Fyfe has worked with Santos several times at its Moomba facility in South Australia. The recently announced carbon capture and storage (CCS) project at Moomba, which received final investment decision in November, aims to substantially reduce carbon emissions and provide a roadmap for future CCS initiatives. Absorber towers are a key part of the project.
Overview
In 2019, Fyfe provided pipeline engineering and survey services at Santos’ Moomba site. We were pleased to return to the site in 2021 to help ensure the safe and correct installation of a CO2 absorber tower.
Santos’ new 220-tonne tower was procured to replace an older model. Manufactured in Korea, the vessel had been shipped to South Australia to await installation at the Moomba facility. As absorber towers are expensive pieces of equipment, an extremely high level of care needed to be taken prior to moving the vessel from a prone position to its final upright installation.
Fyfe’s role was to undertake a variety of in-depth surveying services both before and after the tower was lifted into position.
Approach
In the week before the lift and installation, and while the tower was in a horizontal position in the facility’s Train #7 area, Fyfe carried out various surveys utilising several methodologies.
It was critical that the tower would correctly align with the pre-prepared concrete ring beam hold-down bolts in its intended position. In addition, the vessel’s N6 nozzle needed to be at a specific design elevation, and the tower as a whole needed to meet pre-calculated vertical operating tolerances. Final verticality was a matter of key importance; if it fell outside the limits by mere millimetres, the vessel’s operational tolerance could be affected.
To avoid causing delays to the crane team, issues with the final installation, and several other factors that would hinder the installation, the lift needed to run smoothly — Fyfe’s surveys and calculations were essential.
Before the lift, we conducted exacting set-out surveys, dimensional control surveys of the vessel’s base ring, including in-depth tabulation of its rotation, and the N6 nozzle’s vertical offset. We also conducted a level survey of the corresponding shim locations on the vessel’s concrete ring beam slab to ensure it would meet the pre-calculated shim placement.
A horizontal twist check survey was carried out while the crane was still in position in order to check and adjust the vessel’s rotational twist on its elongated base plate bolt holes.
After the tower was successfully lifted into position, Fyfe checked its verticality to ensure it fell within its operational tolerance range. According to our shim calculations, the tower’s verticality fell within just one millimetre at the base and five millimetres at the top, an excellent result that was well within range.
Seven days after the tower was lifted into position, we conducted a full 3D laser scan and modelling of the vessel, including ultra-high resolution scans of the four tie-in nozzles and the corresponding flanges on the gas exchangers.
Services provided
- Construction set-out surveys
- Laser scanning
- Dimensional control surveys
- 3D modelling
- Verticality survey
When a high degree of precision is needed, quality surveying is essential. Fyfe has the tools and know-how to get the job done right, the first time. Contact us today to find out how we can help.
