membrane separation technology for water treatment in
TRANSCRIPT
James Robinson, 2017
Membrane Separation Technology for Water Treatment in Upstream Oil & Gas Operations
James Robinson, P.E.
Produced Water Society Annual Seminar
Houston, Texas
January 17 - 20, 2017
James Robinson, 2017
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 SocietyEducation • B.S. in Civil Engineering (1990)
Louisiana State University• M.S. in Environmental Engineering (1992)
Rice UniversityContact • [email protected]• (281) 384-3327
James Robinson, 2017
Outline
• Introduction / Overview
• Composition / Characterization
• Seawater,
• Produced Water
• Quantities
• Produced Water Disposition
• Water Treatment Process Design
• Onshore Scenarios
• Offshore Scenarios
James Robinson, 2017
Terms used• PW - produced water
• BPD - barrels per day
• MF - microfiltration membrane
• NF - nanofiltration membrane
• SRM - sulfate removal membrane
• RO - reverse osmosis membrane
• TSS - total suspended solids
• TDS - total dissolved solids
• TPH - total petroleum hydrocarbons (non-soluble organics)
• TOG - total oil & grease (soluble & non-soluble organics)
• EOR - enhanced oil recovery
• ASP - alkali, surfactant, polymer (Chemical-EOR)
• IX - ion exchange (softening)
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Composition / Characterization• Primary Parameters:
• Suspended Solids
• Dispersed Oil (hydrocarbon droplets not soluble in water)
• Additional Parameters (Depending on water re-use / recycling opportunity):
• Dissolved solids:
• Primary cations: Na+, K+, Ca2+, Mg2+,
• Primary anions: Cl-, SO42-, bicarbonate
• Additional Indicators: Hardness, Alkalinity
• Other parameters of interest: barium, strontium, iron, boron, silica, acetate
• Dissolved Oil (hydrocarbon compounds soluble in water)
• Dissolved Oxygen
• Residual water treatment chemicals
• Residual chlorine (from biological control)
• Residual sulfite (from oxygen scavenger)
James Robinson, 2017
Seawater Composition
James Robinson, 2017
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
James Robinson, 2017
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
MF
James Robinson, 2017
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
James Robinson, 2017
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
HardnessNF
MF
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Primary Produced Water Constituents to remove for Low Salinity Waterflood & 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
MF
RO
James Robinson, 2017
Quantities• Seawater Injection
• Many offshore developments inject ~ 1 to 2 bbls seawater per bbl fluid (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
• 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 for all oil & gas operations is ~ 21 billion bbls (882 billion gals) annually(Source: Clark and Veil, 2009)
• Of that amount, flow-back water from hydraulic fracturing of unconventional wells in the US is ~ 1.2 billion bbls (50 billion gals; 5.7% of all produced water)
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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)
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Water Treatment Process Design
• Water Balance & Water Management Plan
• Source Water (Influent) Selection & Water Quality Characterization
• Operational Conditions, Constraints & Priorities
• Treated Effluent Use, Disposal & Water Quality Specifications
• Optimize Water Management (Reduce, Reuse & Recycle)
• Technology Selection
• Integration of multi-technology process (pre-treatment processes)
James Robinson, 2017
Water Balance & Water Management Plan• Water Balance
• Determine Water Needs
• Identify Potential Water Sources and Capacities
• Determine Wastewater Streams
• Identify Wastewater Disposal Options and Capacities
• Optimize Water Management
• Identify Water Efficiency / Reduction Opportunities
• Identify Water Reuse Opportunities (with minimal or no water treatment)
• Identify Water Recycling Opportunities (with significant water treatment)
• Develop a Water Management Plan:
• Meets water needs
• Has available/sustainable water sources
• Ensures adequate wastewater disposal capacity / reliability
• Considers timing of water needs, water sources, wastewater streams
• Maximizes economic benefits of water reduction, reuse & recycling
• Minimized environmental impacts on water supplies and environments where wastewater is disposed
James Robinson, 2017
Treatment Conditions, Constraints & Priorities
• Water Quality & Quantity variability
• Onshore vs Offshore
• Manned vs Un-manned
• Manually Controlled vs Remote Controlled vs Automated
• CAPEX vs OPEX
• Reliability / Redundancy
• Project life-cycle, re-deployment
James Robinson, 2017
Primary Options for Produced Water Disposition• Reuse (minimal or no treatment)
• Waterflood
• Recycling (requires treatment)
• Steam Flood EOR
• Low Salinity Waterflood EOR
• Chemical-EOR Flood
• Beneficial Reuse:
• Agriculture
• Irrigation
• Livestock
• Stream flow restoration
• Groundwater Aquifer restoration
• Disposal (minimal or no treatment)
• Deep well injection
• Surface discharge (offshore discharge)
• Evaporation
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Technology Selection
• 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
• A multi-technology process is often required (pre-treatment, etc.)
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Examples of Onshore Scenarios (Generic/Hypothetical)
• Onshore Produced Water Treatment Process (Ceramic MF & RO)
• Onshore Chemical-EOR Waterflood Process (MF & NF)
• Onshore Gas Gathering and Processing Plant Wastewater Recycling Process (MF & RO)
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Onshore Produced Water Treatment Process (Ceramic MF & RO)
Scenario: Beneficial reuse of produced water used as alternative to water disposal in wells due to limited water disposal capacity and reliability; Ceramic MF used as a pre-treatment for IX and RO
Influent: Produced Water (formation water plus re-produced steam)
Influent Water Characterization:Flowrate: 50,000 BPDTDS: 6,000 mg/LTSS: 10 mg/LTPH: 100 mg/L (after primary oil/water separation)
Treated Effluent Use: Discharge to Surface Wetlands
Treated Effluent Specification:TDS: < 500 mg/LTPH: < 1 mg/L(additional treated effluent specification include organic compounds and metals)
Process:Primary
Oil/Water Separation
PW Gravity Separation IX WetlandsRO
Surface Discharge to River
Gas Flotation
Walnut Shell Filter
Ceramic MF
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Onshore Produced Water Treatment Process
Source: Veolia
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Onshore Chemical-EOR Waterflood Process (Ceramic MF & NF)
Scenario: Ceramic MF used as pretreatment for IX and NF; NF used for PW softening for mixing with ASP for injection into wells for enhanced oil production
Influents:Produced Water (formation water)
Influent Water Characterization:Flowrate: 50,000 BPDTDS: 2,500 mg/LTSS: 10 mg/LTPH: 100 mg/L (after primary oil/water separation)
Treated Effluent Use: Produced Water Recycling for Mixing with ASP for polymer flood
Treated Effluent Specifications:For mixing with ASP and then injection into wells:
Hardness: < 30 mg/LTPH: < 1 mg/L (feed into NF)TSS: < 1 mg/L
Process:Primary
Oil/Water Separation
PW Gravity Separation IX ASP
MixingNF Injection Wells
Gas Flotation
Walnut Shell Filter
Ceramic MF
James Robinson, 2017
Chemical-EOR: Enhanced oil recovery by ASP (alkali, surfactant & polymer) flooding
natural gas
oil
water
NF
James Robinson, 2017
Onshore Gas Gathering and Processing Plant Wastewater Recycling Process (MF & RO)Scenario: Wastewater recycling is an alternative to disposal in wells due to limited well disposal capacity and reliability
Influents:Produced Water (formation water); (oily, saline & TSS)Utility / Process Area Water (UPA: wash water) (oily, non-saline, TSS) IX Brine (non-oily, saline, no-TSS)Cooling Tower Blowdown (CBD: non-oily, saline, no-TSS)Steam Boiler Blowdown (BBD: non-oily, saline, no-TSS)
PW Water Characterization:Flowrate: 1,900 m3/d (12,000 BPD)TDS: 5,000 mg/LTSS: 10 mg/LTPH: 100 mg/L (after primary oil/water separation)
Treated Effluent Use: Produced Water Recycling for feed to Steam Boilers
Treated Effluent Specifications:For reuse in Steam Boilers:
Hardness: < 0.5 mg/L (feed into steam boilers)TPH: < 1 mg/L (feed into NF)TSS: < 1 mg/L
Technology Selection: • PW treatment with gas flotation & nutshell filtration prior to wastewater recycling process• Concentrated brine streams (CBD, BBD, IX Brine) go to disposal wells (not sent to PW recycling process• PW & UPA streams are combined and treated with MF & NF in wastewater recycling process
