Water-alternate-emulsion (WAE): A new technique for enhanced oil recovery

•Water-alternative-emulsion (WAE) flooding technique has been demonstrated.•WAE technique has been compared to traditional flooding techniques.•WAE is proved to be a promising enhanced oil recovery technique.•82% of original oil in place can be recovered with only 0.3 pore volume of emulsion.

To meet the global need for efficient energy recovery, a new water-alternate-emulsion (WAE) technique for enhanced oil recovery is presented here. The key to this technique is the use of ex situ generated emulsion to recover the resident oil phase from reservoirs, where the emulsion is injected along with water in alternate slugs. Three different flooding ratios for water to emulsion (oil-in-water) slugs were investigated here using an unconsolidated sand pack as a model porous medium. It was found that for 5:1 WAE flooding, the total amount of oil recovered is 82% of OOIP for only 0.3 PV injection. This is significantly higher rate of recovery compared to conventional water flooding or emulsion flooding alone. Hence, the WAE flooding technique tested under laboratory conditions appears to be a promising technology for an enhanced oil recovery process, which needs to be tested in field reservoirs.