Wagonwheel explained

What is wagon wheel? Wagon wheel is method in analyzing well drilled based on petroleum systems and elements. A circle has been divided into 4 quadrants namely:
1) Reservoir (top left)
2) Seal (Top right)
3) Trap (Bottom left)
4) Charge (Bottom right)

Analysis can be done by analyzing well logs (GR, mudlog, resistivity log, Neutron Density log and seismic data.

Reservoir
If reservoir is presence, the whole quadrant will be colored YELLOW. 
If reservoir is observed ratty or thin, half of the quadrant will be colored YELLOW.
If no reservoir observed, the quadrant will be WHITE.

Seal
If seal is presence, the whole quadrant will be colored BROWN. 
There are 4 elements of trap failure: Top seal failure, Base seal failure, Juxtaposition leakage and Fault plane leakage. If one of the elements identified, half of the quadrant will be colored BROWN. 
If no seal observed, the quadrant will be WHITE.

Trap
A good 3D seismic data or dense 2D is required for trap classification. If trap is presence, the whole quadrant will be colored GREEN. 
If there are some uncertainty on trap such as faults observed, half of the quadrant will be WHITE.
If there is no trap presence, the quadrant will be WHITE.

Charge
If charge is presence (interpreted oil or gas column or flow from this play level), the whole quadrant will be colored RED. 
If the well has strong oil or gas shows, half of the quadrant will be colored RED.
If no oil show or gas show observed, the quadrant will be WHITE.