Bubble maps are a great way to get a view of the variance of values over your search area. While you do get a very similar view on the Colorized Groups using the Size By property, the bubble map creates a prettier picture.
The bubbles are placed on the bottom hole location. The bubble settings are pretty straightforward.
The Based On field is simply a choice of what property you’d like to use to create the map. The Radius Size is a base size of the circle used for the smallest value of the property your bubble map is based upon.
Cumulative oil bubble map
See more about Customizing Well Spots here.