This work forms part of Cornish Lithium’s broader initiative to develop sustainable domestic sources of lithium for the UK’s green energy transition. The project required the deployment of advanced downhole logging tools to characterise lithology, fracture networks, geochemical profiles and temperature gradients in deep and geologically complex boreholes.
The four visits culminated in the completion of three more boreholes for Cornish Lithium: one at a maximum depth of 800m, one at a depth of 1,210m and the deepest of the three at 1,861m. The deep borehole was completed by four Robertson Geo engineers operating seamlessly in pairs over 12-hour shifts in a 24-hour/day logging campaign. Working on a continuous 24-hour basis minimised project downtime, with the engineers completing over 10km of borehole logging in 8 days.
RGS deployed a suite of cutting-edge logging tools to provide Cornish Lithium with high-resolution, multi-parameter datasets, including:
High Resolution Optical Televiewer (Hi-OPTV)®: Captured detailed borehole wall images for fracture mapping and lithological features.
High Resolution Acoustic Televiewer (HRAT)®: Acoustic imaging for structural and geotechnical interpretation in less optically clear environments.
3-Arm Caliper (Gamma): Measured borehole diameter and natural gamma, locating fractures and potential changes in formation.
Temperature Conductivity: Measured fluid properties and helped identify permeable zones.
Full Waveform Triple Sonic: Determined compressional and shear wave velocities of the formation to highlight changes in lithology, identify fractures and estimate porosity.
Electric Log: Industry reference resistivity logging for formation evaluation.
Impeller Flowmeter: Determined flow profiles and identified producing zones.
Temperature Pressure: Recorded temperature gradients and geothermal characteristics.
Fluid-Gas Sampler: Provided geochemical sampling at specific depths for further laboratory analysis.
Despite the complex and varied geology of the Cornish subsurface, RGS engineers completed each borehole within the project timeframe with the data providing a comprehensive view of each borehole’s profile, critical for resource assessment for Cornish Lithium.
