RockWorks16 Stratigraphy Rule "Insert Missing Units"

[Guest Molly]

In RockWorks16 we've added new "smarts" to the program for data sets with lots of missing stratigraphic data, such as historic data which can be downloaded from commercial and state sources. This topic addresses the "insert missing units" rule. This rule is displayed in the Rules and Filters pane along the right side of many of the RockWorks program menus.

The Insert Missing Units rule was added to the program for situations like this, in which formations have pinched out and are not present in a borehole:

HOLE-A HOLE-B

Fm_A 0 20 Fm_B 0 25

Fm_D 20 30 Fm_C 25 35

Fm_G 30 50 Fm_G 35 50

If the Insert Missing Units rule is on, then it does NOT add missing formations to the database, but WILL determine the location for the unit as it passes points to the modeling routine. For example, it will include a point for FmB in Hole-A at depth of 20 (the elevation represented there), even though it will not add the unit to the Stratigraphy data table.

However, if you have already added the missing formations to the database, manually or via the Striplogs | Insert Missing Stratigraphy program, and your data looks like this:

HOLE-A HOLE-B

Fm_A 0 20 Fm_A 0 0

Fm_B 20 20 Fm_B 0 25

Fm_C 20 20 Fm_C 25 35

Fm_D 20 30 Fm_D 35 35

Fm_E 30 30 Fm_E 35 35

Fm_F 30 30 Fm_F 35 35

Fm_G 30 50 Fm_G 35 50

Then turning on the Insert Missing Units rule may cause duplicate tops. This is most pronounced when you have multiple sequential zero-thickness units.

It is probably best to choose which strategy to use for missing (pinchout) formations and do this throughout the project - either omit them from the database and have the Insert Missing Units rule insert them on the fly, or insert them manually and turn off the Insert Missing Units rule.

More details and examples about the strat rules are in the help messages. There's also a recording of a webinar addressing pinchouts on our website and on Rockware's YouTube channel.

Molly Mayfield

Rockware Inc.