Ground investigation specialist Causeway Geotech deployed a fleet of dual purpose roto-sonic drilling rigs at a site in Wales that is earmarked for future development as a hub for green energy. The successful combination of Royal Eijkelkamp equipment and Causeway Geotech operatives helps to achieve the targets of high quality samples, efficient production, and a safe system of work.
Causeway Geotech, part of the Sealaska Group of companies, is the largest ground investigation contractor on the island of Ireland. They deliver the full turnkey package in terms of ground investigation contracting, from the start of a project to the finish. Of their 22 drilling crews, 8 are now specialised in sonic.
The company has seen demand for sonic drilling increase steadily, says Contracts Director Darren O’Mahony. “We’re seeing it overtake demand for the traditional methods such as cable percussion boring in the main, and also rotary coring through certain geologies. The technology and the process is very well suited to the geology that we have in Ireland and Scotland. Our drillers are used to the toughest geologies out there: the dense and stiff glacial deposits. Adopting the Eijkelkamp rigs on our jack-up barges has worked out really well, with higher safety standards, significant programme benefits and much better quality for the client. Ultimately we are adopting the optimum method, prioritising quality and safety over cost.”
The company started to introduce the sonic drilling method into their contracts, providing an alternative tender which was still compliant but using a different methodology. Instead of the traditional methods, they offered a multipurpose rig that combined sonic and rotary drilling. Darren calls it the ‘Swiss Army knife approach’: one rig that can do it all and still provides the client with what they need. “A really good feature with the sonic tooling is that with the GD7 casing, we’re able to also run Geobor S wireline rotary tooling through it to get Class 1 undisturbed samples.”
In 2022 Causeway Geotech won the Ground Engineering Award for 'Ground Investigation Project of the Year', where the sonic rigs made the difference: “In the Highlands of Scotland we encountered very tricky geology and had maybe 60 to 70 metres of drilling through dense gravels to complete. The sonic rigs managed it admirably. Really good quality, good sample recovery, good test results, efficiency and top safety systems as well,” Darren remembers. “The consultant engineers had scoped it out with traditional methods in mind, and we were able to go in and say, this is actually going to be a better method for you. Ultimately everybody was very happy with the end result.”
The fleet now consists of three CRS 140s and one CRS 170. These mid-sized models work perfectly for the ground that the teams encounter.
When asked about some favourite features of the Eijkelkamp sonic rigs, Darren immediately mentions the speed. He’s happy with the ManipAll as well, and the sonic drill heads. He continues: “The sampling systems are also good, and they have compatibility with traditional sampling systems such as the UT100. They’re also very user friendly rigs, the control panel is very intuitive.”
On previous jobs with different rigs we would have struggled with recovery, but with the sonic rigs we’re seeing fast production rates and full recovery on a lot of the runs.
Causeway Geotech deploys their jack-up barges for any near shore works, many associated with offshore wind. There’s a lot of harbour and port upgrades around the coast of Ireland and the UK as preparations are made for offshore wind in the Irish Sea and North Sea. In the video, the team is working on ground investigation in Wales.
Assistant Project Manager Neil Patton: “We are currently carrying out a ground investigation both land side and marine. In the overburden, the team encounters a variety of geologies, including sand, silty sands, peat, clays and mudstone, coals and siltstone. On previous jobs with different rigs we would have struggled with recovery, but with the sonic rigs we’re seeing fast production rates and full recovery on a lot of the runs.
We have also deployed our Drill’n CPT, because our clients now often request CPTs alongside boreholes. This helps to provide a continuous ground model and a correlation with the boreholes. What I’ve experienced with the Royal Eijkelkamp equipment is it’s very fast, it’s efficient, and the runtime of the project is greatly reduced.”
