Reservoirs macroemulsion flooding

Macroemulsion and Microemulsion Flooding If a suitable surfactant is injected into the reservoir, it can form macroemulsions and/or microemulsions with the reservoir oil depending on the composition and reservoir conditions. Several articles have been published on the recovery of oil by microemulsion and macroemulsion flooding processes.Among various factors, the most important factor of surfactant flooding in the form of an emulsion is the lowering of the interfacial tension (IFT) at the oil/water interface. Microemulsions are more effective in oil displacement as compared to macroemulsions because microemulsions can provide low IFT systems. 

Emulsions are commonly produced at the wellhead during primary (natural pressure driven) and secondary (water-flood driven) oil production. For these processes the emulsification has not usually been attributed to formation in reservoirs, but rather to formation in, or at the face of, the wellbore itself [154]. However, at least in the case of heavy oil production, laboratory [162] and field [156,157] results suggest that W/O emulsions can be formed in the reservoir itself during water and steam-flooding. Macroemulsions, as opposed to microemulsions, can be injected or produced in situ in order to either for blocking and diverting [158,159], or for improved mobility control [160]. 

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