ONGC

Training Programme

on “Recent trends in Environmental

Management strategies in Petroleum,

Petrochemical and Fertilizer Industry” IITR

Sponsored By Central Pollution Control Board

February 11-13, 2008Venue: Continuing Education Center

Conference HallDr. I. D.MallDr. I. D.Mall

Professor Professor Course coordinatorCourse coordinator

Deptt.Of Chemical EnggDeptt.Of Chemical EnggIIT RoorkeeIIT Roorkee

ONGC

Recent trends in environmental management strategies in oil & gas

exploration & production

Dr A K Agnihotri

DGM (Chemistry)

ONGC

Water: Issues

• Nearly half of the world's people will live in water-stressed areas by 2025 (WRI)

• Our population of 1 billion is going to double in next twenty years

• Water resources have been exploited to the extent possible

• No consideration to future generation

• Result: Grave threat to Sustainability

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Oil & Gas Industry

• Less water intensive process

• Aging of reservoir

• Produced Water

• Produced water Treatment

• Water Injection into reservoir/disposal

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ONGC: Treatment Facility

Onshore

21 ETPs treat about 43,000 m3/d of effluent

Offshore

15 PWCs handle about 1,00,000 m3/d of

produced water

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Discharge Standards for oil & Gas Industry

Sl No Parameter On-shore discharge Marine Discharge Offshore Discharge

1 pH 5.5 -9.0 5.5 -9.0 -

2 Oil & grease 10 10 40

3 Suspended solids 100 100 -

4 Total Dissolved Solids 2100 - -

5 BOD at 27°Cfor 3 days 30 30 -

6 COD 100 - -

7 Chlorides 600 - -

8 Sulphates 1000 - -

9 Phenolics 1.2 - -

10 Cyanides 0.2 0.005 * -

11 Sulphides 2.0 - -

12 Zinc 2 0.1 * -

13 Chromium (hexavalent) 0.1 - -

14 Chromium (Total) 1.0 0.1 * -

15 Copper 0.2 0.05 * -

16 Lead 0.1 0.05 * -

17 Mercury 0.01 0.01 * -

18 Nickel 3.0 0.1 * -

mg/L

* The maximum individual pollutant concentration level in sea water within a distance of 50 meter from the discharge point.

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Onshore ETPs

Treatment Technologies

• TPI/CPI• DAF• Elevated Settlers• Biotowers• Aeration Tank• Sand/Activated Carbon Filters

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Typical Onshore Treatment Process

Wash TankEqualization tank

TPI

DAF

Flash Mix

Bio-tower

Aeration tank

Sand/Carbon Pressure

FiltersClarifier

Clarifier

Chemicals

Disposal

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Offshore Effluent Treatment

Treatment Technologies

• CPI• IGF• Hydro cyclones• Compact Flotation Unit

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Typical offshore Treatment Process

HP Separator Flash Vessel CPI

IGF

Sump Caisson

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Hydrocyclone

• Use centrifugal force

• High rate of flow

• No moving parts

• Removes oil drops of size 10-15 micron

• Reduces oil upto 25 ppm

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EPCON Compact Flotation Unit

• Oil drops are made to agglomerate to produce larger drops, creating a oil layer at the top

• Separation is aided by gas flotation effect caused by the release of residual gas

• Efficiency may be enhanced by introduction of external gas or flocculating chemicals

• Residence time - 1 min max

• Size - 2 m3 approx

• Reduces oil to 15 – 20 mg/l

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Microbial Technology

• Bioremediation

• Microbial treatment of effluents

• Microbial Treatment for EOR

API Separator

BPC reactor

BPC secondary

reactor

Settling chamber

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BPC Bioreactor

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Challenges Ahead

• Reservoir health management

• Prominence for Reuse and Recycle

• Promotion of Research & development

• Promotion of new treatment technologies

• Management Commitment

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ONGC

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ONGC

ONGC

Mangrove Conservation

• In line with international practice of Biodiversity conservation ONGC has embarked upon an ambitious programme of mangrove conservation & education.

• 5 Lac mangrove seedlings/plantation in Gandhar area.

• Education & awareness drive about mangrove conservation in Mumbai.

• This project is a joint project with Bombay Natural History Society (BNHS) Mumbai

• Cost of the project is 2 crore.

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ONGC

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Bioremediation

• Bioremediation of oily sludge from tank cleaning

• Bioremediation of drill cuttings/Oily wastes

• 16000 Tonnes of Sludge is already bioremediated & job is still going on.