Horizons

Use this to sequence the missing horizons in a drillhole and to keep the splitting relationships consistent, FixDHD requires a horizon list. This may be provided in three ways.

GDCALC global file

The most common form of horizon list is the GDCALC global file. Click Geology > Drilling Utilities > Horizon List to generate the file from an existing database. The resulting file has the form <project prefix>.gdc_glob.

Horizon list file

The second method is to manually create a horizon list. This file, which must have the extension. hzn, is a simple ASCII list of the horizons with any splits in a space separated form.

For example, we could use a filed called seamlist.hzn which contains the same information as the global file shown in below:

An example of the text file is shown below:

Advanced splits definition file

The menu item which used to create an Advanced Splits Definition file has been discontinued as the functionality is now supported by Geology > Drilling Utilities > Horizon List. This selection has been kept to allow some backward compatibility with older files.

Splits List in Selected File

Provides a preview of the horizons defined in the file selected.

Provides optional, extra control over the use of the horizon field.

Horizon Name Control

Horizon Name Control provides additional control over the use of the horizon field.

Concatenate seam and ply fields from lithology record to form horizon name

This check box is only available if the drillhole database has a PLY field defined by geology synonyms.

Ignore unlisted non-blank horizon names found in a listed horizon

When a horizon is not found in the horizon definitions, that horizon can be ignored or respected.

Important It is important to know when to use this option. Generally, it should be enabled.

If Ignore unlisted non-blank horizon names found in a listed horizon is checked, then the thickness used for the BP horizon would ignore the bow horizon's existence.

If Ignore unlisted non-blank horizon names found in a listed horizon is not checked, then the bow horizon is treated as being the end of the interval.