Statistics indicate that safety in the upstream oil and gas industry has continued to improve in recent years, but a number of issue remain.
One trend has been to move away from prescriptive safety regulations and towards performance-based or goal-setting regulations.
Offshore safety design in the Gulf of Mexico mostly relies on prescribed specification standards unlike the North Sea which has more performance-based safety designs that were an outgrowth of recommendations in the Lord Cullen report on the deadly explosion on the North Sea Piper Alpha platform in 1988 that killed 167 persons.
The Lord Cullen report focused more on the need for safety management and not just on offshore technology improvements. It also led British operators to complete a $7.5-billion program of upgrades to offshore installations to improve safety following the inquiry (OGJ, Dec. 4, 1995, p. 42).
In the offshore environment, the US Minerals Management Service has published figures indicating that 75% of the fatalities experienced offshore are associated with operator error and equipment failure.
Such causes also led to the sinking in 2001 of the Petrobras-operated semisubmersible platform P-36 (Fig. 1), in the Roncador field, off Brazil in Campos basin that killed 11 crewmembers.
Onshore, the leading cause of fatalities is vehicle accidents.
OGP survey
The 2001 safety survey by the London-based International Association of Oil & Gas Producers (OGP) shows the upstream industry's safety performance has improved compared with previous years.
Don Smith, OGP technical manager says, "Despite many years where we have seen little change in the fatal accident rate (FAR), this year [June 2002 report on 2001 data] we will be reporting a FAR of 5.11 (overall), a 30% decrease compared to 2000. The total number of fatalities reported was 101, or 18 less than 2000 despite the increase in work hours. Similarly, the lost-time incident frequency (LTIF) has fallen to 1.59 (a 15% reduction)."
OGP based its 2001 analysis on almost 2 billion work hr reported, the largest ever and more than 20% greater than in 2000.
The improvement seen in 2001 continues the trend reported in the previous year's survey. The 2000 survey indicated that the FAR and LTIF have both lessened since 1985, when OGP first started reporting safety performance statistics.
OGP statistics in 2000, released in June 2001, included data submitted by 39 companies, covering operations in 71 countries and including 1.6 billion hr worked, of which 65% are contractor hours.
These statistics showed 119 fatalities in 2000, of which 27 were company and 92 contract personnel. This was a rate of 7.28 fatalities/100 million hr worked, or slightly higher than the 7.02 rate in 1999.
Vehicle incidents, which are an entirely onshore hazard, caused 30% of the fatal incidents, while the second largest category "struck by" caused 21%.
In 2000, the single incident reported with the most fatalities was in Nigeria. In this incident, 19 workers died because of a reported vapor combustion during the repair of a pipeline damaged by an explosion caused by sabotage.
In this survey, only 1 death was associated with air transportation. This compares to the 114 fatalities during the previous 5 years.
OGP indicated that there were 2,960 lost-time accidents in 2000. Contractors accounted for 72% of them. But the trend in frequency has been down over the last 10 years. The frequency has dropped from about 4.7 lost-time injuries/million hr worked in 1991 to 1.9 in 2000.
In 2000, OGP also began collecting data on occupational illness, with eight companies responding for 235 million hr worked. Back and lower limb problems comprised the largest category reported at 34%. The companies did not report any death or permanent disabilities that could be attributed to occupation illness.
Because of the limited data received, OGP indicated that it is difficult to draw conclusions from the health data.
Safety initiatives
The inquiry commission report on the sinking of P-36 determined that the accident did not result from a single action or mistake. It had a set of causes that, combined, led to the accident. In addition, it determined that if just one factor had not been present, the accident would not have been nearly as serious.
Because many factors have to be considered to eliminate these types of accidents, Petrobras launched a program inside the company called the "Operational Excellence Program" whose main goal is to implement several actions toward increasing the safety of offshore operations in the areas of engineering design, safety, ballast and stability, maintenance, operation, and human resources.
It says one of the most important facts verified was that, in critical activities, such as offshore production, "we need to go beyond the legislation, beyond the norms and practices that are internationally accepted."
Other work in offshore safety discussed at the recent Offshore Technology Conference in Houston, May 6-9, 2002, involves marine evacuation systems and helicopter safety.
Reeni Woolgar and António Simões Ré, National Research Council of Canada, Institute for Marine Dynamics Brian Veitch and Dean Pelley, Memorial University of Newfoundland, Ocean Engineering, said their work looked at how lifeboat evacuation capabilities change as a function of deteriorating weather. The aim of the work was motivated by the trend away from prescribed specification standards in favor of goal-setting regulatory regimes.
The work evaluated a conventional twin-falls davit launched lifeboat system during launching, clearing, and sail-away phases of the evacuation process from a bottom-fixed installation in calm water up to Beaufort 8 weather conditions.
Their experimental results showed that understanding the effect of the set back distance on landing a lifeboat on the face of a wave could reduce the size of the splash-down zone, thereby reducing the size and costs of the associated launch structure.
Transporting personnel by helicopter to serve the deepwater Gulf of Mexico may require new safety considerations, as explained in another OTC presentation by Stephen J Rowe, BMT Fluid Mechanics Ltd., David Howson, UK Civil Aviation Authority, Paul Sparkes, UK Civil Aviation Authority Research Centre.
When one considers the number of hours flown and the often hostile environment, their statistics indicate that offshore helicopter service has a good safety record. The presentation says the 5-year moving average for 1994-99 in the UK was 1.74/100,000 hr, while in the gulf it was 1.4/100,000 hr. Also the UK offshore has not had a fatal helicopter accident since 1992, while in the gulf the 5-year moving average, 1994-99, for fatalities was 0.46/ 100,000 hr.
The presentation cautions that because the gulf's deepwater fields are farther from shore, evacuating them in severe weather poses greater hazards than from nearby shelf platforms.
It says operators in the gulf need to be aware of the work being done in the UK in minimizing the risk posed by aerodynamic hazards in the vicinity of helidecks on large offshore platforms, improving emergency flotation systems for helicopters forced to ditch in the sea, and improving the crash worthiness of flotation systems so that helicopters which crash into the sea are more likely to float following impact.
It also describes the new motion criteria being developed for operations to helidecks on floating vessels and improvements to helideck lighting schemes.
