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exSim exploration simulator software: CET training tool for mineral exploration decision making

by Jason C. Wong, Eun-Jung Holden, Peter Kovesi, Campbell McCuaig on June 3, 2012 technology

The need for undercover exploration is progressively increasing as surface resources are running out.  However, seeking mineral deposits at greater depth into the Earth’s crust brings significant challenges to the exploration industry. To address this, large investment has been made by industry and government in recent years for the development of technologies that allow mapping beneath a thick layer of weathered rock, sediment and soil.  Due to the difficulty and cost of collecting data at greater depths, undercover exploration increasingly relies on the ability of explorers to understand deeper subsurface geology using more limited sets of observations.  Thus undercover exploration presents a great challenge in exploration decision making and consequently, the improvement of skills, behaviour and practices of explorers is critical for successful exploration.

A team of researchers at the Centre for Exploration Targeting (CET) has been developing an exploration simulator called exSim with the specific aim to improve the behaviour of explorers through simulated training.  Harnessing the power of computer simulation, visualisation and an easy to use graphical user interface, exSim will provide an environment where explorers can test their strategies and learn the consequences of their decisions. The on-going development of exSim is geared toward providing a unique platform that will allow customised geological scenarios and situations (e.g. different deposit styles), potentially allowing users to become familiar with a broader range of exploration practices. In addition, this also allows for industry to set up their own scenarios that are relevant to an on-going exploration program. 

Previously, computer simulation has been applied to assist in the planning and training of the exploration process. The CLAIM [1] program allowed a drill test requested by a team of users to be simulated, although the requests themselves are required to be vetted and validated by a human game master.  In another example, drill test simulation through the software FOREUR has been incorporated into a training course, “Practical Course in Resource Economics and Mineral Exploration From discovery to evaluation” at Laval University, Canada [2]. The purpose of this course is for the training of exploration of a mineral prospect through geological analysis, simulated drilling and resource calculation. 

In contrast, exSim provides a simulation environment where exploration decisions at all levels; including greenfield ground selection, collection of various survey data through user defined survey design, targeting and drilling, can be tested through effective user-computer interaction, graphics and simulation. This article highlights the current progress in the development of exSim, including the overview of the workflow and functionalities that are planned.

The exSim workflow

The exSim software caters for strategic decisions in exploration including the selection of geophysical and geochemical surveys, and drill testing in a scenario based simulation. The scenario is concluded when the user has identified an economic deposit, or runs out of resources. 

Using a scenario that is specific for training objectives, the user is provided with; the expected type of mineral deposit being explored, some existing knowledge of the area, a financial and time budget, and also several low resolution datasets (such as regional scale geophysics data available from government surveys). The user is then free to test their exploration strategies by iteratively collecting finer detail datasets and interpreting the results to improve their geological knowledge of the area and to learn the consequences of their decision making. Ideally, the user will gain familiarity with the amount of geological knowledge gain verses the financial and time costs in each step of the simulated exploration.  Clearly, the most effective strategy is to maximise information gain at each step whilst maintaining the goal of targeting mineralisation at a minimal cost. 

For training purposes, it is important for exSim to provide feedback on user progress, thus an exploration scenario requires ground truth models of the area to generate simulations of geophysical and geochemical surveys, and drill tests. With these ground truth models, (whether magnetic, gravity, or 3D block models etc.) exSim can then provide feedback on how effectively the user designed the surveys and understood the area.

Main functionalities

The main functionalities of exSim comprise a compilation of survey tools, interpretation tools and user monitoring tools.

Survey tools allow for the selection of a survey type and the design of the selected survey. Firstly, the user makes a choice between the available survey types. The choices are mainly geophysical surveys such as magnetic, gravity, seismic, and electromagnatics. However, in addition to these, geochem based surveys and drilling can also be included. The current prototype of exSim features; magnetic and gravity surveys, and drill testing.

Once a survey type has been selected, the user is required to design and provide the parameters for the survey. The exSim prototype facilitates airborne and ground modes for both magnetic and gravity surveys and drill testing. Figure 1 shows the exSim interface for designing an airborne magnetics survey, specifying the flight height, line separation, and tie line separation. Figures 2 and 3 show the exSim interface for specifying drill holes (location, azimuth, dip and depth) and the resulting drill core visualisation respectively.

