Emerging Technology for Produced Water And Slop...
Transcript of Emerging Technology for Produced Water And Slop...
Emerging Technology for Produced Water
And Slop Treatment
Center Force – Hydrocyclone Experience
Wholly owned subsidiary of BAR Engineering Co. Ltd. – May 2011
Designed and installed first commercial Hydrocyclone skids:
• Husky’s Lloydminster Heavy Oil Refinery. (1999)
• Husky’s Heavy Oil Upgrader. (2000)
• Cenovus Foster Creek. (2011)
Received License to market the CANMET Hydrocyclone Technology in May 2009.
Locally fabricated and therefore able to provide Hydrocyclone packages registered with ABSA & CSA.
CANMET Hydrocyclone
How a Liquid-Liquid Hydrocyclone Works
The water and suspended solids exit at the
underflow port
The separated oil flows backwards along
the centre axis and exits via the overflow
port
The water phase, being denser, migrates to
the outer wall of the hydrocyclone while the
lighter oil phase migrates towards the centre
Feed enters tangentially directing
the fluid into a high-speed spiral
CANMET Hydrocyclone
CANMET Hydrocyclone
How the Liquid-Liquid Hydrocyclone Works
Utilizes centrifugal force to separate fluids of different densities.
Has no moving parts.
Pump pressure provides the energy for the separation.
Factors Affecting Performance
Density difference
Droplet size
Feed Composition
Flow Rate
Viscosity
Interfacial Tension
Solids
Chemical treatment
Temperature
CANMET Hydrocyclone
Hydrocyclone Advantages
Separation Performance
Design generates significant centrifugal forces. This results in more rapid separation
than conventional gravity separation (ie. FWKO’s Skim Tanks)
Principles of Separation – Stokes Law
CANMET Hydrocyclone
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Hydrocyclone Advantages
Elegant and simple in design:
Much more compact than the equipment
they replace (FWKO, skim tanks, etc.).
Residence time is typically about 2 s.
Easy to relocate and offer a much higher
salvage value.
CANMET Hydrocyclone
Inside a CANMET Hydrocyclone Vessel
Simple to Operate: Absence of moving parts ensures a
minimum maintenance and down time.
Fluctuations in feed rate can be handled without large effects on efficiency.
Hydrocyclone Advantages
CANMET Hydrocyclone
Advantages and Limitations LIMITATIONS
Gas Handling – The presence of gas in the feed impairs the performance of the
hydrocyclone.
Reduced efficiency when oil droplets are smaller than 10 micrometres – Because smaller
droplets move more slowly than larger ones, separation does not occur fast enough
in the hydrocyclone when droplets are very small. This reduces separation
efficiency.
Difficulty in Handling Oil-Wet Clays – Because the fine clays are less dense than water,
and tend to be oil-wetted, they tend to stay with the oil and exit via the overflow
stream of the hydrocyclone instead of the underflow.
CANMET Hydrocyclone
Features of the CANMET Hydrocyclone Design The design was developed throughout extensive research and field testing at several
Western Canadian Heavy Oil Production Facilities.
The CANMET Hydrocyclone design is specifically suited for the treating of difficult
– to – separate oily emulsions.
Unlike conventional hydrocyclones, which have only one inlet port CANMET
hydrocyclones have two, three, or four evenly spaced around the involute, producing
a more axisymmetric vortex flow and oil core.
CANMET Hydrocyclone
Single inlet involute
Multiple inlet involute (CANMET Design)
Involute – This is where most of the separation occurs. The large droplets and sand
particles are separated quickly and easily in this stage.
First Taper – This is the first section where the tube becomes narrower. This causes an
increase in the g-forces and causes some of the smaller droplets to separate.
Second Taper – This is the last section of the hydrocyclone. In this section the g-forces
reach a peak. This is also the section with the longest retention time where only small
droplets remain because they take longer to separate.
CANMET Tube Design
Involute First Taper Second Taper
CANMET Hydrocyclone
Hydrocyclones are designed to produce 2 product streams: o/f and u/f.
In single-stage hydrocyclone treatment. Optimum operating conditions for obtaining the two products are different, the quality of one of the two products must be compromised.
In order to produce 2 quality products at the same time, 2-stage hydrocyclone treatment is required.
