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Case Study: Offshore Produced Water

How we treated offshore produced water to OSPAR oil-in-water limits for compliant overboard discharge.

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Industry Overview

Specialised Solutions for Produced Water

Produced water is the largest volume waste stream generated during oil and gas extraction, typically containing oil, suspended solids, dissolved salts, and production chemicals. Our treatment systems efficiently remove contaminants to meet stringent discharge requirements or prepare water for beneficial reuse and reinjection. Hydrocyclones, flotation, walnut-shell filtration and membrane polishing strip oil and solids to meet overboard, disposal or reinjection specifications. Reynolds & Bauhm size each train to the field’s water cut so it performs as production-water volumes rise.

Oil Separation

Multi-stage oil removal from free oil to emulsified fractions using gravity separation, DAF, and coalescing technologies achieving 95%+ removal efficiency.

Solids Removal

Effective removal of formation solids, scale, and corrosion products through screening, sedimentation, and filtration processes.

Reinjection Ready

Polishing treatment to meet injection well standards, protecting reservoir integrity and maximising oil recovery operations.

Discharge Compliance

Meet environmental discharge limits for oil content, suspended solids, and other regulated parameters in surface waters.

Applications

Produced Water Sources We Treat

Onshore Oil Fields

Treatment of produced water from conventional and unconventional oil extraction including shale oil operations with high volumes.

Offshore Platforms

Compact treatment systems for offshore oil production with space constraints and strict marine discharge standards.

Gas Production

Treatment of water co-produced with natural gas including condensate and associated water from gas wells.

Enhanced Oil Recovery

Treatment of produced water from EOR operations including polymer flooding and steam-assisted gravity drainage.

Coal Bed Methane

Specialised treatment for CBM produced water with high salinity and unique geochemical characteristics.

Reinjection Systems

Polishing treatment for water reinjection to maintain reservoir pressure and enhance oil recovery.

Treatment Process

Multi-Stage Produced Water Treatment

1

Pre-Treatment

Screens and grit removal protect downstream equipment from debris and coarse solids.

2

API Separation

Gravity separation in API separators removes free oil and settleable solids from produced water.

3

DAF Flotation

DAF systems remove emulsified oil and fine suspended solids through microbubble flotation.

4

Clarification

LAMELLA separators provide high-rate solids separation for polishing and reinjection preparation.

5

Final Polishing

Self-cleaning filters provide final suspended solids removal before discharge or reinjection.

Recommended Equipment

Products for Produced Water Treatment

DAF Flotation Systems

High-efficiency dissolved air flotation for oil and suspended solids removal from produced water streams.

Benefit: 95%+ oil removal efficiency

API Oil-Water Separators

Gravity separation systems for free oil removal with robust construction for continuous operation.

Benefit: Low operating requirements

LAMELLA Separator

High-rate clarification for suspended solids removal in compact footprint ideal for offshore platforms.

Benefit: 70% smaller footprint

Self-Cleaning Filters

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

Benefit: Continuous operation

Sludge Dewatering

Screw presses and centrifuges for dewatering oil sludge and solids for disposal.

Benefit: 60-80% disposal requirement reduction

Containerised Systems

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

Benefit: Plug-and-play installation

Key Benefits

Why Choose Reynolds & Bauhm

Meet discharge limits of <10 mg/L oil in water
Reinjection-ready water protecting reservoir integrity
ATEX-certified equipment for hazardous environments
Compact designs for offshore platform constraints
Automated operation reducing labour requirements
Handle high TDS and varying water chemistry
Recovery of saleable oil from waste stream
Global experience in oilfield water treatment

Related Applications

Explore Other Oil & Gas Solutions

Refinery Wastewater

Comprehensive treatment for petroleum refinery effluents containing oil, phenols, and high COD loads.

Explore Oilgas Refinery

Offshore & Platform

Compact treatment systems for offshore platforms with space constraints and marine discharge standards.

