Designing an Internal Corrosion Program NACE Eastern Area Conference Roy D. Fultineer Jr

Designing an Internal Designing an Internal Corrosion ProgramCorrosion Program

NACE Eastern Area ConferenceNACE Eastern Area Conference

Roy D. Fultineer Jr.Roy D. Fultineer Jr.

IntroductionIntroduction

• Plans and ProceduresPlans and Procedures• TrainingTraining• Know the systemKnow the system• When do we get involved When do we get involved • Understand Corrosion MechanismsUnderstand Corrosion Mechanisms• Identify the right monitoring locationsIdentify the right monitoring locations• Monitor and Trend dataMonitor and Trend data• Possible MitigationPossible Mitigation• Follow-upFollow-up

Plans and ProceduresPlans and Procedures

• Internal Corrosion PlansInternal Corrosion Plans– GenericGeneric

• Potential Treats – Acid Gases, Bacteria, Erosion, etc.Potential Treats – Acid Gases, Bacteria, Erosion, etc.

• Types of monitoringTypes of monitoring– Gas samplesGas samples

– Liquid samplesLiquid samples

– CouponsCoupons

• Requirements for internal corrosion monitoringRequirements for internal corrosion monitoring

• Parameters to monitor and trendParameters to monitor and trend


• Internal Corrosion PlansInternal Corrosion Plans– GenericGeneric

• Basic Decision CriteriaBasic Decision Criteria– If indications are found, what is the next step.If indications are found, what is the next step.


• Internal Corrosion PlansInternal Corrosion Plans– SpecificSpecific

• Location of facilityLocation of facility• Specific location of monitoring locationsSpecific location of monitoring locations• Specific timing of monitoringSpecific timing of monitoring• Specific water control methodsSpecific water control methods

– PiggingPigging– DripsDrips– DehydrationDehydration

• Schedule of these control methodsSchedule of these control methods• What action has been taken?What action has been taken?


• Internal Corrosion PlansInternal Corrosion Plans– SpecificSpecific

• What action is planned?What action is planned?

• How will action be evaluated?How will action be evaluated?


• ProceduresProcedures– Procedures go into specific action of how to Procedures go into specific action of how to

conduct sampling and monitoringconduct sampling and monitoring

– Important aspect of internal corrosion planImportant aspect of internal corrosion plan

– Procedures go hand-in–hand with trainingProcedures go hand-in–hand with training

TrainingTraining

• Properly trained personnel is critical to the Properly trained personnel is critical to the success of any internal corrosion programsuccess of any internal corrosion program– In house trainingIn house training

– On the job trainingOn the job training

– NACE and other professional organizationsNACE and other professional organizations

• Collecting accurate data is criticalCollecting accurate data is critical

• The better the data, the better the decisions The better the data, the better the decisions

When do we get involvedWhen do we get involved

• Internal corrosion should be considered in the Internal corrosion should be considered in the initial design phase of any projectinitial design phase of any project

• Things to consider:Things to consider:– Water content and water removalWater content and water removal– Elevation profileElevation profile– Inlets and outlets to the systemInlets and outlets to the system– Gas Quality Gas Quality – Flow regimesFlow regimes

Know your systemKnow your system

• Operation FactorsOperation Factors– Direction of flowDirection of flow– Flow ratesFlow rates– Flow regimeFlow regime– PressuresPressures– ProductProduct– UpsetsUpsets– Elevation ProfileElevation Profile

Elevation ProfileElevation Profile

Understand Corrosion MechanismsUnderstand Corrosion Mechanisms

• Causes– Water

– CO2 Influenced

– H2S Influenced

– MIC

– O2

– Velocity/Flow Related


• Water– Necessary for internal corrosionNecessary for internal corrosion

– TemperatureTemperature• Reaction rates double for every 10 degree Celsius rise Reaction rates double for every 10 degree Celsius rise

– pHpH• Less then 5 can result in increased corrosionLess then 5 can result in increased corrosion

– CarbonatesCarbonates• Acts as a acid bufferActs as a acid buffer


• CO2 Corrosion– Carbon Dioxide + water = Carbon Dioxide + water = Carbonic AcidCarbonic Acid

– Carbonic AcidCarbonic Acid + iron = + iron = iron carbonateiron carbonate + hydrogen + hydrogen

– Carbon dioxide is in the gasCarbon dioxide is in the gas

– Carbonic acid creates corrosionCarbonic acid creates corrosion

– Generally mild corrosion except when with other Generally mild corrosion except when with other corrodentscorrodents


• H2S Corrosion– Hydrogen SulfideHydrogen Sulfide + iron + water = + iron + water =

– Iron SulfideIron Sulfide + water + hydrogen + water + hydrogen

– From sour gas operations or from SRB’s (MIC)From sour gas operations or from SRB’s (MIC)

– Corrosion pitting occurs where FeS forms on Corrosion pitting occurs where FeS forms on the metal the metal surface and creates a local surface and creates a local corrosion cellcorrosion cell


• MIC– Acid Producers - APB’sAcid Producers - APB’s

– Sulfate Reducing Bacteria - SRB’sSulfate Reducing Bacteria - SRB’s

– Controlled with a clean system and Controlled with a clean system and bacteriacides/biocidesbacteriacides/biocides


• Oxygen– OxygenOxygen + iron + water = + iron + water = Iron oxideIron oxide + water + water

