Muhammad Abduh (abduh@reksolindo.co.id)

On 16 April 2001 a fire and explosion occurred at Humber Refinery following the catastrophic failure of an overhead gas pipe. Investigation was carried by The Competent Authority and the plant operator company by legislative mechanism under Control of Major Hazard (COMAH) Regulation 1999. Humber refinery was one of approximately 1000 major hazard site under this regulation. The competent authority consisted of Health and Safety Executive (HSE) UK and Environment Agency (EA).

The cause of the piping system failure was the erosion corrosion
of the 6-inches diameter pipe, known P4363, which carried the overhead line from the De-ethanizer (W413) to the heat exchanger (X452) in saturate gas plant (SGP) unit. The failure occurred down stream of a closely water injection point. Examination to thefailed elbow recovered from the damage site showed wall thickness thinning from 7-8 mm to a minimum 0.3 mm. When the pipe failed it burst open catastrophically causing a full bore type of release the pipe contents.

The water injection point was not the original design of the piping system. Water injection to the vapor stream between the top de-ethanizer column and the heat exchanger was addressed to solve the previous problem of salts or hydrates fouling in heat exchanger X452/3. An injection point was created in P4363 by piping water to an existing 1 inches vent point on the pipe without injection quill or dispersal device and made the water entering the pipe as a free jet.

Erosion-Corrosion
There are studies that noted the synergistic effect ofmechanical impingement and electrochemical corrosion result in greater rate of metal loss than the sum of the two mechanism ( S. Zhuo, N. Stack & R.C Newman)

The highest rate of erosion-corrosion occurred in stagnant region, immediately beneath the jet, where the particles impacted the surface at an angle of 90°, This critical erosion-corrosion region in a piping system are found at the outer side of elbow where the fluid impinges the wall directly at an angle 90°.

NACE 34101: Refinery Injection & Process Mixing
Points
One of the generic guidance to overcome the problem of erosion corrosion in refinery process is NACE 34101 which gas already published as recommended practice for the design consideration of  injection system.

RBI Regime was not Effective
This accident also has shown the effect of in-effective implementation of RBI for inspection management. RBI as a comprehensive method shall be supported with complete and adequate data. The ignorance of the operator company for the significant risk contribution of the injection system to the piping were resulted in the failure.

Similar Accidents:

1. Wilmington California United States – October 8,1992
2. North Rhine West Phalia Germany-  December 10,1991
3. Yokkaichi Mie Japan – May 2, 1997
4. Mina Al-Ahmadi Kuwait-  June 25, 2000

Piper Alpha 1988

Petrobras P-36

BP Thunderhorse

Muhammad Abduh (abduh137@gmail.com)

Figure showing one of the production Platform in Yetagun Field (Marinerthai)

Subsea pipeline transporting gas from Yetagun and Yedana Field Gulf of Martaban Myanmar to Thailand was reported to have leaking in April 2, 2008 (Irrawaddy, Reuter). The operator company reported that there were two cracks causing ruptures found in the line close to Thailand-Myanmar border. Yetugun field was started up for production in 2000, with 400-500 million cubic feet per day gas production (mmcfd), while Yedana Field with 700 mmcfd two years earlier. Gas from these fields are exported to Thailand through 700 km of pipeline system (~80% subsea pipelines).

The leaking was to said not to disrupt Thailand electricity supply as the gas from these fields account only 15 percent of total consumption. However, largely Thailand industrial gas consumer will be in excess of gas shortage of about 5,800 million cubic feet and moreover owner company to suffer about USD 60,000,000 production lost (at natural gas rate = USD 10 per mmbtu).

-

Field Information (PTTEP, OilOnline)

List of Engineering Failures Contributed by Material Failures, Corrosion, Design Flaw, and Construction Defect in Oil and Gas Production Facilities, Hydrocarbon Processing, and Oil and Gas Distribution

(Part 5 of 5) - Muhammad Abduh (abduh@reksolindo.co.id)

–

46. Ghislenghien Belgium- July 30, 2004 (Pipe Leaking, Natural Gas Pipeline, 24 killed, 120 injured)

Figure showing a damaged industrial park as the excess of Ghislenghien Pipeline Explosion

A pipe leak caused a major underground high-pressure natural gas pipeline explosion. Most of the dead are officials and fire-fighters responding to reports of a gas leak. The exact cause of the pipe leak is still not clear. A heat transfer mathematic model can be used to describe a ductile-brittle transition of pipe material due to significant cooling of the surrounding pipe-wall. This brittle transition occurred when the fluid with certain velocity escape through an initial through-wall defect. The significant reduction in the fracture
toughness combined with the accompanying pressure stresses then result in fracture growth and rupture of the pipe segment. (Source 1, 2, Location)

47. Mihama Japan August 9, 2004 (Erosion-Corrosion, Power Plant, 6 killed, 5 injured)

A steam eruption occurred from failed piping system in a pressurized water reactor (PWR). An orifice plate was inadvertently inserted to the pipe network to measure the coolant flow rate. This caused a localized metal loss in cross sectional area of the piping year-to-year, and the stress level became higher, at last plastic collapse was occurred and the pipe segment ruptured. Unfortunately the pipe thickness was not checked for 27 years due to oversights. (Source)

48. Texas City Texas US – March 23, 2005 (High Temperature Hydrogen Attack, Refinery, 15 killed, 170 injured, USD 30,000,000)

Figure showing Severely Damaged Texas City Refinery

On 23 March 2005, 15 people were killed and over 170 harmed as the result of a fire and explosion on the isomerization unit at a refinery plant in Texas City United States. The accident was an explosion caused by heavier-than-air hydrocarbon vapors combusting after coming into contact with an ignition source. The severity of the accident was increased by the presence of many people congregated in the vicinity of origin of explosion. Detailed investigations were carried by the plant operator and United States Chemical Safety Board. From the health and safety perspective high number of fatalities was concluded to be caused by loss of containment, inadequate trailer sitting at the plant layout and the fault of design engineering of the blowdown stack.

Figure showing failed elbow in Texas City Refinery Explosion

The release of gas was originated at the leaking elbow made of carbon steel in the exchanger piping system resid heat hydrotreater unit (RHU). Investigation to this RHU accident determined that inappropriate material as inadvertently installed in a high pressure and high temperature hydrogen line. The failure of the elbow was noted by the mechanism of high temperature hydrogen attack (HTHA). (Source 1, 2)

49. Sidoarjo East Java Indonesia- November 22, 2006 (Pipe Leaking, Natural Gas Pipeline,11 killed)

Aerial view showing location of Sidoarjo rupture pipe nearby mud volcano big hole (KLH)

Natural gas pipeline with 440 psig pressure failed and caused a major explosion. Most of the victims were government officials in an activity of surveying mud volcano site. The mud volcano was a previously major gas blow out event in location near the accident. The most probable cause of pipeline failure was largely associated with geohazard. At least 25 industrial gas consumer affected by the gas supply interuption because of the explosion including national power plant PLN and petrochemical plant Petrokimia Gresik. (Source 1, 2, 3)

50. Free Town Sierra Leone – December 21, 2007 (Pipe Leaking, Natural Gas Pipeline, 17 killed)

A gas explosion on a crowded street killed 17 people. The explosion tore through a crowded shop. There is no clear information on the exact cause of the pipe leaking. (Source)

–

See also: Part 1, Part 2, Part 3, and Part 4

List of Engineering Failures Contributed by Material Failures, Corrosion, Design Flaw, and Construction Defect in Oil and Gas Production Facilities, Hydrocarbon Processing, and Oil and Gas Distribution

(Part 4 of 5) - Muhammad Abduh (abduh@reksolindo.co.id)

–

39. Roncador Brazil – March 15, 2001 (Tank Leaking, Offshore Platform, 2 killed, 8 missed, USD 515,000,000)

Figure Showing P-36 listing and arrangement of EDT

Official investigation report to the fire, explosion, and sinking to P-36 the largest offshore production facility said that the P-36 accident did not occur due to one single cause but was provoked by a series of factors. Chronology of the accident started from the failure of starboard emergency drain tank (EDT). Excessive pressure in Starboard EDT due to a mixture of water, oil, and gas, which caused rupture and leaking the EDT fluids into the fourth level of the column. The unexpected flow through the entry valve of the starboard EDT can be related with the blocking of the vent and the racket absence in the entry valve. The rupture of the EDT caused damage to other vital elements in the column including the sea water service pipe that initiating the flooding of this compartment and released gas to
and ignited explosion. (Source 1, 2, 3, Location)

40. Carson City California US – April 23, 2001 (Pipe Leaking, Refinery, USD 120,000,000/124,000,000)

A pipe segment leak resulted fire in a refinery coker unit. A report said that smoke from the fire rose to over 3,000 feet and the coker unit was shut down for approximately two months. The exact cause of pipe leakin is still under investigation. (Source, Location)

41. Rawdhatain Kuwait – January 31, 2002 (Pipe Leaking, Refinery, 4 killed,18 injured, USD 200,000,000)

A pipe leak resulted in major explosion at an oil gathering center killing four people and made 18 other severely injured. Three main facilities at the production site were destroyed. Production restored to its normal 500,000 bbl/day a month later. (Source)

42. Brookdale Manitoba Canada- April 14, 2002 (Stress Corrosion Cracking, Natural Gas Pipeline, USD 13,000,000)

A 36-inches diameter natural gas pipeline ruptured at a zone of near neutral pH stress corrosion cracking (SCC). Following the rupture the sweet natural gas ignited. Technical investigation report determined that pipeline ruptured due to overstress extension of pre-existing cracks. The cracks had initiated on the outside surface of the pipe and progressed in a mode of failure of transgranular SCC. The pipeline was constructed I 1970 by double submerged arc welded straight seam pipe by the accordance of API 5L Grade X65. (Source, Location)

43. Moomba Australia – January 1, 2004 (Liquid Metal Embrittlement, Gas Processing Plant, USD 5,000,000)

Figure showing failed HE Nozzle of Moomba Gas Plant (Courtesy of AON)

The gas was released that led to vapor cloud explosion. The gas released was caused by the failure of a heat exchanger inlet nozzle in the liquids recovery plant. The failure of the inlet nozzle was due to liquid metal embrittlement of the train B aluminium heat exchanger by elemental mercury. (Source, Location)

44. Skikda Algeria – January 19, 2004 (Liquid Metal Embrittlement, LNG Plant, 27 killed 72 injured, USD 30,000,000)

Figure showing destroyed Skikda LNG Plant

A report noted that the explosion was the consequence of a catastrophic failure in one of the cold boxes of Unit 40, which led to a vapour cloud explosion of either LNG or refrigerant. The most probable source of ignition was the boiler at the north end of Unit 40. The report concluded that the escaped gas was from the cryogenic heat exchanger. (Source, Location)

45. Humber Estuary Killingholme UK – April 16, 2001 (Erosion Corrosion, Refinery, USD 82,400,000)

Figure showing destroyed Humber Estuary Refinery (HSE UK)

On 16 April 2001 a fire and explosion occurred at Humber Refinery following the catastrophic failure of an overhead gas pipe. Investigation was carried by The Competent Authority and the plant operator company by legislative mechanism under Control of Major Hazard (COMAH) Regulation 1999. Humber refinery was one of approximately 1000 major hazard site under this regulation. The competent authority consisted of Health and Safety Executive (HSE) UK and Environment Agency (EA).

Figure showing failed elbow of Humber Estuary Refinery (HSE UK)

The cause of the piping system failure was the erosion corrosion of the 6-inches diameter pipe, known P4363, which carried the overhead line from the De-ethanizer (W413) to the heat exchanger (X452) in saturate gas plant (SGP) unit. The failure occurred down stream of a closely water injection point. Examination to the failed elbow recovered from the damage site showed wall thickness thinning from 7-8 mm to a minimum 0.3 mm. When the pipe failed it burst open catastrophically causing a full bore type of release the pipe contents.
The water injection point was not the original design of the piping system. Water injection to the vapor stream between the top de-ethanizer column and the heat exchanger was addressed to solve the previous problem of salts or hydrates fouling in heat exchanger X452/3. An injection point was created in P4363 by piping water to an existing 1 inches vent point on the pipe without injection quill or dispersal device and made the water entering the pipe as a free jet.

