Offshore Rig Inspection using Remotely Operated Vehicle (ROV)

Offshore Rigs 

Oil rigs are offshore drilling platforms located in oceans or seas for the purpose of exploration and production of oil and natural gas from beneath the seabed. These drilling platforms play a significant role in the contribution of the energy sources to the global economy. There are various types of oil rigs such as fixed platforms, jack-up rigs, and drillships. Rigs are partially submerged in the sea and can be moved from one location to another after completing the drilling operation of that particular location. These rigs consist of many structural components such as pontoons which help in floating the rig in water, sea chest, equidistant columns that help in supporting the deck and the bracings connecting the columns help in providing lateral stability to the rig. 

Need of Rig Inspections

These drilling units are valuable assets and also a minor error in its operations can cause a drastic effect on both humans and the environment. Thus it is of paramount importance that these offshore structures must be inspected periodically which helps to expand the life expectancy of these structures. 

Why ROV instead of Diver-based Inspection

Diver-based inspections for offshore structures involve a lot of risks. Safety procedures and quick response strategies are crucial to lessening the risks in diver-based inspections. Diving operations can become more stressful and challenging when there is low visibility, high currents, and unfavourable weather conditions. The risk of diving accidents, injuries, and fatalities is greatly reduced by ROV operations since they do not require human divers to enter likely hazardous and high-pressure underwater environments. Remotely operated vehicles (ROVs) are adaptable equipment utilized in a wide range of rig inspection applications. They are useful in assuring the safety and integrity of offshore oil rigs and related structures because of their capacity to function in underwater settings at various depths and conditions.

Proposed Solutions

EyeROV TUNA ROV is a robust customizable ROV (Remotely Operated Vehicle) design for essential underwater infrastructure inspection and monitoring functions.EyeROV carried out an underwater videography survey of the Rig using a Remotely Operated Vehicle (ROV) to assess its general condition. The authorities of the Rig wanted to find out the condition of the submerged portions of the Rig. Advanced survey methods using  ROV were the best option as the site conditions were extensively challenging with wind speed of 12-20 knots, water currents of 0.4-1.4 knots and swell height of 1-3m.

Scope of Work 

The primary categories of interest were Connections between columns & pontoons, Connections between columns & bracings, K Joints, Sea chest gratings, Tow Bridle chains, Fairleads, Bollards, Diesel Tanks, Fly by video which were surveyed in a systematic and efficient manner. The region of focus was determined and close proximity video recordings were shot after each section had been examined according to the survey's scope.

Execution

Equipment (ROV) and manpower were mobilized on the rig for the inspection. The control station was set up onboard. The onboard ROV operation was conducted in accordance with all safety guidelines and practices. The ROV was launched from the deck surface into the water by manually. Once the ROV touched the ocean water, the pilot took over the control and guided the ROV to the survey area. ROV collected high-quality visual data of rig structure, all the data was live streamed at the control station monitor. The live data visuals helped the Client to get an idea about the overall condition of the structural part of the Rig.  The Duty Officer and Team were educated on the proper planning for the ROV's deployment site and traversal path while they were aboard the rig.