Jadestone Stag platform – ROV Installed Retro-fit Conductor Spacers

The Challenge:

Subsea conductor spacers on the Jadestone Stag platform had been dislodged by wave loads resulting in a long unsupported conductor span with cyclone season imminent.

The Solution:

he conductor guide in question was surrounded by adjacent conductors which prevented ROV access and prohibited diving.  Cube therefore developed a remotely installable conductor spacer system for installation from above using rope access.  The spacers were developed in 4no. quadrant shapes that could “self-install” when lowered from above.  A release line was then pulled to deploy to 2no. wedges per quadrant to lock the spacer into position.  The spacers were specifically designed such that they could not be dislodged by high vertical hydrodynamic forces, as the original design had.   Engineering checks confirmed the strength & stability of the spacers and the local conductor wall for structural integrity

The Scope:

  • Concept development
  • Detailed engineering design & modelling
  • Manufacture
  • Full scale SIT / Function test
  • Engineering & manufacture documentation

3D modelling of the spacers confirmed fit & functionality prior to manufacture.

Installation sequence confirming fit & functionality.

In order to further verify the design, a mock-up of the conductor and guide was built and a successful System Integration Test carried out for installation, deployment & operation of the spacer system.