Technological synergy for enhancing hydrocarbon recovery and its applications

This study introduces the connotation of technological synergy for enhancing hydrocarbon recovery, and proposes the synergy of secondary recovery (water flooding) with tertiary recovery (CO₂ flooding) (also referred to as the synergy of 3+2) to significantly improve the recovery of mature fields with high water cut, as well as corresponding measures taken to facilitate the technological synergy execution. What's more, the synergy of thermal fluids with multiple displacing mediums is also established to substantially improve heavy oil recovery, and is applied in practice,showing a 21.9 % increase in the recovery for heavy oils that are typically difficult to extract. Furthermore, the synergy of multi-displacing-mediums compounded thermal flooding with multilateral wells is successfully applied to expand the upper limit of the viscosity for heavy oil recovery to 750,000 mPa·s and reduced the lower limit of the produced reservoir thickness to 1.5 m. Future research on the synergy alternatives for enhancing hydrocarbon recovery should focus on the synergy of hydraulic fracturing-assisted oil displacement with waterflooding for low-permeability reservoirs, the synergy of gas flooding, water flooding, and injection-production well pattern optimization for fractured-vuggy oil reservoirs, the synergy of injection-production ratio optimization, artificial lift and gathering system for mature oilfields, as well as combined drainage gas recovery for shale gas.