A press release from the UK RAIB:
RAIB is investigating an incident that occurred at 17:25 hrs on Saturday 7 March 2015, in which train reporting number 1Z67, the 16:35 hrs service from Bristol Temple Meads to Southend, passed a signal at danger on the approach to Wootton Bassett junction, Wiltshire. The train subsequently came to a stand across the junction. The signal was being maintained at danger in order to protect the movement of a previous train. However, at the time that the SPAD occurred, this previous train had already passed through the junction and was continuing on its journey. No injuries, damage or derailment occurred as a result of the SPAD.
Wootton Bassett junction is situated between Chippenham and Swindon stations on the Great Western main line and is the point at which the line from Bristol, via Bath, converges with the line from South Wales. It is a double track high speed junction which also features low speed crossovers between the up and down main lines (see figure below for detail).
Wootton Bassett junction in 2012 – the lines shown from left to right are the Up Goods,
Up Badminton, Down Badminton, Up Main and Down Main (image courtesy of Network Rail)
The junction is protected from trains approaching on the up main from Chippenham by signal number SN45, which is equipped with both the Automatic Warning System (AWS) and the Train Protection and Warning System (TPWS). This signal is preceded on the up main by signal SN43, which is also equipped with AWS and TPWS. The maximum permitted line speed for trains approaching the junction from this direction is normally 125 mph. However, on 7 March, a temporary speed restriction (TSR) of 85 mph was in place on the approach to signal SN45. A temporary AWS magnet had been placed on the approach to signal SN43 to warn drivers of this TSR.
A diagram of the layout of Wootton Bassett junction – note that some features have been omitted for clarity (not to scale)
The train which passed signal SN45 at danger consisted of steam locomotive number 34067 ‘Tangmere’, and its tender, coupled to 13 coaches. The locomotive is equipped with AWS and TPWS equipment.
The RAIB’s preliminary examination has shown that, at around 17:24 hrs, train 1Z67 was approaching signal SN43 at 59 mph, when it passed over the temporary AWS magnet associated with the TSR. This created both an audible and visual warning in the locomotive’s cab. However, as the driver did not acknowledge this warning within 2.7 seconds, the AWS system on the locomotive automatically applied the train’s brakes. This brake application should have resulted in the train being brought to a stand. In these circumstances, the railway rule book requires that the driver immediately contact the signaller.
The RAIB has found evidence that the driver of 1Z67 did not bring the train to a stand and contact the signaller after experiencing this brake application. Evidence shows that the driver and fireman instead took an action which cancelled the effect of the AWS braking demand after a short period and a reduction in train speed of only around 8 mph. The action taken also had the effect of making subsequent AWS or TPWS brake demands ineffective.
Shortly after passing the AWS magnet for the TSR, the train passed signal SN43, which was at caution. Although the AWS warning associated with this signal was acknowledged by the driver, the speed of the train was not then reduced appropriately on the approach to the next signal, SN45, which was at danger. Because of the earlier actions of the driver and fireman, the TPWS equipment associated with signal SN45 was unable to control the speed of the train on approach to this signal.
As train 1Z67 approached signal SN45, the driver saw that it was at danger and fully applied the train’s brakes. However, by this point there was insufficient distance remaining to bring the train to a stand before it reached the junction beyond SN45. The train subsequently stopped, standing on both the crossovers and the up and down Badminton lines, at around 17:26 hrs. The signalling system had already set the points at the junction in anticipation of the later movement of 1Z67 across it; this meant that no damage was sustained to either the train or the infrastructure as a result of the SPAD.
The RAIB has found no evidence of any malfunction of the signalling, AWS or TPWS equipment involved in the incident.
The RAIB’s investigation will consider the factors that contributed to signal SN45 being passed at danger, including the position of the temporary AWS magnet associated with the TSR. The investigation will also examine the factors that influenced the actions of the train crew, the adequacy of the safety systems installed on the locomotive and the safety management arrangements.
RAIB’s investigation is independent of any investigation by the Office of Rail Regulation.
We will publish our findings, including any recommendations to improve safety, at the conclusion of our investigation.
These findings will be available on the our website.
The Houston Chronicle published an article by Rafael Moure-Eraso of the Chemical Safety Board that was titled: “Hazardous work takes toll on Latinos”.
