It doesn't work with recent Krastorio 2's it seems. It seems to pick "mineral water pumpjacks" when trying to map crude oil fields. There are two types of wells (Mineralwater and Crude oil) which their respective pumpjacks (can't use one on the other).
It also fails catastrophically if you right click the planner in inventory;
6914.148 Error MainLoop.cpp:1207: Exception at tick 15350484: The mod Well Planner (0.18.7) caused a non-recoverable error.
Please report this error to the mod author.
Error while running event WellPlanner::on_mod_item_opened (ID 83)
Unknown style CGUI_yellow_logistic_slot_button
stack traceback:
WellPlanner/control.lua:1034: in function 'item_selector_flow_2'
WellPlanner/control.lua:1117: in function 'gui_open_close_frame'
WellPlanner/control.lua:1175: in function 'on_mod_item_opened'
WellPlanner/control.lua:1212: in function <WellPlanner/control.lua:1210>
stack traceback:
[C]: in function 'add'
WellPlanner/control.lua:1034: in function 'item_selector_flow_2'
WellPlanner/control.lua:1117: in function 'gui_open_close_frame'
WellPlanner/control.lua:1175: in function 'on_mod_item_opened'
WellPlanner/control.lua:1212: in function <WellPlanner/control.lua:1210>