Enhanced Oil Recovery (EOR): Optimized Surfactant-Polymer Flooding Technologies
May 1 @ 12:30 PM - 1:30 PM - Neil Armstrong Hall of Engineering, Room B071
In recent years, chemical flooding has regained its popularity worldwide because of diminishing oil reserves, high oil prices, and advances in new chemicals and technologies for enhanced oil recovery (EOR). Among the broad spectrum of chemical EOR technologies, surfactant-polymer (SP) flooding appears particularly promising. It is, at basis, a variation of micellar-polymer (MP) flooding that prevailed during the 1970s and 80s. After the 1990s, fewer MP projects were conducted in oilfields due to the unreasonably high cost of chemicals. Only a handful of field MP projects have been reported in the open literature. The major technical challenges to MP flooding, aside from the cost of chemicals, were poor understanding of interactions between surfactant and polymer, lack of high-quality surfactant and polymers, and loss of surfactant and polymer in reservoir.
In the SP process, a low concentration of surfactant is used to achieve ultra-low interfacial tension between the trapped oil and the injection fluid/formation water, while the high-viscosity injection fluid provides a favorable mobility ratio. SP performs comparably to alkaline-surfactant-polymer (ASP) flooding, but eliminates issues such as scale buildup and polymer degradation associated with ASP. With careful design and optimization, SP flooding could be a technically viable and cost-effective chemical EOR process for various types of heavy/medium/light oil reservoirs with different rock and fluid properties. Comprehensive and systematic laboratory studies should be conducted to provide guidance for field implementations.
The presentation discusses the key recovery mechanisms of SP flooding that capitalize on the synergistically beneficial interactions among the surfactant, polymer, formation brine, and reservoir rocks for efficient oil mobilization and displacement. Several representative SP field flooding projects are discussed in detail from laboratory evaluation to field implementation. It concludes by proposing a number of research topics in two categories for studying the fundamentals of SP flooding: interactions of i) surfactant-polymer systems and of ii) liquids-solid surfaces. Understanding of these fundamental concerns will help better formulate effective SP systems and design field injection schemes for specific reservoir conditions.