Wormlike Micelles for Mobility Control in EOR

Abstract

Abstract A major problem with polyacrylamide, the main polymer used in EOR, is its tendency to degrade under shear forces. Another polymer xanthan gum usually costs more than polyacrylamide and requires a biocide to prevent biodegradation. Micellar flooding has been reported extensively since the 70’s and as in the case of other chemical flooding, it has not been implemented widely due to the high cost of chemicals to form micelles. The high viscosity of the micelles also posed injection problems. However, strategic injection techniques can overcome the problem. The salinity of the formation water and temperature are also important parameters. All these usually restrict application of chemical EOR particularly surfactant and polymer flooding. However, current studies have shown wormlike-micelle surfactants such as those from cetyltrimethylammonium halides (CTAX) and cetylpridium halides (CPyX) can alleviate these problems. Wormlike micelles have been used in other areas such as home cleaner products and personal care products including shampoo and body wash due to its viscoelasticity. It also finds applications as fracturing fluids in oil fields. While earlier micelle studies proposed four or five components in forming stable micelles, the current studies showed that a surfactant and salt can form wormlike micelles. These micelles have the advantage of breaking and reforming under shear stress and therefore maintaining the viscosity. It is also viscoelastic and research has shown that viscoelasticity is able to reduce residual oil. This research studies the surfactants that can form wormlike micelles under high salinity, high temperature conditions and the salts that are required to form the micelles. Displacements studies conducted show good mobility control and work on injection strategy will be discussed.