Troubleshooting VS Calculation Mismatches

If VS values in ZoneVu do not match what the rig is reporting, the cause is almost always related to either:

An incorrect VS Azimuth or

-Mismatched or incorrect Deviation Survey data.

Use the steps below to identify and resolve the issue.

Issue: VS Calculations in ZoneVu Do Not Match the Rig

Solution 1: Verify the VS Azimuth

1. Check the VS Azimuth being used in ZoneVu.

   • If it does not match the rig’s VS Azimuth, the VS calculations will not match.

2. If no VS Azimuth was manually entered, ZoneVu will auto-calculate the value based on the SHL and BHL.

   • When auto-calculated, an orange “Auto” label appears next to the VS Azimuth field in the 2D Viewer.

Correction:

Update the VS Azimuth in ZoneVu so it matches the rig’s value. Once corrected, VS calculations should align.

Related Article: How ZoneVu Calculates VS

Solution 2: Verify the Deviation Survey Data

If the VS Azimuths match, the next step is to compare survey data.

1. Look at the TVD, X/Y Offsets, and the most recent survey station in ZoneVu.

2. Compare these values to the MWD’s survey spreadsheet.

   • If the Deviation Surveys in ZoneVu differ from what the MWD is using, the calculated VS will not match.

Correction:

Update or correct the Deviation Survey data in ZoneVu so it matches the MWD surveys.

Note: If you are using RigStream, you may need to Ignore bad surveys received from the WITSML data feed. Incorrect or corrupt incoming surveys can cause calculation mismatches.

Related Article: Ignoring a Bad Survey