The paper will describe Statoil’s motivation for selecting a light well intervention vessel rather than a semi-submersible drilling unit for perforating two subsea wells offshore Norway during September 2000. The paper will further discuss the challenges and the experiences captured and gained from the operation. The water depth was world breaking for this type of well intervention vessel operation, with a water depth of 341m (1120 ft).
Another world’s first from a vessel, was the deployment of a wireline driven Well Tractor® to convey lowside orientated perforating guns out in the deviated wells, incorporating the shortest tractor length ever deployed. The wells were water injectors, slightly under balanced and treated as live as hydrocarbons could enter the wells after the perforating. The longest well was 5657m MD (18560 ft) and with highly deviated step out of approximately 2973m MD (9754 ft). The paper will conclude with lesson learned and cost benefit issues.