Similar Accident: Wilmington California United States 8 October 1992, North Rhine West Phalia Germany 10 December 1991,Yokkaichi Mie Japan 2 May 1997, Mina Al-Ahmadi Kuwait 25 June 2000. (Source, Location)

List of Engineering Failures Contributed by Material Failures, Corrosion, Design Flaw, and Construction Defect in Oil and Gas Production Facilities, Hydrocarbon Processing, and Oil and Gas Distribution

(Part 3 of 5) - Muhammad Abduh (abduh@reksolindo.co.id)

24. Martinez California US – January 27, 1997 (Creep, Refinery, USD 80,000,000/82,000,000)

An effluent line from reactor in hydrocracker unit failed at pipe body leading to fire and explosion. Released hydrocarbon were auto-ignited because high temperature of the line seconds before explosion. Analysis of the failed pipe noted that the failure mechanism was creep above 1300 °F which expanded the 12-inches pipe circumferentially by 5-inches causing localized bulge in the pipe prior to rupture. (Source)

25. Yokkaichi Mie Japan – May 2, 1997 (Erosion-Corrosion, Petrochemical Plant)

A T-joint of high-pressure piping for recycle ethylene gas failed and lead to explosion. The explosion occurred by the ignition of released ethylene gas by static electricity. Failure was contributed by erosion corrosion event by the evidence of presence of water and a local vortex accompanying a high-speed flow. Erosion corrosion caused a local thinning and the pipe could no longer withstand internal pressure. (Source)

26. Visakhapatnam India – September 14, 1997 (Pipe Leaking, Refinery,50 killed, 27 injured, 100 evacuated, USD 64,000,000)

Piping in loading port and storage tank leaked. The heavier than air gas spread at ground level and ignited. A vapor cloud explosion to this refinery became more severe due to lack of anti-fire foam. The plant layout in which the LPG tanks and pipelines were very close to several administrative building caused large number of fatalities. (Source 1, 2)

27. St Helena California US – December 2, 1997( Corrosion-Pitting, Fuel Pipeline, USD 14,000,000/17,000,000)

36-inches pipe failed with up to 10,000 barrels of gasoline spilled. Both uniform and pit corrosion were found at the failed segment. The pipe was carbon steel with SMYS 52 kpsi, designed at operating pressure 584 psi and maximum allowable pressure at 758 psi. The pressure at the point of failure was 345 psi. (Source)

28. Bintulu Serawak Malaysia -December 25, 1997 (Gas Processing Plant, High Temperature Failure, 12 injured, USD 275,000,000/294,000,000)

Incipient combustion event at air separation unit (ASU) at a gas-to- liquid (GTL) plant and with the presence of liquid oxygen caused the explosive burning of the aluminum heat exchanger elements. The elements ruptured explosively. The plant was shut down for several months for repair. (Source)

29. Longford Victoria Australia -September 25, 1998 (Brittle Fracture, Gas Processing Plant, 2 killed, 8 injured, USD 160,000,000/171,000,000)

Figure Showing GP 905 Heat Exchanger of Longford Gas Plant

Operation error of a bypass valve allowed condensate to spill over into other parts of the system eventually causing the failure of warm oil pumps. Temperature of a heat exchanger decreased sufficiently to lead to material brittle transition. Operator then made error of restarting the warm oil flow which caused the heat exchanger to fracture. An initial release approximately 22,000 pounds of hydrocarbon vapor exploded and made the plant burned for two and a half days. Victoria was said to be in chaos for 19 days. The accident caused a large socio-economic excess. There were 10,000 litigants signed a class action suit that made it a largest class action in Australian legal history. (Source 1,2,3)

30. Berre l’Etang France – October 6, 1998 (Corrosion, Refinery,USD 22,000,000/23,000,000)

A pipe failed due to corrosion and released gas ignited when contacting hot process line. The fire caused the failure of kerosene air cooler and adding more fuel too the fire. The fire created severe damage to 127,000 barrels-per-day crude unit and a 17,000 barrels-per-day reformer. Corrosionwas largely associated with the presence of more corrosive naphtanic acid. (Source)

31. Idjerhe Niger Delta Nigeria – October 17, 1998 (Pipe Leaking,Fuel Pipeline,100 killed)

Pipe leaked a day before the explosion. Large number of victim due to people from surrounding pipeline right of way gathers to fetch the fuel spill. The pipe that burst runs parallel to River Ethiope and has two major foot paths to it from the road. The pipeline was laid in the early 1970. The area is actively cultivated by the local people. Next to the buried fuel pipe is a gas pipeline about 15 meters apart. Poor pipeline maintenance was associated with the leaking. (Source)

32. Knoxville Tennesse US – February 9, 1999 (Brittle Fracture, 15 evacuated, USD 8,100,000)

Figure Showing Circumferential Crack of Knoxville Pipeline (NTSB US)

A pipe failed releasing 53,500 barrels of diesel fuel. The pipe was 10-inches in diameter, API 5L X-42 SMYS 42 kpsi, electric resistance weld (ERW) carbon steel and with 0.25 inches in thickness. Circumferential crack was found at the failed segment. The possible cause for cracking was noted by the low toughness of the manufactured pipe material. The pipe was constructed in 1962 when there was no adequate toughness requirement from available pipe code and design. National Transportation Safety Board had already
given recommendation for toughness requirement to Department of Transportation Research and Special Administration Agency (RSPA) when a similar failure occurred in 1994 in New Jersey. In 2000 responding the request from RSPA, American Petroleum Institute (API) added minimum toughness requirements to API Specification 5L. (Source)

33. Martinez Caifornia US – February 23, 1999 (Corrosion, 4 killed, 1 injured)

Leakage and fire occurred and originated from a heat exchanger. The heat exchganer condensed vapor from a high temperature and high pressure separator at the outlet of the reactor of a fuel oil hydro- desulfurization unit. One heat transfer tube of the fin-fan cooler was was corroded. Corrosion was caused by inadequate re-design of heat exchanger changing service. (Source)

