Maritime Accident Casebook

US Refused The Lessons Of Piper Alpha

In this second article, originally posted as part of a post on the Step Change In Safety website, former Shell International Health and Safety Group auditor Bill Campbell B.Sc. MIET C.Eng. looks at how often blowouts occur and its relevance to Deepwater Horizon tragedy.

BIG OIL: BEFORE THE SPILL

This analysis takes information from the CNN programme broadcast on Sunday 4^th of July in the UK, that is Big Oil: Beyond the Spill. Data on blowouts, severity and frequency is taken from variety of websites such as Wikipedia and Publickeye.blogspot.com

Introduction

In 2008, according to CNN, over 85 energy companies got together in the Superdome in New Orleans and forked out $3.5 billion into the US treasury funds for leases in deep and ultra deepwater. The economics of any investment are dependent on getting a quick return on capital invested so there was always going to be a demand to drill in deepwater to recover the expenditure.

When the US industry put forward the case to the US president et al for drilling in deepwater in the Gulf they are quoted as saying blowouts are rare events. They were confident they could drill in deepwater safely.

Rare events by definition are few and far between, uncommon, unusual or exceptional. But world-wide blowouts have occurred regularly and since 1955 there has been 44 with a mean time between blowouts in this 55 year period of only 15 months. And the consequences of these blowouts have often been catastrophic.

So the argument put forward by Big Oil was entirely flawed because the risks of drilling are the product of the probability that a blowout will happen and the consequences that follow from that undesirable event.

So if the event is credible, and the uncontrolled release of hydrocarbons during drilling is a credible event on a Drill Rig, then the risks are high, and maybe unacceptably so.

So if the US President had been presented with this data by Big Oil including the International Association of Drilling Contractors (Houston). and all those other congressmen and senators lobbying for Drill baby Drill then he might have had a more balanced perspective.

This is all the more of a concern for before the Chemical Safety and Hazard Investigation Safety Board (CBS) has put pen to paper, and many months before the World fully understands the root cause of the Deepwater Horizon, Big Oil is pressurising to recommence drilling in deepwater. The US public need to be made aware that to do so, without a full understanding of the root causes, would be dangerous and could lead to a repeat of disaster still unfolding.

What does history tell us world-wide?

Detail is provided in the 4 tables overleaf.

World-wide since 1955 and prior to Deepwater Horizon there have been 44 notable blowout events causing 79 deaths, with significant loss of assets and one event in 1979 causing massive pollution. In this period 55 year 1955 – 2010 the mean time between blowouts was 15 months.

What does history tell us about the Gulf of Mexico?

In the 37year period 1964 – 2001 there were 10 blowouts or 23% of the world-wide events. This resulted in 27 deaths or 34% of the deaths world-wide. One event, the blowout on the Semi-submersible Sedco 135F caused pollution into the Gulf of an estimated 455 to 480,000 tonnes of oil.

In the 46 year period 1964 – 2010, including the Deepwater Horizon there has been 11 blowouts, resulting in an additional 11 deaths and pollution estimated on 4^th July last of between 333 – 572,000 tonnes of oil.

By comparison in the UK North Sea there has been two blowouts, one in 1977 on a fixed installation, and one in 1988 on a Semi-submersible with one fatality over the 55 years period from 1955 to 2010.

Conclusion

By any definition therefore blowouts are not rare events!

Risk analysis used in the UK post Piper Alpha consider that a safe haven, or Temporary Refuge on an offshore installation should demonstrate by design that its integrity is not threatened by credible events on the installation less than once per 1000 years.

That is one side of the equation. But in any case, a rare event, under any sophisticated quantitative or qualitative analysis, the type of analysis that is mandatory in a UK Offshore Safety Case, would consider risks are tolerable if between 1 in 100 and 1 in 1000 years depending upon the event and its potential consequences.

This is a far cry from what the historic data shows in in the Gulf of Mexico on average 1 in 3.7 years frequency for Blowouts over the 37 year period from 1964 to 2001 and 1 in 4.2 years taken into account the Deepwater Horizon ongoing disaster.

For the industry to say therefore that blowouts could be discounted from the decision to drill into deepwater formations because they were rare events is tantamount to deception. Is it not in the public interest in the US that the other side of this sad story is told.

Bill Campbell B.Sc. MIET C.Eng.

TABLE1: WORLDWIDE BLOWOUTS BY RIG TYPE OVER 52 YEAR PERIOD 1955 – 2007

COMMENTS:

ALL THESE EVENTS IN WHAT IS CURRENTLY TERMED SHALLOW WATER, LESS THAN 500 FT, BLOWOUT FREQUENCY OVER THIS PERIOD CIRCA 14 MONTHS

TABLE 2: GULF OF MEXICO BLOWOUT DISTRIBUTION OVER 37 YEAR PERIOD 1964 – 2001

COMMENTS:

ALL THESE EVENTS IN WHAT IS CURRENTLY TERMED SHALLOW WATER, LESS THAN 500 FT, BLOWOUT FREQUENCY OVER THIS PERIOD CIRCA 3.7 YEARS, MAXIMUM PERIOD BETWEEN BLOWOUTS 20 YEARS, MINIMUM PERIOD 6 MONTHS

TABLE 3; GULF OF MEXICO – DETAILED DATA ON BLOWOUTS PRIOR TO DEEPWATER HORIZON

37 year period 1964 – 2001

GULF OF MEXICO – HISTORICAL DATA on BLOWOUTS INCLUDING DEEPWATER HORIZON

46 year period 1964 – 2010