EV Offshore's Subsea Inspection Saves Rig Time for Nexen

EV Offshore recently carried out a successful subsea well inspection for Nexen Petroleum UK Ltd on the Scott Field, offshore Aberdeen in the North Sea.

Following drilling of an 8 ½-inch section the Vetco wear bushing was pulled from the multi-bowl. Vertical gouging was evident on the outside diameter of the wear bushing, giving rise to concerns that a foreign body -- or a piece of swarf -- had become trapped between the wear bushing and multi-bowl. This fueled further suspicion that the tubing hanger seal areas may have been damaged.

To accurately assess the condition of the tubing seal area by conventional means would have required that the well be suspended with a hurricane packer, with the BOPs and riser nippled down so that the multi-bowl could be visually inspected before the BOPs were reinstated and the hurricane packer retrieved. This operation would have required a minimum of 1-½ days of costly rig time.

Rig-up to Successful Inspection in Just Four Hours

To save rig time, Nexen engineers contacted EV Offshore (EVO) to inspect the tubing hanger seal areas with its RT 120, the company’s drillpipe-deployed camera system. EVO took just four hours to rig up the camera and carry out a full visual inspection of the well head. Because the picture quality of the video images was good, engineers were able to immediately identify a surface mark on the tubing hanger seal area. Based on the images obtained, Nexen engineers decided that the marking was superficial, and would not affect the integrity of the tubing hanger seal. As a result, operations resumed and Nexen engineers continued to run the completion. Finally, the tubing hanger was landed and successfully tested.

According to EVO, the recent inspection operation for Nexen illustrates the value of its camera inspection technology to today’s oil and gas industry.

“This is an excellent example of how technology can directly benefit service companies working offshore to examine potential problems, quickly and efficiently,” said David Clover, Director of EV Offshore. "In just four hours, we were able to provide Nexen with an immediate view of the situation. The fact that they were able to assess the potentially damaged area so efficiently meant that they were to resume the operation with confidence. The ability to do complete the inspection without incurring the substantial cost of renting a rig saved time and money. It was clearly a 'win-win' situation for all concerned," he added.