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Industry Overview

Water Management for Oil & Gas Operations

Oil and gas operations generate challenging wastewater streams including produced water, refinery effluents, and platform discharge containing hydrocarbons, suspended solids, and dissolved contaminants. Our treatment solutions are engineered for hazardous environments with ATEX-certified equipment and robust construction. Hydrocarbon removal, dissolved-contaminant treatment and solids handling are combined into trains rated for hazardous, often remote, environments. Reynolds & Bauhm engineer each system to the specific stream — produced water, refinery effluent or platform discharge — for reliable consent compliance and reuse.

Produced Water Treatment

Treatment of formation water from oil and gas wells to meet discharge or reinjection standards. Remove oil, suspended solids, and dissolved organics efficiently.

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Refinery Wastewater

Comprehensive treatment for petroleum refinery effluents containing oil, phenols, sulphides, and high COD loads with multi-stage processes.

Oil Separation · Biological Treatment · Sour Water · Sludge · Reuse

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Offshore & Platform

Compact, robust treatment systems for offshore platforms with space constraints and harsh marine environments. ATEX-certified options available.

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ATEX Compliance

Equipment engineered for explosive atmospheres with ATEX-certified components, ensuring safe operation in hazardous zones.

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Applications

Oil & Gas Sectors We Serve

Upstream Operations

Produced water treatment from oil and gas extraction including onshore fields, offshore platforms, and enhanced oil recovery operations.

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Midstream Processing

Wastewater treatment for pipelines, terminals, and storage facilities handling crude oil and refined products.

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Downstream Refining

Comprehensive treatment for petroleum refineries processing complex effluents with oil, chemicals, and high organic loads.

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Petrochemical Plants

Specialised treatment for petrochemical manufacturing wastewater with specific contaminant profiles.

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Gas Processing

Water treatment for natural gas processing facilities including dehydration and acid gas removal operations.

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Drilling & Workover

Treatment of drilling muds, completion fluids, and workover waste with high solids and chemical content.

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Typical Oil & Gas Wastewater Profile

Stream chemistry by source — the starting point for treatment-train design

StreamTDS / SalinityOil & Grease (mg/L)BOD / COD (mg/L)Key ContaminantsNotes
Produced water (conventional)5,000 – 300,00050 – 2,000BOD 100 – 2,000; COD 500 – 5,000BTEX, naphthenic acids, dissolved Fe/Mn, NORM (Ra-226/228), residual production chemicalsCl often >50,000 mg/L; pH 6–8
Produced water (shale / fracking)30,000 – 250,00030 – 1,000COD 200 – 1,500Frac fluid additives, boron, biocides, scale formers (Ba, Sr)High BaSO4 scaling risk
Refinery sour water500 – 5,0005 – 200COD 500 – 3,000NH3 50–1,000; H2S 100–3,000; phenols 20–500; cyanide 0–50Two-stage stripping (H2S/NH3) before bio
Refinery process effluent500 – 3,00050 – 1,500BOD 100 – 800; COD 300 – 2,500Phenols, mercaptans, MTBE, residual amines, sulphatesAPI separator + DAF + bio standard train
Tank-bottom water / desalter10,000 – 100,000500 – 10,000COD 1,000 – 8,000Emulsified oil, asphaltenes, fine solidsHeat + demulsifier + electrostatic coalescence
Cooling tower blowdown2,000 – 10,000< 5BOD < 30Cycles-of-concentration scale, biocides, corrosion inhibitorsDriven by cycles N = 3–7
Drilling-fluid / mud waste5,000 – 50,00020 – 500 (OBM higher)COD 500 – 5,000Bentonite, barite, polymers (PHPA, xanthan), lignosulfonatesSolids 5–30% w/w; ZLD often required
Offshore platform drainageseawater + traces10 – 100COD < 200Oil sheen, drilling chemicals, seawaterOSPAR <30 mg/L oil dispersed for North Sea discharge

Discharge limits: OSPAR (North Sea) 30 mg/L oil monthly avg; US EPA NPDES 29 mg/L daily max; reinjection-only for high-salinity onshore unconventional wells. Always confirm permit conditions before sizing.

Treatment Process

Multi-Stage Approach

1

Pre-Treatment

Screening and grit removal to protect downstream equipment and remove debris from process streams.

2

Oil Separation

DAF systems for efficient oil and grease removal through microbubble flotation technology.

3

Solids Removal

LAMELLA separators for high-rate clarification of suspended solids and precipitated contaminants.

4

Biological Treatment

MBBR or SBR systems for removal of dissolved organics and reduction of COD/BOD.

5

Final Polishing

Self-cleaning filters for final suspended solids removal before discharge or reuse.

Recommended Equipment

Products for Oil & Gas Applications

DAF Flotation Systems

High-efficiency dissolved air flotation for oil and grease removal from produced water and refinery effluents. ATEX-certified options available.

Benefit: 95%+ oil removal efficiency

Oil-Water Separation Systems

API separators, CPI, DAF flotation, and coalescing systems for oil removal from produced water and refinery effluents. Achieve discharge compliance down to 5 ppm.

