Drill collars provide weight on the bit to maximize drilling efficiency. Traditional collars utilize steel alloys which also make them highly magnetic. Non-magnetic drill collars substitute specialty alloys to eliminate magnetic interference that can disrupt measurements and steerability.
Advantages:
◆Reduced Magnetic Interference with MWD Tools
Measurement-while-drilling (MWD) tools include magnetometers and accelerometers to continuously survey wellbore position. Magnetic collars distort these sensitive readings, reducing surveying accuracy and jeopardizing precise drilling. Non-magnetic beryllium copper or MONEL collars avoid this electromagnetic interference.
◆Improved Accuracy of Directional Surveys
Magnetic interference from standard drill collars typically requires surveying with no collar joints near the MWD tools. Non-magnetic collars enable surveying while drilling with the full BHA, improving data resolution. They also allow faster surveying during connections. This boosts directional accuracy.
◆Reduced Risk of Magnetic Tool Failures
The powerful magnetic fields in steel drill collar assemblies can damage electronic instrumentation like resistivity and gamma tools. In extreme cases, electromagnetic forces can disable MWD tool motors or circuit boards leading to expensive failures and drilling delays. Non-magnetic metals avert these risks and enable reliable collar-housed tool placements.
Applications of Non-magnetic drill collars
◆Directional Drilling in Highly Magnetic Formations
Formations with high magnetic content create measurement noise and complicate directional control. Non magnetic drill collars significantly improve steering precision in these environments by eliminating distorting magnetic fields from the BHA.
◆Drilling near Magnetic Anomalies
Near subsea infrastructure or downhole magnetic sources like casing valves, standard collars cause survey interference. Non-magnetic variants maintain surveying fidelity regardless of external magnetic fields. This prevents Wellpath deviations when drilling close to magnetic disturbances.
Extended Reach and Horizontal Drilling
As critical precision applications, long horizontal wells require the highest quality directional surveys. Non-magnetic collars paired with continuous inclination MWD equipment provide exceptionally accurate wellbore positioning to drill extended laterals reliably.
While costlier than standard steel collars, Non-magnetic drill collars provide indispensable advantages cementing directional accuracy and reducing tool failures from electromagnetic interference. Their specialized alloys will continue advancing to serve ever more demanding drilling environments and applications.
Vigor can supply multiple API 7-1 Non-Magnetic Drill Collar types including spiral, and slick collars, which comply with API Spec.7-1,5DP and NS-1. Please contact us at info@vigorpetroleum.com.
