Import Drillholes from Target Project

Summary

Imports subsurface drillhole or borehole data from an existing Geosoft Target project to a feature dataset in a geodatabase.

Usage

The imported drillhole data will be stored in a feature dataset (called "Drillholes"), with feature classes created for each data type that is associated with the imported drillholes:

Collars (point features, surface location of each drillhole)
Traces (polylines, created from collar and survey data)
Interval data sets ("from-to" data line segments of varying lengths along the drillhole trace, with attributes)
Point data sets (point features that are located along the drillhole trace, with attributes)

Before importing drillholes from a Target project, you are asked to choose the output geodatabase in which to store the drillhole data. You will also need to specify a valid Target collar database: any constituent databases in the Target project will then be imported along the collar database into the geodatabase feature dataset.

Parameters

Parameter	Explanation	Data Type
Target collar database	The collar database of the Target project. If the database (*.gdb) selected does not appear to be a _Collar database from a Target project, the parameter will be flagged; see the Technical Notes section below for more details on Target projects.	Collar database file (.gdb)
Output Drillhole Dataset	The name of the geodatabase feature dataset in which to store the imported drillhole data.

Parameter

Explanation

Data Type

Target collar database

The collar database of the Target project.

If the database (*.gdb) selected does not appear to be a _Collar database from a Target project, the parameter will be flagged; see the Technical Notes section below for more details on Target projects.

Collar database file (.gdb)

Output Drillhole Dataset

The name of the geodatabase feature dataset in which to store the imported drillhole data.

Technical Notes

About Target Drillhole Projects:

A Target drillhole project consists at a minimum of a collar database that stores the holes location (i.e. collar details) information. Several types of data ranging from surveys (e.g. dip and azimuth), geologic rock types and descriptions, drillhole geochemical assays and borehole geophysical logs, can be available and stored in their own database files. These databases are linked by a common project name, which appears at the start of the individual database names. For instance, in a project named "Prospect" the following databases could be available:

Prospect_Collar.gdb - Collar information: Hole ID, Easting, Northing and Relative Level (Elevation) fields at a minimum.
- If no survey database is available, then the total depth (length) of the hole becomes a required field in the collar table.
Prospect_Survey.gdb - Survey Dip-Azimuth/Easting-Northing information: includes hole orientation/deviation information in the form of Hole ID, Depth, Azimuth, Dip or Hole ID, Depth, Easting, Northing, Elevation formats.
- Survey data is only required if a hole has actually been surveyed and the dip and azimuth change at depth.
Prospect_Assay.gdb - Assay information (the "Assay" label is user-specified): must include the Hole ID, Depth From, Depth To fields and some assay data values.

The drillhole data source of a Target project comes from a variety of formats including, ASCII (e.g. CSV, tab delimited), Database (Excel, Access), ODBC connections. The Target system enables the import of data using a Drillhole Import Wizard tailored to the data format provided. The wizard will create import template files (with the extension i3 or i4) that will contain all of the import parameters including data source type (ASCII, Database, ODBC etc.), data source location, and the type of data (Collar, Survey, From-To, Point). These template files are useful when a re-import of the original data to the constituent databases is needed.

Desurveying Drillholes using Collar and Survey data

The drillholes are always "desurveyed" on import, which means a 3D spatial object (a drillhole "trace") is calculated for each drillhole. The output trace for any given hole can vary depending on what type of data is available during import (collars only, vs. collar and survey data) and which method is selected to do the desurvey calculations, as well as the resolution value selected. The various ways to calculate the traces, depending on which types of data are available, are described below:

With collar locations only, no survey data present:

If collar data includes dip and azimuth, these values are used to create straight segment traces for the entire hole, to the final depth.
If collar data does not include dip and azimuth, the holes are assumed to be vertical.

With collar locations and dip-azimuth survey data:

The survey data is "discretized" at the desurvey resolution interval value and a smooth curve is generated using the selected desurveying method (the default is the "Radius of curvature" method). See Drillhole Settings for more details.
Holes are 'desurveyed' and the new trace geometries are stored in the Traces, Depth Ticks, From/To and Point datasets.
The top-of-hole dip and azimuth values (at depth = 0) will use the values from the Survey feature class, if present.
If top-of-hole survey values are not present, the collar dip and azimuth values will be used instead (with the collar values taking precedence).

Learn more about Resurvey Holes.