Speeding up Scarborough

​​​​​​​​​​​Quick action by Woodside’s geotechnical operations (GTO) and Contracting and Procurement (C&P) teams has resulted in accelerated provision of essential geophysical survey data to the Scarborough Development. 

GTO became aware that Ocean Infinity's vessel the Seabed Constructor would be docking in WA before commencing a charter. GTO inspected the vessel and discovered it boasted seven autonomous underwater vehicles (AUVs) and a suite of cutting-edge supporting technologies. The potential to use this capability to collect geophysical data far quicker than conventional mapping expeditions was clear; the challenge was to mature the opportunity into one that was technically and commercially attractive to Woodside. 

GTO and Ocean Infinity discussed how the multi-AUV capability Seabed Constructor could best be customised for our survey needs for the Scarborough Development, some 375 km west north-west of the Burrup Peninsula. “It’s the only vessel that offers multiple AUVs and it offered us a step change in survey technology,” says survey operations manager Mike Bowler. Scarborough “We have a very tight deadline to deliver data for the front-end engineering and design (FEED) by the end of this year and we identified Seabed Constructor’s visit to WA as a chance for us to get ahead of the curve in delivering the right data quickly.” 

Senior surveyor Lee Woolhouse says C&P initiated accelerated negotiations with Ocean Infinity before the Seabed Constructor left the region. Exploration C&P manager Lee-Ann Pereira says: “An agile and accelerated C&P process is critical to take advantage of market opportunities as they arise. “The team did an excellent job of fast-tracking the process while addressing all contractual delivery requirements and ensuring contractual and commercial risks were managed.” 

After the Seabed Constructor had completed the contract which had brought it to WA, it sailed directly to Dampier. It then conducted a survey of the field area and proposed trunkline route for the Scarborough Development. “Traditionally AUV surveys are conducted with one AUV in a supervised mode,” says Lee. “With up to six AUVs in the water, Ocean Infinity operated the fleet in a fully autonomous mode. “And because they travel about 70 metres above the seabed, the AUVs compile a high-resolution bathymetric data.” 

The survey amassed a significant amount of data, with many terabytes of raw data being acquired during the operation. This data has enabled the earlier assessment and selection of a preferred trunkline route from the Scarborough fields and supported pre-FEED engineering to provide confidence in the feasibility and the cost of building this important asset. “In total we surveyed about 6800-line kilometres and while doing so provided preliminary data back to shore,” says Lee. “And the speed with which they delivered the data allowed our engineers to make real-time decisions about the trunkline.” 

In addition, the highly versatile Seabed Constructor, which is equipped with two remotely operated vehicles (ROVs), conducted environmental inspections for Woodside. 

Mike says there were a number of “firsts” with the survey, including the real-time route selection for the proposed trunkline.

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Trunkline Q3 2018