Surfactants Selections Criteria for Enhanced Oil Recovery in High Temperature and High Salinity Environment

Abstract

AbstractSurfactants are used as suspending and foaming agents. Crude oils deposited and found in sandstone and high temperature environment are often very light. But, Pore throats restrictions made it difficult for such oil to flow unaided. Specially designed surfactants, called IbileSurfac, will serve as a carrier to crude oil, while overcoming barriers posed by saline water. This study was primarily conducted on locally sourced surfactants, called IbileSurfac. IbileSurfac, together with Tween 80, Teepol, and Lauryl Sulphate were screened with NaCl-only brines and n-octane fluid at a unitary value of water/oil ratio for temperatures between approximately 900C and 120°C; at intervals of 5°C. All test cases were performed in the absence of methanol or ethanol (No alcohols present) and other co-solvents, in a Pressure-Volume-Temperature cell. Both volume and pressure were kept constant. Varying phase behavior was observed for each class of surfactants, with minimum salinity value of 0.001parts per thousand and maximum value of 0.002 parts per thousand of NaCl for IbileSurfac and others. IbileSurfac has highest Oil solubilization, and lowest in Teepol, with Tween 80 and Lauryl Sulphate, maintaining middle positions. The test results for 120°C at unitary-water-oil-ratio (WOR) show that Ibile Surfac homogenized to form transparent and aqueous single phase liquid, which can flow easily through pore throat restrictions. This provides a useful lead for initial selection of appropriate surfactants for EOR processes. IbileSurfac is very promising because it has a natural structure that needed the least comparative treatment cost for high temperature and saline environment.