Establishing Integrity Operating Windows (IOWs)

IPEIA ConferenceFebruary 2, 2006Banff, AlbertaJohn ReynoldsSteamboat Springs, CO, USARecently retired from Shell Global Solutions (US) Inc.

*Outline for this PresentationThe 10 Shell (US) Process Safety Initiatives (PSI)The Pressure Equipment Integrity (PEI) InitiativeCorrosion Control Documents (CCD)Integrity Operating Windows (IOW)Standard and Critical IOWsIntegration of IOWs into the 10 PSIsTraining of Operators on IOWsThe Pressure Equipment Integrity Pyramid

*Ten Process Safety Initiatives (PSI) Initiated in May, 2000Pressure Equipment Integrity (PEI) - IOW creation processEnsure Safe Production (ESP) - IOW monitoring process Operator Training and Procedures - IOW knowledge transfer Management Of Change (MOC) - IOW change processInvestigations 3 Levels up to RCAProtective Instrument Systems (IPF SIL)Reliability Centered Maintenance (RCM) Causal LearningAudits and Assessments Process Hazards Analysis (PHA)

*Process Safety Initiative MetricsEach of the 10 PSIs were required to have four main metrics to track implementation progress (10 X 4 = 40 metrics total)For the PEI process safety initiative we tracked:Numbers of Corrosion Control Documents (CCDs) completedNumbers of process units with RBI completedNumbers of process units with all IOWs implementedNumbers of operators trained on their CCD & IOWsBut there was only one bottom line metric for the aggregate of the ten process safety initiatives > numbers of process safety incidents per year

*Results of the Process Safety InitiativesNumbers of Process Safety Incidents in last 6 years A real success story

*Primary Aspects of the Pressure Equipment Integrity (PEI) InitiativeIdentify all necessary Integrity Operating Windows (IOWs)Create OEMI Teams (Operations - Engineering - Maintenance - Inspection) in each operating area to create and manage CCDs and IOWsCreate Corrosion Control Documents (CCDs), which document all process IOWsTrain operators on the CCD and IOWsImplement IOWs and Risk-Based Inspection (RBI)Implement PEI Focused Asset Integrity Reviews (FAIR) to monitor progress of the PEI Initiative

*ESPRBICCDs & IOWsOEMI Teams101 Essential ElementsPEI PSI Pyramid

*Corrosion Control Documents Contents

Relatively comprehensive documents for managing equipment degradationDescription of the process unit and process conditionsShutdown and start up conditions that may affect corrosion and degradation mechanisms, as well as normal operation Process Flow Diagram (PFD) and Materials and Corrosion Diagram (modified PFD showing construction materials)Corrosion Control Loops (areas of similar corrosion within the PFD) e.g. overhead system, slurry system, reflux system, etc.All potential types of degradation (and fouling) in each process unit and history of problem areasQuantitative and predictive models for degradation mechanismsVital corrosion control procedures, injections, inhibitors, etc.Recommended inspection & corrosion monitoring, process changes, construction materials changes, etc.Integrity Operating Windows (IOWs)

*Corrosion Control Documents Construction

Unit specific CCDs completed by an OEMI team which includes:Site corrosion engineer/specialistUnit process engineerUnit inspectorOne or more experienced unit operations representativesFacilitator (knowledgeable / experienced corrosion engineer) Final document represents an agreement between the OEMI Team involved and clearly benefits by the synergistic interaction of all team members

*Establishing Integrity Operating Windows

Historical operating, maintenance & inspection records Design data; lab data; operating dataMetallurgical and corrosion data and modulesProcess chemistry and engineering knowledgeReactive chemistry knowledgeRecommended practices (industry and company)Process and corrosion modeling toolsSubject matter expertise and experience (heavy dose)

Result: Reasonable, practical IOWs not too conservative not non-conservative

*Integrity Operating Windows

*Integrity Operating Windows Examples

Typically fall into 2 categories: PhysicalVarious limits on pressures and temperatures, including design, operating, partial pressures, dew points, dry points, heating and cooling rates, delta P, etc.Flow rates, injection rates, inhibitor dosage, amperage levels on Alky contactor motors, slurry content, hydrogen flux, vibration limits, corrosivity probes, etc.ChemicalpH, water content, acid gas loading, sulfur content, salt content in crude, NH4HS content, NH3 content, TAN, acid strength, amine strength, inhibitor concentration, chloride contamination levels, oxygen content, etc.

