Ouija Board is a method that directional drillers use to calculate inclination and azimuth at the bottom or distance and tool face to drill at required direction. Figure 1 is an Ouija board.
Figure 1 – Ouija Board
I got an excellent Excel Spreadsheet that will help you calculate the direction at bottom, distance to drill and tool face. I will give you a couple of examples to give you an idea what results from the Ouija Board spread sheet.
These are current directional parameters
Current Inclination (degree) = 28.00
Current Azimuth (degree) = 230.00
Distance to Drill (ft) = 60.00
Dog Leg Interval (ft) = 100.00
Average Tool Face = 30.00
Average DLS (degree/100 ft) = 6.00
Result is “Inclination and Azimuth on Bottom”.
Inclination on Bottom (degree) = 31.17
Azimuth on Bottom (degree) = 233.31
You can use this part to project the inclination and azimuth at the bottom.
Figure 2 – Inclination and Azimuth on Bottom
This is another example below.
Current Inclination (degree) = 32.50
Current Azimuth (degree) = 90.00
Required Inclination (degree) = 35.00
Change in Azimuth (degree) = 5.00
Dog Leg Interval (ft) = 100.00
LEFT or RIGHT (L,R) = L
Average Dog Leg (degree/100 ft) = 6.00
Result is “Distance to Drill and Optimum Tool Face”.
Distance to Drill (ft) = 64.35
Optimum Tool Face (degree) = 52.19 L
Figure 3 – Distance to Drill and Optimum Tool Face
If you are interested in this Excel Spreadsheet, please download here – https://oilfieldmania.files.wordpress.com/2015/07/ouija-board-final.xlsx