Chemical Enhanced Oil Recovery Methods

This chapter describes the main principles related to chemical enhanced oil recovery (EOR) techniques: polymer, surfactant‐polymer (SP), and alkali‐surfactant‐polymer (ASP) flooding; microgels; and other conformance methods. Polymer flooding consists of adding powder or emulsion polymers to the injection water of a waterflood, thereby viscosifying the water and decreasing its mobility. Polymer and surfactants can be injected together to maximize oil recovery by taking advantage of macroscopic and microscopic sweep efficiencies. For SP and ASP, polymer is required to improve mobility control and ensure that a large part of the reservoir is contacted by all chemical components in the EOR slug. The chapter provides a comparison of polymer flooding with other chemical techniques such as crosslinked gels, colloidal dispersion gels, and microgels. It also provides a brief knowledge summary of some field cases.