8/13/2019 SRB2 http://slidepdf.com/reader/full/srb2 1/20 Microbial Induced Corrosion Microbial Induced Corrosion A rapidly growing problem in pipe lines, under A rapidly growing problem in pipe lines, under water structures, bridges etc. water structures, bridges etc. MIC attacks both Steel and cement MIC attacks both Steel and cement Caused by rapidly generating bacteria which feeds Caused by rapidly generating bacteria which feeds on organic matter on organic matter Gives rise to toxic Hydrogen Gives rise to toxic Hydrogen Sulphide Sulphide Goes undetected till its too late Goes undetected till its too late
CoCo--exist with Iron Reducingexist with Iron Reducing
Bacteria, causing sever damage,Bacteria, causing sever damage,unnoticed.unnoticed.
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SRB IndicationsSRB Indications a reddish or yellowish nodule on metal surfacesa reddish or yellowish nodule on metal surfaces
when broken exhibits black corrosion bywhen broken exhibits black corrosion by--products.products. When the complete nodule is removed, a brightWhen the complete nodule is removed, a bright
silver pit is found.silver pit is found.
Severe localized pitting is evident.Severe localized pitting is evident.
If hydrochloric acid is added to the black deposit,If hydrochloric acid is added to the black deposit,hydrogenhydrogen sulphidesulphide will be released giving off awill be released giving off a
“ “rottenrotten” ” egg smellegg smell
pH values of water will reduce to almost 5.0pH values of water will reduce to almost 5.0 Very high CFU count of bacteria detected in water Very high CFU count of bacteria detected in water
Foul smelling water along with dark colorationFoul smelling water along with dark colorationand turbidityand turbidity
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Ideal ConditionsIdeal Conditions SRBsSRBs favor an anaerobic (oxygen free) environment.favor an anaerobic (oxygen free) environment.
SRB can thrive under deposits where no oxygen is presentSRB can thrive under deposits where no oxygen is presenteven though aerobic conditions exist in the main body ofeven though aerobic conditions exist in the main body ofwater.water.
Excessive amounts of dirt, algae, oils and other bacteriaExcessive amounts of dirt, algae, oils and other bacteria
will provide ideal conditions for growth.will provide ideal conditions for growth. SRB will coSRB will co--exit with Iron Reducing Bacteria creatingexit with Iron Reducing Bacteria creating
massive problems.massive problems.
Even small amounts of oils and grease will provideEven small amounts of oils and grease will provide
nutrients for growth.nutrients for growth. Stagnant water and low flow conditions will increase theStagnant water and low flow conditions will increase the
chance of SRB growth.chance of SRB growth.
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SRB Growth MechanismSRB Growth Mechanism SRBSRB’ ’ ss obtain their energy from the anaerobic reduction ofobtain their energy from the anaerobic reduction of
SulphatesSulphates, using oxygen to generate enzymes, using oxygen to generate enzymes SulphatesSulphates are available in most waters due to outsideare available in most waters due to outside
contamination during water injection for examplecontamination during water injection for example
This bacteria develops an enzyme, (This bacteria develops an enzyme, (hydrogenasehydrogenase) that) that
enables it to use elemental hydrogen generated at theenables it to use elemental hydrogen generated at thecathodiccathodic site to reducesite to reduce SulphateSulphate to hydrogento hydrogen sulphidesulphide..
It therefore acts as aIt therefore acts as a cathodiccathodic depolarizing agent.depolarizing agent.
The corrosion of iron by this process is very rapid andThe corrosion of iron by this process is very rapid and
unlike ordinary rusting, is not self unlike ordinary rusting, is not self --limiting.limiting.
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Conventional wisdomConventional wisdom Control of this type of bacteria is accomplished withControl of this type of bacteria is accomplished with
biocide treatment.biocide treatment.
Bacterial control is accomplished by using bromine,Bacterial control is accomplished by using bromine,chlorine, DBNPA, MBT,chlorine, DBNPA, MBT, CarbamatesCarbamates oror isothiazaloneisothiazalone,,GluteraldahydesGluteraldahydes
These biocides will all control SRB in bulk water, but not inThese biocides will all control SRB in bulk water, but not in
oily environmentsoily environments When the bacteria becomes encapsulated, i.e. when formsWhen the bacteria becomes encapsulated, i.e. when forms
a hard protective shell around itself, control then becomesa hard protective shell around itself, control then becomesa problem.a problem.
Many of the above listed biocides will not penetrate theMany of the above listed biocides will not penetrate theprotective capsules.protective capsules.
Some are even deactivated by theSome are even deactivated by the sulphidesulphide released byreleased bythe bacteria.the bacteria.
