Uncertainty Cone for Drillholes

When planning underground mining operations, it is essential to monitor the positions of existing exploration drillholes, as these drillholes may be waterlogged. If penetrated, high-pressure water can flood the excavation, leading to additional dewatering measures and posing a risk to mining operations. This issue may arise due to errors in determining the depth of the measuring device, instrument inaccuracies, human factors, and so on. Uncertainty cones allow for predicting the likelihood of a drillhole intersecting the mining area, which, in turn, helps minimize or avoid adverse consequences from water discharge from the drillhole. The cone is a model of uncertainty used in cases where the parameters of potential errors are unknown.

With Micromine Origin & Beyond you can create an uncertainty cone solids by following these steps:

1. Go to the Wireframe tab.

2. Choose Drillholes Cones of Uncertainty option in Calculations group.

3. On the Input tab, specify the database or drillhole trajectory in STR format.

4. On the Output tab create a wireframe type, select a profile shape, Cone or Ellipse of Uncertainty and set a constant cone angle. If necessary, you can set a custom profile depending on the depth of the holes.

This will result in error-adjusted wireframes.

5. On the Pierce Points tab you can specify the wireframes that will be evaluated for intersection with drillholes. You can then optionally create an event file that reports intersection points so that you can take into account the probability of hitting exploration wells during penetration.

The risks of penetration are classified as follows:

1) If the uncertainty cone of the hole intersects any part of the underground development solids, it indicates a low risk that the explosion during drilling may expose the hole. In such cases, the cones will be categorized as "low-risk" - green hole cones.

2) If the uncertainty cone of the hole intersects the UG solids twice (for example, the roof and the ground), the risk becomes high. In such cases, the cones will be categorized as "high-risk" - red hole cones.

Additionally, after running the function, you can visualize the events file and examine the points of intersection between the hole and the underground development solids.

This way, you can take into account errors in determining hole parameters when designing underground mining solids.

For your convenience, you can visualize the cones of uncertainty (as shown in the example below in a 2D cross-sectional view) and create a horizontal section at the projected horizon. The visible well contours on the horizon enhance the safety of designing mining operations.

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