NPE worked on the design, supply, function test, mobilisation, commissioning, operation and project management of a specialised submersible dredge pumping spread, required for recovery of the principal tunnel boring machine (TBM), commissioned for the Wheatstone LNG trunkline installation. A redundant back up spread was also supplied.
Being a challenging remote marine environment, all works were required to be prepared and executed to a flawless standard. NPE’s delivery of works resulted in outcomes which surpassed the client’s expectation. Indeed, NPE received high praise from the client regarding the equipment preparation, mobilisation, execution and quarantine compliance procedures.
Furthermore, the project execution team received a Chevron Australia Safety Award accolade for HSE performance throughout delivery of the works. NPE’s emphasis on communication and flexibility was appreciated by the client. This enabled both parties to work in harmony, with maximum efficiency, to achieve a remarkable result.
NPE’s customised solution was fully compliant and modular for safe assembly and efficient offshore use. The design involved a unique solids agitation system whereby the intake of the submersible dredge pump was equipped with a specialised jet-ring, which sprayed water at 80 litres per second @ 9 bar from 20 x 20mm nozzles.
The powerful water flow broke up the solids into the dredge pump intake. Slurry discharge flow was approximately 100 litres per second. NPE removed several thousand cubic metres of sand from above the TBM. This enabled the TBM to be effectively detached, recovered, and towed to the nearby port of Beadon Creek.
Prior to mobilisation, all equipment was prepared and function tested at NPE Welshpool headquarters using our sophisticated pump test tank. The submersible dredge pump spread was mounted on lift certified flat racks complete with all hoses, spooling and floating discharge line.