RESULT : Resistance to Biocides.RESULT : Resistance to Biocides.
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Associated Problems Associated Problems
SulphateSulphate Reducing Bacteria gives rise to hydrogenReducing Bacteria gives rise to hydrogen
SulphideSulphide, a toxic gas., a toxic gas. SRB gives rise to corrosion which is generallySRB gives rise to corrosion which is generally
undetected due to the pipelines being submergedundetected due to the pipelines being submerged
or due to corrosion internally and also due to aor due to corrosion internally and also due to afalse protective like layer formed by the bacteria.false protective like layer formed by the bacteria.
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Chemical ReactionsChemical Reactions The resultant accelerated corrosion mechanism of iron byThe resultant accelerated corrosion mechanism of iron by
Reservoir SouringReservoir Souring Reservoir souring is the increase in hydrogenReservoir souring is the increase in hydrogen sulphidesulphide concentration inconcentration in
reservoirs that were initially sweet.reservoirs that were initially sweet.
The reason for souring are theThe reason for souring are the sulphatesulphate--reducing bacteria (SRB) that live inreducing bacteria (SRB) that live in
reservoirs and feed on the fatty acids, present in the formationreservoirs and feed on the fatty acids, present in the formation water.water.
As oxygen source they use the As oxygen source they use the sulphatesulphate from injected seawater.from injected seawater.
Another sort of souring is caused by the injection of contaminat Another sort of souring is caused by the injection of contaminated water. Ined water. Inthis case the souring is seen at the injection well.this case the souring is seen at the injection well.
Sometimes the bacteria are so prosperous that they can plug theSometimes the bacteria are so prosperous that they can plug the injectioninjectionwell.well.
The mass forming around the injection well is a rubbery black maThe mass forming around the injection well is a rubbery black massssconsisting of bacteria remains and blackconsisting of bacteria remains and black ironsulphideironsulphide ((pyrhhotitepyrhhotite).).
When uncontaminated seawater is used, the souring occurs at theWhen uncontaminated seawater is used, the souring occurs at the boundaryboundaryof injection water and formation water where both fatty acids anof injection water and formation water where both fatty acids andd sulphatesulphateare present.are present.
The hydrogenThe hydrogen sulphidesulphide moves in the reservoir water and the oil towards themoves in the reservoir water and the oil towards theproduction well but a large part is consumed by iron minerals suproduction well but a large part is consumed by iron minerals such as pyrite,ch as pyrite,hematite, siderite and magnetite.hematite, siderite and magnetite.
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Conditions for SRB survivalConditions for SRB survival
Presence of SRBPresence of SRB
Absence of Oxygen Absence of Oxygen
Presence of Nutrients such as fatty acids, oilPresence of Nutrients such as fatty acids, oil
Low velocity flowLow velocity flow
Adherence mechanism Adherence mechanism
Free energy source such as Iron whichFree energy source such as Iron which
contributes to free ionscontributes to free ions
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Mitigation MethodsMitigation Methods
Two part processTwo part process
Shock removal of BacteriaShock removal of Bacteria
Sustenance Program to prevent Bacterial growth.Sustenance Program to prevent Bacterial growth.
Sustained treatment to remove bacteriaSustained treatment to remove bacteria
Making conditions hostile for bacteria to resideMaking conditions hostile for bacteria to reside
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H2S and SRB MitigationH2S and SRB Mitigation Shock Treatment by rapid oxidationShock Treatment by rapid oxidation
Rapid oxidation, dissolves protective shell of the bacteriaRapid oxidation, dissolves protective shell of the bacteriaand renders them inactive.and renders them inactive.
High mortality rate in oxygen rich conditions.High mortality rate in oxygen rich conditions.
Rapid oxidation convertsRapid oxidation converts sulphidessulphides toto sulphatessulphates.. H2S mitigation is immediateH2S mitigation is immediate
SRB Mortality rate of above 99% achieved on contactSRB Mortality rate of above 99% achieved on contact
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Oxidation MethodsOxidation Methods
RAPID OXIDATION AGENTSRAPID OXIDATION AGENTS
Hydrogen Peroxide (unstable gas, not suitable for PL)Hydrogen Peroxide (unstable gas, not suitable for PL)
Ozone (unstable Gas, not suitable for Pipe Lines)Ozone (unstable Gas, not suitable for Pipe Lines)
Chlorine Dioxide (stable gas, difficult to transport, can beChlorine Dioxide (stable gas, difficult to transport, can beexplosive)explosive)
MicroMicro22 (Stable Liquid oxidizer, safe to transport)(Stable Liquid oxidizer, safe to transport)
OTHER OXIDATION AGENTSOTHER OXIDATION AGENTS
PentoxidesPentoxides
PhosphatesPhosphates
NitratesNitrates
Very Slow acting chemicals not suitable for Pipe Line Very Slow acting chemicals not suitable for Pipe Lineapplicationsapplications
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MICROMICRO22
Micro2 is a liquid oxidizerMicro2 is a liquid oxidizer
Instantaneous reactions, completely mitigates H2s on contact.Instantaneous reactions, completely mitigates H2s on contact.
