Establishing Integrity Operating Windows John Reynolds [PDF]

Zitiervorschau

Establishing Integrity Operating Windows (IOW’s)*

Inspector Summit January 27, 2006 Galveston, TX *Based on article published in Inspectioneering Journal, April, 2005

John Reynolds Pro-Inspect, Inc. Steamboat Springs, CO, USA

Outline for this Presentation •

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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 IOW’s Integration of IOW’s into the 10 PSI’s Training of Operators on IOW’s The Pressure Equipment Integrity Pyramid 2

Ten Process Safety Initiatives (PSI) – Initiated in May, 2000 • • • • • • • •

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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 3 Process Hazards Analysis (PHA)

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Process Safety Initiative Metrics Each of the 10 PSI’s were required to have four

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main metrics to track implementation progress (10 X 4 = 40 metrics total) For the PEI process safety initiative we tracked: -

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Numbers of Corrosion Control Documents (CCD’s) completed Numbers of process units with RBI completed Numbers of process units with all IOW’s implemented Numbers of operators trained on their CCD & IOW’s

But there was only one bottom line metric for the aggregate of the ten process safety initiatives –>

numbers of process safety incidents per year 4

Results of the Process Safety Initiatives

Numbers of Process Safety Incidents in 6 years after implementation– A real success story

YTD Totals 1999 2002 25

20

2000 2003

2001 2004

23 19

20

15 15

10

5

9

3

0 5

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Primary Aspects of the Pressure Equipment Integrity (PEI)Integrity Initiative Identify all necessary Operating Windows (IOW’s) Create OEMI Teams (Operations - Engineering Maintenance - Inspection) in each operating area to create and manage CCD’s and IOW’s Create Corrosion Control Documents (CCD’s), which document all process IOW’s Train operators on the CCD and IOW’s Implement IOW’s and Risk-Based Inspection (RBI) Implement PEI Focused Asset Integrity Reviews (FAIR®) to monitor progress of the PEI Initiative

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PEI PSI Pyramid

RBI

IOW’s CCD’s Management of Change

101 Essential Elements 7

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Corrosion 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 (IOW’s)

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Corrosion Control Documents – Construction

Unit specific CCD’s completed by an OEMI team which includes: -

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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 9

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Establishing Integrity Operating Historical operating,Windows 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 IOW’s – not too conservative – not non-conservative

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Integrity Operating Windows

Operating Operating Window Window

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Integrity Operating Windows – Examples

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Typically fall into 2 categories:

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Physical -

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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. 12

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IOW 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 13

Integrity Operating Windows – Typical Numbers per Operating Unit (before & after an intensive review) •

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Typically start with 5 -10 IOW’s that may already be in place, along with other operating quality variable limits Typically end up with 30 – 50 IOW’s 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) 14

Definitions: 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 15

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Critical IOW Limit – Examples Boiler Feed Water Level -

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Hydroprocess Reactor Temperature -

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Metal temperatures below the MDMT could give rise to brittle fracture

Heater Tube Skin Temperature -

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Lost of boiler feed water level could quickly cause boiler tube rupture

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 16

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 containment • Non-orderly shutdown

• A negative impact to the long term unit performance and its ability to meet turnaround run length • Excessive financial impact 17

Standard Level Examples •

REAC NH4HS Concentration -

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Heater Tube Skin Temperature -

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Sustained operation below dew point could cause damage to fractionator internals or potential loss of containment.

pH of Crude Tower Overhead -

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Metallurgical creep could lead to eventual tube failure.

Crude Fractionator Dew Point Temperature -

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Corrosion of the air cooler and downstream piping

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 18

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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 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 19

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Operator Training on CCD’s and IOW’s

Level 1 -

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Level 2 -

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Awareness and Overview of the PEI Process Safety Initiative SSA Video / CCD / RBI / OEMI / Operator Training

Introduction to Corrosion Control Documents What they contain; where they’re stored; how to use them

Level 3 -

Details contained within each operator’s unit-specific CCD Specific IOW’s and the reasoning behind them What can happen if the IOW is exceeded 20

PEI PSI Pyramid

RBI

IOW’s

CCD’s Management of Change

101 Essential Elements 21

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Implementing 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 (IOW’s) 22

Integration of CCD’s, IOW’s & RBI Feedback

Confidence in plant integrity

Creating the CCD:  Type of degradation

RBI planning:

 Location of degradation

Method of inspection

 Susceptibility to degradation

Where to inspect

 Degradation rates

Frequency of inspection

IOW limits:  Determination & management of the operating limits to avoid degradation 23

Integration of Multiple Work Processes Leading To Sustained Asset Integrity Long Term Asset Integrity

Focused Asset Integrity Reviews Design and Materials Selection

Corrosion Control & IOW’s

Risk-Based Inspection

Asset integrity management is a balancing process designed to achieve lowest total cost of ownership 24

Along with Asset Integrity Comes Proven Better Process Safety YTD Totals Performance 1999 2000 2001 Numbers of Process 2002 2003 2004 25 23 Safety Incidents 20 19 in 6 years after 20 15 implementation in 15 Shell (US) Refining 9 10 Operations – Facts, 5 not just hopes for 3 the future 0 25

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Experience with Integrity Operating Windows (IOW’s)*

Time for Discussion *Based on article published In Inspectioneering Journal, April, 2005

[email protected] Recently retired from Shell Global Solutions (US) Inc.