Humber Refinery Fire and Explosion United Kingdom, 2001
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Case History Humber Refinery Fire and Explosion United Kingdom, 2001 Edna Mendez PhD Student Mary Kay O’Connor Process Safety Center Artie McFerrin Department of Chemical Engineering Texas A&M University Steering Committee Meeting, April 25th 2017 Outline • Background • Incident description • Consequences • Chemical and process description • Analysis • Lessons learned 2 Humber Refinery • Located 0.5 km east of the village South Killingholme • Constructed in 1969 and commissioned in 1969/1970 • Employees: 1,200 including contractors • Crude Capacity: 221,000 bbl/day http://latitude.to • Products: - Petroleum coke, propane/butane (LPG), gasoline, diesel, and aviation fuel - Low sulfur oil and vacuum gas oil - Specialty graphite cokes 3 Sequence of Events • April 16th, 2001: Holiday – 185 staff onsite instead of usual 800 • Shift handover scheduled at 3:00 pm 2:20 pm: Pipe failure and release 20-30 sec later: Cloud found ignition source Massive explosion and fireball 2:35 pm: Release from adjacent pipework Additional explosion and fireball 2:50 pm: Further pipework failure Explosion and fireball Photo courtesy of Andy Trott (HSE, 2005) 3:30 pm: Fire under control 9:01 pm: Fire completely extinguished 4 Consequences • 180 tonnes of flammable liquids and gases released • Hydrogen sulfide (1/2 tonne) • 71 claims for injuries • Short-term environmental impact • Significant damage to refinery – shutdown for weeks • Damage within a 1 km radius offsite including adjacent refinery Damage to the SGP after the explosion (HSE, 2005) • Fined with £895,000 plus £218,854 costs by HSE 5 Release • Propane/butane (LPG), H2S and trace salts (400 psi) • 80 tonnes released from Saturate Gas Plant - 65 tonnes gas and 15 tonnes liquid • 100 tonnes from adjacent plants Liquefied Petroleum Gas (LPG): Liquefied through pressurization comes from natural gas processing and oil refining Property Butane Propane Boiling Temperature -1 to 1 °C (30 to 34 ° F) -42 °C (-43.6 °F) Flammability Limits 1.86% – 8.41% 2.15% – 9.60% Flash Point -60 °C (-76 °F) -104 °C (-155 °F) AIT 288 °C (550 °F) 470 °C (878 °F) 4 4 1 0 2 0 6 Saturate Gas Plant (SGP) • Separation of hydrocarbon products Feed water Line P4363 Pipe failure Propane condenser Static Feed water mixer Reflux From naphtha stabilizer From catalytic Sour water reformer Product to De-ethanizer next stage (removes methane, ethane, H2S) Diagram prior to incident (HSE, 2005) 7 Water Injection System Purpose: Remove salts that can deposit in the system and cause fouling 1-inch Water Injection Point (9 meters above ground level) Free water jet 300 °F, 300 psi Water Line P4363 Injection Point Failed Elbow Heat exchangers De-ethanizer Failed Elbow 8 Analysis: Ruptured Pipe • Failure of the 6” elbow close to a water injection point • Water injected washed away passivation layer • Exposed carbon steel attacked by corrosive agents • Wall thinning of pipe wall - From 7-8 mm to 0.3 mm • Rupture due to erosion corrosion - Full bore rupture Erosion corrosion: • Acceleration in rate of corrosion due to motion of corrosive fluid/metal surface Ruptured Elbow (HSE, 2005) - Design creating turbulence - Flow restrictions - Abrupt changes in flow direction 9 Analysis: MOC for Water Injection Point • Water injection system not well-documented 1995 1981 Intermittently or as Continuous use required Not part of the No MOC original design 2000-2001 2000 Water injection back MOC to modify to continuous use nozzle diameter No MOC MOC form completed MOC: Management of Change 10 Analysis: Corrosion Management Technical Advisory Bulletin (1992) 1994 Inspection • Mentioned vulnerability of • Extensive corrosion of first carbon steel pipework near to injection point water injection points • Inspection to P4363 water • Action: Reviewed water injection injection points in continuous use • Elbow not included P4363? - Recommendation: Frequent inspections (Not in database) 1996: Inspection Survey P4363 not inspected: Injection point taken as blinded – erosion corrosion considered halted After 1996: No inspections to this pipe 11 Analysis: Corrosion Management • No procedure for inspecting pipework around water and chemical injection points • Database to document results of inspections of pipework was poorly populated and alerts were unreliable Risk-Based Inspection (RBI) Program (2000) • The injection point was not considered • Report still identified pipe as high risk • No criteria for unacceptable risk level • Inspection planned for July 2001 12 Analysis: What Went Wrong? Failed to conduct MOC for process changes Lack of communication and information sharing Failed to keep updated inspection database