ConvertsConverts SulphidesSulphides toto SulphatesSulphates Can be easily introduced into flowing pipelinesCan be easily introduced into flowing pipelines
Safe and easy to transport liquid form Micro2Safe and easy to transport liquid form Micro2
Bacteria does not generate resistance to Micro2, thus long actinBacteria does not generate resistance to Micro2, thus long actingg
No side effectsNo side effects NonNon--toxic to human beings, safe to handle, Nontoxic to human beings, safe to handle, Non--HazardousHazardous
Does not form harmful reaction ByDoes not form harmful reaction By--productsproducts
Above 99% kill rate of bacteria Above 99% kill rate of bacteria
Broad spectrum BiocideBroad spectrum Biocide Oxidizes harmful products such asOxidizes harmful products such as MercaptansMercaptans, Phenols,, Phenols, THMsTHMs, all, all
water borne bacteriawater borne bacteria
Effective over a wide pH rangeEffective over a wide pH range
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Sustenance TreatmentSustenance Treatment
Make the environment hostile for Bacterial buildMake the environment hostile for Bacterial build
upup Provide a fine protective coat on the pipe lineProvide a fine protective coat on the pipe line
surfacessurfaces
Continuous conversion of low rateContinuous conversion of low rate sulphidessulphides totosulphatessulphates
Mitigate small dosages of H2S as generatedMitigate small dosages of H2S as generated
Maintain a kill rate of microbesMaintain a kill rate of microbes
Answer : Answer : DesulphDesulph
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How does it work?How does it work? New generation surfactants penetrate molecularNew generation surfactants penetrate molecular
The BioThe Bio--dispersant present indispersant present in DesulphDesulph penetrates thepenetrates thehard protective shell of bacteria and thus making bacteriahard protective shell of bacteria and thus making bacteriavulnerable for destructionvulnerable for destruction
Active ingredient enters the interphases Active ingredient enters the interphases
Sulphur radicals replaced by Surfactant moleculesSulphur radicals replaced by Surfactant molecules SulphidesSulphides convert to Sulphates due to oxidation reactionconvert to Sulphates due to oxidation reaction
Sulphates dissolve in water and hence pumped out alongSulphates dissolve in water and hence pumped out alongwith water.with water.
Complies with ISO14000 requirementsComplies with ISO14000 requirements NonNon--Hazardous, safe to handle, easy to transport,Hazardous, safe to handle, easy to transport,
Water soluble and oil soluble, hence active in both oil and wateWater soluble and oil soluble, hence active in both oil and waterr
phases as a mitigation agentphases as a mitigation agent Directly pumped into pipeline through injection pointsDirectly pumped into pipeline through injection points
Can be used as a surface treatment chemical for injection waterCan be used as a surface treatment chemical for injection water
Resident in Pipe Line surface as a thin film, prevents slime buiResident in Pipe Line surface as a thin film, prevents slime build upld up
Active chemical released on contact with water and it Active chemical released on contact with water and it’ ’ s a slows a slowcontinuous release, always activecontinuous release, always active
Converts sulfides to sulfates.Converts sulfides to sulfates.
No filters needed to filter byNo filters needed to filter by--product.product.
Pipe Lines put on a weekly or monthly dosage as needed.Pipe Lines put on a weekly or monthly dosage as needed.
Very economic and easy to use. Very economic and easy to use. Acts as a low grade corrosion inhibitor Acts as a low grade corrosion inhibitor
Economic usage due to very lowEconomic usage due to very low ppmppm dosages.dosages.
Effective over a wide pH rangeEffective over a wide pH range
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DESULPHDESULPH – – CHEMICAL STRUCTURECHEMICAL STRUCTURE
R = Chemical Group that makes the molecule a liquid with highR = Chemical Group that makes the molecule a liquid with high
solubility in water.solubility in water.
CHCH22
CHCH22
CHCH22
CHCH22
CHCH22CHCH22
NN
NNNN
SS SS SS
R R
R R R R
Noor Jasni BZakaria
Digitally signed by Noor Jasni BZakariaDN: CN = Noor Jasni B Zakaria, C= MYDate: 2005.02.17 20:36:27 +08'00'