34. Winchester Kentucky US – January 27, 2000 (Crude Oil Pipeline, Fatigue, USD 7,100,000)

Figure showing Winchester fatigue cracked pipeline

A 24-inches pipeline ruptured and released 11,644 barrels of crude oil. Laboratory examination of the failed segment showed a transgranular cracks that had the appearance of typical fatigue progression. The fatigue cracking was caused by a dent in pipe with the combination of fluctuating pressures within the pipe producing high local stress in the pipe wall. (Source)

35. Hunt Texas US- March 3, 2000 (Corrosion, Fuel Pipeline, USD 40,000,000)

28-inches in diameter pipe failed due to external corrosion causing 13,400 barrels of gasoline spill. The failed segment was submerged below ground. Leaking originated at the body pipe. The material was carbon steel with SMYS 52 kpsi, designed at 751 psi to maximum 955 psi. The pressure at the failed segment was 705 psi. (Source)

36. Prince Georges US – April 7, 2000 (Pipe Leaking, Fuel Pipeline, USD 50,000,000/ 57,000,000)

A submerged pipe carrying refined petroleum product failed. At the time of failure, the pipe was 27 years in operation, has SMYS 1.61 kpsi and designed pressured at 550 psi/1600 psi. This pipe failure caused the largest loses of fuel spill that recorded by US DOT PHMSA. A report said that no corrosion significantly susceptible for the cause of failure neither in the weld. (Source)

37. Mina Al-Ahmadi Kuwait – June 25, 2000 (Erosion-Corrosion, Refinery, 5 killed, 50 injured, USD412,000,000/ 433,000,000)

FIgure Showing Mina Al-Ahmadi Refinery Exploded

A condensate line between a NGL plant and refinery failed. The operators were trying to isolate the leaking line and the explosion occurred. Three crude units and two reformers were damaged. Accident to this national biggest oil refinery made an enormous economic looses and excess in sociopolitic when Kuwait oil minister offers resignation. The failed pipe was an aging pipe that suffered erosion-corrosion and slipped through the inspection and maintenance. (Source)

38. Carlsbad New Mexico US – August 19, 2000 (Corrosion-Pitting, Gas Pipeline, 12 killed, USD 100,000,000)

Figure showing micrograph corroded-pit of Carlsbad Pipeline

A 50-years, 30-inch-diameter natural gas transmission pipeline ruptured. The release gas ignited and burned for 55 minutes. Investigation of the failed segment revealed severe internal pit-corrosion as major contributing cause of the failure. At the time of failure the pipe withstand 80% of maximum design pressure. National Transportation Safety recommended amendment in 49 Code of Federal Regulations (CFR) Part 192 to require that new or replaced pipelines be designed and constructed with features to mitigate internal corrosion and to National Association of Corrosion Engineer (NACE) to establish more guidelines to control internal corrosion . Pipeline operator spend USD 15,500,000 for legal fine and USD 86,000,000 for pipeline modifications. (Source)

–

See also : Part 1, Part 2, Part 4, Part 5

List of Engineering Failures Contributed by Material Failures, Corrosion, Design Flaw, and Construction Defect in Oil and Gas Production Facilities, Hydrocarbon Processing, and Oil and Gas Distribution

(Part 2 of 5) - Muhammad Abduh (abduh@reksolindo.co.id)

–

9. Piper Alpha North Sea UK – July 8, 1988 (Gas Leaking, Offshore Platform, 167 killed, US$965,000,000/1,270,000,000)

It was dominantly operation error when gas leaking from two blind flanges then gas ignited and exploded. A pump from two available pumps was tripped, and an operator inadvertently changing the backup pump with pressure relief valve that had been removed for maintenance. Severity damage of the explosion was due to large part the contribution of oil and gas pipelines connected to Piper Alpha. While the platform was in fire two other platform Tartan and Claymore continued pumping gas and oil. (Source 1,2, Video)

10. Antwerp Belgium – March 7, 1989 (Fatigue/Weld Failure, Petrochemical Plant, US$ 77,000,000/99,000,000)

Explosion is believed initiated from a hairline crack in welded seam of piping at the aldheyde column. Ethylene oxide escaped from the leak, formed polyethylene glycol (PEG) in the insulation material and accumulated for a period of time. Sequential explosion was believed by the chemical mechanism inside the insulating material and PEG. The explosion caused extensive damage to the plant and it was closed for at least 24 months with total business interuption cost up to US$ 270,000,000. (Source, Location)

11. Richmond California US – April 10, 1989 (Weld Failure, Refinery, 8 injured,US$87,170,000/112,000,000)

Failed line carrying hydrogen gas caused a high pressure hydrogen fire and resulted in flame impingement to calcium silicate insulation of the hydrocracker reactor skirt. The reactor which was 10 to 12 feet in diameter and wall thickness of seven inches failed subseqently. The reactor was in maintenance cycle for hydrogen purging. It is believed that leaking started from a failed elbow of 2-inch line at 3,000 psi. (Source, Location)

12. Baton Rauge Louisiana US – December 24, 1989 (Brittle Fracture, Refinery,US$ 68,900,000/89,000,000)

The record for low temperature (10 oF and 700 psi) at the region is believed as the major contributor to the failure of 8-inches pipeline carrying gas mixture of ethane and propane. After few minutes of vapor cloud was ignited and piperack containing 70 lines ruptured subsequently. Also with two storage tanks containing 3,600,000 gallons and 12 small tanks containing 882,000 gallons of lube oil also contribute to subsequent fire. (Source, Location)

13. Coatzacoalcos Mexico – March 11, 1991 (Pipe Leaking, Petrochemical Plant,US$ 91,300,000/112,000,000)

Gas leaking from pipe rack lead to explosion. The first explosion occured and caused additional damage to the pipe rack. Second explosion was more powerful and could be felt more than 15 miles from the facility creating damage to offsite third party facility. The explosion and fire made this vinyl chloride plant, a significant output for Mexico national demand, shut down for seven months. (Source, Location)

