Ageing rigs are becoming an increasing concern for the Oil and Gas Industry. Not only do they fall short of production capabilities versus modern facilities, they also increase risks for companies who operate them. As operators face tighter budgets in the current industry climate and are forced to extend the life of ageing rigs, these risks will mount.
It is estimated that within the next seven years, over half of the world’s oil rigs will be more than 30 years old. In the Gulf of Mexico (GoM) for instance, there are currently over 100 rigs in operation that were built before 1960. Approximately 50% of the GoM’s 3,000 plus platforms are over 20 years old and are considered by federal regulators to be past their intended design lifetime.
When it comes to older infrastructure, dropped object hazards are often overshadowed by the threat of systematic failures such as pipeline leaks and/or equipment breakdowns. However, year after year in the oil and gas industry, dropped objects rank among the top 10 causes of fatalities and serious injury incidents. For an industry predicated on safety and productivity, this has become a major issue.
Over 70% of dropped objects in the Oil and Gas Industry are from equipment parts or unsecured objects, and over half of all dropped objects fall from a height of more than 5 metres.
Two main factors contribute to dropped object hazards on ageing rigs. 1) Ageing equipment on older rigs causes much higher levels of vibration compared to modern counterparts and 2) material degradation (e.g. oxidisation and galvanic action).
Material degradation or corrosion is typically the most common cause and is the most difficult to identify. Corrosion on ageing fixtures is often concealed by layers of heavy paint, from a long history of maintenance work. Serious corrosion often occurs internally, making it virtually impossible to detect. Internal corrosion in mounting structures is especially hazardous due to the fact that fixtures generally have to support weight at height, making them more prone to structural failure.
While routine inspections can be effective at identifying problematic areas, many rigs have changed ownership so many times that maintenance records are either missing or unreliable. Regardless of the situation, action should be taken to ensure that personnel working on older rigs are protected from dropped object hazards.
There are a variety of Non-Destructive Testing (NDT) options available to assess the structural integrity of offshore fixtures. Ultrasonic Thickness Gauging is used to check material thickness and measurement, whilst Magnetic Particle Inspection, Eddy Current Testing and Ultrasonic Flaw Detection Testing can be used to identify defects and imperfections in the test area. Non-Destructive Testing methods can be used in combination to provide a comprehensive analysis of ageing rig structures.
Another vital safeguard against dropped objects is the use of secondary retention on fixtures located at height. Historically slings and wire tethers were used as makeshift methods to secure fixtures (lights, cameras, speakers, anodes, pipe clamps, etc.) located above personnel or important equipment. These methods were not entirely satisfactory since they were difficult to attach, were not rated, and did not fully enclose the fixtures or the fixture’s components. Dropsafe Nets were designed in direct response to the need for a more effective and robust method of securing overhead fixtures with third party validation.
Dropsafe Nets are secondary securing systems comprised of marine grade (SUS/AISI 316) stainless steel wire and components providing an instant safety solution to dropped object hazards. They fully enclose and tether overhead fixtures preventing both the fixture and components from falling.
Dropsafe has become the global industry standard for securing and tethering overhead fixtures. The company has helped drilling contractors and operators around the world improve rig safety by delivering mesh-safety solutions that minimise the risk of dropped object hazards. The largest Oil and Gas drilling contractors and more than 300 customers industry-wide currently use Dropsafe products at their facilities.
As the current market forces companies to extend the operational life of their ageing rigs, the role of NDT and secondary safety measures will become increasingly prominent in the future.
“Ageing is not simply about the physical age of an asset, the risks associated with ageing start when the asset enters the sea. The management of equipment begins with an awareness that ageing is not about how old the equipment is, but is about what is known about its condition, and the factors that influence the onset, evolution and mitigation of its degradation”.
 Wall Street Journal http://www.wsj.com/articles/SB10001424052748704584804575644463302701660
 Drops Online. http://www.dropsonline.org/downloads/DROPS%20Intro.pdf
 Dropped objects register of incidents and statistics (D.O.R.I.S) May 2013
 Health and Safety Executive, UK http://www.hse.gov.uk/offshore/ageing/background.html