Page 67: of Offshore Engineer Magazine (Mar/Apr 2026)

66 68

TECH FEATURE INTERVENTION

Fixed-to-Bottom Platforms as the Intervention

Solution

The offshore industry does not need to look far for a solution to this challenge as the tools required are already in daily use at another stage in the well lifecycle. In APAC, jack-up rigs remain the dominant platform for shallow wa- ter drilling across the region, while lift boats are similarly in demand in support of offshore construction, mainte- nance and well servicing.

Fixed to the seabed, jack-ups and lift boats remove reli- ance on dynamic positioning and allow operations to be planned around a fxed geometry, removing one of the most signifcant execution risks associated with intervention. A riser-based well-access setup can be vastly simplifed, as it does not require an emergency disconnection package or complex subsea pressure-control equipment. This, in turn, reduces loading on the tree and wellhead through the use of a top-tensioned lightweight riser system.

The practical outcome is a wider intervention window and the ability to execute more demanding work reliably, as the well access solution between seabed and surface is riser-based, supporting a complete range of light and heavy intervention services. Modern riser systems incorporating quick-connection technology, offine handling, and com- patibility with a range of wellhead and BOP confgura- tions now provide effective well access for intervention and abandonment campaigns. When deployed from fxed-to- bottom platforms, these systems directly address the sta- bility and access constraints that have historically limited intervention in shallow water.

Putting it into Practice

Crucially, they are available today and already being de- ployed in live offshore operations. In West Africa, for ex- ample, we are working with Intrepid Energy Limited (IEL) offshore Nigeria to deploy a riser-based intervention sys- tem from jack-ups or lift boats to restore production from intervention and removal of the subsea tree, followed by mature shallow water subsea wells. By providing a full deployment of a subsea drilling riser onto the subsea well- seabed-to-surface riser-based well access solution without head to allow the complete abandonment and removal reliance on foating intervention vessels, the programme of the wellhead restoring cap rock integrity and a clean enables repeatable intervention across multiple wells and seabed. This demonstrates that the same fxed-to-bottom, unlocks production that would otherwise remain stranded.

riser-based delivery model applies whether the objective is

A different application of the same approach can be production recovery or the removal of long-term liability seen in the Middle East, where we are supporting a ma- from an operator’s balance sheet.

jor offshore operator with riser-based well access to enable

Jack-up deployed subsea intervention hardware is only late-life well management and permanent abandonment one part of what is required to increase intervention ac- of subsea wells. In this case, a turnkey well access solu- tivity in shallow water. As discussed, a key driver behind tion was provided that allows a single rig to complete the the success and appeal of LWIV campaigns is the con-

MARCH/APRIL 2026 OFFSHORE ENGINEER 67