In the article, Rafael Moure-Eraso claims that Latinos’ “… fatality and injury rates are disproportionately high.” He provides statistics on Latino fatalities and injuries in various industries. He references a report that states the obvious (as many Latinos are recent immigrants, they tend to get lower paying and more dangerous jobs). He also states that latinos are more likely to be at risk as residents near chemical plants (once again, obviously rich people usually don’t site their mansions next to chemical plants and the poor are more likely to buy cheap housing in a less desirable locations – like next door to an industrial site).
The article seems to be a mix of environmental justice political speech and a call for new federal regulations to improve chemical plant safety.
He ends the article with:
“You can’t put a price on someone’s life. Latinos help drive the country’s economy working hard for companies big and small, often in dangerous occupations. They have a right to safer workplaces and communities.“
That made me think …
- Are new rights (the right to safety … whatever that is) and new federal programs really the way to improve safety in the workplace?
- Do accidents really target specific races?
- Would a federally run workplace be safer than those run by commercial companies?
- Would safety improve faster with more federal direction?
- Does the government know better than those in commercial industry how to improve safety?
- What does management at major companies need to do if they want to avoid a whole new level of “one size fits all” government regulation of process safety and industrial safety?
These are all very interesting questions that take considerable thought. I’d be interested in your opinions. Leave a comment here.
Like this if you are a fire fighter…
The UK Rail Accident Investigation Branch announced the start of two rail incident investigations.
The first is an investigation of the injury of a passenger that fell between a London Underground train while being dragged by the train. See the preliminary information at:
This is an accident that was prevented from being worse by the alert actions of the train’s operator.
The second incident was container blown off a freight train. The preliminary information can be found here:
Here’s a CSB video …
What do you think? Has PSM improved in the past ten years? What can we learn?
Is “inherently safer designs” the answer?
Are PSM regulations going to stop accidents?
Are government approaches to PSM inadequate?
Are the suggestions of the CSB inadequate?
Leave your comments here.
On March 20, 1905, 58 employees died and 150 people were injured during a boiler explosion in Brockton, Massachusetts. Among the 300+ employees who worked at the factory, about 100 went unharmed.
The Grover Shoe Factory is the largest boiler disaster ever recorded in American Industrial Industry.
What happened? An over-worked pressure boiler exploded and shot through the roof of the factory causing the roof to collapse. The floors below collapsed because of the extra weight added by each collapsing floor, leaving the workers trapped in the rubble.
The combination of broken gas lines, air, and ventilation caused the factory and the buildings around it to become a blazing inferno.
The boiler traveled several hundred feet causing damages to a number of buildings and eventually landing on a house.
To read the full PDF about this incident click here.
Having run an excavator, a track loader, a bulldozer, and a dump truck, this is what your nightmares look like…
Monday Accident & Lessons Learned: Crane Accident at Tata Steel Plant in the UK brings £200,000 Guilty VerdictMarch 16th, 2015 by Mark Paradies
Tata Steel was found guilty of violating section 2(1) of the Health and Safety at Work etc. Act 1974. The result? A fine of £200,000 plus court costs of £11,190.
HSE Inspector Joanne carter said:
“Given the potential consequences of a ladle holding 300 tonnes of molten metal spilling its load onto the floor, control measures should be watertight. The incident could have been avoided had the safety measures introduced afterwards been in place at the time.”
The article listed the following corrective action:
“Tata has since installed a new camera system, improved lighting, and managers now scrutinise all pre-use checks. If the camera system fails, spotters are put in place to ensure crane hooks are properly latched onto ladle handles.
Here are my thoughts…
- Stating that corrective actions would have prevented an accident is hindsight bias. The question should be, should they have learned these lessons from previous near-misses?
- Reviewing the corrective actions, I’m still left with the question … Should the crane be allowed to operate without the camera system working? Are spotters a good temporary fix? How long should a temporary fix be allowed before the operation is shut down?
- What allows the latches to fail? Shouldn’t this be fixed as well?
What do you think? Is there more to learn from this accident? Leave your comments here.
The International Business Times reports that a Ukraine coal mine that recently had an accident that killed 34 miners is responsible for 300 fatalities since 1999. See the story at:
The whole rescue process is being complicated by the fighting in the Ukraine.
Another story claim that investment in “safety technology” could have prevented the methane blast at the mine.
