Thinking Small Delivering BIG
Anadarko is among the largest independent oil and natural gas exploration and production companies in the world, with 2.28 billion barrels of oil equivalent (BBOE) of proved reserves at year-end 2008. Ryan Miller, Anadarko’s Integrity Coordinator, had a serious and perplexing challenge with the Redhawk production rig in the Gulf of Mexico.

Designed and built by Technip, and put into service in 5300 feet of water in 2004, the Red Hawk required inspection inside the massive cell spars that floated the rig. The interior of the spars had never been inspected since the completion of construction. One of the major benefits of the floating spar facility is the ability to move it and drill additional wells under the spar. This allows for phased development of deepwater fields. Ryan agreed with Anadarko’s classification society, the American Bureau of Shipping (ABS,) that an inspection inside the spars was critical before the rig was moved or repurposed.

Anadarko is a recognized leader in innovation. They often safely leverage leading-edge technology to solve problems like this one. In this case traditional solutions would not work. The kinds of ROVs that Anadarko had used up to this point were too large to fit into the spars, and might have damaged them. The use of divers was too dangerous. A new solution was needed.

An Anadarko crew member inspects the tow bollards of the
Red Hawk with a VideoRay ROV.

 
image from the ROV after breaking the surface of the water
inside the spar tube. This turned out to be a valuable image of
the integrity of the coating inside the structure.



Looking up inside tube 6 at the interior underside of the spar tube.


 
Sponge growth and NOT corrosion coats one of the support rings
inside tube 6 – an important distinction for this inspection.




Steve Van Meter, of SVM consulting in Cocoa, Florida, was certainly no stranger to unique and difficult underwater inspection challenges. In his long career – including 22 years with NASA as their Hazardous Duty Robotic Specialist – he was accustomed to reviewing this kind of job, and the tools best suited to solve the problem. As he often does, he selected VideoRay for this inspection. Explaining his choice, he commented “This task required VideoRay’s unique combination of small size, powerful thrusters, and extreme maneuverability. No other commercial ROV available could have performed this inspection and produced these results.”

 
VideoRay ROV pilot Steve Van Meter of Cocoa, Florida based Van Meter Consulting
on the deck of the support vessel in front of the imposing Red Hawk platform.



Illustration of the Red Hawk Cell Spar and the entrance to the 300 foot spar tube
where the ROV entered.

Steve and his assistant were helicoptered to the rig, about 200 miles south of Houma, LA. The entire inspection was performed from the spar deck, about 75 feet above the water surface. All of the equipment required – the submersible, control box, and hundreds of feet of tether – weighed less than 200 pounds (90 kilos.) No single component weighed more than 50 pounds (22 kgs.) Therefore, no special preparation or permitting was required for helicopter transport.


Red Hawk Spar tubes out of water – highlighted is the 16 foot diameter entrance to
the 300 foot tube that the VideoRay inspected internally.

Getting the submersible into the spar required several tries, lowered from different orientations to the spar and the water current. However, the entire inspection was completed in less than one day. While inside the spar, Steve was able to inspect the trapped air space inside by swimming the VideoRay on the surface and pointing his color camera up. He approached each area and feature of interest to the ABS inspector, Arinjit Roy , and produced high quality stills and video to his satisfaction. Time inside the spar was less than one hour.

Within hours of the inspection, Ryan was reviewing the video and still images captured by the ROV. All agreed that they showed minimal degradation. Not only had the inspection been performed in record time with minimal cost and no disruption to the rig, but a new inspection technique had been proven, and will be used in the future.

For more information on VideoRay ROVs visit www.videoray.com.
To contact Van Meter Consulting email Steve Van Meter at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .