Desurveying Data and Importing Drill Holes

Desurvey Drill Hole Data

The Desurvey Tool allows users to convert interval data from drill holes (in .CSV format) into data points represented as curve objects along a continuous drill hole trace. This tool interpolates the survey data (including azimuth and dip) to create a 3D representation of the drill hole based on the collar, survey, and drill hole interval data. To use the Desurvey Tool, go to Drilling -> Desurvey Data

Input Data

• Drill Hole Data: Must contain intervals defined by from_depth and to_depthcorrelated to a unique hole IDplus any numerical or categorical data columns.
• Survey Data: Must contain the azimuth and dip measurements at specified depths for each hole ID.
• Collar Data: Must contain the easting (X), northing (Y), and elevation (Z) of the drill hole collars.

NOTE collar data CSV can act as the survey data if you do not have survey data or do not wish to use the survey data. In this case, upload your collar sheet in place of the survey sheet and and include the azimuth and dip of each hole and include a final depth column as the depth of survey

How it Works

1. Initial Setup:

   • The tool first sorts the drill hole data by hole_id and to_depth, ensuring that the intervals are processed in sequence from shallowest to deepest.
   • Each drill hole is uniquely identified by its hole_id, and the collar data provides the initial starting coordinates (easting, northing, and elevation).

2. Interpolating Survey Data:

   • For each interval, the tool uses the survey data to interpolate the drill hole's trajectory. The azimuth and dip values are retrieved from the survey data by looking up the appropriate depth.
   • The tool approximates the x, y, and z coordinates for the next point using the depth difference between consecutive intervals and the survey data.
   • The calculation for each interval follows these steps:
     • Change in x (Δx): Calculated as the horizontal distance in the easting direction based on the azimuth and dip: $$Δx = (depth_{to} - depth_{from}) * sin(azimuth) * cos(dip)$$
     • Change in y (Δy): Calculated as the horizontal distance in the northing direction: $$Δy = (depth_{to} - depth_{from}) * cos(azimuth) * cos(dip)$$
     • Change in z (Δz): Calculated as the vertical distance based on the dip of the hole: $$Δz = (depth_{to} - depth_{from}) * sin(dip)$$
   • These calculations are performed iteratively, accumulating the coordinate changes as the tool progresses down the drill hole trace.

3. Handling Infill Rows:

   • If there are gaps between consecutive intervals, the tool automatically generates additional rows for missing intervals. These infill rows help to ensure that the drill hole trace remains continuous, especially in cases where no data is available for specific depths. (i.e. you want to desurvey assay data but only assayed a select part of the hole)

4. Error Handling:

   • The tool checks for missing data in the collar or survey files and ensures that all drill holes are represented correctly. It also warns users if a hole ID is missing from either the collar or survey data.

5. Output:

   • After completing the desurveying process, the tool offers users the option to export the desurveyed data as a CSV file which can then be used in the Import Drill Holes fucntion

Importing Drill Holes

1. Go to Drilling -> Import Drill Holes (.CSV)

2. Click Load CSV to bring up the file browser and navigate to the desurveyed data file.

3. Once the data file is selected, the drop downs will automatically populate; fill in the appropriate data columns for Hole_id, X (your desurveyed x coordinate), Y (your desurveyed y coordinate) and Z(your desurveyed elevation coordinate). Click Import Drill Holes

4. Three collections will populate into your scene and outline; Drill Hole Collection, Hole ID Collection and Drill Hole Traces

• Drill Hole Collection: This collection holds the all the interval data, i.e. each row in your CSV corresponds to a curve object along the drill trace.
• Hole ID Collection: This collection holds all the unique hole IDs. The Name is turned on so that labels are present.
• Drill Hole Traces: This collection holds the drill holes traces, this is a single curve object as line to represent the full extent of the drill hole. This is a nice light-whieght way to show the drill holes without having thousands of object visible in the scene. It also comes in handy when querying the data.

5. All your data is now brought in as custom properties under its respective interval object (the individual curve objects under Drill Hole Collection). You can access these properties by selecting the object and navigating to Object Properties and apply the drop down for Custom Properties. Scroll down to view all the custom properties.