Free Online Well Trajectory Planner: Minimum Curvature and Anti-Collision

Drilling Engineering
All tools
Report
Well A survey (MD m, Inc deg, Azi deg per line)
Well B survey (optional, for anti-collision)
Paste survey stations or load the demos. Minimum curvature runs entirely in your browser.
Left: rotatable 3D view (drag the rotation slider). Top right: plan view, north up. Bottom right: vertical section along the closure azimuth. Well A in teal, well B in purple, closest approach marked in orange. Stations exceeding your DLS limit are flagged red on the path.

A well trajectory planner in your browser

Paste survey stations, measured depth, inclination, and azimuth, and the tool above computes the full well path by the minimum curvature method, the industry standard used by every directional drilling contractor. You get true vertical depth, northing and easting at every station, closure distance, dogleg severity flagged against your limit, a rotatable 3D view alongside plan and section views, and the computed stations exported as CSV. Paste a second well and it computes the closest approach distance between the two paths, the first-order anti-collision screen every multi-well pad needs.

Diagram of a directional well path in section and plan view computed by minimum curvature, with build section, tangent hold, target, an offset well, and the closest approach distance for anti-collision marked
Minimum curvature turns survey stations into a well path: section and plan views, dogleg flags, and the closest approach to an offset well.

This is the fifth tool in the Geoscience Workbench. Like the rest of the suite, everything runs locally: survey data is often confidential well information, and it never leaves your browser.

How minimum curvature works

Between two survey stations, the method fits a circular arc that honors the inclination and azimuth measured at both ends. The dogleg angle between the two station orientations sets the arc, and a ratio factor smooths the straight-line assumption onto that curve. It is more accurate than tangential or average angle methods because real wellbores actually do bend smoothly between stations, which is why minimum curvature is what filing agencies and anti-collision software expect. Dogleg severity, the dogleg angle normalized per 30 meters, is the number that tells you whether the bend will pass tools and casing without damage: the tool flags any station above your chosen limit in red.

Using the anti-collision check

  • Load the demo J-well and demo offset well together to see the closest approach computation working: the orange dashed line in the 3D view connects the nearest points.
  • The closest approach reported here is center-to-center distance. Real anti-collision adds survey uncertainty ellipses around both wells; treat separations under about 30 meters as needing a proper ellipse-based scan.
  • Watch the plan view: paths that look safely separated in section can cross in plan, and the reverse. That is exactly why the tool draws both.
  • The CSV export carries TVD, coordinates, and DLS for every station, ready for a spreadsheet or mapping package.

What this tool is for

Checking a proposed plan before it goes to the directional company, teaching the minimum curvature method with numbers students can verify by hand, converting a legacy survey listing into coordinates, and first-pass pad layout screening. It assumes a shared surface reference for both wells and does not model survey error ellipses or magnetic corrections; those belong to dedicated anti-collision software once this screen says the geometry is worth pursuing.

Related Calculators and Reference