Amorer, G, Duffield, S, De Ross, J & Viegas, G 2022, 'Surface hydraulic fracturing trial at Cadia East', in Y Potvin (ed.), Caving 2022: Proceedings of the Fifth International  Conference on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 1173-1188, https://doi.org/10.36487/ACG_repo/2205_81
(https://papers.acg.uwa.edu.au/p/2205_81_Amorer/)
Abstract: Historically, preconditioning practice at Newcrest’s Cadia Valley Operations has been to conduct the drilling and fracturing activities associated with hydraulic fracturing from underground excavations. In 2020, Newcrest undertook a trial to investigate the application of oil and gas industry techniques from the surface as an alternative to the approach from underground. Prior to this trial, these techniques had not been tested in a hard rock mining environment.
The trial was designed to show that hydraulic preconditioning operations, including drilling, fracturing and monitoring, could be successfully completed solely from surface. The primary objective of the trial was to investigate the potential safety, logistical, schedule and financial benefits that could be realised from executing hydraulic preconditioning from surface. The trial consisted of preparation of the surface drill pad and water supply, the drilling of three boreholes each over 1,520 m deep, collection of detailed geophysical logging, execution of 132 fractures and the monitoring and verification of execution outcomes.
The results of the trial greatly exceeded expectations for hydraulic fracture extents and the volume preconditioned. This paper discusses the Surface Preconditioning Trial stages and summarises the outcomes against the trial objectives.

Keywords: hydraulic fracturing, preconditioning, block caving, microseismics