for a unified theory of hydrocarbon accumulation and preservation below 8,000 meters. Solving that problem could clarify how temperature, pressure, mineral reactions, fluid migration, and rock deformation interact in the deepest reservoirs, potentially extending effective exploration toward 10,000 meters. Another question concerns the survival limit of liquid hydrocarbons in ultra-deep formations. If researchers can determine how organic molecules remain stable—or transform—at temperatures approaching 250 degrees Celsius, they could revise long-standing assumptions in organic geochemistry about where liquid petroleum can exist.
Several of the highlighted problems connect petroleum engineering directly to climate technology. One concerns water-free fracturing using supercritical carbon dioxide, a fluid state reached above its critical temperature and pressure in which carbon dioxide combines gas-like mobility with liquid-like density. Researchers must understand how this unusual phase changes during injection, how it transports proppant into fractures, and how it interacts with rock and formation fluids. A successful approach could reduce freshwater use in hydraulic fracturing while creating a pathway for carbon dioxide storage. The authors suggest that, if technical and economic barriers are overcome, such systems could help shift carbon capture and storage from a costly obligation toward a revenue-generating industrial process.
Another proposed breakthrough is the development of reservoir nanotracers capable of revealing the distribution of remaining oil at pore scale. These engineered particles would need carefully designed surfaces so they can travel through complex porous networks, resist chemical degradation, and produce detectable signals without becoming trapped prematurely. In principle, their movement could provide a form of “underground CT” imaging, allowing engineers to map fluid pathways that conventional well measurements cannot resolve. The resulting information could improve recovery strategies by showing where oil remains, how it is connected, and which microscopic channels control its movement through the reservoir.
The list also treats the subsurface as a potential platform for renewable energy and large-scale storage. In enhanced geothermal systems, engineers inject fluid into hot rock to create or reactivate fractures through which heat can be recovered. A central challenge is understanding the dynamic interaction between artificial fractures created by stimulation and natural fracture networks already present in the rock. Better control of these interactions could improve heat extraction while reducing the risk of induced seismicity, a major social and regulatory concern. For underground hydrogen storage, researchers must determine how hydrogen reacts geochemically and biologically with depleted reservoirs. Microorganisms may consume hydrogen, while minerals and formation fluids can alter its composition; controlling these losses could raise the working-gas ratio from below 50 percent to above 80 percent.
Ultra-long gravity heat pipes represent another proposed route to extracting heat from hot dry rock. These devices use phase changes in a working fluid to transport thermal energy over long distances, but their performance depends on evaporation, condensation, flow resistance, material stability, and pressure management at extreme temperatures. Identifying the limits of heat transfer and selecting suitable working fluids could lower the cost of geothermal electricity, with the authors estimating a possible levelized cost of 5 to 8 U.S. cents per kilowatt-hour. Such a target would place geothermal power closer to the cost range of other competitive low-carbon energy sources, although substantial engineering validation would still be required.
Artificial intelligence appears throughout the roadmap not simply as a tool for faster computation, but as a force changing how petroleum science is practiced. More than 30 of the challenges depend heavily on data, algorithms, or intelligent systems. Physics-informed neural networks can combine governing equations with observations, while differentiable programming allows models to be optimized through machine-learning methods. Neural operators can learn relationships between fields, such as pressure, temperature, and saturation, across changing geological conditions. Together, these techniques could produce “grey-box” models that retain the flexibility of data-driven systems while preserving some physical interpretability. Digital twins would extend this approach by continuously updating virtual representations of reservoirs as new measurements arrive, potentially turning reservoir management from periodic, experience-based intervention into real-time adaptive control.
The roadmap also identifies a rapidly expanding frontier in energy economics and global infrastructure. Satellite observations, vessel tracking, and machine-learning forecasts could enable daily monitoring of tanker capacity and freight rates, offering an independent view of oil and gas transportation markets. At the same time, subsurface data—once treated mainly as technical records—could become a factor of production with measurable ownership rights, economic value, and pricing mechanisms. The authors argue that future research must establish how geological information is created, shared, protected, and monetized. More broadly, the 100 questions reflect a transition from petroleum as a discipline of resource extraction to what the authors call “smart integrated energy science,” combining subsurface storage, oil, gas, hydrogen, electricity, heat, carbon-cycle management, and intelligent decision-making. The list is deliberately open-ended: as researchers solve existing problems, new uncertainties will emerge. Its central message is that defining what remains unknown may be the first step toward transforming the energy system.
Subject of Research: Not applicable
Article Title: One hundred grand challenges in petroleum science.
Web References: https://doi.org/10.1016/j.petsci.2026.06.013
Image Credits: Xiao, L. Z., Jin, Y., Zhang, L. B., et al. (journal cover)
Keywords: petroleum science, ultra-deep reservoirs, artificial intelligence, digital twins, carbon capture and storage, geothermal energy, underground hydrogen storage, supercritical carbon dioxide fracturing, reservoir nanotracers, energy transition