James Robinson, 2017
Onshore Gas Gathering and Processing Plant Without Wastewater Recycling Process
River Water Intake
River Water Treatment
Water Distribution
Network
Sour Water
Stripper
BoilerWater
Treatment
Cooling Water Towers
Steam Injection: 2000 m3/d
Boiler Blowdown: 100 m3/d
Evaporation: 1000 m3/d
Cooling Tower Blowdown: 50 m3/d
Sour Water: 100 m3/d
Utility / Process Area Wash-down
Water Utility/Wash-down Water;100 m3/d
Steam Boilers
IX Brine: 100 m3/d
Produced Water:
2000 m3/d
Produced Water
Treatment
Wastewater Disposal
Wells
2100 m3/d
2200 m3/d
1050 m3/d
100 m3/d
100 m3/d
3450 m3/d
2450 m3/d
Produced Water; 2000 m3/d
James Robinson, 2017
Onshore Gas Gathering and Processing Plant With Wastewater Recycling Process
River Water Intake
River Water Treatment
Water Distribution
Network
Sour Water
Stripper
BoilerWater
Treatment
Cooling Water Towers
Steam Injection: 2000 m3/d
Boiler Blowdown: 100 m3/d
Evaporation: 1000 m3/d
Cooling Tower Blowdown: 50 m3/d
Sour Water: 100 m3/d
Utility / Process Area Wash-down
Water
Utility/Wash-down Water;100 m3/d
Steam Boilers
IX Brine: 20 m3/d (was 100 m3/d)
Produced Water:
2000 m3/d
Produced Water
Treatment
Wastewater Disposal
Wells
MF & NFWastewater Recycling Process
Retentate(Waste Stream):
210 m3/d
Permeate(Recycled Water):
1890 m3/d
210 m3/d
230 m3/d
1050 m3/d
100 m3/d
100 m3/d
1480 m3/d
480 m3/d
(was 3450 m3/d)
(was 2450 m3/d)
James Robinson, 2017
Examples of Offshore Scenarios (Generic/Hypothetical)
• Offshore Waterflood Process (MF)
• Offshore Sulfate Removal Membrane (SRM) Process (NF)
• Offshore Low Salinity Waterflood Process (NF & RO)
• Offshore Chemical-EOR Waterflood Process (NF)
James Robinson, 2017
Offshore Waterflood Process (MF)
Scenario: MF used as an alternative to multi-media filters for suspended solids removal; Seawater injection is to maintain reservoir pressure and improve oil production
Influent: Seawater
Influent Water Characterization:Flowrate: 100,000 BPDTSS: 2 mg/L
Treated Effluent Use: Injection into wells for reservoir pressure maintenance
Treated Effluent Specification:TSS: < 0.1 mg/L; max solids particle size < 10 microns
Process: Seawater Lift Pumps
Coarse Strainers MF Deaeration
TowersInjection
Wells
James Robinson, 2017
Offshore Sulfate Removal Membrane (SRM) Process (NF)
Scenario: sulfate removal membranes (SRM) used as mitigation to prevent barium sulfate scale precipitation and/or reservoir souring; Seawater injection is to maintain reservoir pressure and improve oil production
Influent: Seawater
Influent Water Characterization:Flowrate: 100,000 BPDTSS: 2 mg/LSO4: 2,700 mg/L
Treated Effluent Use: Injection into wells for reservoir pressure maintenance
Treated Effluent Specification:TSS: < 0.1 mg/L; max solids particle size < 10 micronsSO4: < 40 mg/L
Process: Seawater Lift Pumps
Coarse Strainers MF Deaeration
TowersInjection
WellsSRM(NF)
James Robinson, 2017
Sulfate Removal Membranes (SRM)
• Used to mitigate scale formation:
• Where oilfield reservoir formation water contains significant amounts of barium and/or strontium, injection of seawater can cause barium and strontium sulfate scale to be formed.
