Offshore oil and gas reservoirs will continue to play a significant role in the global hydrocarbon supply in the near future while the industry continues to face economic challenges to sustain decarbonization efforts. Additional environmental challenges pose risks to activities that provide key data for subsurface characterization like seismic surveys and drilling. This session focuses on tools and methods to improve subsurface understanding via reservoir characterization at different scales including remote sensing, seismic to reservoir applications, well logging, fiber optics, upscaling methods and machine learning algorithms with the goal to reduce uncertainty and improve asset performance, both critical for sustainability during and post energy transition. It is intended for scientists and engineers working in field development and operations with focus on subsurface disciplines.