James Robinson - Conventional Produced Water Training Course - Produced Water Society Seminar 2018

1. Training Workshop:
Conventional Produced Water
Instructor:
James Robinson,
Oxidane Engineering

2. Outline
• Produced Water
• Quantity, Disposition
• Production Profile
• Composition
• Treatment Technologies
• Process Scenarios & Block Flow Diagrams
• Best Practices

3. Quantities
• Produced Water
• On average, 8 bbls water produced per bbl oil produced
• Some mature field are economically operated at up to 98% water cut
(50 bbls water produced / bbl oil produced)
• U.S. produced water from all oil & gas operations is ~ 21 billion bbls annually
(Source: Clark and Veil, 2009)
• Seawater Injection
• Many offshore developments inject ~ 1 to 2 bbls seawater per bbl of total fluids (oil &
water) produced
• Typical offshore injection wells are designed to inject ~ 10,000 to 20,000 BPD seawater
• Several large offshore facilities inject ~ 500,000 BPD seawater
• Typically, injected seawater is re-produced as produced water

4. Produced Water Disposition
• Onshore
~ 95% PW is re-injected into injection wells
(either water flood or disposal)
~ 5% PW is treated for beneficial reuse
(generally, where disposal capacity is limited or where water is scarce)
• Offshore
~ 85% PW is treated for discharge into the sea
(disposal overboard)
~ 15% PW is re-injected into injection wells
(either water flood or disposal; generally, where required by regulation)

5. Production Profile
ProductionRate(BPD)
Years on Production
Oil Produced Water Total Produced Fluids Water Injection

6. Produced Water
Composition

7. Primary Produced Water Constituents
Produced Water
Organic Inorganic
Insoluble SolubleInsoluble Soluble
Cations Anions
Monovalent Multivalent
Produced Water
Organic Inorganic
Insoluble SolubleInsoluble Soluble
Cations Anions
Monovalent Multivalent

8. Primary Produced Water Constituents to remove
for Produced Water Re-Injection (PWRI)
Produced Water
Organic Inorganic
Insoluble SolubleInsoluble Soluble
Cations Anions
Monovalent Multivalent
TPH TSS

9. Primary Produced Water Constituents to remove
for Offshore Discharge
Produced Water
Organic Inorganic
Insoluble SolubleInsoluble Soluble
Cations Anions
Monovalent Multivalent
Produced Water
Organic Inorganic
Insoluble SolubleInsoluble Soluble
Cations Anions
Monovalent Multivalent
TPH
TOG

10. Primary Produced Water Constituents to remove
for Beneficial Reuse
Produced Water
Organic Inorganic
Insoluble SolubleInsoluble Soluble
Cations Anions
Monovalent Multivalent
Produced Water
Organic Inorganic
Insoluble SolubleInsoluble Soluble
Cations Anions
Monovalent Multivalent
TSSTPH
TOG
TDS

11. Primary Produced Water Constituents to remove
for Chemical-EOR Flood
Produced Water
Organic Inorganic
Insoluble SolubleInsoluble Soluble
Cations Anions
Monovalent Multivalent
Produced Water
Organic Inorganic
Insoluble SolubleInsoluble Soluble
Cations Anions
Monovalent Multivalent
TSSTPH
TOG
Hardness

12. Produced Water
Treatment Technology

13. Technology Selection
• Treatment often requires multiple technologies in series
• Some technologies require pre-treatment
• There are often many ways to design a process, depending
on priorities (capex, opex, space/weight, cost, reliability, etc.)
• Select the most appropriate (economical / reliable /
compact) technology(s) that will achieve the
Treated Effluent Specifications, given the
Source Water Characterization and
Operational Conditions, Constraints & Priorities

14. Produced Water Treatment
Influent
Treated
Effluent
Concentrate
Treatment Process
1000 L
100 g XXX
100 mg/L XXX in water
950 L
0.95 g XXX
1 mg/L of XXX in water
50 L
99.05 g XXX
1981 mg/L of XXX in water
&

15. PW Treatment Technology
Treatment Objectives:
De-sanding
De-oiling
Desalination
Softening
Soluble
Organic
Reduction
Types of Technologies:
Filtration (size exclusion:
cartridge, bag, screen)
Gravity separation (flotation,
coalescence, settling)
Centrifugal separation
(hydrocyclone, centrifuge)
Membrane separation
(MF, UF, NF, RO)
Distillation / Evaporation
Adsorption (multimedia,
walnut shell, IX, GAC, clay)
Oxidation