14. Dhaka Bangladesh – June 20, 1991 (Weld Failure, Petrochemical Plant, US$ 71,000,000)

The fertilizer plant which was constructed in 1970 suffer significant damage due to an explosion. The failure of a welded joint between carbondioxide stripper and main cylindrical body resulted in the release of high pressure gas which consisted of ammonia, carbon dioxide, and carbamate liquids. (Source)

15. North Rhine Germany – December 10, 1991(Erosion-Corrosion, Refinery, US$ 50,500,000/62,000,000)

A Pipe failed at T-junction in hydrocracker unit resulted in hydrocarbon and hydrogen release. The release of the gas ignited and explosion occured and made severe damage to the hydrocracker unit and adjacent substantial part of the plant. The hydrocracker unit was shut down for seven months. The failure of the pipe was contributed by erosion-corrosion due to plant aging. (Source)

16. Guadalajara Mexico – April 22, 1992 (Corrosion, Fuel Pipeline, 206 killed, 500 injured, 15,000 evacuated, US$ 300,000,000)

Guadalajara, Mexico second largest city, experienced series of ten massive explosion that equals to 7,0 richter scale from fuel pipeline blast. An investigation into the disaster revealed that the most possible cause for the explosion was the interference of fuel pipeline with new water piping system. The fuel pipeline was carbon steel and the sewer system was zinc-coated copper. These two lines were close enough to interfere each-other. Three days before the explosion, there were complaints from the city residents
about gasoline-like smell coming from the water pipe and sewer system. (Source 1, 2, Location)

17. Westlake Louisiana US – July 28, 1992 (Weld Failure/Corrosion, Petrochemical Plant, US$ 25,000,000/30,000,000)

A reactor vessel in urea manufacturing unit exploded. The force of the explosion could be felt in areas up to 10 miles from the plant. The fragmented shell of the column propelled up to 900 feet from their original location. The reactor was constructed 25 years earlier with 90 feet tall and 6 feet in diameter. The shell consisted of 4-inches laminations including 3/8 inches stainless steel liner. The explosion resulted from carbamate leaking at the inside vessel. Improper weld on a bracket supporting a tray inside the reactor created carbamate leak and subsequent corrosion and containment of the vessel. (Source, Location)

18. Wilmington California US – October 8, 1992 (Erosion-Corrosion, Refinery, US$ 73,300,000/96,000,000)

An explosion initiated from hydrogen processing unit. Sequential fire and explosion occured to hydrocracker unit, and hydrode sulfurization. The explosion could be felt approximately 20 miles from the plant. The explosion made the plant operator reduce production capacity to 50 percent from its normal 75,000 barrels per-day. It took 8 months to recover the production capacity. The explosion resulted from ruptered carbon-steel-elbow suffering locally thinning due to long term erosion-corrosion. (Source, Location)

19. Sodegaura Japan- October 16, 1992 (Fatigue, Refinery, 10 killed, 7 injured, US$ 160,500,000/196,000,000)

An explosion from failed heat exchanger in the hydrode-sulphurization unit caused hydrogen release and ignited fire and explosion. Technical investigation to the failure noted a complexity of the failure mechanism. The cause of the failure initiated by repetition of variation of temperature lead to decrease of diameter gasket retainer and bending deformation of rock ring. These events contributed to break out of rock ring and made spouts hydrogen gas. (Source, Location)

20. La Mede, France November 9, 1992 (Pipe Leaking, Refinery, US$ 260,000,000/318,000,000)

A pipe failed at T-junction in hydrocracker unit resulted in hydrocarbon and hydrogen release detection. Subsequent fire and explosion caused severe damage to FCC unit, gas plant, control room, and two new process unit under construction. The explosion also causing offsite damage nearby residential within the radius of 6 miles away. The business interuption loss due to this accident is estimated at US$ 180,000,000. (Source, Location)

21. Baton Rouge Louisiana US – August 2, 1993 (Creep, Refinery Plant, USD 65,200,000/78,000,000)

An elbow in the feed line of coker unit ruptured when feed switching were performed. Other pipes in unit ruptured subsequently releasing more hydrocarbons and fueling more fire to the plant. Because of the accident the coker unit was shut down for three weeks. Investigation to the failed elbow noted that carbon steel elbow was wrong material chosen with less creep resistance instead of 5Cr alloy steel.

22. Simpsonville Sacramento US- June 6, 1996 (Pitting Corrosion, Fuel Pipeline, USD 27,000,000/33,000,000)

An aboveground pipe segment failed by corrosion releasing 22,800 barrels of diesel fuel. The pipe manufactured in 1962 with 36-inches in diameter, 0.28-inches in thickness, and has specified maximum yield strength (SMYS) 52 kpsi. The pressure of pipe at the time of failure was 399 psi, the designed maximum pressure was 803 psi. (Source)

23. Rio Piedras San Juan Puerto Rico – November 21, 1996 (Wrong Material in HCA, Gas Distribution Pipeline, 33 killed, 69 injured, USD 5,000,000)

Polyethylene pipe transporting propane gas to consumer was failed leading to fire and explosion. The explosion occurred in five stories full occupied business center at shopping district Rio Piedras San Juan Puerto Rico. The leaking of plastic pipe was believed due to construction excavation damage around the pipeline. More than 20 pipes and conduits surrounding the plastic pipe which were being constructed, being used and had been abandoned. Construction excavation damage to plastic pipe was rather unavoidable and there should be pipeline design with higher integrity within high consequence area (HCA) like Rio Piedras shopping district. (Source)

–

See also : Part 1, Part 3, Part 4, Part 5

List of Engineering Failures Contributed by Material Failures, Corrosion, Design Flaw, and Construction Defect in Oil and Gas Production Facilities, Hydrocarbon Processing, and Oil and Gas Distribution

(Part 1 of 5) - Muhammad Abduh (abduh@reksolindo.co.id)

As key chain in world energy supply, the industry within oil and gas production, hydrocarbon refinery, storage and distribution, and power plant industry strive to achieve the highest level of integrity and reliability of their facilities, structures, tool and equipment system. Industry stakeholders that ranging from oil and gas producer, engineering, procurement, contractors, material suppliers, and inspection companies from day to day improve the quality standards, discovering new tehcnologies, develop new techniques and methodologies in order to raise the engineering integrity for the improvement of safety for people , environment conservation, and securing economic investment.

