Offset Selector - C2C Global Scan

Details changes to the global scan tool in the Well Seeker Pro offset selector, in versions or later.


The offset selector dialog is available for any survey, actual wellbore, plan or planned wellbore in Well Seeker Pro and the Web Portal. It allows the user to select any offset wells which are to be displayed on plots or used in anti-collision scans.

Global Scan is a filtering method available in the offset selector, which allows the user to select a radius from the reference well surface location. Any offset wellheads located within this radius are automatically selected when the user clicked Select.

As of Well Seeker Pro version, the global scan tool has been replaced with the Global Scan (C2C) tool. The differences in these tools will be explained in the below sections.


Global Scan (Old):

The old Global Scan tool simply ran a center to center distance scan from the reference well surface location to any offset well surface location, based upon the Distance From Well value entered. This method captured a large number of wells that were not necessarily an anti-collision risk.

Global Scan (C2C) (New)

The new Global Scan (C2C) tool on the surface looks identical. However the calculation going on behind the scenes is more complex:

  1. A surface location scan will select all wellheads within a 20 mile radius of the reference well/plan surface location. The only exception to this is if the value entered in the Distance From Well cell is greater than 20 miles, in which case this value will be used

  2. A full center to center anti-collision scan is then run between the reference well/plan trajectory and all of the offset trajectories. Any wells that have a C2C distance equal to or less than the value entered in the Distance From Well cell will be selected and all others discarded.

Note: If an actual well has a measured depth that is less than the measured depth of the principal plan, the scan will be run against the principal plan. In the event that the scan results in a center to center distance value that is less than the Distance From Well cell value, the principal plan and the actual wellbore will be counted in the scan results. This is to ensure that wells that are yet to be drilled, or partially drilled are correctly assigned as offset wells, based upon the predicted trajectory.

Once the scan is complete, the user must press the Select button, followed by Apply, for these wells to be selected as offsets.


The Global Scan (C2C) tool is a more refined search tool which returns a more relevant offset well selection, based upon the user’s input center to center distance value. This reduces the number of offset wells selected compared to the old surface location based global scan, ensuring that only relevant data is selected which reduces calculation times and results in noticeable performance gains.

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