Press Release from the UK Rail Accident Investigation Branch: Bridge strike and collision between a train and fallen debris at Froxfield, Wiltshire, 22 February 2015March 11th, 2015 by Mark Paradies
Image of debris on track before the collision, looking east.
Train 1C89 approached on the right-hand track
(image courtesy of a member of the public)
Bridge strike and collision between a train and fallen debris at Froxfield, Wiltshire, 22 February 2015
RAIB is investigating a collision between a high speed train (HST) and a bridge parapet which had fallen onto the railway at Oak Hill, an unclassified road off the A4 on the edge of the village of Froxfield, between Hungerford and Bedwyn. The accident occurred at about 17:31 hrs on Sunday 22 February 2015, when the heavily loaded 16:34 hrs First Great Western service from London Paddington to Penzance (train reporting number 1C89) hit brick debris while travelling at about 90 mph (145 km/h). The train driver had no opportunity to brake before hitting the debris, and the impact lifted the front of the train. Fortunately, the train did not derail, and the driver applied the emergency brake. The train stopped after travelling a further 730 metres (800 yards). There were no injuries. The leading power car sustained underframe damage and there was damage to the train’s braking system.
The bridge parapet had originally been struck at about 17:20 hrs by a reversing articulated lorry. The lorry driver had turned off the A4 at a junction just north of the railway bridge, and crossed over the railway before encountering a canal bridge 40 metres further on which he considered to be too narrow for his vehicle. A pair of road signs located just south of the A4 junction warn vehicle drivers of a hump back bridge and double bends but there were no weight or width restriction signs. The lorry driver stopped before the canal bridge and attempted to reverse round a bend and back over the railway bridge without assistance, and was unaware when the rear of his trailer first made contact with, and then toppled, the brick parapet on the east side of the railway bridge. The entire parapet, weighing around 13 tonnes, fell onto the railway, obstructing both tracks. This was witnessed by a car driver who was travelling behind the lorry. The car driver left his vehicle to alert the lorry driver and he then contacted the emergency services by dialing 999 on his mobile phone at about 17:21 hrs.
RAIB’s investigation will consider the sequence of events and factors that led to the accident. The investigation will include a review of the adequacy of road signage and the overall response to the emergency call made by the motorist who witnessed the collapse of the bridge parapet. It will identify any safety lessons from the accident and post-accident response.
RAIB’s investigation is independent of any investigations by the railway industry or safety authority.
The RAIB will publish the findings at the conclusion of the investigation on it’s website.
Press Release from the Chemical Safety Board: CSB Releases Technical Analysis Detailing Likely Causes of 2010 Zinc Explosion and Fire at the Former Horsehead Zinc Facility in Monaca, Pennsylvania, that Killed Two Operators, Injured a ThirdMarch 11th, 2015 by Mark Paradies
CSB Releases Technical Analysis Detailing Likely Causes of 2010 Zinc Explosion and Fire at the Former Horsehead Zinc Facility in Monaca, Pennsylvania, that Killed Two Operators, Injured a Third
Washington, DC, March 11, 2015 – The July 2010 explosion and fire at the former Horsehead zinc refinery in Monaca, Pennsylvania, likely resulted from a buildup of superheated liquid zinc inside a ceramic zinc distillation column, which then “explosively decompressed” and ignited, according to a technical analysis released today by the U.S. Chemical Safety Board (CSB).
Two Horsehead operators, James Taylor and Corey Keller, were killed when the column violently ruptured inside the facility’s refinery building, where multiple zinc distillation columns were operating. The rupture released a large amount of zinc vapor, which at high temperatures combusts spontaneously in the presence of air. The two men had been performing unrelated maintenance work on another nearby column when the explosion and fire occurred. A third operator was seriously injured and could not return to work.
The incident was investigated by multiple agencies including the CSB and the U.S. Occupational Safety and Health Administration, but its underlying cause had remained unexplained. In the fall of 2014, CSB contracted with an internationally known zinc distillation expert to conduct a comprehensive review of the evidence file, including witness interviews, company documents, site photographs, surveillance videos, laboratory test results, and data from the facility’s distributed control system (DCS). The 57-page report of this analysis, prepared by Mr. William Hunter of the United Kingdom, was released today by the CSB. Draft versions of the report were reviewed by Horsehead and by the United Steelworkers local that represented Horsehead workers in Monaca; their comments are included in the final report as appendices.
