RBF added to implicit modelling

Maptek Vulcan 10 will include expanded implicit modelling options with the addition of uncertainty modelling and radial basis function modelling. Vulcan 10 is due for release in March 2016.

Uncertainty

Defining a geological structure from drillhole data is inherently uncertain. Huge orebody volumes are often inferred from relatively small samples. Drillholes may be widely spaced and the data does not necessarily provide an accurate picture of the geology.

Geologists must rely on their experience and judgement to determine a realistic model for an unseen orebody. There are many possible alternatives that need to be evaluated in a short time.

Maptek has responded to this challenge. Uncertainty modelling will be added to implicit modelling options in the next release of Maptek Vulcan. Multiple models of the orebody can be automatically generated from the same drillhole data.

Being able to apply financial information to these scenarios results in greater confidence in the economics of a model for assessing the viability of mining.

According to Vulcan Product Manager Eric Gonzalez, ‘When evaluating models for uncertainty, a big component - the geological structure - tends to be ignored, usually due to the complexity involved in building these models.’

‘An easy to use tool that produces several scenarios for the same set of geological structures allows for a more comprehensive assessment of risk at any stage of a project.’

Radial basis function

Vulcan will also include a new radial basis function (RBF) option, which will complement the existing proven geostatistical estimation technique for implicit modelling.

Geologists will be able to choose both methods from the same mine planning software, and verify which technique suits their deposit, leading to greater confidence in the final model

Implicit modelling allows geologists to quickly assess a potential model and make adjustments before building it.

The key benefit is that geologists can easily analyse the risk for the many possible alternatives.

‘They can evaluate the risk and perhaps decide it’s worth paying for more drilling’, said Gonzalez. ‘We integrate RBF, faulting and uncertainty modelling within a single system and workflow. Engineers and geologists can assess risk at all stages of modelling and mine planning.’

‘Users can tailor their modelling approach to what works best for each scenario.’

Structural trends

Structural trends are a key input for most complex geological modelling. Implicit modelling using either RBF or the geostatistical technique takes better advantage of shared structural trends for related domains. Domains with shared or independent structural trends will be defined and modelled together in a single run. Implicit modelling will now include an enhanced smoothing method that still honours the drillhole data. Users will also be able to leverage existing anisotropies. The new release also delivers several new methods for creating local anisotropies for implicit modelling, grade estimation or simulation. This will allow the grade estimation to match the complex folded structures identified through implicit modelling.

‘Our primary aim is to help users be more productive with Vulcan. We continue to improve implicit modelling so that as much information as possible is available for making smarter decisions,’ concluded Gonzalez.

The Radial Basis Function (RBF) approach has become a table stake for geologists looking to create an implicit model from drillhole data