Vertical Deviation (msVD)
Definition - What does Vertical Deviation (msVD) mean?
A vertical deviation (msVD) describes the differences between the actual and planned paths of directional drilling in terms of “high” and “low”. It is a lineal deviation measured in feet. Vertical deviation is a component of technical hole deviation. The measurement of vertical deviation stands in direct contrast to horizontal deviation (msHD) in a trenchless horizontal drilling process.
Trenchlesspedia explains Vertical Deviation (msVD)
The perspective for the vertical aspect of these components is to look down the planned hole – in the mind’s eye. A vertical deviation is a lineal difference that may be thought of as high or low.
Technical hole deviation is made up of eight components. Four of these are horizontal and four are vertical. The msHD calculation is captured using technical hole deviation logging. Differences noted between the planned and actual paths contribute to the quality control of the directional steering process.