In the years following the 2010 incident, the Horsehead facility in Monaca was shut down and dismantled. The “New Jersey” zinc process, a distillation-based method that was first developed in the 1920’s and was used for decades in Monaca, is no longer practiced anywhere in the United States, although a number of overseas companies, especially in China, continue to use it.
“Although this particular zinc technology has ceased being used in the U.S., we felt it was important to finally determine why this tragedy occurred,” said CSB Chairperson Dr. Rafael Moure-Eraso. “Our hope is that this will at last provide a measure of closure to family members, as well as inform the safety efforts of overseas companies using similar production methods.”
The Hunter report was based on expert professional opinion, and did not involve any onsite examination of the evidence. CSB investigators made several short deployments to the Horsehead site in 2010 following the incident, interviewing a number of witnesses and documenting conditions at the site.
The explosion involved an indoor distillation column several stories tall. The column consisted of a vertical stack of 48 silicon carbide trays, topped by a reflux tower, and assembled by bricklayers using a specialized mortar. The bottom half of the column was surrounded by a masonry combustion chamber fueled by natural gas and carbon monoxide waste gas. Horsehead typically operated columns of this type for up to 500 days, at which time the columns were dismantled and rebuilt using new trays.
The explosion on July 22, 2010, occurred just 12 days after the construction and startup of “Column B.” Column B was used to separate zinc – which flowed as a liquid from the bottom of the column – from lower-boiling impurities such as cadmium, which exited as a vapor from the overhead line. The column, which operated at more than 1600 °F, normally has only small amounts of liquid metals in the various trays, but flooding of the column creates a very hazardous condition, the analysis noted. Such flooding likely occurred on July 22, 2010.
“Under extreme pressure the tray wall(s) eventually failed, releasing a large volume of zinc vapor and superheated zinc that would flash to vapor, and this pressure pushed out the combustion chamber blast panels,” Mr. Hunter’s report concluded. “The zinc spray and vapor now had access to large amounts of workplace air and this created a massive zinc flame across the workplace.”
After examining all the data, the report determined that the explosion likely occurred because of a partial obstruction of the column sump, a drain-like masonry structure at the base of the column that had not been replaced when the column was rebuilt in June 2010. The previous column that used this sump had to be shut down prematurely due to sump drainage problems, the analysis found. These problems were never adequately corrected, and various problems with the sump were observed during the July 2010 startup of the new Column B. Over at least an hour preceding the explosion, DCS data indicate a gradual warming at the base of Column B, as liquid zinc likely built up and flooded the lower trays, while vapor flow to the overhead condenser ceased.
Ten minutes before the explosion, an alarm sounded in the control room due to a high rate of temperature change in the column waste gases, as zinc likely began leaking out of the column into the combustion chamber, but by then it was probably too late to avert an explosion, according to the analysis. Control room operators responded to the alarm by cutting the flow of fuel gas to Column B but did not reduce the flow of zinc into the column. The unsafe condition of Column B was not understood, and operators inside the building were not warned of the imminent danger.
The technical analysis determined that there was likely an underlying design flaw in the Column B sump involving a structure known as an “underflow” – similar to the liquid U-trap under a domestic sink. The small clearance in the underflow – just 65 millimeters or the height on one brick – had been implicated in other zinc column explosions around the world, and likely allowed dross and other solids to partially obstruct the sump and cause a gradual accumulation of liquid zinc in the column. Liquid zinc in the column causes a dangerous pressure build-up at the bottom and impairs the normal evaporation of vapor, which would otherwise cool the liquid zinc. Instead the liquid zinc becomes superheated by the heat from the combustion chamber, with the pressure eventually rupturing the column and allowing the “explosive decompression.”
The report noted that the Column B sump had previously been used with a different type of column that had a much lower rate of liquid run-off through the sump, so the problem with the sump was only exacerbated when Column B was constructed to separate zinc from cadmium, increasing the liquid flow rate into the sump by a factor of four to five.
The report concluded that Horsehead may have missed several opportunities to avoid the accident, overlooking symptoms of a blocked column sump that were evident days before the accident. “Missing these critical points indicates that, in large measure, hazardous conditions at Monaca had been ‘normalized’ and that process management had become desensitized to what was going on. This raises the question whether sufficient technical support was provided to the plant on a regular basis,” according to Mr. Hunter.
