The Alpala Deposit is a Tier 1 copper-gold porphyry deposit located at the Cascabel Project in the Imbabura province of Northern Ecuador. The project is located in the Ecuadorian segment of the in the Andean Copper Belt which extends from Chile to Panama and, in its entirety, represents just under half of the world’s Copper production. SRK UK was commissioned in early 2019 to work and acquire data in support of a Preliminary Economic Assessment and subsequent Pre-feasibility Study for Cascabel. SRK continued to be involved with the project throughout 2019 and into 2020.
In 2019, SolGold undertook a geotechnical drilling programme which involved various boreholes targeting the proposed decline and mine areas. SRK undertook permeability testing on these boreholes using both the IPI Standard Wireline Packer System (SWiPS ®) and the STX-60 ®. These tools allow sections of a borehole, as small as 1m in length, to be segregated and tested. The testing at Cascabel focussed on the deep groundwater system relating to the planned underground mining development.
During a packer test, water is injected at a specified pressure into isolated intervals of a formation with the data 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 using the STX-60 tool. 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 over time and this data can be used to derive a permeability result where injection rates would be impractically low.
At Cascabel, both packer testing types were used successfully from depths of 50m (~160ft) up to depths of over 1800m (~5900ft) downhole. To date, 70 successful tests have been completed in 11 boreholes.
During the programme, SRK also provided technical training to SolGold site staff on both the SWiPS and STX-60 packer systems. SolGold has since been undertaking the packer testing with remote support from SRK as required.
