Experimental and numerical investigation of oil-water separation

Abstract

Separation of oil-water mixtures is essential to prepare the productsprior to transportation. This is, among others things, due to salesspecifications, minimisation of corrosion, and reduction of transporta-tion costs. The work in this thesis has been dedicated to investigatingliquid-liquid separation in horizontal gravity separator numericallyand experimentally. Experiments have been carried out to validateexisting dispersion layer- and separation performance models. Nu-merical simulations of the test separator were performed with thesteady-state multiphase Euler-Euler model. They showed that, forpractical purposes, numerical simulations cannot be used to evaluateseparation parameters quantitatively. Instead, the simulations can beused to validate the flow pattern. The experiments measured the dis-persion layer thickness and separation performance at different flowrates, water cuts, and pressure drops. They showed correspondencebetween the dispersion height and water flux. This suggests thatPolderman s model should take the effect of water cut into account.Experiments showed high separation performance, due to the use of amodel oil. A correlation between the oil phase Reynolds number andthe BS&W is indicated. The effect of drop size distribution on thedispersion has been investigated. Increased pressure drop changed thedispersion characteristics into an emulsion.