The report noted that New Jersey-type zinc distillation columns have been involved in numerous serious incidents around the world. In 1993 and 1994, two column explosions at a former French zinc factory killed a total of 11 workers. An international committee of experts who investigated the incidents in France identified up to 10 other major incidents at other sites attributable to sump drainage problems. The Monaca facility had suffered five documented column explosions prior to 2010, but none with fatalities, according to the CSB-commissioned report.
For more information, contact Daniel Horowitz at (202) 261-7613 or (202) 441-6074 cell.
Whenever you deal with a hazard, someone has to decide how many safeguards are enough.
Moving oil by tank cars is probably not the safest method of transporting oil. Pipelines are probably preferable. But pipelines don’t go from every oil source to every refinery. (And getting new pipelines permitted can be difficult – as we know.)
Rail accidents bring up the question … Should we be working on preventing the root causes of rail accidents OR should we be coming up with better safeguards (better rail cars) OR should we be working on getting more pipelines built as a longer term solution?
Here’s the article from the Journal News that got me thinking about this issue:
What do you think? What corrective actions would be SMARTER and what is enough? Leave your comments here.
What happens when the driller forgets to shut off the mud pump?
Monday Accident & Lessons Learned: Fatal accident involving a track worker near Newark North Gate station 22 January 2014March 2nd, 2015 by Mark Paradies
Summary from the UK Rail Accident Investigation Branch …
At around 11:34 hrs on 22 January 2014, a track worker was struck by a passenger train as it approached Newark North Gate station. He was part of a team of three carrying out ultrasonic inspection of two sets of points at Newark South Junction and was acting in the role of lookout. The accident happened around 70 metres south of the platforms at the station.
A few minutes before the accident, the lookout and two colleagues arrived at the yard adjacent to the tracks in a van. One colleague was in charge of carrying out the inspections and the other, the ‘controller of site safety’ (COSS), was in overall charge of the safety of the team. They had planned to carry out the inspections on lines that were still open to traffic in accordance with a pre-planned safe system of work. All three had many years of relevant experience in their respective roles and were familiar with the work site.
Upon arrival at the yard, the lookout and tester proceeded to the track to start the inspection work; the COSS remained in the van. Shortly after they had started the inspection, the 10:08 hrs London to Newark North Gate passenger service approached. It was due to stop in platform 3, which required it to negotiate two sets of crossovers. The train blew a warning horn and the two staff on site acknowledged the warning and moved to the nominated place of safety. However, just before the train moved onto the first crossover, the lookout turned to face away from the train, walked towards the station and then out of the position of safety. He moved to a position close to where he had been before the train approached, most probably to check for trains approaching in the opposite direction, having decided that the approaching train was proceeding straight into platform 1. Although the train braked and blew a second warning horn, the lookout did not turn to face the train until it was too late for him to take evasive action.
As a consequence of this accident, RAIB has made two recommendations and identified a learning point. The recommendations are addressed to Network Rail and relate to:
- improving work site safety discipline and vigilance, especially for teams doing routine work with which they are familiar; and
- improving the implementation of Network Rail’s procedures for planning safe systems of work so that the method of working that is chosen minimises the risk to track workers so far as is reasonably practicable, as intended by the procedure.
The learning point relates to improving the implementation of Network Rail’s competence assurance process by providing training and sufficient working time to enable front line managers to implement the associated procedures as intended by Network Rail.
150216_R012015_Newark_North_Gate.pdf (5,166.00 kb)
Monday Accident & Lessons Learned: How Much Root Cause Analysis Can You Buy for $5.6 Million Dollars?February 23rd, 2015 by Mark Paradies
Here are the headlines from The Bakersfield Californian:
“CPUC proposes $5.6 million fine against PG&E for 2012 demolition fatality in Bakersfield”
As reported by the paper, one of the findings of the PUC that led to the fine was:
“PG&E gave the CPUC an accident analysis prepared by Cleveland, as well as the utility’s own evaluation. But commission staff said both ‘failed to provide an adequate or comprehensive root cause analysis for the incident’ to help determine corrective actions.”
So here are some questions to consider:
- Do you require that your contractors perform adequate accident investigations?
- What root cause tools do your contractors use? Shouldn’t they be using TapRooT®?
- Are you waiting for fatalities to require better root cause analysis and incident investigation? Why don’t you have someone attend an 5-Day TapRooT® Advanced Root Cause Analysis Team Leader Course ASAP (this month?).
