Case studies

Grout monitoring

Overview

One method for subsea pile installation involves drilling seabed sockets and cementing the piles in place.

Ashtead Technology was contacted by a customer to develop a solution that could monitor grout levels within WTG subsea foundation pile boreholes during grouting operations.

By monitoring grout levels, the customer was able to ensure the integrity of annulus grouting and confirm when the grout pumping operation should stop.

Solution

Ashtead Technology developed a bespoke autonomous monitoring package with sacrificial grout sensor arrays.

The system incorporated optical data telemetry for real time level monitoring via an ROV. It also incorporated a subsea display as a backup indicator.

This information ensures that the grout pumping operation achieves the specified level allowing the customer to confidently stop pumping grout at the right time.

This system saves cost and uncertainty ensuring the foundation is installed efficiently and within specification.

Benefits and value

  • Fully integrated service delivery providing a cost effective solution to monitoring requirements for the installation of 168 cemented pile foundations
  • 100% redundant system ensured reliable operation along with low cost dual parameter grout level sensor arrays
  • Low power optical data telemetry enabled high speed reliable data transfer without data interference from acoustic noise
  • Vessel time and cost saving through efficient grouting operations