In addition, exSim also features a novel blending tool to encourage the perusal of multiple datasets. This circular blending tool allows for quick combined visualisation of multiple datasets (up to 5). Figure 4 illustrates an example where three datasets, namely; magnetics, gravity, and a geology map are blended with the circular tool. The final weighted combination of the datasets is determined by the position of the blue cursor dot. Note that Figures 1 and 5 also display blended images.

In combination, these tools provide training for the user to achieve a balance between the cost of the survey and the level of significant information it attains for exploration. In other words, it is ideal for a user to become adept at designing surveys whilst being aware of the effect of survey resolution versus cost and the subsequent likelihood of detecting targeted sized deposits.

Interpretation tools allow for the annotation of the user’s interpretation of the survey area. The current exSim prototype provides two layers for interpretation annotation; structural and lithological layers. For each of these layers, simple tools are available to mark like-line, or closed polygon features with labels of structure or lithology. In order to encourage flexibility, exSim will also have an export functionality that allows datasets to be displayed in other GIS packages. In this way, it is possible to use all the user’s usual interpretation methods and use exSim for annotating the interpretation. Figure 5 shows an example annotation of structural and lithological interpretation in exSim.

If the exploration scenario includes a pre-defined ground truth interpretation by an expert, exSim provides a feedback system to compare the user’s interpretation with the ground truth. In the exSim prototype, this feedback is given in terms of general accuracies of interpretation positioning and feature identification. This process is intended to be useful in giving guidance to the user in correctly understanding the results. Our on-going development includes refining and further enhancing the current feedback system.

User monitoring tools allow exSim to collect and store the user’s decisions (strategy) over the course of the exploration scenario. These strategy data will highlight the difference between expert and novice explorers, and aid in identifying the value and style of exploration experience. We also aim to collect statistics on the favoured survey tools and datasets used, and the comparative effectiveness in discovery. In the end, these sorts of analyses will lead to a better understanding of good and bad decisions in exploration, and ultimately, more effective exploration. Development of these tools will be a major focus of on-going research.

Potential Applications

The exSim software has many potential applications. For example, exSim can be used for training within industry by using customised scenarios, specific to the training objectives. Also, exSim is useful for interpretation assistance and thus interpretation training to improve consistency amongst and within-individual interpreters. In addition, exSim could also be used for survey planning (in verifying effective survey parameters before running it in real life), as well as a research tool (with the collected information on how a user interacts with data, and thus ascertaining the value of certain data).

Summary

The exSim software aims to provide simulation at all levels of exploration decisions, from area selection, survey design, to target drilling. With the open-sandbox approach of providing these tools and leaving the ultimate decisions to the user, exSim enables the user to freely experiment with different strategies. Coupling this with flexible and customisable scenarios, exSim’s scope is very broad and thus with the many potential directions exSim can take, and the main challenge is steering the project in a way that maximises benefits to industry and education. Regardless, it is the hope of the researchers that exSim will become a cost and time effective tool, useful for refining exploration experience in the near future.

Acknowledgements: We like to thank Jon Hronsky, Lisa Vella, Mark Armstrong, and Mark Jessell for their invaluable advice and input. We acknowledge Geoscience Australia for the aeromagnetic and ground gravity data of the Kalgoorlie area shown in Figures 1, 4 & 5; the Geological Survey of Western Australia for the aeromagnetic data of the West Musgraves shown in Figure 2.

[1] Bauchau C.; Jaboyedoff M.; Vannier M., CLAIM: a new personal computer-assisted simulation model for teaching mineral exploration techniques. International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts, Volume 33, Number 6, September 1996, pp. 265A-265A(1).

[2] Beaudoin G., Practical Course in Resource Economics and Mineral Exploration, http://mineral.cuso.ch/courses-and-meetings/details-of-course/item/courses/practical-course-in-resource-economics-and-mineral-exploration, Jan 2012.

Source: CET Quarterly News, Issue 19, March 2012 available for download from the CET Member site.