The
DRAG plugin is designed to apply a drag ratio to fault traces (see section on
Traces and Fault zones for further information). Although not recommended, it can also be used to modify the value of aveThrow. Since aveThrow is the summation of the system throw (which cannot be altered since it is a function of the input
ZCORN geometry) and any user-defined throw input using the
TGTHROW keyword, the effect of modifying aveThrow in the plugin is to modify the user-defined component of aveThrow.
HINT:- Alternatively, the drag on fault traces can be defined either by including the TGDRAG keyword (and associated data) or using equation(s), i.e. for Probablistic throw uncertainty and/or Deterministic normal drag.
The
DRAG (and
FZONE plugins) complement the existing TransGen plugins (
i.e. CELLPROP, PERM, THICK, AREA - see
Using Plugins in TransGen). The two new plugins are run after all system traces have been identified and any deterministic user-defined modifications to these traces using the new keywords (
TGTHROW,
TGDRAG, TGTRACE,
TGFZONE) have been applied. Both new plugins are called once for every trace in the model, with the DRAG plugin called before the FZONE one. Hence any modifications made to trace properties in the DRAG plugin are reflected in the input to the FZONE plugin.
If you want to input user-defined criteria to determine how drag is modelled on fault traces, select the
Use a plugin option on the
Drag applied to fault traces page of WizGen (as shown below). Then click on
Next>>,
<<Back or
Save to access the
Edit plugin pop-up and on
Yes to access the
User-defined plugins page.
The default DRAG plugin (shown above) is one automatically generated by the WizGen plugin tool including both probabilistic throw uncertainty (+/- 20m) and the deterministic normal drag equation with default values (see
Using equation on
Drag applied to fault traces page of WizGen). A few notable bits of C++ functionality used in the plugin are discussed in the section on
C++ functionality in DRAG & FZONE plugins.
Alter or input from scratch your required DRAG plugin code.
For example, an alternative user-defined DRAG plugin could be defined with the following code:-
if (t.dragFlag == false) {
}
This applies a drag ratio of 0.75 to all traces that have not already been applied a drag ratio using the
TGDRAG keyword.
NOTE:- Only trace properties are available for use in the DRAG (and FZONE plugins) which must be referred to using the t. prefix. The list of available trace properties is shown below.
