Umbilical Installation

The Challenge

The topside pull-in arrangement was located within a highly congested area of an ageing offshore asset, where limited original information was available and existing pipework had to remain protected throughout the installation.

Restricted head height above the J-tube limited the available overpull arrangement and reduced the space available for conventional pull-in equipment.

The engineering solution therefore had to minimise modifications to the platform while providing a compact arrangement capable of safely transferring the required pull-in loads.

The Solution

Point cloud data was incorporated into the design process to review the existing platform geometry, identify potential clashes and screen pull-in arrangements before the site visit.

This allowed the site visit to focus on the most practical options and helped minimise the amount of offshore survey work required.

Pull-in analysis was then used to establish the required winch loads and support accurate specification of the topside equipment.

The winch and pull-in system were designed to be as compact as practical so the equipment could be transported offshore and assembled in situ. Bolted connections were used throughout the system to reduce individual component size and simplify offshore handling and load testing.

The resulting pull-in arrangement provided the engineering basis for the wider umbilical installation campaign, including the associated lay spread, seafastening and installation analysis.