Tak ada gading yang tak retak. As an ancient Indonesian proverb is also happened to engineering structure: there will be no design without flaw and there will be no construction without defect. Failures sometimes occur. In several cases the aftermath of failures have a significant impact to the people safety and economic risk. But industry gain a valuable experience each accident occurs. There always be opportunities to improve operation procedures, value perceptions, technical code revisions, and regulatory improvements.

This publication as a result of literature work is aimed is to develop an alternative engineering failure database associated with material failures,corrosion, design flaw and construction defect that lead to material failure in oil and gas production, hydrocarbon industry, oil and gas distribution network, and energy power plant.

1. Umm Said Qatar – April 3, 1977 (Weld Failure, Gas Processing Plant, 3 killed, US$ 76,350,000/179,000,000)

A tank containing 236,000 barrels of refrigerated propane at 45 °F failed at weld. Near-miss-accident a year earlier reported at similiar tank weld caused 14,000 barrels of propane released. The possible cause of weld failure was corrosion by the influence of sulphate reducing bacteria that remained inside the tank after hydrotest with seawater. The wave of liquid propane swept over the dikes before igniting a near tank contained 125,000 barrels of buthane. It took eight days to completely extinguished the fire. (Source, Location)

2. Abqaiq Saudi Arabia – April 15, 1978 (Corrosion, Gas Processing Plant, US$ 53,700,000/117,000,000)

A 22-inch pipe operated at 500 psig in gas transmission system corroded and releasing vapor cloud. The first ignition occured from a flare 1,500 feet downwind. The second ignition occured when jet whipped pipe section struck the vapor space of a 10,000 barrels spheroid tank. (Source, Location)

3. Ekofisk Norway – March 27, 1980 (Weld Failure, Offshore Platform, 123 killed)

Alexandra L Kielland Platform, a semi-submersible oil drilling platform located at Ekofisk field North Sea capsized during a storm. The platform supported by five columns standing on five 22 meter diameter pontoons. The five 8.5 diameter columns on the pontoons were interconnected by a network of horizontal bracings. The cracked bracing made five other bracing broke off due to overload, and the vertical column connected with the cracked bracings became separated from the platform. The platform subsequently became unbalanced and capsized.

The investigation showed that a fatigue crack had propagated from the double fillet near the hydrophone mounted to one of the horizontal bracing. Some cracks related to lamellar tearing were found in the heat affected zone (HAZ) of the weld around the hydrophone. Learning from this accident some countermeasures were undertaken including the amendment of the standards in for stability, motion characteristics, manueverability, watertight doors, and structural strength in Mobile Offshore Drilling Units (MODU) Code by the International Maritime Organization. (Source 1, 2)

4. Edmonton Canada – April 18, 1982 (Fatigue, Petrochemical Plant, US$ 21,000,000/33,000,000)

Vibration from the reciprocating compressor was believed causing transverse fatigue of 1/8 stainless steel instrument tubing. High pressure ethylene released causing a fire by static electricity ignition. Although the compressor building equipped with gas detection system the gas release was not accurately relayed to the control room. Automatic fail-safe valves functioned properly by blocking the flow of more ethylene which was up to 11,000 pounds of gas already released causing damage to this low density polyethylene plant. (Source)

5. Remeoville Illinois US- July 23, 1984 (Weld Failure, Refinery, 17 killed, US$ 191,000,000/273,000,000)

A vessel for monoethanolamine absorber was constructed ten years earlier with one-inch thick ASTM A516 Gr 70 steel plates rolled and welded with full submerged arc without post weld heat treatment. Just prior to rupture a 6- inches crack detected at circumferential weld and by the time operator close inlet valve crack spread to 24 inches. The area was already cleared for evacuation and when fire brigade arriving the explosion occured. This explosion created sequential fire and explosion within refinery plant. A boiling liquid expanding vapor exposion (BLEVE) occured in a alkylation unit vessel.
Technical investigation pointed that crack initiated at HAZ of welded shell of the column by hydrogen cracking, and progressed by the mechanism of hydrogen induced stepwise cracking (HISC). Test according to NACE procedure confirmed that material was susceptible to HISC. (Source 1, 2)

6. San Juan Ixhuatepec Mexico City Mexico – November 19, 1984 (Pipe Leaking, LPG Terminal, 650 killed 64,000 injured, US$ 19,940,000/29,000,000)

A 12-inches pipeline between cylinder and sphere storage ruptured. Initial blast caused a series of BLEVEs. The oustanding cause of escalation was the ineffective gas detection system and as a result of lack of emergency isolation. This explosion and fire is perhaps the most devastating incident ever. The high death toll was due to the proximity of the LPG terminal to residence complex. Until now there is no clear information about the cause of pipe rupture. (Source 1, 2)

7. Las Piedras Venezuela- December 13, 1984 (Hydrogen Embrittlement, Refinery, US$ 62,076,000/89,000,000)

A fracture occured in 8-inch line carrying hot oil from hydrode sulfurizer. Crack found in heat affected zone about 1 – 1/2 inches from weld. Hot oil at 700 psi and 650 oF sprayed and ignited at the hydrogen units. Fire causing sequential rupture of 16-inch gas line and successively blow torch to piping system in adjacent areas. Vibration analysis nine years earlier judged that the failed line was having excessive vibration and it strengthened the confidence that the hot oil line failed in fatigue dominantly due to hydrogen embrittlement. (Source)

8. Norco Louisiana- US May 5, 1988 (Erosion-Corrosion, Refinery, 4 killed, 20 injured, 4500 evacuated US$ 254,700,000/336,000,000)