Failed to implement effective inspection and maintenance Pipe failure explosion and fireballs 13 Barrier Analysis Prevention Detection Control Release Mitigation Design Emergency MOC Monitoring, maintenance and inspection Gas detectors Shutdown systems PHA Blast resistant buildings (e.g., control room) Emergency response team 14 Actions Implemented After the Incident . HSE safety alert to all UK for water injection points . Company listed all water injection points and developed inspection strategies . New procedure for wash water inspection based on API 570 . Updated database and revalidated RBI . Inspection program of higher risk piping system started – £10.16 million (15% refinery piping) . Further inspection of lower risk piping – £3 million . Third party audit in 2001 of all company facilities . Refinery’s Community Advisory Panel to share information with the local community 15 Actions Implemented After the Incident • Inspection, RBI and Corrosion groups UK US OSHA - Mandatory reviewers of MOC Regulations PSM 14 (COMAH Elements • New division of Asset Integrity and Requirements) Reliability: - Process Management Function • Rebuilt SGP and recommissioned in 2003 New Injection - Modern design and following injection Point engineering standards point - Washing system improved - Overhead washing system modified Heat exchangers De-ethanizer COMAH: Control of Major Accident Hazards 16 Lessons learned • Pipework inspection program based on industry practices and adjusted to the process conditions • Management of Change programs need to be established and used for plant and process modifications • Communication among departments and record keeping of process changes and inspection results • Companies with potential high impacts to communities need to develop programs to communicate risks and train the public in case of emergencies 17 References • Health and Safety Executive (2005) Public Report of the Fire and Explosion at the ConocoPhillips Humber Refinery on 16 April 2001. [Online] Available: http://www.hse.gov.uk/comah/conocophillips.pdf • Jonathan Carter, Peter Dawson and Robert Nixon, Explosion at the Conoco Humber refinery – 16th April 2001, Hazards XIX: Process Safety and Environmental Protection. What do we know? Where are we going? Symposium Series 151, IChemE, 2006, available at https://www.icheme.org/communities/subject_groups/safety%20and%20loss%20prevention/resources/hazards%20archive/~/med ia/Documents/Subject%20Groups/Safety_Loss_Prevention/Hazards%20Archive/XIX/XIX-Paper-70.pdf • David Hughes, ConocoPhillips response to the Saturate Gas Plant fire and explosion incident, XIX: Process Safety and Environmental Protection. What do we know? Where are we going? Symposium Series 151, IChemE, 2006 • The Phillips 66 Humber Refinery, www.phillips66.com • What is LPG? http://www.elgas.com.au/blog/492-what-is-lpg-lpg-gas-lp-gas • Erosion, NACE International, https://www.nace.org/Corrosion-Central/Corrosion-101/Erosion/ • BBC News, Major blast at oil refinery, April 17 2001, Available at http://news.bbc.co.uk/2/hi/uk_news/1281221.stm • The Guardian, Major blast at oil refinery, April 16 2001, Available at https://www.theguardian.com/uk/2001/apr/16/1 • BBC News, Oil firm fined £ 1m over explosion, June 2005, Available at: http://news.bbc.co.uk/2/hi/uk_news/england/humber/4635301.stm • Sam Fletcher, Blast shakes Conoco’s Humber refinery in England, April 16 2001, Oil & Gas Journal, http://www.ogj.com/articles/2001/04/blast-shakes-conocos-humber-refinery-in-england.html • Martin Wainwright, Two hurt in oil refinery explosion, The Guardian, April 16 2001, https://www.theguardian.com/uk/2001/apr/17/martinwainwright • Dave Mark, ConocoPhillips admits breaches which led to 'potentially catastrophic' gas explosion in 2001 Oil firm's £1m 'safety error' bill, The Yorkshire Post, 2005, Available at at http://www.yorkshirepost.co.uk/news/conocophillips-admits-breaches-which- led-to-potentially-catastrophic-gas-explosion-in-2001-oil-firm-s-163-1m-safety-error-bill-1-2423098 • The Swiss Cheese Model, https://stratog.rcog.org.uk/tutorial/human-factors/the-swiss-cheese-model-8888 • The James Reason Swiss Cheese Failure Model in 300 Seconds, 2005, https://whatsthepont.com/2015/08/03/the-james-reason- swiss-cheese-failure-model-in-300-seconds/ • James Reason Swiss Cheese Model. Source: BMJ, 2000 Mar 18:320(7237): 768-770 • Michael Deighton, Facility Integrity Management: Effective Principles and Practices for the Oil, Gas and Petrochemical Industries, Gulf Professional Publishing, 2016 18 Acknowledgements • Dr. Sam Mannan • Dr. Bin Zhang • Research team • Sankhadeep Sarkar • Valerie Green • Alanna Scheinerman • Members of Steering Committee • Members of MKOPSC 19 THANK YOU! [email protected] 20 .