Complete Asset Well Trajectories Database QA/QC

To properly assess the risk of collision in its infill drilling environment, an operator reached PathControl to audit their database before planning multiple complex wellpaths.

The risk of collision between existing and planned wells is a major issue that shall be investigated and evaluated to avoid potential accidents at all times. In fact, building an up-to-date, complete, well defined and QA/QC’ed wellbore trajectory database is the basis of an organised and systematic anti-collision analysis.

An automatized level of QA/QC was processed to detect gross errors and bad survey quality associated to human mistakes or too old measurement tools accuracy. This typically does not require raw data files but includes review of surveys files to:

• Ensure the correct information about references, surveys, and error models
• Correct for most of the large errors
• Ensure correct use of Error Models

Over a batch of 154 trajectories, the basic QA/QC demonstrated the following:

• One third of definitive trajectories contains gross errors
• One third of final survey programs are incorrect
• An unneglectable number of trajectories showed a large survey spacing
• Maximum of 25m in TVD, 32m in Eastern direction and 43m in Northern direction
• One trajectory of very bad quality with recommendation to re-survey