Woodside Energy – Goodwyn Alpha
Goodwyn A is an offshore production platform in Commonwealth waters about 135 km north-west of Karratha in Western Australia and has been operating since 1995. This offshore production platform produces dry gas and condensate from the Goodwyn, Perseus and Searipple area reservoirs. Gas and condensate from these reservoirs is transported via a network of pipelines to Goodwyn A and then on-shore to the Karratha Gas Plant for processing.
The Goodwyn A is more than 290 metres tall and stands in a water depth of 131 metres. The platform combines production, re-injection, utilities and accommodation facilities. The 55,000 tonne production facility is secured to the seabed by 36 piles, which allow the structure to support its operating load and withstand cyclone conditions.
It is designed for up to 30 production wells, including five re-injection wells, and has a daily production capacity of up to 36,000 tonnes of gas and 11,000 tonnes of condensate.
The work scope involved replacement of an existing staircase. The primary structural steel had to be removed and replaced, and to gain access to this, the engineers had to cut through stainless steel cladding and hand rails. The accommodation walls needed to be cut in order to allow for new steel to be installed. To avoid the accommodation area being compromised, habitat technicians had to ensure that there was a constant level of over-pressurisation throughout.
The location is also prone to high winds as it was situated over the side of the platform.
Our technicians worked closely with the client’s maintenance and scaffolding teams to ensure weather conditions did not interfere with the functioning of the habitats. Detailed planning was also required to ensure pressurisation of accommodation during hot work.
Detailed planning ensured the habitat was set-up in such a way so as to be unaffected by the exposed location. The work took place during the height of summer with temperatures in excess of 40°C, so we enabled a more comfortable working environment with an internal habitat temperature of 20°C. This was achieved using insulated panels and a SafeCool air conditioning unit which greatly assisted in combating worker fatigue, and therefore increased productivity.
Multiple GSM’s were also used to eliminate the risk of gas ingress.
Outcome and benefits
The client carried out an audit of the project during the red hot work scope job, with the habitat component of the audit delivering zero corrective actions. In total, three habitats were installed and maintained over a four week period – equivalent to 500 safe man hours. All work was successfully completed ahead of schedule with no fatigue issues for workers, and no loss of production for the operator.