Riser-less Light Well Intervention System

Project sanctioned:

December 2018

Industry sponsors:



Entry TRL

Target TRL




Project summary

The OGTC is working with Well Safe Solutions on a feasibility study to evaluate the options available to deploy a Riser-less Light Well Intervention System (RLWI) from a Mobile Offshore Drilling Unit (MODU) for subsea well plugging and abandonment activities. This combined system would enable low cost access to existing subsea wells by providing a fully integrated package of well control barriers and fluid circulation/injection facilities into a single package. A single integrated delivery solution gives continuity, flexibility, reduced multi operation interfaces and technical options when re-entering subsea wells for the first time after many years of operation. An integrated MODU would provide a total well decommissioning solution preventing the need for the current RLWI followed by MODU approach that is commonly deployed in the UKCS, which would lead to significant cost reductions during the execution of the projects and with associated engineering planning and contract management. Phase 1 of the project will look at developing the concept of combining a MODU and a RLWI system to TRL 5.

Field trial


Economic value

  • Cost Reduction

Non-economic value

  • Risk Reduction