Home  »  Resources  »  Webinars  »  Halliburton Landmark Online Events  »  Webinar | How to Stop Your Ellipses of Uncertainty


Directional survey error models are used to generate well uncertainties known as ellipses of uncertainty. These shapes are translated into minimum safe distances from other wells to avoid collisions. A lot of focus is paid to the quality of the directional data and the derived results. While this issue has been dealt with for a long time in offshore directional drilling, current onshore horizontal pad drilling through old fields with expired vertical wells has recently increased interest in collision avoidance calculations.

This webinar will outline the principles of the standard survey error model and collision avoidance calculations used in the industry. It will also describe some of the pitfalls and counterintuitive behavior of the error model in terms of ellipses trends and collision separation factors.

Speaker | Jerry Codling, Senior Technical Advisor, Halliburton Landmark

Jerry Codling is a Senior Technical Advisor with Halliburton Landmark, and has worked at Landmark for over 23 years on directional drilling and well budgeting applications. A mining engineer and geophysicist, he has previously worked with directional drilling and survey companies, developing survey technology. He has published three papers on this subject, and is an active participant with the Industry Steering Committee on Wellbore Survey Accuracy (ISCWSA), which is affiliated with the Society of Petroleum Engineers (SPE) Wellbore Positioning Technical Section.


  • Observe the latest developments in directional survey uncertainty modeling
  • Understand the importance of having quality directional survey data and the correct survey tool assignments
  • Understand some of the myths regarding the accuracy of directional survey modeling ​


  • Operating company drilling engineers and managers
  • Directional drilling company wellbore positioning specialists        
Planar Client Options
Layout Style
  • Wide
  • Boxed
Theme Preview