The Cascabel Project is a copper-gold porphyry deposit located in northern Ecuador. SRK UK was commissioned in early 2019 to acquire data in support of a preliminary economic assessment and subsequent pre-feasibility study.
In 2019, SolGold undertook a geotechnical drilling programme targeting the proposed decline and mine areas. SRK undertook permeability testing on boreholes using both the IPI Standard Wireline Packer System (SWiPS®) and the STX-60®. These tools allow sections of a borehole to be segregated and tested.
During a packer test, water is injected at a specified pressure into isolated intervals of a formation. The data are used to derive a permeability of discrete structures or longer intervals of rock mass. For extremely low permeability sections, ‘shut-in’ tests can be completed. During such a test, the STX-60® allows a specified pressure to be locked into the test formation. The pressure is then left to dissipate and these data can be used to derive a permeability result.
At Cascabel, both packer testing types have been used successfully. To date, 70 successful tests have been completed in 11 boreholes.
SRK provided technical training to SolGold site staff on both packer systems. SolGold personnel now perform the packer testing with remote support from SRK as required. SRK Chile has been supporting SolGold in carrying out the geotechnical and geomechanical studies required for the pre-feasibility study.
The geotechnical and structural data were used to assess the rock masses at Cascabel according to the main classification systems such as Bieniawski RMR (1989), Laubscher RMR (1990), Laubscher & Jakubec IRMR (2001), Grimstad & Barton Q (1993) and Hoek et al. GSI (2013).
Structural data collected from oriented cores and televiewer were used to build a 3D structural model at mine scale and to define and characterise structural domains.
Geotechnical and structural assessment were used as input to estimate caveability, fragmentation, subsidence and pillar stability, rock support, seismic risk analysis and requirement for dynamic rock support and recommendations for geomechanical monitoring.
