A vessel of opportunity for riserless light well intervention (RLWI) can lead to accelerated oil recovery. Since a rig was not an economical solution and a slot on a purpose built intervention vessel was unavailable (9 mo. away), a vessel of opportunity was utilized for riserless light well intervention (RLWI) leading to accelerated oil recovery 6 months ahead of schedule.
Slickline and Wireline diagnostic operations (including a riserless PLT) in a gas well in GOM with a subsea tree at 2,506', 6,200 psi SWHP, 12,600' TD and 650 well inclination, have been anticipated and in a cost effective manner.
To meet these complex subsea challenges in a tight schedule, it was fundamental to clearly define the intervention objectives and determine an intervention strategy defining which techniques and equipment would be needed in the well. Then a risk analysis was developed highlighting key areas of concern and meditations/contingencies. Once the strategy was defined, source an available intervention system and integrate the selected service companies creating a detailed procedure with contingencies. Another key was to identify a vessel early and start detailing a deck layout for the equipment. The final step was component and SIT testing of equipment.
By understanding the limitations of a vessel of opportunity as compared to a purpose built vessel, an operator can plan a successful intervention. Key areas of focus are system integration, vessel layout, lack of a multipurpose tower and crew inexperience. Despite the learning curve associated with a vessel of opportunity, the accelerated schedule and gains in oil recovery make this an attractive option.