• These scales can become deposited in production pipe internals and may also have the effect of reducing reservoir permeability.
• Barium and strontium sulfate scales are difficult to remove since they are not easily dissolved.
• Uses nano-filtration membranes to remove sulfates from seawater
• Reduces seawater sulfate ion concentration from around 2,700 ppm to less than 40 ppm.
• May help mitigate formation souring by limiting the action of sulfate reducing bacteria (SRB)
James Robinson, 2017
Sulfate Removal Membranes (SRM) SRM Package 1 SRM Package 2
SeawaterFeed
(mg/L)
SRM Permeate
(mg/L)
% Reduction
SeawaterFeed
(mg/L)
SRM Permeate
(mg/L)
% Reduction
Sodium Na+ 11,200 10,690 5% 10,897 10,042 8%Potassium K+ 370 320 14% 460 419 9%
Calcium Ca2+ 400 330 18% 428 72 83%Magnesium Mg2+ 1,400 330 76% 1,368 68 95%
Chloride Cl- 19,750 19,000 4% 19,700 16,119 18%Bicarbonate HCO3- 140 20 86% 124 80 35%
Sulfate SO42- 2,650 40 98% 2,960 30 99%
Dissolved Solids TDS 35,910 30,730 14% 35,937 26,830 25%
Hardness (as CaCO3) 6,768 2,185 68% 6,706 460 93%
James Robinson, 2017
Sulfate Removal Membrane (SRM) Packages
90,000 BPD 250,000 BPD
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Offshore Low-Salinity Waterflood Process (NF & RO)
Scenario: A combination of NF and RO used to partially desalinate and remove sulfate from seawater; Low-salinity seawater injection is to maintain reservoir pressure and enhance oil production
Influent: Seawater
Influent Water Characterization:Flowrate: 100,000 BPDTDS: 35,000 mg/LTSS: 2 mg/LSO4: 2,700 mg/L
Treated Effluent Use: Injection into wells for reservoir pressure maintenance
Treated Effluent Specification:TSS: < 0.1 mg/L; max solids particle size < 10 micronsTDS: < 4,000 mg/L SO4: < 40 mg/L
Process:Seawater
Lift PumpsCoarse
Strainers MF Deaeration Towers
Injection Wells
NF
RO
James Robinson, 2017
Offshore Chemical-EOR Waterflood Process (NF)
Scenario: NF used to soften seawater; Softened seawater is mixed with ASP for injection to maintain reservoir pressure and enhance oil production
Influent: Seawater
Influent Water Characterization:Flowrate: 100,000 BPDTDS: 35,000 mg/LTSS: 2 mg/LSO4: 2,700 mg/L
Treated Effluent Use: Mixing with ASP for polymer flood injection into wells for enhanced oil production
Treated Effluent Specification:TSS: < 0.1 mg/L; max solids particle size < 10 micronsSO4: < 40 mg/LHardness: < 300 mg/L
Process: Seawater Lift Pumps
Coarse Strainers MF Deaeration
TowersASP
MixingNF Injection Wells
James Robinson, 2017
Emerging Membrane Technologies
• Organo-phobic / Oleo-phobic MF (PW)
• Current MF is susceptible to fouling by suspended oil droplets in PW coating the membrane surface. Surface repulsion of oil droplets would enable less-frequent membrane cleaning cycles and less intensive pre-treatment for dispersed oil removal
• Subsea Seawater MF, NF & RO (on the Seafloor)
• Placement of seawater treatment processes at the location of subsea injection wells would enable farther off-sets from host facilities thereby allowing greater areal sweep of the reservoir, while also reducing weight and footprint on the host production facility
• Membrane Distillation (PW & Seawater)
• Membrane Distillation (MD) is a thermally-driven separation process, in which only vapor molecules transfer through a microporous hydrophobic membrane. The driving force in the MD process is the vapor pressure difference induced by the temperature difference across the hydrophobic membrane.
James Robinson, 2017
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 SocietyEducation • B.S. in Civil Engineering (1990)
Louisiana State University• M.S. in Environmental Engineering (1992)
Rice UniversityContact • [email protected]• (281) 384-3327