Manual Level Gauging of Hydrocarbon Production Tanks

An NPR article, Mysterious Death Reveals Risk in Federal Oil Field Rules, highlights a big problem with rules by the U.S. Bureau of Land Management pertaining to manual tank level gauging. The article’s author writes:

On a cold night in January 2012, Dustin Bergsing climbed on top of a crude oil storage tank in North Dakota’s Bakken oil field. His job was to open the hatch on top and drop a rope inside to measure the level of oil. But just after midnight, a co-worker found him dead, slumped next to the open hatch.

In an Emerson Exchange 365 global user community thread, Oil field automation, a question is posed:

Do you think that hand dipping tanks in the oil fields is needed to protect investors? Or would automation be better to protect both investors and oil field workers? Here is an NPR article about the topic.

I’ll excerpt part of Emerson’s Christoffer Widahl response which explains the situation and what is being done to fix this situation. I’ve added a few hyperlinks pointing to additional information.

Emerson's Christoffer Widahl


Manual gauging of production tanks is a dangerous operation. This has recently been highlighted in a Hazardous Alert (HA3843) issued by National Institute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA). Nine oil worker fatalities related to manual gauging or sampling of production tanks has been identified by OSHA during 2010-2014. The workers have been exposed to extensive amounts of toxic hydrocarbons when thief hatches has been opened for manual gauging.

Automated Tank Gauging (ATG) is a viable option to keep workers safe on the ground and thief hatches closed in line with OSHA’s recommendations. Currently there is no standard that supports cost effective ATG on smaller production tanks (<1000bbl) as the existing standard API18.1 only covers manual gauging for custody transfer while API3.1B covers automated tank gauging for custody transfer in inventory storage tanks (>1000bbl). Transmitters used for custody transfer according to API 3.1B is a non-viable option for small production tanks as the cost would be too high.

However, there is a new standard in writing, API18.2, which allows automated tank gauging to be used for custody transfer on production tanks. API 18.2 will most probably be released before summer. The accuracy requirements in API 18.2 are has been adapted for small production tanks and are in correlation to what’s already installed in field, where thousands of radars have been used for level monitoring, overfill prevention and truck scheduling for years. Operators with existing radar level measurement can immediately start to adopt the new standard, relying on their radar level measurements for custody transfer, as long as they can prove the accuracy of the instruments. As with all instrumentation used for custody transfer, the radar level transmitter accuracy must be verified periodically.

Read the rest of Christoffer’s response in this discussion thread in the Oil and Gas group in the Emerson Exchange 365 community.

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