Remotely operated vehicles (ROV), often described as “robot submarines”, have been used by the oil and gas industry for many years.
Equipped with very sophisticated electronic devices, they are the eyes, ears and hands of those who operate them from ships or offshore platforms.
Attempts to develop a ROV were made as far back as the mid-1860s when Luppis-Whitehead Automobile developed a kind of torpedo, the Programmed Underwater Vehicle (PUV). Almost a century later, in 1952, Dimitri Rebikoff built the first underwater scooter which evolved into the world’s first tethered ROV, named the Poodle. In the 1960s, technological advances came from the US Navy. Their Cable-Controlled Underwater Vehicle (CURV) was destined to perform deep-sea rescue operations.
Essential to the oil and gas sector
The oil and gas industry quickly saw a future for ROVs: they could assist in the development and deployment of offshore oil rigs. From the 1980s onwards, ROVs have been used for an ever increasing number of tasks that could never have been undertaken by human divers, from the simple inspection of subsea structures, platforms and pipelines to connecting pipelines and placing manifolds.
Over the years, there has been a growing need for more powerful and more reliable ROVs that could go deeper and accomplish increasingly complex tasks. One major improvement, in the early 1980s, was the use of control data and video over fibre optic in the offshore oil and gas sector. This meant that ROVs, which previously used data over copper, could operate in greater depths.
Depending on their category, ROVs may be equipped with video cameras and variable lighting; acoustic and tracking sensors (tracking and measurement devices, scanning sonars, profiling sonars, bathymetric systems and pipe trackers); non-destructive testing sensors used to check structural integrity; cleaning devices (rotating wire, nylon brushes, water-jetting, etc.) to clean offshore infrastructure; and multiple single-purpose or multi-mode work tools; simple bars, hooks and knives.
Today’s most technologically advanced ROVs, equipped with machine vision and motion sensors, can manoeuvre to a precision of 5-10 mm and attain high levels of safety and efficiency in subsea operations.
Sensors, connectors, switches or cameras are just a few items that equip ROVs, AUVs and AIVs. When these vehicles are intended for the oil and gas industry, they have to meet very specific and strict requirements to be explosion-proof, as any equipment or material used in explosive atmospheres. The fact that they operate underwater doesn’t make any difference.
The IEC has been at the forefront in this field for many years, preparing International Standards and establishing a Conformity Assessment System that provides testing and certification for Ex equipment.
IEC Technical Committee (TC) 31: Equipment for explosive atmospheres, has a complete series of international standards that cover all specific requirements for Ex equipment and systems, from general requirements to protection levels for apparatus used by all sectors that operate in hazardous environments. But producing devices and equipment based on Ex standards is not enough. Most manufacturers and suppliers trade on the global scene and have to meet the very strict requirements put in place by national regulations and legislation.
The IEC, through IECEx, the IEC System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres, has the mechanisms in place to help industry, authorities and regulators ensure that equipment and the people working in Ex locations benefit from the highest level or safety.
Read more in the latest edition of e-tech.
Photo: Autonomous inspection vehicle (AIV) – Subsea 7 (credit: Heriot-Watt University)