- Isn’t it time that you learned how to use root cause analysis proactively to stop fatalities before accidents happen? You should attend the Using TapRooT® Proactively Course.
How many lessons can your company learn from this accident?
On February 16, 1979, 14 employees died and 17 were injured during a flour dust explosion at The Roland Mill located in Bremen, Germany. The explosion covered 30 acres of ground in flour rain.
The accident investigation indicated a cable fire started in the flour sample camber that created a powerful explosion. The fire spread across the conveyor bridge causing little flour explosions. The explosions caused the upper storage room to fill up with more flour than usual. In the upper storage room another small explosion happened that caught the flour silo on fire.
The burning silos caused enormous amounts of pressure that ripped off roofs and collapsed walls. Allowing the building to burst into flames.
The Mill has since then been restored and is still in operation to this day.
What do you think? Was this accident preventible? Learn the essentials of TapRooT® at a 2-Day TapRooT® Incident Investigation and Root Cause Analysis Course. Click on the link below to see what course are available in your area.
The damaged floor of the train
RAIB is investigating a train fire that occurred on the evening of Friday 30 January 2015, and which caused serious damage to the structure of the train.
The 19:53 hrs South West Trains service from Windsor & Eton Riverside to London Waterloo had travelled about 400 metres after starting from Windsor station, when a small bang was heard under the sixth carriage of the ten-carriage train, followed by about five seconds of severe sparking and flashing.
The train, which was formed of two class 458/5 electric multiple units and was travelling at about 15 mph at the time, stopped immediately. Some smoke entered the carriages through ventilators. There were two passengers in the sixth carriage, and they moved quickly into another part of the train. The guard of the train moved from the rear to the sixth carriage to investigate, and the driver also moved to the middle of the train. They could see that there was still smoke coming from below the sixth carriage, so the driver returned to the front of the train from where he contacted the signaller by radio to ask for the electric power to be switched off. While he was doing this, the floor of the sixth carriage was penetrated by fire, and smoke rapidly filled the vehicle.
There were eleven passengers on the train. The guard, assisted by the crew of another train that was in Windsor station, evacuated the passengers to the track, and helped them walk back to the station. The fire brigade were called, and confirmed by 20:50 that the fire was out. None of the passengers were hurt, but the guard was taken to hospital and treated for smoke inhalation.
RAIB’s preliminary examination found that the fire had originated in severe arcing in a junction box fixed under the carriage floor, where power cables from the collector shoes on either side on the train are connected to the main power cable (‘bus line’) which runs along the train. The arcing had burnt through the floor of the carriage, and had also destroyed parts of the structural members of the carriage body.
RAIB’s investigation will focus on the cable joint in this junction box, and how this joint was designed and assembled. It will also examine how the train’s structure and equipment, and the people in it, might have been protected from the consequences of a failure of this nature.
RAIB’s investigation is independent of any investigation by the Office of Rail Regulation.
RAIB will publish the findings, including any recommendations to improve safety, at the conclusion of our investigation. This report will be available on their website.
Here’s a description of an car/train accident:
How could things go from a minor error and fender bender to a multi-fatality accident?
It happens when someone makes a bad decision under pressure.
Don’t think it couldn’t happen to you. Even with good training and good human factors design, under high stress, people do things that seem stupid when investigating an accident (looking at what happened in the calm light of the post accident investigation).
Often, the people reacting in a stressful situation aren’t well trained and may have poor displays, poor visibility, or other distractions. Their chance of choosing the right action? About 50/50. That’s right, they could flip a coin and it would be just as effective as their brain in deciding what to do in a high-stress situation.
FIRST: Avoid decisions under high stress. In this case, KEEP OFF THE TRACKS!
Never stop on a railroad track even when no trains are coming.
That’s true for all hazards.
Stay out from under loads. Stay away from moving heavy equipment.
You get the idea.
Don’t put yourself in a position where you have to make a split-second decision.
SECOND: NEVER TRY TO BEAT A TRAIN or PULL IN FRONT OF A TRAIN.
Always back off the tracks if possible. This is true even if you hit the gate and dent your car.
FINALLY: Think about how this train accident could apply to hazards at your facility.
Are people at risk of having to make split-second decisions under stress?
If they do, or if it is possible, a serious accident could be just around the corner.
Try to remove the hazard if possible.
