Chapter 9 Oil Displacement in the Hele-Shaw Model Using Microbes and Synthetic Surfactants

Abstract

This chapter presents the oil displacement in the Hele-Shaw model by using microbes and synthetic surfactants. Pluronic surfactants of varying hydrophdic-lipophilic balance (HLB) are used to reduce the interfacial tension between oil and the aqueous phase. Under reservoir conditions, surfactants serve to reduce capillary pressure that aids in removing oil from the capillary pores in the porous media. Evaluation of oil displacement ability by surfactant solutions in the single-pore Hele-Shaw model was performed. Oil recovery in a large single pore, typified by the Hele-Shaw model, by surfactant solutions at a constant viscosity seems to be affected predominantly by two main factors: (1) spreading coefficient and (2) interfacial tension. The difference between interfacial tension and spreading coefficient may be used to generate curves very similar to those seen for the percent of oil recovered for surfactant solutions. There appears to be a balance between the two, produced by an optimal concentration of surfactant, which is desirable to enhance oil recovery in the Hele-Shaw model. Conditions that optimize displacement of oil from the Hele-Shaw model are a low spreading coefficient and a critical interfacial tension as it relates to reduction of fingering.