To determine the location and orientation of mechanical mixers inside the LFHO tank to achieve maximum homogenization inside the LFHO Storage Tanks.
The Lower Fars Heavy Oil (LFHO) development is targeted at a large heavy oil accumulation of approximately 7 to 15 billion barrels of oil-in-place located in a desert area some 1,200 km2 in northern Kuwait.
In the mathematical modelling, following assumptions are made for mixing operation inside the LFHO Tank, and a Computational Fluid Dynamics (CFD) simulation has been run.
•Mixing flow is three-dimensional and steady state.
•Low Fars Heavy Oil (LFHO) in the tank and BS&W in the stirred tank are incompressible, isothermal and Newtonian fluids.
•Considering the volume concentration of BS&W inside the tank, the model is single phase without accounting for multiphase interactions.
Based on analyses, it can be concluded that with given impeller arrangement, homogeneity is maintained for the given design condition. The blending time has been considered conservatively as four (4) time the circulation time estimated from CFD simulations. However, once the flow attains steady-state operation, even in the maximum density case, the mixing time will be 40 minutes. The sump design guarantees that all oil droplet greater than 16 µm will not remain present inside the BS&W region after 24 hours of settling time, in the designed operating conditions. Therefore, with 16 µm oil droplets entrained in in BS&W region, 30 ppm oil at oily water outlet will be guaranteed.