16. PW Treatment Technology
Treatment Objectives:
De-sanding
De-oiling
Desalination
Softening
Soluble
Organic
Reduction
Types of Technologies:
Filtration (size exclusion:
cartridge, bag, screen)
Gravity separation (flotation,
coalescence, settling)
Centrifugal separation
(hydrocyclone, centrifuge)
Membrane separation
(MF, UF, NF, RO)
Distillation / Evaporation
Adsorption (multimedia,
walnut shell, IX, GAC, clay)
Oxidation

17. PW Treatment Technology
Treatment Objectives:
De-sanding
De-oiling
Desalination
Softening
Soluble
Organic
Reduction
Types of Technologies:
Filtration (size exclusion:
cartridge, bag, screen)
Gravity separation (flotation,
coalescence, settling)
Centrifugal separation
(hydrocyclone, centrifuge)
Membrane separation
(MF, UF, NF, RO)
Distillation / Evaporation
Adsorption (multimedia,
walnut shell, IX, GAC, clay)
Oxidation

18. PW Treatment Technology
Treatment Objectives:
De-sanding
De-oiling
Desalination
Softening
Soluble
Organic
Reduction
Types of Technologies:
Filtration (size exclusion:
cartridge, bag, screen)
Gravity separation (flotation,
coalescence, settling)
Centrifugal separation
(hydrocyclone, centrifuge)
Membrane separation
(MF, UF, NF, RO)
Distillation / Evaporation
Adsorption (multimedia,
walnut shell, IX, GAC, clay)
Oxidation

19. PW Treatment Technology
Treatment Objectives:
De-sanding
De-oiling
Desalination
Softening
Soluble
Organic
Reduction
Types of Technologies:
Filtration (size exclusion:
cartridge, bag, screen)
Gravity separation (flotation,
coalescence, settling)
Centrifugal separation
(hydrocyclone, centrifuge)
Membrane separation
(MF, UF, NF, RO)
Distillation / Evaporation
Adsorption (multimedia,
walnut shell, IX, GAC, clay)
Oxidation
MF
Ceramic MF
RO
NF

20. PW Treatment Technology
Treatment Objectives:
De-sanding
De-oiling
Desalination
Softening
Soluble
Organic
Reduction
Types of Technologies:
Filtration (size exclusion:
cartridge, bag, screen)
Gravity separation (flotation,
coalescence, settling)
Centrifugal separation
(hydrocyclone, centrifuge)
Membrane separation
(MF, UF, NF, RO)
Distillation / Evaporation
Adsorption (multimedia,
walnut shell, IX, GAC, clay)
Oxidation

21. PW Treatment Technology
Treatment Objectives:
De-sanding
De-oiling
Desalination
Softening
Soluble
Organic
Reduction
Types of Technologies:
Filtration (size exclusion:
cartridge, bag, screen)
Gravity separation (flotation,
coalescence, settling)
Centrifugal separation
(hydrocyclone, centrifuge)
Membrane separation
(MF, UF, NF, RO)
Distillation / Evaporation
Adsorption (multimedia,
walnut shell, IX, GAC, clay)
Oxidation
MM, WS
WS, clay
IX
GAC

22. PW Treatment Technology
Treatment Objectives:
De-sanding
De-oiling
Desalination
Softening
Soluble
Organic
Reduction
Types of Technologies:
Filtration (size exclusion:
cartridge, bag, screen)
Gravity separation (flotation,
coalescence, settling)
Centrifugal separation
(hydrocyclone, centrifuge)
Membrane separation
(MF, UF, NF, RO)
Distillation / Evaporation
Adsorption (multimedia,
walnut shell, IX, GAC, clay)
Oxidation

23. PW Treatment Technology
Treatment Objectives:
De-sanding
De-oiling
Desalination
Softening
Soluble
Organic
Reduction
Types of Technologies:
Filtration (size exclusion:
cartridge, bag, screen)
Gravity separation (flotation,
coalescence, settling)
Centrifugal separation
(hydrocyclone, centrifuge)
Membrane separation
(MF, UF, NF, RO)
Distillation / Evaporation
Adsorption (multimedia,
walnut shell, IX, GAC, clay)
Oxidation

24. Treatment Process
Scenarios &
Block Flow Diagrams

25. Produced Water Treatment Process
Conventional Example 1: Onshore PWRI
Scenario: Treatment of produced water for injection into wells (Waterflood)
Influent Water Characterization:
TSS: 10 mg/L
TPH: 100 mg/L (after primary oil/water separation)
Treated Effluent Specifications:
TSS: < 10 microns particle size diameter
TPH: < 20 mg/L
Primary
Oil/Water
Separation
PW Gravity
Separation
“Wash Tanks”
(oil skimming)
Cartridge
Filtration
Injection
Wells

