25-01-2013, 03:20 PM
PUBLIC SAFETY AT OIL AND GAS STORAGE FACILITIES
PUBLIC SAFETY.pdf (Size: 4.44 MB / Downloads: 31)
Executive Summary
Oil and Gas Storage Sites Present a Hazard in Rural Areas
On October 31, 2009, two teenagers, aged 16 and 18, were killed when a petroleum storage tank exploded
in a rural oil field in Carnes, Mississippi. Six months later a group of youths were exploring a similar tank
site in Weleetka, Oklahoma, when an explosion and fire fatally injured one individual. Two weeks later, a
25-year-old man and a 24-year-old woman were on top of an oil tank in rural New London, Texas, when
the tank exploded, killing the woman and seriously injuring the man. In April 2010, the U.S. Chemical
Safety Board (CSB) initiated an investigation into the root causes of these tragic incidents. All three
incidents involved rural unmanned oil and gas storage sites that lacked fencing and signs warning of the
hazards, which might have otherwise deterred members of the public from using them as places to gather.
Oil and gas storage sites are part of the landscape in many rural American communities and an important
component of the country’s vast system of oil and gas exploration and production. Over 800,000 crude oil
and natural gas producing facilities are distributed across the U.S., often located in wooded clearings or
other isolated locations.
However, in many states, these sites can be placed as close as 150 to 300 feet from existing residences,
schools, churches and other structures. Only in a few large cities where these sites exist – Houston,
Oklahoma City, and Los Angeles – are constraints placed on the location of the facilities within the city
limits.
CSB Study
To prevent future deaths and injuries, the CSB investigated the root causes of the three incidents and
conducted an analysis of the regulatory framework that contributed to the prevalence of this type of event.
The CSB examined federal, state, and local regulations; inherently safer designs of tanks; and industry
standards and practices recommended by the American Petroleum Institute (API) and the National Fire
Protection Association (NFPA). The CSB also administered a survey to gauge the public’s view of these
sites and the issues arising from their presence in the community. Among 190 survey recipients in a rural
Mississippi community, 11 percent of respondents stated they had “hung out at oil sites.” When asked
about the type of activity engaged in at oil sites, 14 percent stated they socialized; 19 percent said that
they rode four-wheelers at oil sites; and 11.5 percent stated that they hunted.
Hazard at Oil and Gas Production Facilities
Between October 2009 and April 2010, four teenagers and young adults lost their lives from explosions at
three different oil and gas production sites in rural Mississippi, Oklahoma, and Texas. The CSB first
became aware of this hazard in 2003 when a similar explosion in Palestine, Texas, fatally injured four
teenagers. In 2010, the CSB initiated an investigation to further examine the issue. The CSB found 26
similar incidents involving explosions and fires at oil and gas production sites.
CSB Outreach
After the CSB’s initial deployment to a tank explosion in Carnes, Mississippi, the agency created a safety
video targeting individuals under the age of 25 to increase awareness of the hazards posed by oil and gas
sites. The safety video, “No Place to Hang Out: The Danger of Oil Sites,” incorporates the experiences of
the victims’ friends, families, and community leaders in Carnes, and is intended to be integrated into high
school and middle school curricula. The CSB distributed this video to school superintendents across
Mississippi and continues to work with safety advocates in an effort to reach young people who live in oil
and gas producing communities.
Study Methodology
To further understand why these incidents were occurring across the country, the CSB deployed to and
investigated the three oil and gas tank explosions discussed above and collected information on 23 similar
explosions across the country. Investigators interviewed key witnesses and first responders at each of the
three incident sites and gathered exploration and production (E&P) site records from each state oil and
gas regulator. Incident reports for the 23 additional incidents were requested from local responders. A
survey of high school students and community members in Carnes, Mississippi, was administered to
understand the use of and hazard awareness at oil and gas facilities.
Characteristics of Oil and Gas Storage Facilities
Process Overview
At typical E&P sites, crude oil and natural gas are pumped from underground hydrocarbon reservoirs to
the surface. The well stream is connected to a piping system that transports hydrocarbons to an oil-gas
separator where gas and water are removed from crude oil. The oil is then transferred to storage tanks in
a tank battery2 until it is pumped into a transport truck for eventual sale (Figure 3-1).
In states where vapor recovery systems3 are not mandated,4 oil tanks are usually equipped with a tank
hatch5 and an atmospheric vent on the surface (Figure 3-1). Oil field workers regularly check liquid levels
through the hatch, which is accessible by a walkway or catwalk.6 The oil-gas separator also contains an
atmospheric vent that releases hydrocarbon vapors. 210-barrel capacity atmospheric storage tanks –
which were involved in two of the three explosions investigated by the CSB – are commonly used to store
crude oil and condensate at E&P facilities throughout the U.S. These tanks are rated for petroleum
liquids with a vapor pressure of less than 0.5 psig7 and are selected “based on vapor pressure, flash point,
potential for explosion, temperature and specific gravity.