[Dassault case-study] Resources estimation with GEOVIA Surpac

GEOVIA Surpac has enabled Regis Resources to significantly save time and budget on resource exploratio

Regis Resources  is a publicly traded company headquartered in Perth, Australia, specializing in gold mining and exploration. The Company operates in the northeastern goldfields of Western Australia and the central-western region of New South Wales.

The company uses Dassault Systèmes' GEOVIA Surpac™ at its Perth headquarters and three mining operations at its Duketon project, located 130 kilometers north of Laverton, Western Australia.

Jarrad Price, Senior Prospector at Regis Resources, has been using Surpac for geologic resource estimation for 8 years. Recent updates to Surpac, especially in the geostatistical tools, have expanded the resource estimation capabilities, saved the company time and effort, and even eliminated the need for a separate geostatistical program.

Surpac’s improved geostatistics capabilities provide me with greater confidence in my exploration data and block model validation, enabling more accurate estimations. Improved charting and data processing means my workflow is more streamlined and faster, in particular its declustering feature that generates a representative data distribution through sample weighting

Surpac supports declustering in software, which saves Jarrad from having to install a macro for declustering each time. Swath plots are a tool used to validate a resource estimate by comparing the average grade in the estimate to the grade in the data over a range of north, east, and elevation directions.

Fast charting

Comparing the estimate grade to the declustered composite grade is more realistic as it will remove the bias of high-grade samples. Surpac’s ability to create swath plots is very fast and will save roughly 10 minutes per swath plot.

Surpac also has a Grade Tonnage Curves feature that allows for quick visual analysis of resource estimates at a range of cutoffs. These curves are usually time-consuming, especially if the number of estimation iterations exceeds 50, but Surpac makes them quick and easy to create. Using the Grade Tonnage function in Surpac is as time-saving as using the swath diagram function.

Surpac’s basic statistics window can now produce a mean or variance plot to help determine what assays require cutting or removal prior to complete variography and estimations. It enables quick and easy determination of what uppercut is required to reduce the variability of the estimation input data to reduce the chances of grade over-estimation

Dynamic anisotropy

Surpac's recently developed dynamic anisotropy accounting features allow the company to perform more accurate resource estimation by linking sample searches to the diagram or orientation of mineralization that users specify.

This feature is particularly useful when estimating deposits that have undulating or folded mineralization. It’s simple to operate as I just have to generate a DTM that follows the trend, which is assigned to the model prior to estimation. We have started looking at this feature and can see the possibilities for its application on our deposits at resource and grade control scale

Resource estimation with GEOVIA Surpac

Additionally, Surpac can perform resource estimation into different cell sizes within the same model; useful for instances when a deposit has differing mineralization thicknesses, welldrilled or poorly drilled areas.

We can see this being used at our Moolart Well operation in Duketon, which has densely drilled flat-lying l aterite mineralization underlain by moderately dipping primary mineralization that is not as well-drilled

Field evaluations are typically performed in multiple passes, with the first pass searching for distances to analyze zones with densely drilled wells, and the second and third passes evaluating larger areas. Surpac has the additional option to perform passes for each estimate, which reduces the size and complexity of macros and reduces the potential for errors.

These geostatistical functions are also implemented in the GEOVIA GEMS package.

Source: https://www.3ds.com/insights/customer-stories/regis-resources

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