Tore R. Andersen Hydro O&E Operations 2007-09-10 Current Status and Need for Future Research Corrosion in water injection
Tore R. AndersenHydro O&E Operations2007-09-10
Current Status and Need for Future Research
Corrosion in water injection
Date: 2007-09-10 • Page: 2
Water injection modes - I
Seawater
For EOR
Corrosion by oxygen, chlorine and bacteria
Corrosion control by deoxygenation, biocide, nitrate and cleaning pigging
Date: 2007-09-10 • Page: 3
Water injection modes - I
Seawater
For EOR
Corrosion by oxygen, chlorine and bacteria
Corrosion control by deoxygenation, biocide, nitrate and cleaning pigging
Aquifier water
EOR
Corrosion CO2 and bacteria
Corrosion control by materials selection, inhibition, biocide
Date: 2007-09-10 • Page: 4
Water Injection Modes - 2
Produced water
For EOR
Reduce discharge of produced water
UK
Norway
DenmarkNetherlands
Discharge of produced water1993-2004MSm3/year
Date: 2007-09-10 • Page: 5
Produced water characteristics
Low CO2 partial pressure
H2S from wells and SRBs in process system
Traces of oxygen
Bacteria
Deposits
CaCO3
BaSO4
Iron oxides
Elemental sulphur
Soft scales (schmoo)
Date: 2007-09-10 • Page: 6
Experiences
Crevice corrosion and SCC of AISI 304 filters
Corrosion of 13%Cr steel
0
1
2
3
4
5
Cor
rosi
on d
epth
[mm
]
20032006
Corrosion in PWRI pipeline
Replacement of carbon steel piping and wells
Date: 2007-09-10 • Page: 7
Replacement of carbon steel piping and wells
After 3.5 years produced water + some aquifier injection:
Local corrosion with depth 1-11 mm in piping
Remaining wall thickness 8 mm in manifold weld,nominal thickness 40 mm
Thick deposits of iron oxides, some iron sulphide
Elemental sulphide has been identified
MIC nodules were identified
Extensive deposition and corrosion in wells
Date: 2007-09-10 • Page: 8
Mitigation
Corrrosion inhibition
Biocide treatment
Cleaning pigging
Materials selection
Stainless steel
Lined carbon steel
Date: 2007-09-10 • Page: 9
The influence of nitrate on corrosion - I
Side stream test Laboratory test
No nitrate
Nitrate
Date: 2007-09-10 • Page: 10
The influence of nitrate on corrosion - II
Addition of nitrate to produced water with CO2 can cause a large increase in corrosion rate on carbon steel.
Nitrate should not be added to produced water containing CO2.
Different microorganisms able to utilize hydrogen were detected. This microbial hydrogen consumption can stimulate corrosion.
Date: 2007-09-10 • Page: 11
Future research
Estimation of corrosivity
Characterisation of produced water properties
Corrosion mechanisms
MIC
Tools for corrosivity assessment
Deposition mechanism
Chemical treatment
Date: 2007-09-10 • Page: 12
Thank you