Federal worker safety investigators are looking into the dangers of flowback tanks at oil and gas sites, in response to the deaths of at least four men who collapsed while taking measurements at tanks in the Bakken Shale.
In a posting yesterday, the National Institute for Occupational Safety and Health asked for help from the oil and gas industry and others in determining the risks of “flowback operations.” The agency also posted recommendations for avoiding danger around the tank hatches.
The post said that while oil field operators are aware of the lethality of hydrogen sulfide, or “sour gas,” they may not realize the dangers of other substances — volatile hydrocarbons — that can accumulate in crude oil tanks.
“Less recognized by many employers and workers is that many of the chemicals found in volatile hydrocarbons are acutely toxic at high concentrations,” said the posting from NIOSH, part of the Centers for Disease Control and Prevention.
Employees and operators could avoid some of the dangers of flowback in a number of ways, according to NIOSH, including having a least two people working at a time. They could also find alternative procedures so that workers don’t have to open hatches on the tops of the tanks to take readings.
The agency also recommends wearing respirators when dealing with flowback and developing emergency response plans for employees who are overcome.
The agency has already done some “exposure assessments” to determine what substances may present a threat to oil field workers. Researchers are seeking to partner with companies, academics or others to learn more about the issue.
“We are also looking to convene a meeting in the near future with our partners to look at the data that we currently have and discuss a path forward in collecting additional data, potentially through environmental sampling or other avenues,” NIOSH officials said in a statement to EnergyWire.
The high-volume hydraulic fracturing that has made the Bakken oil boom possible creates a large amount of flowback, a toxic waste fluid that can include toxic hydrocarbons from the producing formation.
The flowback is typically stored temporarily in tanks or man-made ponds called pits. Workers periodically gauge the fluid levels in flowback and production tanks with hand-held gauges (sticks and tapes) through access hatches located on the top of the tanks.
At least four workers have died since 2010 from what NIOSH said appears to be “acute chemical exposures” near tanks at oil well sites in North Dakota and Montana.
Media accounts indicate that Zach Buckles, 20, a flowback operator working for Black Gold Testing at a Continental Resources Inc. well site, died in late April. His autopsy is pending, but the McKenzie County Sheriff’s Department said in a news release that because he was found over the open cover of a crude oil tank, “it is believed that he died as a result of [hydrogen sulfide] gas exposure.”
In January 2012, Dustin Bergsing, 21, of Edgar, Mont., was found dead at a Marathon Oil Corp. oil well in Mandaree, N.D., where he was a tester for Across Big Sky Flow Testing. The cause of death was listed as hydrocarbon poisoning due to inhalation of petroleum vapors. After determining that hydrogen sulfide was not a factor, OSHA officials said a citation of the employer for work-related exposure “could not be supported.”
An employee whose name has not been made public was found dead with his face to the side of a tank hatch in July 2013 at a well site near Watford City, N.D. OSHA officials did not cite the company but issued a “hazard warning letter” to the employer, Falco Energy Transportation.
There was a similar death in Montana in 2010, but the cause of death was listed as natural causes — hypertensive and atherosclerotic cardiovascular disease. The NIOSH post said volatile hydrocarbons can also affect the heart.
The oil and gas industry’s fatality rate is more than seven times higher than the all-industry average of 3.2 deaths per 100,000 workers, according to data from the Bureau of Labor Statistics. In 2013, BLS reported an oil and gas fatality rate of 24.2 deaths per 100,000 workers, higher than the 21.2 reported by the notoriously dangerous agriculture, forestry, fishing and hunting sector. Last year, the industry lost a record number of workers (EnergyWire, Aug. 20, 2013).
North Dakota, with 17.7 deaths per 100,000 workers in 2012, recorded the highest fatality rate in the nation for the second year in a row, according to an AFL-CIO report published earlier this month. That’s up from 12.4 in 2011 and double the state’s pre-boom 2007 rate of 7 (EnergyWire, May 9).
Following North Dakota were Wyoming (12.2), Alaska (8.9), Montana (7.3) and West Virginia (6.9) — all of which have an energy presence.
In North Dakota’s oil and gas extraction sector, the fatality rate was an “alarming” 104 per 100,000 workers, more than six times the rate of 15.9 for the industry nationwide, according to the AFL-CIO report.
Click here to read the NIOSH posting.
By Mike Soraghan for EnergyWire