Drillhole Map

A Drillhole Map is your primary tool for visualizing the path and properties of boreholes, shafts, or wells. Whether you are looking at a simple 2D surface plot or a complex 3D model of contaminant plumes, Surfer uses these maps to turn raw table data into a spatial story.

You can display these paths as simple lines and symbols in 2D, or as shaped 3D cylinders. By using Interval Data, you can even create segmented views that show how variables—like ore grade or lithology—change as you move down the hole.

Creating a Drillhole Map:

• To add to an existing map: Select the map and click the Map Tools | Create Layer | Drillhole command.

• To create a new map : SHIFT + Click the Home | Create Layer | Drillhole command.

Both of these commands will open the Import Drillhole Data dialog, where you will load and define your drilling datasets.

Table of Contents

• Drillhole Data Requirements

  • Collars Data (Required)

  • Survey Data (Optional)

  • Intervals Data (Optional)

  • Points Data (Optional)

• Tips and Hints

• Drillhole Map

• Drillhole Map

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Drillhole Data Requirements

Unlike standard maps that usually only require a single XYZ data file, drillhole maps often rely on multiple related tables to accurately build the geometry and display downhole data. Surfer allows you to “map” your headers (like TD or East_m) to the required fields during import so you have some flexibility of how your data is formatted.

Collars Data (Required)

The collars data file defines the surface location and the basic geometry of each drillhole. At a minimum, this file must contain a Hole ID and the X, Y, and Z coordinates for the top of the hole.

Surfer expects your data to be organized in columns. You do not need to use exact column names in your spreadsheet; Surfer will allow you to map your specific column headers to the required fields during the import process.

Collars Data Columns:

• Hole ID (Required): A unique identifier for each drillhole.

• X / Easting / Longitude (Required): The X-coordinate for the collar. Geographic coordinates (Longitude/Latitude) are fully supported.

• Y / Northing / Latitude (Required): The Y-coordinate for the collar.

• Elevation / Z (Required): The surface elevation of the collar.

• Length (Optional): The total measured length of the drillhole from top to bottom. Note: Surfer uses the length and the inclination to automatically calculate the true vertical depth of the hole; you do not need to manually calculate the true depth.

  • Note: Use Length here rather than calculating vertical depth yourself. Surfer uses the length and the inclination to calculate the "True Vertical Depth" (TVD) for you!

• Starting Depth (Optional): The starting depth of the hole. If left blank, Surfer defaults to 0.

• Azimuth (Optional): The compass direction the hole is drilling toward, measured in degrees from 0 to 360.

• Inclination (Optional): The angle of the drillhole. Important: Surfer measures inclination in degrees from vertical. An inclination of 0 means the hole is drilling straight down, while an inclination of 90 means the hole is horizontal.

Example Collars Data :

Here is an example of a properly formatted collars data file:

ID	Easting	Northing	Elevation
MW-1	595299	3968125	2145
MW-2	595203	3968210	2145
MW-3	595176	3968113	2145

Survey Data (Optional)

To determine if you need a survey file, you only need to know if your holes are straight. If they are, the Collars file has all the info required. If they bend or deviate as they go deeper, you’ll want a Survey file to define the trajectory of curved or deviated holes over their length.

Survey Data Columns:

• Hole ID (Required): The unique identifier matching the Collars data.

• Depth / MD (Required): The Measured Depth (MD), which is the distance measured along the actual path of the drillhole.

• Azimuth (Optional): The compass direction at the specified depth (0 to 360 degrees).

• Inclination (Optional): The angle at the specified depth, measured in degrees from vertical (0 is straight down, 90 is horizontal).

Example Survey Data

Here is an example of a properly formatted collars data file:

ID	MD	Azimuth	Inclination
MW-1	0	370	44.62
MW-2	20	370	44.89
MW-3	0	315	45.44

Intervals Data (Optional)

Intervals data defines properties, classifications, or measurements that occur over a specific depth range (a "From" and "To" depth). This is the file you use to import your stratigraphy, lithology, assay results, or alteration zones.

Intervals Data Columns:

• Hole ID (Required): The unique identifier matching the hole in your Collars data.

• From (Required): The starting depth of the specific interval. This value must be 0 or greater.

• To (Required): The ending depth of the interval. This value must be strictly greater than the From depth.

• Data Columns: The actual variables or information associated with that depth interval. You can include as many data columns in this table as you need (e.g., text-based rock codes, numeric assay concentrations, etc.).

Example Intervals Data

Here is an example of a properly formatted Intervals data file:

ID	From	To	TiO2	MnO
MW-1	10	30	2.903	0.302
MW-2	20	40	2.915	0.299
MW-3	40	60	2.83	0.282

Points Data (Optional)

Points data defines numeric or text variables that are measured at a single, specific depth down the hole. This is the file you use to import discrete measurements like geological contact points, specific spot samples, or individual downhole sensor readings.

Points Data Columns:

• Hole ID (Required): The unique identifier matching the hole in your Collars data.

• Depth (Required): The exact depth along the actual path of the drillhole where the measurement was taken. This value must be 0 or greater.

• Data Columns: The actual variables or information collected at that specific depth. You can include as many data columns in this table as you need (e.g., numeric assay values, text-based notes, etc.).

Example Points Data

Here is an example of a properly formatted Points Data file:

ID	Depth	TiO2	MnO
MW-1	10	2.903	0.302
MW-2	30	2.915	0.299
MW-3	50	2.83	0.282

Tips and Hints

You can create a 3D model of vertical drillholes or boreholes using just collars data, if your collars data include ending depth values. The example below shows the first four columns of the collar data in the sample data file, with added end depth values (shown in blue). During the data import of the collars data, associate the collars table End Depth field with the end depth values in your collars data. You can also associate the collars Start Depth field to start depth values in your data. If you don't have or don't associate start depth data, Surfer will use a start depth of 0.

Example collars data with added EndDepth values:

ID	Easting	Northing	Elevation	EndDepth
MW-1	595299	3968125	2145	690
MW-2	595203	3968210	2145	670
MW-3	595176	3968113	2145	500

 

See Also

2D Drillhole Properties

3D Drillhole Properties

Drillhole Manager

Coordinate System Page

Info Page