SUBSURFACE ENERGY APPLICATIONS: CROSS-CUTTING RESEARCH NEEDS AND THE ROLE OF DEEP GEOSCIENCE OBSERVATORIES

Subsurface energy resources currently provide or enable >80% of U.S. primary energy, and the trend of relying on the subsurface to meet U.S. energy needs is expected to increase. The subsurface is also a vast reservoir that can be used for the transient storage of energy and for the permanent disposal of energy waste streams (such as CO₂ and nuclear waste). However, the complexity and difficulty involved in characterizing subsurface reservoirs currently hinder our ability to utilize the full potential of these systems. For example, we cannot accurately image, predict, or control subsurface fractures or flow with the confidence needed to effectively guide subsurface energy operations. Developing the comprehensive understanding and capabilities needed to gain mastery of Earth’s complex subsurface requires a new cross-cutting R&D paradigm, as it is currently envisioned in the U.S. Department of Energy’s SubTER (Subsurface Technology and Engineering Research, Development and Demonstration) technology team.

This presentation first discusses selected cross-cutting challenges to be addressed by SubTER that, if achieved, could transform our utilization of the subsurface for both energy production and waste storage. The talk then moves on to the important role that geosciences field observatories can play in this context. First, controlled field experiments in geoscience observatories can be used to improve process understanding and apply methodologies developed. Second, geoscience observatories are useful for testing effects of heterogeneity and real‐world conditions which can sometimes lead to unexpected effects and mechanisms not predicted by theory or laboratory work. Finally, geoscience observatories can be community builders that tie research and development to industry and stakeholders, through demonstrations and ultimately adoption. Several existing and planned examples of deep geoscience observatories are presented and discussed, addressing a range of R&D challenges in several subsurface energy applications such as geologic carbon sequestration, geothermal energy, hydrocarbon extraction, and nuclear waste isolation.