The county of Cornwall in the UK is well-known for its base metal and tin production in the 18th and 19th century. Now, with the global demand for electronics, electric vehicles and renewable energy increasing, a new exploration target in the region is lithium.
Cornish Lithium Ltd, an exploration company that started in 2016, commenced its first drilling programme in late 2019 by drilling two research boreholes at the United Downs site designed to intersect geological structures hosting potentially lithium-bearing geothermal waters. SRK was commissioned to plan and supervise the extraction of samples of these waters from specific intervals for testing of lithium content.
In collaboration with the client, SRK developed a sampling procedure for the programme. The procedure involved using the IPI Standard Wireline Packer System (SWiPS ®), a tool that allows specific intervals in a borehole to be segregated and tested or sampled. The SWiPS tool is typically used for targeted permeability testing in boreholes. Water can be injected at a specified pressure into isolated intervals within a formation and the data used to derive a permeability for discrete structures or longer intervals of rock mass.
A groundwater sampling pump was then used in conjunction with the packer to extract waters from those intervals. The groundwater chemistry was monitored until parameter stabilisation was reached before samples were taken for laboratory testing. During the test work programme, samples were successfully taken from 11 intervals ranging up to and just over 1,000 m depth.
SRK has extensive experience using both the SWiPS and STX-60 IPI packer systems for permeability testing down to depths of 1,600 m. SRK UK has also developed and tested a groundwater sampling procedure for the SWiPS tool to isolate and sample groundwater from discrete intervals up to 1,000 m deep. Both methods can be adapted to suit the specific needs of a project.
