Define Drillhole

Define Drillhole is a prerequisite to creating, importing and processing drillholes. This is a configuration file containing settings for manual drillhole entry, data storage, predefined attributes and the default key density. There is no geologic data stored in this *.CH file. The following describes each option in Define Drillhole:

• Drillhole/Strata Attributes: These are strata and drillhole attributes that can be predefined and set for the drillholes. To enter new ones, select the green + button and type the name in the Attribute field. If they are already defined with the command Define Attributes, then they will appear on the dropdown arrow.  Strata attributes can be specific to Key or Non-Key strata. There is no limit to the number of attributes that may be entered. Adding attributes to this list will place this name in each drillhole, whether it has a value or not. Sample attribute names include sulfur, BTU, acid, base, moisture, etc. There are a few reserved names. Attribute FERM is assumed to be a Ferm Code. Another attribute is used to define horizons. This name is defined in Define Horizon Codes and is HORIZON by default. Attribute names that begins with the '=' symbol defines an equation and its value is calculated using values of other attributes. The attribute name LBS may be used in equations to represent strata density. The following are examples of equation attributes, and will be used for processes such as gridding or contouring.

        Such a variety of attribute assignment methods provide high flexibility in attribute usage.

        Drillhole descriptions are intended for storing of drillhole specific information in the drillhole. One general drillhole attribute called Description is predefined and others may be defined for specific drillhole descriptions. Typical                 additional description examples are DRILLER, DATE, TOWNSHIP, and etc. You will be prompted for values of these descriptions in Place Drillhole if they are predefined here.

• Manual Drillhole Entry Options: When using the command Place Drillholes to manually enter drillholes, the items to be prompted for can be preset here.
  
• • Method to Locate Strata: Based on what value the user has, there are three choices: Thickness, Elevation or Depth. If importing from an external file, data will come in no matter what is set here, this is just for prompting with Place Drillhole.
    
  • Prompt for: When manually placing drillholes with Place Drillhole, there is the option to prompt to enter Non-key strata names such as overburden or parting, a Bed Name (or just the Strata Name) and Drillhole type. During Place Drillholes, each strata must be set as either "Key" or "Non-Key". Then you will be prompted to enter values for the corresponding attribute names if any are entered here. Typically, the ore that is being mines, such as coal, limestone, trona and ore are Key and overburden, partings and waste strata are Non-Key. Distinguishing between Key and Non-Key allows for different sets of attributes and enables the program to calculate the Key to Non-Key strip ratios in the Surface Reserves from drillholes. If there is data only for the key strata, then don't specify the Non-Key option for prompting. This option will prompt for the thickness and elevation of the key strata, and then it will fill in the distance up to the last key strata with a non-key strata named after the key strata's name plus "_OB" at the end. On the other hand, if there is data for all the strata then do turn on NonKey and enter it as well. In this case, either the thickness or elevation of each strata must be entered. Entering both thickness and elevation is not necessary because given one the other can be found from the neighboring strata. So there is a choice to enter each strata by thickness or by elevation. The elevation can be specified as either the absolute bottom elevation or as the elevation difference between the surface elevation of the drillhole and the bottom elevation of the strata. The Bed name option will prompt for the bed name in Place Drillhole. Otherwise the bed names will be set to blank. The Drillhole type option will prompt for the drillhole type number or type name. Otherwise the drillhole type will be set to the first one on the list, 0.
  • Enter Values in: This also applies to Place Drillhole, prompting for thickness. Set to Inches or Feet/Meter (drawing units), whichever is being entered.
    

• Use External Database / Database Type: There are a couple of options for storing the geologic data. This setting defines which method to use. If the option is not selected, then the geologic data is stored in the AutoCAD drawing, within the drillhole symbol as extended entity data, stored in the AutoCAD Dictionary. This is a very clean and simple approach, and will run very efficiently. Selecting this option allows for two database options that will be linked live to the drawing. Any changes and edits in the drawing will update the database, and vice-versa. The types of databases used are SQLite with the CDB file type (Carlson Database), Microsoft EXCEL, Microsoft Access ACCDB file and Microsoft Access MDB file. The MDB is not fully supported and functioning on x64bit machines with AutoCAD. So for faster and better linking, use the SQL approach. If on an x32Bit PC, then the Access MDB option will work fine. SQLite is an open source database that is widely used. There are many free programs that allow for opening, viewing and editing an SQLite database. One example is shown here that is an add-on for Mozilla Firefox.
  

• Key Density: The Key Density field is the default density used to calculate key tons in routines like Surface Mine Reserves. In other places in the program, density can also be made strata-specific by using the Define Strata command. In Surface Mine Reserves, the Use Density Attribute option can be used to model the density for each strata by using a strata attribute defined in the Geologic Model grids, or in the drillholes. If neither of those options are used, then this is the value that will be used for tonnage calculations.
  
• Restrict Strata/Bed/Attribute Names to Predefined Lists: This option will not import or use any names that don't match up with the predefined names set here, in the Drillhole/Strata Attributes. This allows for a filter to not use attributes unless they are defined here.
  

Prompts

Select Existing/New Drillhole Configuration File: Selection Dialog Box
Select Drillhole Configuration File Selection Dialog Box
Specify a file name in which to store the drillhole definition.
Define Drillhole Dialog

Drop-Down Menu Location: Drillhole
Keyboard Command: chdef