Abstract

The energy transition demands a dual strategy: adopting renewable energy sources while optimizing existing oil and gas technologies. This thesis addresses the critical challenge of enhancing oil-water separation processes and shale gas production to meet the projected 25% increase in global energy demand by 2040, with oil and natural gas expected to supply 60% of this demand. Shale gas, noted for its significant reserves and lower greenhouse gas emissions compared to coal and crude oil, is pivotal in this context.To optimize shale gas recovery, this research focuses on understanding adsorption, desorption, and gas transport within low-permeability and low-porosity reservoirs. The study explores engineering techniques such as CO₂-enhanced gas recovery (EGR). In CO₂-EGR, CO₂ is injected into reservoirs to displace methane, enhancing recovery rates and contributing to carbon sequestration. Various protocols and modeling approaches are reviewed to evaluate the effectiveness of CO₂-EGR under different geological conditions.The research delves into the adsorption mechanisms of energy fluids like natural gas, hydrogen, and CO₂ in shales. It examines how molecular characteristics and shale components impact adsorption capacities and storage efficiency. Competitive adsorption phenomena, influenced by shale formation environments and mineralogy, are also explored.The study investigates cyclic CO₂ injection as a method for improving methane recovery and carbon capture. Cyclic injection involves alternating periods of CO₂ injection and depressurization to optimize recovery and storage. Experimental results demonstrate significant improvements in methane recovery with CO₂ injection, though challenges such as dead volumes are noted.Furthermore, the research evaluates the dynamic replacement of methane by CO₂ through breakthrough column experiments. The findings reveal that CO₂'s higher adsorption affinity compared to methane enhances both methane recovery and CO₂ storage. These insights highlight the potential of CO₂-EGR in advancing sustainable energy practices and mitigating climate change.In summary, this thesis offers a comprehensive understanding of shale gas recovery, CO₂ storage, and droplet-interface interactions, contributing to more efficient energy production and environmental sustainability.