26. Produced Water Treatment Process
Conventional Example 2: Onshore Beneficial Reuse
Scenario: Beneficial reuse of produced water for agricultural irrigation
Influent Water Characterization:
TDS: 6,000 mg/L
TSS: 10 mg/L
TPH: 100 mg/L (after primary oil/water separation)
Treated Effluent Specification:
TDS: < 500 mg/L
TPH: < 1 mg/L
(additional specifications include soluble organic compounds and metals)
RO
Discharge
to
Irrigation
Gas
Flotation
Walnut
Shell
Filter
IX
Primary
Oil/Water
Separation
PW Gravity
Separation
“Wash Tanks”
(oil skimming)

27. Produced Water Treatment Process
Conventional Example 3: Offshore Discharge
Scenario: Treatment of produced water for overboard discharge to sea
Influent Water Characterization:
TSS: 10 mg/L
TPH: 100 mg/L (after primary oil/water separation)
Treated Effluent Specifications:
TOG: < 29 mg/L
Primary
Oil/Water
Separation
Overboard
Discharge
De-oiling
Hydro-
cyclones
Gas
Flotation

28. Produced Water Treatment Process
Conventional Example 4: Offshore PWRI
Scenario: Treatment of produced water for injection into wells (Waterflood)
Influent Water Characterization:
TSS: 10 mg/L
TPH: 100 mg/L (after primary oil/water separation)
Treated Effluent Specifications:
TSS: < 10 microns particle size diameter
TPH: < 20 mg/L
Primary
Oil/Water
Separation
De-oiling
Hydro-
cyclones
Gas
Flotation
Cartridge
Filtration
Injection
Wells
De-sanding
Hydro-
cyclones

29. Produced Water
Treatment
Best Practices

30. Produced Water Treatment - Best Practices 1
• Know your produced water
• Composition of the oil in water: Dispersed, Soluble
• Oil droplet size distribution
• Composition and origin of Suspended Solids
• Particle size distribution of Suspended Solids
• Ionic composition (salts) / Scale precipitation potential

31. Produced Water Treatment - Best Practices 2
• Know your process
• Recycled Streams / Reject Streams
• Points of shearing - pressure drops
• Production chemicals
• downhole, wellhead, flow lines, primary separation
• inhibitors: scale, corrosion, hydrate, wax, asphaltene

32. Produced Water Problems, Solutions & Morals 1
• Problem: disposal well injectivity decline; frequent work-overs needed
• Potential Solutions considered:
• Install coalescing filters to reduce oil-in-water - high Capex
• Install cartridge filters to reduce solids - high Opex
• Install self-cleaning solids filters to reduce solids - high Capex
• Prevent oxygen ingress throughout the process to prevent oxidation of dissolved
iron - gas blanket in gravity separation tanks
• Moral: Understand the composition and origin of oil and solids throughout the process

33. Produced Water Problems, Solutions & Morals 2
• Problem: High oil-in-water concentration in produced water discharged to evaporation
ponds, resulting in excessive air emissions of VOHs
• Potential Solutions considered:
• Install coalescing filters - effective on dispersed oil only
• Install GAC adsorption filters - high Opex, regen necessity
• Change type of corrosion inhibitor injected downhole in wells - not 40% IPA
• Change corrosion inhibitor injection mechanism so that appropriate dosing can be
injected (don’t over-treat)
• Morals: 1) Understand the entire process, starting at the wells; & 2) Additional
treatment process equipment at “end-of-pipe” is often not the solution

34. Produced Water Problems, Solutions & Morals 3
• Problem: High oil-in-water in overboard discharge following well flow-backs with LDHI
• Potential Solutions considered:
• Improve performance of gas flotation unit - gas injection ratio, gas bubble size
• Install second stage gas flotation unit - high Capex, footprint, weight
• Use temporary flowback treatment skid - high Opex, footprint, weight, logistics
• Install permanent flowback treatment process - high Capex, footprint, weight
• Modify flow-back procedure to isolate fluids in test separator, then slip-stream into
produced water treatment process
• Moral: Understand the impact of production chemicals on the performance of
treatment equipment

35. James Robinson, P.E.
Experience
• Upstream Water Treatment
Engineering Advisor
• Chevron (2011-2015)
• BP (2000-2009)
• Upstream Water Management
Engineering Consultant
• Oxidane Engineering (2009-2011, 2015-present)
• Cypress Engineering (1991-2000)
Professional
• Professional Engineer
• Society of Petroleum Engineers
• Produced Water Society
Education
• B.S. in Civil Engineering (1990)
Louisiana State University
• M.S. in Environmental Engineering (1992)
Rice University
Contact
• jcr.tx@icloud.com
• (281) 384-3327