The primary scope of work entailed a temporary well abandonment operation using Helix’s Intervention Riser System (IRS).
This required latching the IRS onto the well’s vertical tree with a dual string riser system, connecting it to the surface flowhead, and establishing a closed return system.
The project originally comprised only one well, but the client requested an additional choke replacement at an adjacent well be performed during the operation. Because the Q4000 manages simultaneous operations with two work-class ROVs and two subsea cranes, the additional project was conducted over the side of the vessel in open water.
This resulted in immediate cost savings to the client, as they were not required to mobilize a separate ROV support vessel with a subsea crane to complete the project.