1 reply to this topic

[janson_kaniaz]

I would like to understand why oil with higher density (ie lower API) is allowed longer residence time (liquid) criteria? I was under the impression that the higher the density, the lower the volumetric flow, which means it's easier for the separation to take place.

[ColinR33]

Are you talking 2-phase (gas-liquid), 3-phase (gas-oil-water) or liquid/liquid (oil/water) separation?  If it is 3 phase or liquid/liquid, as the oil becomes heavier (°API decreases) your residence time requirements increase because the density of the oil is getting closer to that of water.  Because separation is by gravity, two non-miscible liquids of similar density will take much longer to separate compared to two non-miscible liquids with significantly different densities.  Oil density can also be a factor in two phase (gas-liquid) separation, although to a lesser extent as typically the heavier the oil, the bviscosity also increases and depending on the situation, this ay have an effect on how quickly the gas can "break out" from the oil.  This viscosity effect can also play a part in the separation of oil/water phases.