There are two options for creating traveling cylinder plots, “High Side” referenced or “North” referenced.
The first example shown in this section is a “High Side” referenced traveling cylinder plot. This option has the advantage of being easier to understand but it suffers from a peculiarity in top hole as follows.
Consider how a vertical well would appear against a well drilled roughly towards and then away from it.
The red well is our well and from points A to C it would be plotted on our high side. However from points D to F it would be plotted on our low side since we have changed direction. This is the example “High Side” traveling cylinder plot shown on the right above. It appears that we will drill or have drilled straight¬¬¬¬¬ through the blue well.
One solution is always to plot your high side values along a line representing your current azimuth. This makes the traveling cylinder plot look a little different. Now North is at the top of the plot and for the first three points high side is plotted along my current azimuth e.g. 45°.
When the well is turned around before passing through points D, E, and F, the high side is now plotted along the new azimuth e.g. 225°. The points are correctly plotted to low side and appear to go out the same way they came in rather than causing unnecessary alarm with an apparent collision.
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