CANMET Hydrocyclone
Typical Single Stage Vessel with Variable Orifice
Pressure Differential Ratio (PDR)
PDR is the difference between the pressure of the feed and oil outlet over
the pressure difference between the feed and water outlet:
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/
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FUFEED
FOFEED
PP
PPPDR
CANMET Hydrocyclone Operational Control
Orifice Size
The overflow orifice size determines
the size of the core that exits via the
overflow outlet. A smaller orifice size
increases overflow oil concentration
at the expense of underflow water
quality. A larger orifice size allows for
a cleaner underflow stream, while
decreasing overflow oil
concentration, since more water
exits with that stream.
Operational Control
CANMET Hydrocyclone
Applications
Refinery Desalter – Water Effluent
Produced Water Treatment (Deoiling)
Slop Oil Conditioning – Bench & Field Tests
CANMET Hydrocyclone
CANMET Hydrocyclone
Applications - Treatment of Desalter Effluent
Objective:
To produce a stream of clean water from desalter effluent.
Issue:
Long retention time required to separate oil and solids from water phase due to
similar densities.
Integration for Treating Desalter Effluents
CANMET Hydrocyclone
Treatment of Desalter Effluents - Normal Operation
At the Husky Lloydminster Refinery the CANMET hydrocyclone is run under two conditions, normal and desanding.
Under normal conditions the oil content is in the ppm levels.
Oil concentrations:
Feed ~3000 ppm
Overflow ~4%
Underflow <1000 ppm
Solids concentrations:
Feed ~1%
Overflow - traces
Underflow ~2%
CANMET Hydrocyclone
Treatment of Desalter Effluents - Desanding Operation
Under desanding operation, feed stream contains approximately 5% oil and solids content is about 4%. Like emulsions, it does not settle quickly.
Oil concentrations:
Feed ~5%
Overflow ~40%
Underflow <traces
Solids concentrations:
Feed ~4%
Overflow - traces
Underflow ~4%
CANMET Hydrocyclone
Desalter effluent was separated into:
a clean water stream containing low ppm levels of oil, suitable for disposal or
reuse.
a concentrated oil stream
Solids in the water (underflow) stream separated more quickly in skim tanks
because their oil coatings were reduced.
Treatment of Desalter Effluents - Summary
CANMET Hydrocyclone
Applications – Produced Water Treatment Deoiling
Objective:
To reduce the oil concentration from 500-3000 ppm to 100 ppm.
Separation challenges:
Small Difference in oil and water densities.
Oil Droplets are very small (~10 µm).
CANMET Hydrocyclone
CANMET Hydrocyclone Applications – Produced Water Treatment Typical – Process Flow Sheet
-Testing at a Heavy Oil Operation
CM LA CM LA CM LA CM LA CM LA
PW-1 400 736.0 50 35.1 >1400 9000 <50 27.9 150 135.0
PW-2 >2000 833.0 350 71.6 >2000 - 100 35.8 >1400 -
PW-3 >2000 9000.0 350 210.0 >2000 13200 100 190 >1400 -
PW-4 600 789.0 50 44.3 >2000 - <50 17.3 200 -
PW-5 500 455.0 50 33.4 >2000 289 <50 20.2 200 -
PW-6 400 365.0 <50 69.8 >2000 - <50 39.3 100 -
PW-7 600 472.0 50 112.0 >2000 - <50 43.5 200 -
PW-8 1200 1900.0 100 528.0 >2000 104000 50 98.8 200 331.0
PW-9 700 1900.0 100 354.0 >2000 - <50 109 250 -
PW-10 1200 709.0 100 487.0 >2000 - 50 109.0 300 -
PW-11 >2000 1259.0 250 331.0 >2000 30200 100 37.2 >2000 465.0
PW-12 >2000 980.0 400 73.0 >2000 4700 100 35.2 1400 943.0
PW-13 >2000 2690.0 300 30.0 >2000 - 50 37.2 250 -
PW-14 100 - <50 26.0 >2000 - <50 32 250 -
AVERAGE 1700.0 171.8 59.4
Sample I.D.
LA = Lab Analysis by Agra.
U/F2 O/F2Feed U/F1 O/F1
- = No sample sent to laboratory
Oil Content (ppm)
CM= Onsite Colour Match.
Produced Water Treatment Results
CANMET Hydrocyclone
A slipstream of produced water (before skim tank) with an average
inlet oil concentration of 1700 ppm
The typical inlet flow rate is around 40 L/min (57 m3/d), and the outlet
water flow rate (underflow from stage two) is around 25 L/min
(36 m3/d).