Explore Oilgas Offshore

Drilling & Workover

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

Explore Oilgas Drilling

ATEX Compliance

Equipment engineered for explosive atmospheres with ATEX-certified components.

Explore ATEX

Related Pages

Chemical Atex

Chemical industry wastewater treatment for atex-certified equipment.

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Global Standards Reference

Directory of international wastewater treatment regulations and equipment compliance standards Organised by country and region.

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Oil Water Separation

Oil and gas wastewater treatment for oil-water separation systems.

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Oilgas Atex

ATEX-certified wastewater treatment equipment for explosive atmospheres in oil, gas and petrochemical facilities.

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Oilgas Downstream

Refinery wastewater treatment including API separators, DAF, advanced biological treatment and polishing for strict discharge.

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Oilgas Drilling

Treat drilling muds, cuttings wash water and site runoff.

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Produced Water — Design Parameters

From influent characterisation to treatment-train sizing for offshore, onshore and unconventional produced water.

Free Oil Removal Target

Inlet free oil typically 200–2,000 mg/L. First-stage gravity (skim tank or API separator) reduces to 50–200 mg/L. Sized for 30–60 minute residence time, slot velocity < 15 mm/s.

Hydrocyclone Sizing

Liner-type deoiling cyclones operate at 600–1,200 kPa differential pressure. Oil-in-water reduces from 100–500 mg/L to 10–40 mg/L. Compact footprint for offshore installations.

Compact Flotation Unit (CFU)

Combines gas flotation with internal coalescence. Final-polish oil to <15 mg/L for overboard discharge under OSPAR. Hydraulic loading: 25–40 m³/m²·h.

Walnut-Shell Filter

Tertiary polishing filter, downflow at 25–35 m/h. Removes residual oil and TSS to <5 mg/L. Backwash uses produced water; backwash water returned to skim tank.

Salinity & TDS

Field-dependent: 5,000–200,000 mg/L. Use SS316L below 60,000; duplex 2205 to 120,000; super-duplex or GRE/glass-reinforced epoxy above. Specify chloride limits at design stage.

Reuse Path

For waterflood injection: clarify to <50 mg/L TSS, <5 mg/L oil; control SRB with biocide; degas to remove dissolved oxygen to <20 ppb.

Treatment stageInlet oil (mg/L)Outlet oil (mg/L)Hydraulic loadingFootprint indicator
Skim tank / API200–2,00050–20010–25 m³/h·m²Large
Deoiling hydrocyclone100–50010–40Linear, low ΔPCompact — ideal offshore
Compact flotation (CFU)40–1005–1525–40 m³/h·m²Compact
Walnut-shell filter10–30<525–35 m/hMedium
MF/UF membrane5–30<140–100 LMHMedium

Indicative ranges — actual sizing requires field-specific characterisation including salinity, gravity, emulsion stability, residual chemistry and discharge consent.

API Separators — Engineering Deep-Dive

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

Produced Water Engineering Guides

Scientific and compliance guides for produced water treatment, discharge and reuse

Oil-in-Water Chemistry

Free, dispersed and dissolved oil fractions, droplet-size distribution and emulsion stability that govern deoiling design.

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Deoiling Technologies

Separators, hydrocyclones, induced and dissolved gas flotation and nutshell media selected by droplet size and outlet target.

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Dissolved Hydrocarbons & BTEX

Air stripping, adsorption and biological treatment for the dissolved aromatics that set the reuse limiting case.

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Scale, Souring & Metals

Antiscalant, sulphide oxidation and precipitation control for scaling ions, H2S and trace metals.

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Discharge Standards

OSPAR 30 mg/L, US EPA ELG and regional limits, reference methods and online oil-in-water monitoring.

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Reuse & Reinjection

Waterflood, disposal-well and beneficial-reuse quality targets and the treatment to meet them.

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Need Produced Water Treatment Solutions?

Contact our experts to design a system tailored to your oilfield requirements.

Industries We Serve

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