*IOW Example Hot Hydrogen ServiceMechanical design window set by the design code e.g. ASMEIOW set by material limit for high temperature hydrogen attack in API RP 941 SOR process temperature definitely within the IOWEOR process temperature possibly beyond the IOW need to know the hydrogen partial pressure and duration of EOR conditions

TemperaturePressureMechanical Design LimitsSOR Process TempEOR Process TempIOWBased on H2 ppBased on Total Pressure

*Integrity Operating Windows Typical Numbers per Operating Unit(before & after an intensive review)Typically start with 5 -10 IOWs that may already be in place, along with other operating quality variable limitsTypically end up with 30 50 IOWs with about 5 -10% being critical limits (requires drastic and/or immediate action), and the rest being standard limits (requires attention within a specified timeframe to get back into control)

*Definitions: IOW Critical LimitA limit at which the operator has one last opportunity to return the process to a safe condition and, if exceeded, could result in one of the following in a fairly short timeframe:

A Catastrophic Release of Hydrocarbons or Hazardous fluids Loss of ContainmentNon-orderly ShutdownSignificant Environmental ImpactOther Unacceptable Risk

*Critical IOW Limit Examples

Boiler Feed Water Level Lost of boiler feed water level could quickly cause boiler tube ruptureHydroprocess Reactor Temperature Metal temperatures below the MDMT could give rise to brittle fractureHeater Tube Skin TemperatureTube could rupture quickly if overheated, caused, for example, by a no flow or hot spot condition.Sulfuric Acid Strength in AlkylationToo low acid strength could cause runaway reaction

*Definition: Standard Level A limit that, if exceeded over a defined period of time, could cause one of the following to eventually occur:

A catastrophic release of hydrocarbons or hazardous fluids Loss of containmentNon-orderly shutdownA negative impact to the long term unit performance and its ability to meet turnaround run lengthExcessive financial impact

*Standard Level ExamplesREAC NH4HS ConcentrationCorrosion of the air cooler and downstream pipingHeater Tube Skin TemperatureMetallurgical creep could lead to eventual tube failure.Crude Fractionator Dew Point TemperatureSustained operation below dew point could cause damage to fractionator internals or potential loss of containment.pH of Crude Tower OverheadSustained operation below standard pH level could lead to corrosion of tubing and piping and potential loss of containment.Desalter Outlet Salt ContentSustained operation above standard level could lead to corrosion and potential loss of containment

*Integrity Operating Windows Successes

In the CCD review, one IOW team noticed that a previous project had installed the wrong construction materials immediate inspection revealed significant HTHA damageAn operator on the team disagreed with the unit process engineer and said that we actually operate much hotter than you think because we use the by-pass immediate inspection revealed significant localized damageA corrosion engineer questioned the higher level of NH4HS in the REAC system of an HCU immediate inspection revealed a previously-missed localized spot of significant corrosion An IOW was set on NH4HS concentration at another refinery, which then began to take routine lab samples soon thereafter discovered the concentration was too high and took steps to increase wash water and adjust feedstock

*Operator Training on CCDs and IOWsLevel 1Awareness and Overview of the PEI Process Safety InitiativeSSA Video / CCD / RBI / OEMI / Operator Training Level 2Introduction to Corrosion Control DocumentsWhat they contain; where theyre stored; how to use themLevel 3Details contained within each operators unit-specific CCDSpecific IOWs and the reasoning behind themWhat can happen if the IOW is exceeded

*ESPRBICCDs & IOWsOEMI TEAMS101 Essential ElementsPEI PSI Pyramid

*Implementing Risk-Based Inspection (RBI)

Another major part of our pressure equipment integrity process safety initiativeWe use both a Shell developed more qualitative RBI (S-RBI), as well as the more quantitative API RBI, both successfully for different needs at different sitesBut RBI will not be covered today a topic for another day, if you likeSuffice it to say that any inspection program, be it risk-based, condition-based, or time-based may not be fully reliable without effective identification and implementation of integrity operating windows (IOWs)

*Integration of CCDs, IOWs & RBIConfidence in plant integrityCreating the CCD: Type of degradation Location of degradation Susceptibility to degradation Degradation rates

IOW limits:

Determination & management of the operating limits to avoid degradationRBI planning:Method of inspectionWhere to inspectFrequency of inspectionFeedback

*Integration of Multiple Work Processes Leading To Sustained Asset IntegrityDesign and Materials Selection

CorrosionControl & IOWsRisk-BasedInspectionLong Term Asset IntegrityAsset integrity management is a balancing process designed to achieve lowest total cost of ownership Focused Asset Integrity Reviews

*Along with Asset Integrity Comes Proven Better Process Safety PerformanceNumbers of Process Safety Incidents in last 6 years in Shell (US) Refining Operations Facts, not just hopes for the future

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Shell Experience with Integrity Operating Windows (IOWs)

Time for DiscussionJohn.Reynolds@shell.comRecently retired fromShell Global Solutions (US) Inc.

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