The Effect of Oil and Gas Content on the Controllability and Separation in a De-Oiling Hydrocyclone

The effect of free gas on cyclonic oil–water separation was examined using a geometry which sought to minimize problems with gas. Tests were carried out using the purpose built oil–water separation facility at Bradford University where pre-choke conditions could be partially simulated. Firstly, tests were carried out with water and gas–water to look at flow behaviour and control parameters, then comparative separation tests carried out with gas–oil–water. Comparisons were also made with test data from a conventional de-oiling hydrocyclone. The effects of gas content, feed drop size distribution, overflow size diameter and feed pressure were all investigated. A threshold effect of free gas on flow stability and separation efficiency was observed. The see-through hydrocyclone allowed the collection of semiquantitative data on gas core diameter and behaviour and on gas slip velocity at inlet.