Loading Dynamic Drillhole Data

Loading drillhole data tables to generate dynamic drillholes

Introduction

Your application supports two mechanisms for creating and displaying drillholes. The first is the static method which uses the HOLES3D process and the second is the dynamic method which creates drillholes from data 'on-the-fly'. This topic discusses the requirements and options for creating dynamic drillholes.

The principal difference between static and dynamic drillholes is that static drillholes are created as a desurveyed drillhole file, using a process, from Datamine format files; whereas dynamic drillholes use data in memory (from any data source) to create drillholes in memory.

You can load many drillhole data tables into memory and combine them intelligently into a single Dynamic Drillholes object in memory, without altering the component data. It can calculate composite values "on-the-fly" and make changes to sample values automatically, immediately reflecting them in all composite values.

Use Dynamic Drillholes for the following:

advanced visualization and presentation in the selected data windows
generation of drillhole Logs in the Logs window
string modeling in a 3D window using drillhole segment startpoints/endpoints as a reference
plotting from the Plots window.

Required Data

The format of the source data is not important provided there is a driver available to load the data into memory. The desurveying algorithm requires certain data as a minimum before it can create drillhole trace and sample composites. The following drillhole tables are used to generate holes:

collars - required; contains drillhole XYZ collar coordinate, coordinate system, coordination and drilled date data
surveys - required; contains drillhole survey depth, survey bearing and dip data
assays - required; sample interval start and end depth, mineral grade or quality data; rock density data
lithology - required; sample interval start and end depth, lithology codes, short and long descriptions; rock density data
interval log(s) - interval start and end depth; interval data e.g. mineralized zone identifiers, rock mass rating values
depth log(s) - depth; point measurement data e.g. geophysical survey data, other download log data.

If there is no survey table and there is no Azimuth and Inclination in the collars table, the desurvey algorithm will create vertical hole traces.

Typical data table descriptions are:

Collars

Field	Description
BHID	Hole name
Easting	X co-ordinate of the collar
Northing	Y co-ordinate of the collar
Elevation	Z co-ordinate of the collar
Length	Length of the hole
Azimuth	Azimuth at the collar
Inclination	Dip at the collar

Surveys

Field	Description
BHID	Hole name
Depth At	Depth of survey point down hole
Azimuth	Azimuth at survey point
Inclination	Dip at survey point

Assays

Field	Description
BHID	Hole name
Depth From	Distance down the hole of start of sample
Depth To	Distance down the hole of end of sample
Density	Rock density
Sample 1	First grade or quality data column
Sample 2	Second ...
Sample 3	Third ...
Sample 4	Fourth ...

Lithology

Field	Description
BHID	Hole name
Depth From	Distance down the hole of start of sample
Depth To	Distance down the hole of end of sample
Density	Rock density
Sample 1	First rock description data column
Sample 2	Second ...
Sample 3	Third ...
Sample 4	Fourth ...

Loading Data and Defining Holes

The easiest way to create dynamic drillholes is to use the wizard to load the component tables into memory. This will load each table, allocate table types (e.g. collars, surveys etc) map the fields appropriately and then desurvey the drillholes. The tables are loaded by means of the Data Load Wizard or independently using one of the following methods:

Using theDataribbon, selectLoad | Hole Wizard
Using theDataribbon, selectLoad | External | Collars..., Surveys... etc.

Alternatively, undefined tables in memory can be defined as collars, surveys, assays etc. using the Define Hole Tables dialog accessible by selecting theSample Analysisribbon andDefine Holes.

There are two desurvey methods: straight line segments and radius of curvature; which can be selected by clicking the Desurvey Method button on the Define Hole Tables dialog. Radius of curvature is the default method as most holes are curved. There is an option for subdividing samples to smooth the trace. All drillhole traces are made up of straight lines so, for presentation purposes, it can be advantageous to divide the samples.

Dynamic drillholes require a collars and survey table to be specified, as a minimum, in order for Studio 3 to construct the base drillhole objects in memory. Additional tables, such as assays information, can be included in the process, but is not essential.

Gaps, Overlaps and Duplicates

Your application is tolerant of sampling gaps, overlapping samples and duplicated samples, which may be unintentional data errors. These are all detected and reported to the appropriate sheet in the Reports window.

Gaps

Where there are gaps between samples, the values of all data fields within the gap interval will be treated as absent data when calculating composite values.

Overlapping and duplicated samples

Studio's compositing algorithms handle overlaps and duplicate samples correctly without calculating biased results.

For duplicate records Studio uses the arithmetic average for grade values.
For overlapping records, it uses a length weighted average value. There is no limit on the number of overlaps or duplicates for an interval.

Absent Data, Weighting and Composites

Absent Data

Studio deals with absent data values encountered in a composite by ignoring them when calculating the weighted or dominant text value of the composite. If all samples in the composite have absent values, the composite value will be absent. If the Specific Gravity Weighting method is being used but there is no S.G. value then the weighting method will revert to standard length weighting.

Weighting Method

The weighting of composite sample values may be by either Length or by weight (Length x Specific Gravity, assuming a uniform sample cross-section).

Compositing Text Values

The dominant text value in a composite is determined by calculating the total length of each text value e.g. lithology codes, and assigning the value with the maximum length to the composite.

	Related Topics
	Define Holes Dialog Build Holes Dialog