I am trying to show route events for depths with trajectory data. The depth data has both positive and negative values (starts 50m above sea level and ends km's below the sea level). The below process was followed:

  1. Convert Well Trajectories to Pts using – Feature Vertices to Points (Data Management) Tool
  2. Create Field in Resulting Points Feature Class called Depth. Populate field using geometry calculator and the Z coordinate of the Pt
  3. Use field calculator to convert the negative depths to positive depths.
  4. Create Routes for the well trajectories using – Create Routes (Linear Referencing) Tool.
  5. Calibrate the Routes with the points created earlier using – Calibrate Routes (Linear Referencing) make the measure attribute the positive depth attribute calculated before.
  6. Now reference your event tables against these calibrated routes using - Make Route Event Layer (Linear Referencing) Tool. Note that an event layer is in memory and will need to be exported or sorted to a new feature class. I prefer sort. Note the depths in your reference tables will need to be positive.
  7. Export/ complete a multiple sort to a new Feature Class using – Sort (Data Management) Tool. Sort on Borehole number and depth.
  8. Compute fields for Eastings, Northing and Depth for each point if required and use in whatever application you want.

This process was applied across a number of borehole trajectories in each case the Z-value for borehole event data was distorted for the start of the trajectory, see example below -

Route events layer Z/M (Event Depth)

  • -717.9916/139.1
  • 415.6526/160
  • 386.7207/162
  • 186.5/186.5
  • 191/191

Points used to create route Z values

  • 27.15
  • -114.45
  • -176.53
  • -181.65
  • -206.77

I assuming the distortion of the events depth is due to the negative lengths (as per link below) used to create route originally. Is there a possible work around for this that will avoid having to change the height datum?

ESRI Linear Referencing and negative lengths


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