Title: Establishing Integrity Operating Windows (IOW
1Establishing Integrity Operating Windows
(IOWs)IPEIA ConferenceFebruary 2, 2006Banff,
Alberta
- John Reynolds
- Steamboat Springs, CO, USA
- Recently retired from
- Shell Global Solutions (US) Inc.
-
2Outline for this Presentation
- The 10 Shell (US) Process Safety Initiatives
(PSI) - The Pressure Equipment Integrity (PEI) Initiative
- Corrosion Control Documents (CCD)
- Integrity Operating Windows (IOW)
- Standard and Critical IOWs
- Integration of IOWs into the 10 PSIs
- Training of Operators on IOWs
- The Pressure Equipment Integrity Pyramid
3Ten Process Safety Initiatives (PSI) Initiated
in May, 2000
- Pressure Equipment Integrity (PEI) - IOW creation
process - Ensure Safe Production (ESP) - IOW monitoring
process - Operator Training and Procedures - IOW knowledge
transfer - Management Of Change (MOC) - IOW change process
- Investigations 3 Levels up to RCA
- Protective Instrument Systems (IPF SIL)
- Reliability Centered Maintenance (RCM)
- Causal Learning
- Audits and Assessments
- Process Hazards Analysis (PHA)
4Process Safety Initiative Metrics
- Each 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)
completed - Numbers of process units with RBI completed
- Numbers of process units with all IOWs
implemented - Numbers of operators trained on their CCD IOWs
- But there was only one bottom line metric for the
aggregate of the ten process safety initiatives
gt numbers of process safety incidents per year
5Results of the Process Safety Initiatives
Numbers of Process Safety Incidents in last 6
years A real success story
6Primary Aspects of the Pressure Equipment
Integrity (PEI) Initiative
- Identify all necessary Integrity Operating
Windows (IOWs) - Create OEMI Teams (Operations - Engineering -
Maintenance - Inspection) in each operating area
to create and manage CCDs and IOWs - Create Corrosion Control Documents (CCDs), which
document all process IOWs - Train operators on the CCD and IOWs
- Implement IOWs and Risk-Based Inspection (RBI)
- Implement PEI Focused Asset Integrity Reviews
(FAIR) to monitor progress of the PEI Initiative
7ESP
PEI PSI Pyramid
RBI
CCDs IOWs
OEMI Teams
101 Essential Elements
8Corrosion Control Documents Contents
- Relatively comprehensive documents for managing
equipment degradation - Description of the process unit and process
conditions - Shutdown 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 areas - Quantitative and predictive models for
degradation mechanisms - Vital corrosion control procedures, injections,
inhibitors, etc. - Recommended inspection corrosion monitoring,
process changes, construction materials changes,
etc. - Integrity Operating Windows (IOWs)
9Corrosion Control Documents Construction
- Unit specific CCDs completed by an OEMI team
which includes - Site corrosion engineer/specialist
- Unit process engineer
- Unit inspector
- One or more experienced unit operations
representatives - Facilitator (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
10Establishing Integrity Operating Windows
- Historical operating, maintenance inspection
records - Design data lab data operating data
- Metallurgical and corrosion data and modules
- Process chemistry and engineering knowledge
- Reactive chemistry knowledge
- Recommended practices (industry and company)
- Process and corrosion modeling tools
- Subject matter expertise and experience (heavy
dose) - Result Reasonable, practical IOWs not too
conservative not non-conservative
11Integrity Operating Windows
12Integrity Operating Windows Examples
- Typically fall into 2 categories
-
- Physical
- Various 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. - Chemical
- pH, 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.
13IOW Example Hot Hydrogen Service
- Mechanical design window set by the design code
e.g. ASME - IOW set by material limit for high temperature
hydrogen attack in API RP 941 - SOR process temperature definitely within the IOW
- EOR process temperature possibly beyond the IOW
need to know the hydrogen partial pressure and
duration of EOR conditions
Temperature
Mechanical Design Limits
EOR Process Temp
IOW
SOR Process Temp
Pressure
Based on H2 pp
Based on Total Pressure
14Integrity 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 limits - Typically 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)
15Definitions IOW Critical Limit
- A 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 Containment
- Non-orderly Shutdown
- Significant Environmental Impact
- Other Unacceptable Risk
16Critical IOW Limit Examples
- Boiler Feed Water Level
- Lost of boiler feed water level could quickly
cause boiler tube rupture - Hydroprocess Reactor Temperature
- Metal temperatures below the MDMT could give rise
to brittle fracture - Heater Tube Skin Temperature
- Tube could rupture quickly if overheated, caused,
for example, by a no flow or hot spot condition. - Sulfuric Acid Strength in Alkylation
- Too low acid strength could cause runaway
reaction
17Definition 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 containment
- Non-orderly shutdown
- A negative impact to the long term unit
performance and its ability to meet turnaround
run length - Excessive financial impact
18Standard Level Examples
- REAC NH4HS Concentration
- Corrosion of the air cooler and downstream piping
- Heater Tube Skin Temperature
- Metallurgical creep could lead to eventual tube
failure. - Crude Fractionator Dew Point Temperature
- Sustained operation below dew point could cause
damage to fractionator internals or potential
loss of containment. - pH of Crude Tower Overhead
- Sustained operation below standard pH level could
lead to corrosion of tubing and piping and
potential loss of containment. - Desalter Outlet Salt Content
- Sustained operation above standard level could
lead to corrosion and potential loss of
containment
19Integrity 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 damage - An 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 damage - A 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
20Operator Training on CCDs and IOWs
- Level 1
- Awareness and Overview of the PEI Process Safety
Initiative - SSA Video / CCD / RBI / OEMI / Operator Training
- Level 2
- Introduction to Corrosion Control Documents
- What they contain where theyre stored how to
use them - Level 3
- Details contained within each operators
unit-specific CCD - Specific IOWs and the reasoning behind them
- What can happen if the IOW is exceeded
21ESP
PEI PSI Pyramid
RBI
CCDs IOWs
OEMI TEAMS
101 Essential Elements
22Implementing Risk-Based Inspection (RBI)
- Another major part of our pressure equipment
integrity process safety initiative - We 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 sites - But RBI will not be covered today a topic for
another day, if you like - Suffice 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)
23Integration of CCDs, IOWs RBI
Feedback
Confidence in plant integrity
- Creating the CCD
- Type of degradation
- Location of degradation
- Susceptibility to degradation
- Degradation rates
- IOW limits
- Determination management of the operating
limits to avoid degradation
RBI planning Method of inspection Where to
inspect Frequency of inspection
24Integration of Multiple Work Processes Leading To
Sustained Asset Integrity
Long Term Asset Integrity
Focused Asset Integrity Reviews
Design and Materials Selection
Corrosion Control IOWs
Risk-Based Inspection
Asset integrity management is a balancing process
designed to achieve lowest total cost of
ownership
25Along with Asset Integrity Comes Proven Better
Process Safety Performance
Numbers of Process Safety Incidents in last 6
years in Shell (US) Refining Operations Facts,
not just hopes for the future
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28Shell Experience with Integrity Operating Windows
(IOWs)Time for Discussion
- John.Reynolds_at_shell.com
- Recently retired from
- Shell Global Solutions (US) Inc.