– Oxygen creates an oxidizing effect and with Oxygen creates an oxidizing effect and with other corrodents = accelerated corrosionother corrodents = accelerated corrosion

– Oxygen concentration cells create corrosion due Oxygen concentration cells create corrosion due to oxygen depletion areasto oxygen depletion areas


• Velocity/Flow related attacks– High surface fluid or particle velocitiesHigh surface fluid or particle velocities– ErosionErosion

• High Energy with or without particlesHigh Energy with or without particles• Removes metalRemoves metal• Leaves smooth surfaceLeaves smooth surface

– Erosion CorrosionErosion Corrosion• Erosion removes protective film or scaleErosion removes protective film or scale• Exposes metal surface to environmentExposes metal surface to environment

Pick the right monitoring locationsPick the right monitoring locations

• Representative of systemRepresentative of system• Right locationRight location

– Know what your looking for and put monitoring Know what your looking for and put monitoring devices in right location.devices in right location.

– Top of the line versus bottom of line corrosionTop of the line versus bottom of line corrosion

• Right deviceRight device– Pick the monitoring device that is designed for the Pick the monitoring device that is designed for the

applicationapplication

Monitor and trend dataMonitor and trend data

• Collect the data you need and compare it to all Collect the data you need and compare it to all other dataother data

• Be careful not to add to much weight to any Be careful not to add to much weight to any one data setone data set

• Determine if action is requiredDetermine if action is required

Possible Mitigation MethodsPossible Mitigation Methods

• Do nothingDo nothing– Sometimes the best answer is to continue to Sometimes the best answer is to continue to

monitor and studymonitor and study

– More information will lead to better decisionsMore information will lead to better decisions

– More technical or sophisticated analysis may be More technical or sophisticated analysis may be appropriateappropriate

– Chemicals can actually make the situation worseChemicals can actually make the situation worse


• Liquid removalLiquid removal– Drip BlowingDrip Blowing

• Drip should be monitored and blown on frequencies that Drip should be monitored and blown on frequencies that ensure no free liquidsensure no free liquids

• Used to monitor for corrosion parametersUsed to monitor for corrosion parameters

– PiggingPigging• Ran on frequencies that ensure no free liquidsRan on frequencies that ensure no free liquids

• Thought should be given to the type of pigs usedThought should be given to the type of pigs used

• Speed of pigging can influenceSpeed of pigging can influence


• DehydrationDehydration– Removal of water through dehydration can greatly

reduces possibility of internal corrosion

– High initial cost and added O&M cost

– Does not necessarily remove the need for chemical


• Control Inlet Product QualityControl Inlet Product Quality– Monitor product quality entering systemMonitor product quality entering system

– Have control to shut in suppliersHave control to shut in suppliers


• Chemical TreatingChemical Treating– Batch Batch

– Slug Slug

– ContinuousContinuous

– SqueezeSqueeze


• DesignDesign– One of the most effective means of controlOne of the most effective means of control

• Use of proper materialsUse of proper materials

• Size pipeline properly (oversized = liquid hold-up)Size pipeline properly (oversized = liquid hold-up)

• Modeling and/or flow regime will dictate location Modeling and/or flow regime will dictate location and/or need for drips, pigging, etc.and/or need for drips, pigging, etc.

• Material selection can be keyMaterial selection can be key– Steel is not always the best solutionSteel is not always the best solution

– Example: Fiberglass piping in acid gas environmentExample: Fiberglass piping in acid gas environment

Follow-up (Did it Work?)Follow-up (Did it Work?)

• CouponsCoupons

• Liquid SamplingLiquid Sampling

• Residuals MonitoringResiduals Monitoring

• In Line Inspection (ILI)In Line Inspection (ILI)

• Gas MonitoringGas Monitoring

CouponsCoupons

• Weight LossWeight Loss– Compare previous rates to new ratesCompare previous rates to new rates

– Compare pretreated versus post-treatmentCompare pretreated versus post-treatment

– CID – Copper Ion Displacement – monitoring CID – Copper Ion Displacement – monitoring chemical distributionchemical distribution

Liquid SamplingLiquid Sampling

• Monitor effects on water chemistryMonitor effects on water chemistry– pH (increasing or decreasing)pH (increasing or decreasing)

• Increase – ScalingIncrease – Scaling

• Decrease – CorrosionDecrease – Corrosion

– Metals (increasing decreasing)Metals (increasing decreasing)• Mn/Fe ratioMn/Fe ratio

• TrendingTrending

– Bacteria levelsBacteria levels

Residual MonitoringResidual Monitoring

• Are chemicals getting where you need themAre chemicals getting where you need them

• Are the residuals adequateAre the residuals adequate

• If not,If not,– Adjust existing facilitiesAdjust existing facilities

– Add new injection pointsAdd new injection points

– Change application (continuous to pigging)Change application (continuous to pigging)

ILI InspectionILI Inspection

• Need base lineNeed base line

• Follow-upsFollow-ups– Monitor corrosion growthMonitor corrosion growth

– Monitor for new corrosion.Monitor for new corrosion.

Gas MonitoringGas Monitoring

• Monitor QualityMonitor Quality– COCO22

– HH22SS

– WaterWater

– OO22

• Monitor for changesMonitor for changes

Questions?Questions?

Documents

Designing an Internal Corrosion Program NACE Eastern Area Conference Roy D. Fultineer Jr