An elbow at depropanizer column piping system in a fluid catalytic cracking (FCC) unit failed. A large vapor with estimated 20,000 pounds of C3 hydrocarbon cloud escaped from the failed elbow and ignited in FCC charge heater. The explosion of FCC unit was the most severe damage. A report pointed that the failed elbow suffering excessive locally thinning. The failed elbow was located downstream of the injection point where ammoniated water was added to reduce propanizer condensation or fouling.(Source 1, 2)

–

See also: Part 2, Part 3, Part 4, Part 5

Muhammad Abduh (abduh@reksolindo.co.id)

Print Version Published for PetroEnergy February-March 2008 Edition

Remarkable fires and explosions to several production and processing sites in Cilacap, Tuban, and Belawan and also the remaining public controversy of Sidoarjo Mud Volcano recently should be learned within the industry to better manage engineering accidents. Every accident was triggered by multi-event of failures. Those failure events are contributed by faults of one or more elements that build the system (e.g. design, health and safety policy, operation and maintenance). Oil and gas industry that have of facilities with high pressure system, corrosive medium, and hostile environment have a large engineering failure experiences from the fire in Piper Alpha to the recently explosion of Texas City Refinery. This paper will present an overview of major engineering failures in oil and gas and hydrocarbon industry and to look for an alternative perspective for the mitigation management in Indonesia.

Figure 1. Cilacap Pipeline Fire 2008 and Belawan Pipeline Fire 2008 (liputan6.com)

I. Major Engineering Failures (1977-2007)

Compilation of engineering failures that has significant impact both in economic and personnel safety have been already developed by several integrity engineering companies, government bodies, health and safety authorized body, engineering risk consultants, insurance companies, and loss adjusters Table 1.

II. FAILURE ANALYSIS AND FAILURE MAPS

Every failure is an unexpected event. But if it happened, we can track back to find out the failure path, contributing events, and root causes. This methodology in broader term will refer as failure analysis. In the development failure analysis methodologies, there are several approach to express the structure of failures including root cause analysis (RCA), failure mode effect analysis (FMEA), event tree analysis (ETA), and fault tree analysis (FTA). One recent development in failure analysis is the expanding of the failure elements domain to the overall company organization (e.g. HSE, Human Resources, Quality Policy) and the socio-economic environment (regulatory systems, societal), Figure 2 .

Figure 2. Failure Map

Expanding the Root Cause

Engineering failure is triggered by multi-event of failures. The term of root cause then becomes relative. As we can see from above figure, surrounding societal aspects that include regulatory system can trigger the failure. Technical investigation to find out the nature of the accident should be beneficial in order to make necessary improvement in technical regulation. As we know that the first issue of American Society of Mechanical Engineer (ASME) Code for Boiler and Pressure Vessel was driven by the explosion of shoe factory in Boston in 1914. United States regulation on pipeline safety 49 CFR 192 has been already amended for several times following previously some significant pipeline explosions. The amendment was expected the close the void in the regulation that makes the accident occurred.

III. TECHNICAL MEASURES OF FAILURES

Technical measures which failed or were not adequately implemented in each of the accidents are:

Figure 3. Accident Mitigation Scheme

IV.ACCIDENT MITIGATION

Accident mitigation differs in every country. In several countries regulatory system defines and provides the procedure for the formation of an investigation authority. In United Kingdom the formation of this official investigation body is ruled under COMAH (Control of Major Hazard) Regulation 1999. The competent authority under this regulation minimally consists of Health and Safety Executive (HSE) and Environment Agency. Additionally, in United States the investigations are performed by several government agency including Chemical Safety Board (CSB), Pipeline Hazardous Material Safety Administration (PHMSA), and National Transportation Safety Board (NTSB) supported by third party investigation company (e.g. integrity engineering, explosion engineering, failure analyst, risk analyst, loss adjustor). In other case like P-36 Sinking, Petrobras performed an in-house investigation and the results were validated by third party company.

The investigation authorities performed task as follows:

- Find out the root cause, contributing event, chronology;

- Give necessary recommendation for the company to prevent the occurrence of the failure;

- To propose amendment in regulation;

- To propose revision for technical code and designs;

- To publish neutral public information;

One important action in accident mitigation is technical investigation. Technical investigation is an activity to find out the technical nature of the accident that includes failure analysis. Outputs expected from technical investigation are:

Conclusion

From engineering accident experience, stakeholders in oil and gas industry have an opportunity to develop better managed accident mitigation. Reference shows that more managed accident mitigation action will reduce non-technical excess of the accident (e.g. public miss-perception, distortion of information), improvement in technical code and design regulations, and to solve legal or contractual disputes.

Reference

1. Duddy Yan Purnadi (duddy@reksolindo.co.id)
2. Dr. Ir. Slameto Wiryolukito (slameto@material.itb.ac.id)
3. Muhammad Abduh ( abduh@reksolindo.co.id)
* Print Version Published in PetroEnergy Magazine Edition Nov-Des 2007
I. Introduction
Engineering integrity is a subsystem of integrity management. As a system of a whole, engineering integrity works together with the overall operations policy, health safety and environment standard, integrity performance standard, and legislative compliance. Engineering integrity becomes the major concern for oil and gas operator as a result of high impact of catastrophic accident in many countries. Both integrity standard API 1160 and ASME B31.8 were originally addressed for industry consensus in United States. These documents also referred as governing documents for pipeline safety regulation US DOT CFR 49 192. This paper will present an overview of engineering integrity, the elements and approaches to build and develop in oil and gas industry. Since integrity management covers multi aspects, there is a need to be more focus and to limit boundaries for engineering integrity, what are the elements, and how can this subsystem affects and interacts with other subsystem.
II. Engineering Integrity as Systematic Approach
Engineering structures, equipments, and components play a vital role in oil and gas industry as such to maintain production target. Any threat to these components will also threaten the performance overall structures. We may understand that engineering integrity is an integrated system, which is every element, affects other element in overall system. Then simply we can understand that integrity of a pressure vessel once depend on the welding quality. Any defect in welding will threaten overall performance of the pressure vessel. These process elements in developing engineering integrity can be described in Figure 1.

