drilling · directional
Vertical Section
click formula to derive ↑
Inputs
ft
°
°
Description
Projects the wellbore's horizontal closure onto a single fixed reference azimuth (the vertical section azimuth), producing the single 2D distance-vs-depth trace conventionally plotted on a well plan's vertical section diagram — the standard directional-drilling display for tracking progress toward a target along one chosen plane.
Variables
| Symbol | Unit | Description |
|---|---|---|
| VS | ft | Vertical Section |
| C | ft | Horizontal closure distance from the surface location, typically the output of closure_distance. |
| θc | ° | Compass direction of the closure vector, measured clockwise from true north — typically the direction output of closure_distance. |
| θvs | ° | The fixed reference azimuth chosen for the well plan's vertical section plot — typically the azimuth toward the target. |
Assumptions
- Closure and its azimuth are referenced to the same north reference (true, grid, or magnetic) as the chosen section azimuth
- The vertical section azimuth is a single fixed value for the whole well plan (the standard convention) rather than varying with depth
Limitations
- A 2D projection only — two different closure vectors (different magnitude and direction) can project to the same VS value, so VS alone does not fully describe wellbore position
- If actual closure azimuth drifts far from the planned section azimuth, VS becomes a misleading progress indicator even though 3D position is tracking correctly — check closure_distance's direction output directly in that case
- Mixing true-north and grid-north referenced azimuths between closure and the section reference will produce an incorrect VS
Use Cases
- → Well plan vertical section diagram: Generate the depth-vs-horizontal-distance trace conventionally plotted alongside a plan or as-drilled directional survey.
- → Progress-to-target tracking: Track how a well's actual trajectory is progressing toward the target along the planned section azimuth as drilling proceeds.
- → Directional program QC: Quickly flag when actual closure azimuth is drifting away from the planned vertical-section azimuth, indicating unplanned walk.
Related Calculations
Region Notes
Global
Vertical section azimuth is conventionally set to the target azimuth (or the pad's primary development direction) at well-planning time and held fixed for the life of the well plan, even if the as-drilled closure azimuth wanders.
References
Need geoscience support? BauerCalc is just one of the tools we build. If you're looking for independent expertise in well planning, geosteering, reservoir characterization, or opportunity evaluation, visit BauerSubsurface.com.