Drillhole Database

Traditionally, downhole or drillhole data refers to data contained in four types of file: Collar, Survey, Event and Interval. These are the files commonly used by the Drillhole functions to display and manage drillhole data.

In the case of Trench data, Collar and Survey files are replaced by a Trench file that contains a unique identifier for each trench and the coordinates of trench deflection points.

The data contained in these files can be defined as part of a Drillhole Database (a database file with a .DHDB extension). The data contained in Collar/Survey (or Trench) files can be added to the database and can be refreshed when necessary to reflect changes to the underlying file or files. External Interval and Event files may also be associated with the database.

The use of a Drillhole Database offers several advantages:

  • Once the relationship between Collar, Survey (or Trench) files and Interval and Event files has been defined for a Drillhole Database, the drillhole functions in the application need only reference one database, rather than several external (Collar, Survey (or Trench), and Interval and Event) files.
  • A drillhole trace need only be generated once. When a Drillhole Database is created, each hole is desurveyed and trace coordinates are generated and stored in the database. When the database is opened, trace coordinates are held in memory. This improves the speed of any drillhole functions that access that database.
  • Since a database is being used to store and manage the association between Collar, Survey (or Trench) and Interval and Event files, the same database can be used to store associated metadata and display settings.

Collar File

The Collar file contains the location, in Northing, Easting, and Z coordinates of each drillhole collar. If there are no surveys, the holes are vertical.

The Collar file also contains the Hole ID, Total Depth, and optionally, the Azimuth and Inclination of the hole at the collar. If collar survey information is not provided in the Collar file or a Survey file, the holes are assumed to be vertical.

A Collar file may also have Additional Atributes such as Prospect and Drill Date.

Survey File (Optional)

The Survey file contains the downhole surveys for each drillhole in the Collar file. It is required when there are changes in azimuth and/or inclination down the length of the hole.

Trench File

For a Trench Database, a Trench file is specified which contains a unique identifier for each trench and the coordinates of trench deflection points.

Event Files

Events denote points down drillholes (or along a trench) where something of interest has happened. For example, you may want to show the point where oxidation stops. A typical Event file is unlike an Assay file in that it does not have From/To intervals. The depth at which an event occurs is recorded in a Depth field.

In addition to Hole (or Trench) ID, Event, and Depth fields, an Event file will usually contain a Symbology field that can be used to display symbols where each event occurs.

If you use either the FROM or the TO interval to define the depth of an event, you can use an Assay file as an Event file.

Interval Files

An Interval file contains information such as assays or lithology for successive intervals down each hole (or along each trench). Usually Assay and Geology data are kept in separate files though they are similar in form.

Import

To import information from various files to a drillhole database, on the Drillhole tab, in the Database group:

  • Click Import to import external collar, survey, interval and event data into a drillhole database.

    See: Drillholes

New Database

To create a new database, select one of the following options on the Drillhole tab, in the Database group:

Alternatively:

  1. Right-click in a Database name response in a form and select New Database from the right-click menu (F5).
  2. Select an option to create a Drillhole Database or a Trench Database.
  3. Enter a name for the new database and click the Create button.

In order to create a database in a sub-folder you must enter the sub-folder name in the Create New Drillhole Database dialog, for example:

MyFolder\database

The folder must exist beforehand. Alternatively, you can create a database in the root of the project folder and then move it to a sub-folder, without damaging it.