Abstract
<jats:title>Abstract</jats:title> <jats:p>Methane infusion improved oil recovery (MI IOR) demonstrates technical viability and economic attractiveness for unconventional reservoirs. Multi-scale investigations spanning nanoscale characterization, petrophysics, nuclear magnetic resonance (NMR) experimentation, and reservoir simulation corroborate the method. Field-emission scanning electron microscopy of core samples informed pore-scale classification and MI operational parameters. Integrated well logging quantified petrophysical properties across the Bakken stratigraphy, while NMR relaxometry measured laboratory sweep efficiency at 3,750 psi, yielding recovery factors of 45–60% from Nanopore 1 (0 -5nm), Nanopore 2 (5-10nm), and Nanopore 3 (10-20nm) size pores. Field-scale reservoir simulation of MI 1-Cycle and 4-Cycle scenarios revealed well lifetime production gains of 13.3–14.8% for volatile alkanes (C1–C4) and medium-to-heavy liquid fractions (C8–C36). Intermediate fractions (C5–C7) exhibited dual-phase partitioning: vapor-phase recovery increased 16.4–20.5%, while liquid-phase production rose 3.8–11.7%, validating multi-contact miscibility and molecular diffusion as primary displacement mechanisms. Gas utilization factors of 0.54 Mscf/STB (1-Cycle) and 1.34 Mscf/STB (4-Cycle) provide strong positive indicators. Commercial economics forecast $3.80 present-worth gain per CAPEX dollar and $4.64 incremental CAPEX per barrel. MI IOR shows great potential for a capital-efficient, de-risked pathway toward field pilot deployment.</jats:p>