Effect of Hydrocyclone Inlet Device (HID) in Three Phase Gravity Separator for Oil-Water Separation Improvement

As the oil production field reaches its mature phase and the surface processing
facilities reaches its maximum capacity, more water is produced together with the
reservoir fluid. The management and control of water production have become a vital
activity in order to enhance the quality of crude oil processing in meeting customer
satisfaction. The option that is currently adopted in the oil and gas industry is the
introduction of Hydrocyclone Inlet Device (HID) in a gravity separator. This new design
takes advantage of both the centrifugal force of HID and gravity torce of a gravity
separator. The main advantage of this HID is the reduction in foaming of the inlet flow of
the gravity separator. isy applying Hiü at One inlet or gravity separator, the rejuvenation
of new separator vessel is not required since it is more economical to replace the current
inlet with cyclone inlet. The HID helps to increase separation capacity without additional
vessel and major modification to the existing facilities. However, for the application of
HID in high water cut from oil production field, the mixture of oil and water is of
difficult oil-water emulsion pattern. This complex emulsion pattern is caused by the
changes in oil-water composition and also different sizes of oil droplets due to the choke
variations. The retention time taken by the droplets to coalescence during gravity settling
process is affected and this causes the reduction in the efficiency of separator in oil-water
separation. Apart from that, this oil and water mixture exhibits different properties at
certain operating parameters such as at high temperature, flowrate and oil-water
proportion. Therefore, the interest of this project is to investigate the effect of HID in
gravity separator at certain parameters. An experimental approach for oil and water
separation with constructed prototype using waste crude oil at different operating
temperature, flowrate and oil-water proportion is performed in this project to improve the
oil-water separation. Results obtained from the experiment shows that the HID performs
better at high operating temperature and high incoming fluid flowrate. However, at high
water cut, the performance of HID is lesser compared to typical plate diverter, since the
swirling action exerted by HID causes more complex reverse water-in-oil emulsion.