The Role of Gas Detection in Offshore Applications

Off-shore drilling is a highly hazardous process with dangers of complexes equipment, harsh environments, severe weather as well as toxic gases and volatile organic compounds (VOCs) which can be found mixed in with the products being extracted.

Toxic gas emissions are a danger in the environments in which offshore applications are found, creating unsafe conditions for personnel. This results in various long-term health issues, injuries and fatalities Whilst the ignition of flammable gases or vapors can lead to fire and even sudden, normally fatal explosions.

Hydrocarbons, hydrogen sulphide, benzene and mercury vapour are a few of the gases that exist within offshore applications.

Hydrocarbons are a group of  gas made up of Hydrogen and Carbon atoms, all of which are combustible and may be released under pressure from the well. Releases may also occur on the rig floor, around the vicinity of the test separator and about the choke manifold of an application.

Hydrogen sulphide is a toxic gas that occurs naturally as a contaminant in sour wells and is one of the most regulated in offshore applications. Concentrations often exist at the lowest points of rigs, such as the cellar deck.

While hydrogen sulphide is one of the most well-known and regulated of the toxic gasses there are other substances which are not as widely regulated or considered to be of concern in offshore applications.

Benzene is one of these VOCs and exposure to benzene has been associated with a range of acute and long-term adverse health effects and diseases, including cancer and aplastic anemia. Benzene evaporates easily and most people can just detect its distinctive smell at concentrations between 2.5 and 5 parts per million (ppm) in air.

Rather than having to rely on human senses in a workplace setting it is advisable to use an appropriate form of quantitative monitoring; indeed, the onus is on the employer to assess the risk. Remembering the adage attributed to Lord Kelvin that you can’t manage what you don’t measure. There are methods published by NIOSH in the USA that can be used to capture air samples for later analysis but this occurs after exposure could have taken place. Therefore, real-time methods are preferable which can range from fixed, permanent systems for fence line applications, hand-held devices for area measurements or confined space entry and most recently developed, personal monitors that can alert a worker of an immediate hazard, these personal devices are currently being used in offshore applications within the Gulf of Mexico and across Europe

Mercury is a natural component in oil and gas and during drilling operations, it can accumulate on pipes and other processing equipment. As processing fluids are cooled, the liquid mercury condenses within heat exchangers, separators, valves, and piping.

Gas detectors are often installed throughout off-shore applications to allow staff to monitor the quality of the air and be alerted if any VOCs are present.

With over 30 years of knowledge in the oil and gas industry, ION Science offers a full range of proven PID sensors and instrumentation designed to meet customer requirements and provide the best detection capabilities available. All our PID technology incorporates resistance to humidity and contamination for reliable performance within the harshest working environments, minimizing drift issues and maximizing uptime of your instrument–providing a true safety solution.


To learn more about our products for your offshore applications by contacting us on E: or T: +44 (0) 1763 208 503.