1. Mahbubur Rashid
Process engineer
[Company]
October 2011

2. Produced water – nature of the problem
Water handling - range of technologies
Water discharge quality specifications
Measurement of oil in water
Criteria for choosing technology(ies)
Key suppliers
Sample concepts in produced water handling
Future developments
Final messages and referrals to more information

3. Mixture of formation water and injected water that is produced to
surface facilities with oil and gas, not including drilling or well
treatment fluids.
Requires surface facilities for separation, treatment and disposal.
Contains dispersed oil, suspended solids, production
chemicals, traces of heavy metals,
dissolved organics (including hydrocarbons)

4. Separation
Treatment
Disposal
Settling
Hydrocyclones
Flotation
Media filtration
Membrane High pressure membranes
Reverse osmosis
Ultrafiltration
Basic
Adsorption
Oxidation / disinfection
Multi-technology processes
Vapour compression
Multieffect distillation
Multistage flash
Ion exchange
Ultraviolet disinfection
Ozonation
Thermal technologies
Company proprietary
processes
Media filters Activated carbon filters
Advanced Biological treatment
Potable water treatment
Offshore - Discharge to sea
Onshore - Evaporation pond
Water re-use
Produced water re-injection
Key references for comparison of technologies
Technical Assessment of Produced Water Treatment Technologies, Colorado School of Mines, Nov 2009
Techniques for the Management of Produced Water from Offshore Installations, OSPAR Commission 2002

5. Dispersed oil in water measured in mg/l or ppm.
Sample regulation from North Sea basin
Set by Oslo Paris Convention (OSPAR) 2002 was
Maximum discharge limit of 30 ppm oil-in-water
with overall discharges reduced by 15% from 1999 levels
Industry-leading standard. Other oil producing regions will have local and national limits
Oil-in-water in ppm is
related to the population
of oil droplets of varying
sizes, in mm.
Oil-in-water
measurement , both in
ppm and mm, is an
emerging field in itself.
Specifications have dealt with dispersed oil so far,
not dissolved hydrocarbons, though the focus is changing
Technology Removes oil droplet sizes
greater than size (microns)
API gravity separator 150
Corrugated plate separator 40
Induced gas flotation without chemical addition 25
Induced gas flotation with chemical addition 3 - 5
Hydrocyclone 10 - 15
Mesh coalescer 5
Media filter 5
Centrifuge 2
Membrane filter 0.01
(US Dept of Energy white paper, 2004, ref. 3, pg 63]

6. ‘Grab sampling’ practices still very common, followed by lab based analysis
techniques e.g. infrared, colourimetric etc.
Online real-time measurement clearly advantageous for process control.
But beset with problems of interference, lack of repeatability and inability to
cope with rapid operational upsets on plant
Characterisation of produced water comparatively underdeveloped –
yet critical to choosing correct treatment method

7. Solution for given oil/gasfield almost always a combination of ‘coarse’
separation and ‘fine’ separation processes.
Difficult to define ‘decision tree’ style selection method because of large
number of criteria and different weighting of each, depending on the
individual oilfield

8. Sample criteria for choosing equipment:
•Off- or on-shore location; OR water is from coal seam gas deposit
•Produced water characterisation (species of ions, contaminants present)
•Volumes of water expected (over field life cycle)
•Any special needs / initiatives of operator company
•Scope for profitable use by re-injecting into reservoir, economic feasibility
thereof
•Local discharge specification; eventual fate of water in the localised
environment
•Scope for re-use of water by local population
•Play-off between equipment cost / available footprint / operability / ease of
maintenance / energy consumption / associated chemicals consumption /
by-products generated

9. Design solutions
Siemens
Veolia Water
Sample equipment suppliers for primary separation
Hydrocyclones Clear Water Group Salter Cyclones
Weir Minerals Alderley Group
API separators WesTech Mercer International
Hydro Flo Technologies
Induced gas flotation Separation Specialists Inc.
EnviroTech Systems ProSep

10. Produced GE O&G greenfield package for BP Iraq, Rumaila field.
Water Wood Group project for unnamed N Sea operator
Re-injection Optimisation of PWRI system modifications increased both
(PWRI) oil production and water injection capacity
Onshore Veolia Water package for Chevron, San Ardo, California
application induced gas flotation - walnut shell filtration –
OPUS ™ technology – to reduce total dissolved solids, boron and hardness
Coal bed Siemens project for PetroCanada, Powder River Basin
Methane Reverse osmosis (RO) and brine recovery RO systems

11. Downhole separation
Subsea separation
Mechanical shutoff of water inflow to well
Chemical shutoff of water inflow to well
Sidetracking of wells
Dual completion wells
Troll pilot subsea unit, ref. 7
Sidetracking of wells, ref. 7

12. Produced water characterisation is key – if online continuous measurement,
even better
Despite above, choice of treatment system is outcome of interplay of criteria
Leading-edge designs seek to prevent the water ever coming to surface
Legislative driver forcing companies to ‘clean up’ – much more so than
economic driver.
Exceptions are water re-injection or water re-use options.
Comparisons of treatment technologies available in References page

13. 1. Report of RPSEA Project 07122-12, An Integrated Framework for Treatment and Management of Produced Water,
Technical Assessmentof Produced Water Treatment Technologies, Colorado School of Mines, Nov 2009
http://aqwatec.mines.edu/research/projects/Tech_Assessment_PW_Treatment_Tech.pdf
2. OSPAR Commission, Offshore Industry Series, Background Document concerning Techniques for the Management of Produced Water
from Offshore Installations, published 2002
http://www.ospar.org/documents/dbase/publications/p00162_Techniques%20for%20the%20management%20of%20Produced%20Water.p
df
3. Argonne National Laboratory, report prepared for US Department of Energy, A White Paper describing Produced Water from Production
of Crude Oil, Natural Gas and Coal Bed Methane, Jan 2004, Sections 5 and 6, pgs 42 - 68
http://www.evs.anl.gov/pub/doc/ProducedWatersWP0401.pdf
4. Tyrie, C.C., Caudle, D.D., Comparing Oil in Water Measurement Methods, Exploration and Production: The Oil and Gas Review 2007,
Issue II, Nov 2007 reproduced in Touch Oil and Gas webpage
http://www.touchoilandgas.com/comparing-water-measurement-methods-a7704-1.html
5. Jangbarwala, J., CBM-Produced Water: A Synopsis of Effects and Opportunities, [Journal of] Water Conditioning and Purification, Dec
2007
http://www.wcponline.com/pdf/0712Jangbarwala.pdf
6. Rice, C.A., Nuccio, V., Water Produced from Coal Bed Methane, US Geological Survey Factsheet FS-156-00, Nov 2000
http://pubs.usgs.gov/fs/fs-0156-00/fs-0156-00.pdf
7. Nature Technology Solution company promotional document, Introduction to Produced Water Treatment
http://naturetechsolution.com/images/introduction_to_produced_water_treatment.pdf
8. Interstate Oil and Gas Compact Commission and ALL Consulting, report prepared for US Department of Energy, A Guide to Practical
Management of Produced Water from Onshore Operations in the United States, Oct 2006, Sections 4 and 5, pgs 39 – 112
http://fracfocus.org/sites/default/files/publications/a_guide_to_practical_management_of_produced_water_from_onshore_oil_and_gas_o
perations_in_the_united_states.pdf