It was found that the first stage produced an underflow stream
containing an average oil concentration of 172 ppm and the underflow
from stage two contained less than 60 ppm oil
Summary of Produced Water Treatment Results
CANMET Hydrocyclone
Objective:
To obtain a treatable crude oil from a stream of slop oil generated from skim
tanks and/or treaters.
Separation challenges:
Small differences in oil and water densities
High viscosity of oil reduces settling rate.
Applications - Slop Oil Treatment – Bench Test
CANMET Hydrocyclone
Applications – Slop Oil Treatment
Processing Scheme for Slop Oil Treatment
CANMET Hydrocyclone
Micrograph of a conditioned slop oil sample Micrograph of an unconditioned slop oil sample
Slop Oil Treatment
Conditioning of Slop Oil
CANMET Hydrocyclone
Treatment of Slop Oil with Conditioning of Feed
Temp Oil Content
(vol%)
Flow rate
(L/min in)
Oil
Recovery
Separation
Efficiency
Slop Oil
Test #
(ºC) Feed U/F O/F QF QU (%) (%)
SOT-1 88 15 0.15 65 21.5 18 99.2 58.8
SOT-2 90 5 0.03 53 26. 24 99.4 50.5
SOT-3 88 5 0.20 43 30 27 96.4 40.0
SOT-4 83 13 2 74 31 28 86.1 70.1
SOT-5 85 18 6 64 33 31 68.7 56.1
SOT-6 87 19 8 74 28 25 62.4 67.9
SOT-7 89 12 10 68 30 27 25.0 63.6
SOT-8 81 12 6 60 34 29 57.4 54.5
SOT-9 85 18 8 60 36 30 63.0 51.2
SOT-10 91 10 1 74 31 27 91.3 71.1
SOT-11 88 12 10 68 34 29 28.9 63.6
SOT-12 88 14 8 76 31 26 52.1 72.1
SOT-13 84 8 4 66 33 30 54.5 63.0
SOT-14 84 9 4 70 36 32 60.5 67.0
CANMET Hydrocyclone
Feed containing ~10% oil was concentrated
to 76% oil in stage 1.
Second-stage underflow oil concentration
averaged at high ppm levels with the lowest
at 150 ppm.
Results from Slop Oil Treatment
CANMET Hydrocyclone
Slop Oil – Field Test Background:
Test completed at a Heavy Oil Treating Facility
Utilizes a pressure treating system.
Average Volume:
• 1300 m³/day of trucked-in emulsion
• 1100 m³/day of sales oil
• 200-250 m³/month of slop oil
Sources of Slop Oil
• Skim Oil from water & desand tanks
• Interface Draw from treaters.
CANMET Hydrocyclone
Slop Oil – Field Test
Background Continued:
Attempts to process the slop oil in the treaters was unsuccessful.
Slop oil was trucked offsite.
CANMET Hydrocyclone
Slop Oil – Field Test
Process/Test Configuration
A test unit consisting of a two stage - single Hydrocyclone tube was utilized.
Feed
• Slop oil tank
• Feed was conditioned by adding produced H²0
• Increased water cut to 80%.
Overflow
• Returned to slop oil tank or to the treating system
Underflow
• Return to water tanks
CANMET Hydrocyclone
CANMET Hydrocyclone
Applications – Slop Oil Treatment
Solids Water Emulsion Oil
Slop Oil 5.4% 19.5% 14.0% 61.1%
Feed (includes
make-up H20)
1.1% 81.9% 0.7% 16.6%
Overflow 1.0% 63.5% 0.2% 35.1%
Underflow 2.0% 97.4% 0.0% 0.3%
236 m³ of slop treated
Minimal impact to treater operation.
No slop trucked offsite
Slop Oil – Field Test Summary of Results:
CANMET Hydrocyclone
Slop Oil – Field Test
Conclusion
Hydrocyclone demonstrated that it could condition the facility’s slop oil so it could
be treated on site.
Assuming a saving of $100/m³ of slop, the total saving for the test period $25.6 K.
CANMET Hydrocyclone
Center Force Test Skid
Capacity – Two Stage – 50 m3/d, Single Stage – 100 m3/d
5 HP Progressive Cavity Pump – TEXP
Design Pressure & Temperature: 1170 kPag @ 93 oC
Ability to tie into piping system with high pressure hoses.
CANMET Hydrocyclone
Questions?