A New Class of Viscoelastic Surfactants for Enhanced Oil Recovery

Abstract

Abstract A new class of viscoelastic surfactants for chemical enhanced oil recovery is presented. The triphenoxmethanes (TPM) show promise under harsh conditions of high salinity and high temperatures. The TPM's are viscoelastic at low concentrations (<0.5%w/w), show good stability in highly saline brine (18.6% TDS) that contains high concentrations of divalent cations at elevated temperatures (>70°C). Static adsorption measurements show acceptable values for the harsh conditions under study. Rheological measurements demonstrate that the viscoelasticity is not from formation of wormlike micelles and displays non-Maxwell behavior. We propose a novel supramolecular structure that explains the laboratory and rheological observations to date. The compounds show good injectivity into 2 Darcy Gildehaus sandstone The development of this class of compounds combines the efforts of a team comprised of synthesis, analytics, rheology, core lab and computational chemistry. The goal is to develop an understanding the system's behavior from the molecular level in-silico via computational chemistry, through coreflood tests -and beyond- for a future field pilot. The structure- property-relationships that are being developed will lead to further refinement and targeted development of next generation molecules with improved properties.