Separation ef¿ ciency Brine/Oil
Department of Multi Scale Ph
ysics,
Fa
cult
y of Applied Sciences
Introduction
Oil is produced as oil/water mixture from oil wells. Increas-ing water cuts, production of heavier oils and oil/water emul-sions make current separation technology insuf¿ cient: the mix-ture is split using gravity in big and heavy settling tanks: a slow process. There is a strong demand from the ¿ eld for more ef¿ cient oil/water separators.
This ISPT project aims at a better in-line oil/water separator based on swirling À ow. Practically, this means understanding the physics and ad-just the design based on results.
Hypotheses
Relevant phenomena:
• Forces acting on droplets Balance between Fcentrifugal and Fturbulence
• Flow pattern / phase distribution
BackÀ ow, shear between continuous phases Æ droplet formation
• Coalescence
Enough force and coalescence time needed
Oil/Brine Mixture Oil/Brine Mixture
Light Phase Outlet (LPO): Oil Heavy Phase Outlet (HPO): Brine
Swirl section data:
Length: 3.8 m Diameter: 0.10 m
Max azimuthal velocity: ~ 12 m/s
Swirl Generator with static vanes Deswirler with
pick-up tube
Experimental
design and results
for oil/water
separation
L.J.A.M. van Campen, J.J. Slot,
R.F. Mudde and H.W.M. Hoeijmakers
Electric conductability
32 x 32 mesh of wires with 3 V potential difference - eletrical resistance correlates with water/oil fraction
Conclusions
• Oil is concentrated in the LPO, but needs improvement
• Single phase experiments and numerical results are different: air entrain-ment in the core region is likely cause
• The oil core created has a vortex-precession like behaviour
Future work
• Remove air/oil from single phase core for better agreement numerics/ experiments
• Investigate time-dependent behaviour of oil core • Optimize design and conditions for best separation
t = 0.10 s t = 0.20 s t = 0.30 s
Wiremesh: À uctuating oil core
I = 0.0 A I = I_max
Brine/Oil
Laurens van Campen
Leeghwaterstraat 39 2628 CB Delft The Netherlands L.J.A.M.vanCampen@tudelft.nl http://www.msp.tudelft.nl High pressure on outside Low pressure in center
An Axial
Cyclone
MethodA test rig has been constructed • tests up to 60 m3/h
• 5 m3 brine
• 4 m3 Shell Vitrea 10 oil
• À exible test section, with possibilities for optical ac-cess, droplet sampling and length variation Differential Volume 2000 1000 400 200 100 40 20 10 6 4 2 1 0.4 0.2 0.1 0.04 Particle Diameter (μm) 5 4 3 2 1 0 Volume (%) (Untitled)
Single phase À ow: Laser Doppler and numerical
Differential Volume 2000 1000 400 200 100 40 20 10 6 4 2 1 0.4 0.2 0.1 0.04 Particle Diameter (μm) 14 12 10 8 6 4 2 0 Volume (%) (Untitled) Differential Volume 2000 1000 400 200 100 40 20 10 6 4 2 1 0.4 0.2 0.1 0.04 Particle Diameter (μm) 14 12 10 8 6 4 2 0 Volume (%) .$00002 Droplet sizing InÀ ow
Outer region centre
Liquid is taken from the rig using a 5 mm sample tube, stabilized with
emulsi¿ er and then examined
us-ing a Beckman Coulter LS 230 (laser diffraction based)
In swirl section, the larger drop-lets are more present in the centre region
Optimization
Different parameters inÀ uence separation ef¿ ciency.
The À owsplit affects the core stability and therewith the per-formance. 3 mm measure-ment spot pickup tube
