Safe Sidetrack Relative Positioning with PCTrack® Ranging

After a 7’’ liner got stuck and lost in hole, the decision was made to side-track the well in the 8-1/2’’ section just outside the 9-5/8’’ shoe.
The sidetrack wellbore was planned to stay close from the main borehole with less than 50 ft of separation for 600 ft. Thus, the magnetic interferences generated by the parent wellbore are monitored with the standard MWD tool.

The parent well 7” Liner tally was used to determine theoretical presence of magnetic poles. These simulation results were then used to suggest and optimize the PCTrack® program accordingly.
‍

The Passive Ranging Technique (PMR) was chosen to benefit from the interferences, using PCTrack® technology rather than suffer and mitigate their impact.

The main value of the PCTrack® technology was to mitigate the impact of magnetic interferences, and allow:

• Drilling forward based on synthetic surveys resulting from Passive Magnetic Ranging analysis.
• Avoiding the time spent on gyro run since synthetic surveys residual uncertainties were within the MWD Error Model budget.

‍

A second benefit was to be able to QC the relative wellbore positioning between the drilling wellbore and the main wellbore.