Intervention is often a necessity, but pre-planning can mitigate the impact on production.
Oran Tarlton of Oil States Industries summed up this point a the Offshore West Africa conference in Abuja, Nigeria: "Nobody wants to do an intervention, but pre-planning makes doing an intervention a little less painful."
According to Tarlton, Oil States' new Intervention Y tool is a versatile solution. It can be pre-installed on the topsides, above the flex joint on steel catenary risers, on manifolds, or subsea on in-line sleds. The unit can be installed by a diver or using an ROV, he said.
The tool is designed with a 5D bend to facilitate introducing coiled tubing by guiding the tubing through the bend. Intervention can be carried out without halting production, he said, and pigging can be done bi-directionally. Most significantly, coiled tubing can be introduced without a vessel, Tarlton said, and using the new tool is also economical. "Conventional intervention can cost an awful lot of money and take a lot of time," he said.
Three of the units have been installed to date in water depths from 4,800 ft to 7,200 ft. None have yet been used for coiled tubing.