WITH CRUDE prices climbing, producers have a strong incentive to get every barrel out of the ground and into the marketplace. But primary oil-recovery techniques, which rely on natural underground pressures to push hydrocarbons into the wellbore and up to the surface, have limited effectiveness. Eventually reservoir pressure diminishes and the flow stops, leaving 60-70% of the original oil in place.
For decades, operators have boosted production from ageing oilfields by flooding them with huge volumes of water, which repressurises the formation and sweeps out up to 20% more oil. But even with this secondary-recovery method, significant volumes of oil remain trapped in the reservoir. Enhanced oil-recovery (EOR) techniques go further, by combining additives with the water or injecting steam or gases into the reservoir to boost production.
According to the International Energy Agency (IEA), about 300bn barrels of oil could be unlocked using EOR methods. Although EOR techniques are...