Figure 1 – Element of Process in Engineering Integrity Approach

III. Materials Selection
As we know materials properties depend on its microstructure, any treatments that alters microstructure will alter material properties. Phase transformation occur when steels are in process of heat treatment, welding, and other thermal affected treatments. Materials integrity can be sustained if we can maintain as received microstructure against all process subjected to it. A reliability of an equipment or engineering structures (piping, fixed offshore platform, floating structures) started from the process materials selection. Basic control points for material selection should be:

- Mechanical properties (acceptable of mechanical load)
- Corrosion Properties (sweet corrosion or sour corrosion)
- Failure Resistance, crack resistance (pitting, HIC, toughness)

Some of the codes for material selection guideline in oil and gas industry:

- Material Load Design: ASME Boiler and Pressure Vessel Section II, IX, X
- API 5L Specification for Linepipe
- Material Selection: Norsok M-001 Material Selection
- Corrosion Resistance Material/ SSC Resistance Material: NACE MR 0103-2003, MR 0175/ISO 15156, EFC Document No 16
- Plastic or Fiber Reinforced Plastic Material Design Basis: ASME Boiler and Pressure Vessel Section X, PPI TR-3/2004, API 15LR, API RP-15S

Trend of corrosion resistance alloy (CRA) steel in Oil and Gas
A story of CRA Steel was setback in 1970 era when clad steel and duplex stainless steel were first applied by Dutch operator company NAM1. The story of duplex stainless steel in oil and gas flowlines begins with its greater range of application in term of corrosion resistance. By the end of 2002 duplex stainless steel still the dominant material for flowlines. When facing more corrosive or more sour condition, the choice turned to clad steel. Clad steel with clad material AISI 316L or alloy 825 clad then become the material of choice in H2S environment. It was in Indonesia, for the first time martensitic stainless steel applied by Exxon for Arun Field. Since martensitic stainless steel is less expensive in less corrosion environment and the development of low carbon weldable 13Cr MSS, a research predicted that MSS will dominate the choice for CRA flowlines in the future, Figure 2.

Figure 2. CRA Trend in Flowlines

New Materials Conversion
Facing corrosion problem, oil and gas industry get alternative material choice. The use of fiber reinforced plastic pipe is more economically attractive. Some advantages of this material type compared to conventional steel materials:

- Corrosion resistance;
- More flexibility because FRP is coilable and the installation can be faster;
- Low maintenance cost

The advance material conversion to plastic and plastic reinforced pipe somewhat should consider some limitations as:
- Limited range of pressure application;
- Pipeline integrity program for available methods are for steel materials. There should be further development for developing plastic pipe integrity since the tools and equipment of inline inspection, NDT inspection, and defect assessment is designed for steel material;
- Creep failure of these materials reported. BP Amoco experiencing creep in higher temperature and cyclic loading condition;
- Reactivity of resin with H2S reported by Saudi Aramco for their shallow casing liners;
- Compatibility for connection with other component;
- Brittle like crack in plastic pipe;

IV. Fabrication and Construction
Fabrication and construction become crucial issue when as many studies reported that failure associated with welding and handling. Typical fabrication defect of stainless steel shown in Figure 3. To ensure processes in fabrication and construction maintain materials property there is knowledge demand in phase transformation and material thermodynamic. Unwanted phase transformation can occur during welding. The most stable protective passive film over stainless steel is introduced by passivation. During welding metal is reheated to its melting temperature and variably differ along heat affected zone. Free air exposed to this metal region will produce unstable porous and dense passive film. Unexpected oxidizing during welding can be prevented by application of shielding gas.

Pitting during transport, storage, hydrostatic testing and prior to service
The presence of iron contaminants in contact with stainless steel in aerated water environment tends to break passive film. Effect of pitting becomes worst in stagnant water. Longer periods of stagnant water exposure will create severe pitting attack over stainless steel. A case in relation with pipe handling was experienced by VICO Indonesia in Badak-Bontang pipeline project in 1999. The debris formed during pipe transport to storage in open sandy tropical climate lead to the formation of iron oxide (Fe2O3, Fe3O4) and iron sulfide (FeS). A fingerprint inspection had detected significant 40.000 defect features that can be related with the existence of debris. There were 10 sections replaced against ASME B31.G acceptance limit.

Figure 3 . Typical Welding Related Defect

Deadly Failed Coating
TWI UK said this case as “Deadly Corrosion Failure” as the explosion and fire led to death of several personnel. The pipeline was designed according to ASME B31.4. The breakdown of external coating made cathodic protection overload which cause pitting. Pit coalescence causing a large area to cause failure of rupture exposing and ignite methane gas to open air.
Welding Defect Disaster
Another TWI classic case was the rupture of amine absorber column (designed according to ASME Section VIII Section I, ASTM A516) in 1984, Figure 4. A report said that 17 people dead and economic loss over $ 100 million. Investigation report said that root cause of failure was the formation of hard HAZ in welded part of column shell.

Figure 4. Explosion of Amine Absorber Column (TWI Case, 1984)

Poor Workmanship
Writer’s Company recently had an opportunity to asses a gas plant facility in seashore environment. Investigation has found that some critical components (elbows, etc) experiencing residual stress by the evidence of magnetic properties change. Possible causes of this residual stress are the weld spatter and impact contact with hammer or bolt with the pipe segment.
Lesson learnt from above case is that there is a demand of multidisciplinary peer review for the integrity of fabrication and construction structures, involving stress analyst, inspection engineer, and material engineer. Since all of these structures were already fulfill their design code, multidiscipline validation process is important to reduce potential failure. Every engineer involved in fabrication and construction has responsibilities to give more attention to the small issues big impact as follows:
- Material handling: keep stainless steel clean from iron dust, stagnant water, sand, clay that tend to form debris, pitting, and crevice corrosion, avoid contact with steel component with different composition which make cathodic potential for corrosion.
- More attention to condition of stainless steel pipe in outdoor material storage, in a time between post-commissioning prior to service.
- Welding for critical components should assure acceptance welded joint for design life;
- Be careful with critical components, any impact contact with other tools or weld spatter can make localized cold deformation phase transformation which leads to residual stress. This could be harmful in case of erosion-corrosion phenomenon.