2020 q2 highlights

The latest instalment of the MinExCRC vNews is now available. Whilst the production of this COVID-19 impacted episode may not be as sharp; we can assure you the content is just as good!

DYNAMIC LOOP” DRILL HOLE SIMULATION FACILITY COMPLETE AND READY FOR EXPERIMENTS

The “Dynamic Loop” is a one-of-a-kind experimental facility that has been designed and built by MinEx CRC in the laboratories of our Curtin University Drilling Optimisation and Automation research team. At the core of the Dynamic Loop is an instrumented plumbing system that simulates fluid circulation within drill holes under carefully controlled conditions. The facility enables development, characterisation and testing of fluid additives, hardware and software for development and rapid prototyping of Drilling Fluid Automation, without requiring field deployment.

Multiple drilling scenarios can be simulated using the dynamic loop. The monitoring system of drilling fluid automation unit detects the deviation and variation of fluid properties and provides input to the dosing system of the drilling fluid automation unit. Based on the algorithms, the deviation from target fluid property is quantified, and additional additives will be added to the system by the dosing system to optimize the fluid properties. The drill string and borehole are simulated in the dynamic loop and sensors are connected on the simulated NQ annulus to characterize the dynamic response. The loop is also equipped with a field scale centrifuge decanter which will be used in future experiments to include the effect of cuttings and residual solids in the mud.

MinEx CRC researchers are using the Dynamic Loop to fast track experiments and prototype development with the first version on the Drilling Fluid Automation unit due for delivery in the second half of 2020.

WORLD’S FIRST SQUARE KILOMETER OPTIC FIBRE DISTRIBUTED ACOUSTIC SENSING (DAS) 3D SEISMIC REFLECTION EXPERIMENT

MinEx CRC researchers in collaboration with Matsa Resources, MRIWA and HiSeis have conducted the World’s first square kilometer optic fibre distributed acoustic sensing (DAS) 3D seismic reflection experiment over the hyper-saline lake.

One of the aims of MinEx CRC is to reduce the cost and logistic difficulties associated with borehole and surface seismic acquisition to the point where it is considered a routine mineral exploration and deposit definition technique. 3D DAS reflection seismic offers the potential for rapid, cheap acquisition from surface and boreholes during the same deployment, whilst maintaining high resolution.

Some 25km of fibre optic cable, which could be compared to a conventional receiver pattern of 37,300 geophones separated by 0.67m, was laid out in approximately 10 hours with the use of equipment designed by the MinEx CRC team from Curtin University. Two interrogators were used, each sensing an fibre optic segment of approximately 6,200 m in length. The interrogators were shifted down the spread as shooting progressed. Two Betsy guns utilising 12 gauge blank cartridges, fired at 30 cm depth and spaced every 10m along the fibre, provided seismic energy for the survey. Compared to an equivalent survey conducted with a conventional geophone array, the fiberoptic system saved days of deployment, movement and collection of the receivers by a seismic crew.

Processing is underway and results of the survey will be presented at the MinEx CRC annual conference in November 2020.

STATE-OF-THE-ART MINERAL SYSTEMS MAPPING AND PROSPECTIVITY ASSESSMENT TECHNIQUES FOR THE NDI

MinEx CRC researchers are developing and applying state-of-the-art mineral systems mapping and prospectivity assessment techniques in support of the National Drilling Initiative (NDI). Our focus is to incentivise and guide future mineral exploration investment in frontier terrains with limited and sparsely distributed pre-existing data.

Mineral prospectivity mapping is the process of assembling the ‘mappable’ criteria of minerals systems and applying algorithms that highlight areas with a high probability of containing an economic mineral deposit. The MinEx CRC team apply a combination of ‘knowledge-driven’ and ‘data-driven’ approaches. The former using data constrained by expert knowledge of mineral system processes and the latter using measured relationships (for example the distribution of known deposits) to train algorithms that find similar patterns in multi-dimensional data.

MinEx CRC researchers from CSIRO, universities and geological survey organisations have collaborated to deliver a state-of-the-art review on mineral prospectivity analysis. The review provides the theoretical background to analyse exploration frontiers with low data density and identify which techniques are best suited to each area. Emphasis has been given to practises that are commodity non-specific. The techniques identified have been applied to highlight prospective areas and aid drill targeting within the East Tennant NDI campaign area, where drilling is due to commence in September 2020.

The NDI provides the opportunity to develop, apply and improve a range of mineral prospectivity analysis techniques in multiple geological settings with a continuous validation by drilling.