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Shell Scotford Quest Carbon Capture and Storage

Shell Scotford Quest Carbon Capture and Storage
Date: 2013

The Shell Quest Carbon Capture and Storage Project entailed the upgrading of and addition to the Shell Scotford Upgrader Base Plant and Expansion 1 site to allow for the capture of excess carbon dioxide for disposal at another site. The works included the transformation of an existing parking lot into a new process unit, the installation of new foundations, equipment and structures within existing HMU plants and the installation of interconnecting pipe racks between the various facilities. The maximum factored pile loads for the various structures, including the large compressor, were in the order of 2000 kN (compression) and 1000 kN (tension). The varying ground conditions and limitations imposed by existing structures and equipment required several different piling methods to be employed.

Solution:

The AGRA Foundations Limited team used both hydraulic hammers and diesel hammers for the installation of H-beam (200 mm to 360 mm diameter) and pipe piles (219 mm to 406 mm diameter). The length of the driven material ranged from 12 m to 20 m, and welded splices were used to extend piles up to 25 m depth. The CIP concrete piles were constructed with shaft diameters ranging from 600 mm to 750 mm and drilled to depths of 21.6 m to 22.3 m below the existing ground surface. Segmental casing was used to seal the holes from sand, water and sloughing, but production rates were not as required, leading to a redesign of the piles using CFA technology to complete the works. The CFA piles were constructed with shaft diameters of 600 mm and drilled to depths ranging from 12.6 to 25.3 m. Eliminating the need for casing, they were the ideal solution to achieve maximum production rates. Screw piles of 406 mm diameter were installed to 5.5 m depths in very tight, low clearance areas.