Characterisation of crude oil for enhanced oil recovery: study with anionic surfactant

摘要

A chemically enhanced recovery technique is used where thermal recovery is not feasible. It reduces the interfacial tension by forming a microemulsion. In this paper, characterisation of crude oil in terms of chem-ical bonds present is investigated by Fourier transform infrared spectroscopy (FTIR). The peaks at different wave number show saturated groups such as n-alkane -CH, -CH_2, -CH_3 and short chain of n-alkane C-C bond present in the oil samples. Since the crudes are collected from an anionic reservoir, sodium dode-cyl sulphate (SDS) of 0.4% critical micelle concentration is suitable. It has been seen that the particle size increases in the case of a surfactant solution with oil compared to one without oil indicating entrapment of oil components inside the surfactant micelle. The larger absorptions of SDS from UV spectroscopy are caused by electrons moving between π and π* orbitals due to the presence of more unsaturated groups in the solution.