How could have the hazard been removed in this case?
An overpass or underpass for cars is one way.
Other ideas? Leave them below as comments.
Monday Accident & Lessons Learned: IOGP SAFETY ALERT – KICK TAKEN WHILE DRILLING 8 1/2” RESERVOIR SECTION IN DEEPWATER EXPLORATION WELLFebruary 2nd, 2015 by Mark Paradies
KICK TAKEN WHILE DRILLING 8 1/2” RESERVOIR SECTION IN DEEPWATER EXPLORATION WELL
The event took place on a Drillship while drilling the 8-1/2” section of an exploration well.
Well architecture consists of 36” CP at 939 m, 20” casing at 1274 m, 14” casing at 1666 m and 9-5/8” casing at 2702m.
Drill 8-1/2” section at 2860mMD/RT.
Made connection, resumed drilling.Observed 4.5% connection gas.
Observed gas increase to 27%.
Picked up string off bottom & circulated out gas (reciprocating string).
Observed 0.9m3 gain in active pit while circulating gas out of hole.
Shut in well & monitored for pressure evolution.
Observed increase in SIDPP, SICP & WHP.Continued to monitor pressure evolution.
Pressure stabilized at: SIDPP 480 psi & SICP 320 psi.
Spaced out and hung off string on Middle Pipe Rams.
ECD increase. SPP increase. Possible change in formation.
Sign of under-compaction on the resistivity log. Well Control: (Driller’s Method).
Flush each of Lower, Middle and Upper Choke fail safes. 131 psi (9 bar) back pressure on Choke.
Circulate down string and flush KL. 203 psi (14 bar) back pressure on well.
Open MPR and reduce UAP pressure. Close CMC.
Attempt to strip up and down, negative – string differentially stuck. 40 MT over pull and 36 MT set down weight.
Displace riser through boost line to 1.42sg kill mud. 17.7% max. gas observed.
Displace choke line volume to 1.42sg kill mud
Close MPR, displace KL with 4.5m3 base oil.Open UAP allowing 1.42sg kill mud in riser to u-tube up KL to sweep BOP stack.
Observe 2.5m3 drop in trip tank volume. Close UAP and open MPR.
Displace kill line volume to 1.42sg kill mud through gas relief line.
Perform flow check: well static.
Work drill string free with different parameters.
Circulate down string: FR 380 – 1000 lpm, 624 – 1305 psi (43 – 90 bar). Apply 14KN.m, 36 MT below SOW and 45 MT overpull.
Increase torque to max of 22.5KN.m. Observe drill string free.
Displace Choke, Kill & Boost lines to 1.47sg NABM.
Displace well to 1.47sg NABM.
WHAT WENT WRONG?
- Failure to recognize the potential/risk: Despite warning signs and pre-job meetings alerting on the nature of the activity, crew was not vigilant and sensitive to the nature of the activity (exploration drilling).
- Underbalanced Well Warning signs missed: Mud loggers and Geologist not following properly the gas and resistivity trends and not communicating adequately on gas and under-compaction trends seen.
- Procedure not followed: Established procedure called for reducing BGG to <1% at all times before drilling resumes. Drilling resumed with high BGG.
- Poor supervision : With warning signs of kick, team failed to recognize the appropriate action to take. And signs of entering high pressure zone unrecognized.
CORRECTIVE ACTIONS & RECOMMENDATIONS
- No mud transfer should be done when drilling an exploration well without proper and laid out procedure. Follow mud transfer protocol.
- After each connection and flow check, the corresponding bottoms-up circulation must be monitored.
- Drilling of exploration wells should not have continued with 10% background gas.
- Fingerprint of flow back in active system during pumps shut off should be monitored and analyzed.
- The well site geologist should do more to alert the company man of such observations as decrease of resistivity log.
- As a follow up, drillers should charge the mud loggers to employ more monitoring tools like ROP break, d-exponent….etc, that give direct indication of a kick.
- Consideration should be given to having a manual joystick on the cyberchair for choke control. The buttons on the digital display is too small to operate.
- There was no kill sheet available by the time the kick was taken; not with the drilling contractor or company representatives. Going forward, a kick sheet should be prepared for every phase where a reservoir is to be encountered, compulsory for exploration wells. Kick sheet must be reviewed as operation progresses.
- Communication with base is mandatory in this type of event.
Aafety Alert nNumber: 263
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