Benefit: 95%+ oil removal, compliance guaranteed

LAMELLA Separator

High-rate clarification for suspended solids removal. Compact design ideal for space-constrained offshore platforms.

Benefit: 70% smaller footprint

Biological Reactors

MBBR and SBR systems for removing dissolved organics and reducing COD from refinery and petrochemical wastewater.

Benefit: Up to 95% COD removal

Self-Cleaning Filters

Automatic backwash filtration for final polishing and protection of downstream equipment or injection wells.

Benefit: Continuous operation, no operator needed

Containerised Systems

Mobile treatment plants for remote locations, temporary operations, and rapid deployment to production sites.

Benefit: Plug-and-play installation

Formation Water Storage Tanks

ASME-certified storage tanks for produced water, formation water, and chemical storage with corrosion-resistant coatings.

Benefit: H2S and CO2 resistant

Process Tanks

Pressure vessels and process tanks for chemical conditioning and treatment, mixing, and reaction applications in oil & gas operations.

Benefit: ASME VIII certified

Petroleum-Standard Treatment Skids for Oil & Gas

Pre-assembled, factory-tested treatment skids engineered, fabricated and certified to international oil & gas standards for rapid, compliant deployment — onshore, offshore and at remote well sites.

Engineered, Fabricated & Certified To

API Standards

API 421 oil-water separator design, API 650 welded storage tanks, API 610 / 682 pumps & mechanical seals, and API 614 lube/seal systems.

ASME Codes

ASME VIII Div 1 U-stamped pressure vessels and ASME B31.3 process piping — full weld procedures, NDT and hydrotest records.

Shell DEP & NORSOK

Built to client Shell DEP (Design & Engineering Practice) and NORSOK M-501 / M-630 coating & material requirements for offshore service.

Sour Service & Materials

NACE MR0175 / ISO 15156 for H2S sour service — duplex, super-duplex and CRA selection with defined corrosion allowance.

Hazardous Area

ATEX & IECEx Zone 1 / Zone 2 certified motors, instruments and panels; Ex d / Ex e enclosures and intrinsically-safe loops.

Quality & Testing

ISO 9001 / 14001 management systems, full FAT/SAT, material traceability (MTRs) and document-dossier handover.

Example Skid-Mounted Equipment

API Separator / CPI Skid

Gravity and corrugated-plate interceptor skids for bulk free-oil and solids removal ahead of polishing.

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Induced Gas Flotation (IGF) Skid

Compact IGF for dispersed-oil removal to <20 ppm on produced water, with inline chemical conditioning.

Dissolved Air Flotation (DAF) Skid

DAF skids for oil, grease and TSS in refinery and produced-water streams — ATEX-rated for hazardous areas.

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Deoiling Hydrocyclone Skid

High-G liquid-liquid hydrocyclones for compact, no-moving-part deoiling of high-flow produced water.

Walnut-Shell Filter Skid

Nutshell media filters for final oil-in-water polishing to tight discharge or re-injection limits.

Chemical Dosing Skid

ATEX dosing skids for demulsifier, coagulant, and scale / corrosion inhibitor with duty-standby metering pumps.

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Explore Skid-Mounted Systems Request Bespoke Design

Benefits & Efficiency Gains

Operational, Environmental & Economic Advantages

Operational Benefits

  • ATEX-certified for hazardous zones
  • Robust construction for harsh environments
  • Automated operation reduces labour
  • Remote monitoring via SCADA
  • Compact design for offshore platforms

Environmental Benefits

  • Meet stringent discharge standards
  • Enable water reuse and recycling
  • Reduce environmental liability
  • Minimise freshwater consumption
  • Support sustainability goals

Efficiency Gains

  • Avoid regulatory fines and penalties
  • Reduce disposal requirements by 60-80%
  • Lower freshwater purchase costs
  • Minimise operational downtime
  • Extended equipment service life

Related Applications

Explore Other Industries We Serve

Chemical Processing

Wastewater treatment for chemical manufacturing facilities.

Chemical Processing Solutions

Industrial Pre-treatment

Pre-treatment solutions for industrial facilities.

View Pre-Treatment Solutions

Mining & Minerals

Water treatment for mining and minerals processing.

Mining & Minerals Solutions

Power Generation

Water treatment for power plants and utilities.

Power Generation Solutions

API Separators — Engineering Deep-Dive

Stokes’-law sizing, API Publication 421 design methodology, rectangular API / CPI / TPI configurations and refinery-train integration.

Site Off the Map?

Packaged, containerised, skid-mounted and research-station families engineered for sites with no road, no grid, no operator and no local supply chain.

Discuss Your Oil & Gas Water Treatment Needs

Contact our experts for ATEX-compliant solutions for your operation.

Applicable API Standards

Oil & gas water-treatment packages are engineered to the relevant API standards for tanks, separators, pumps and overpressure protection.

See these API standards in detail →

Industries We Serve

Our expertise spans multiple industries with sector-specific water treatment solutions.

Related Pages

Explore closely-related topics, equipment and guides