What is a Non-Mag Drilling Collar?– Non-mag drilling collars, also known as non-magnetic drill collars, are an essential part of the bottom hole assembly (BHA) in drilling operations.– They are constructed from non-magnetic materials, typically a special type of stainless steel that maintains its mechanical properties while exhibiting minimal magnetic permeability.– Non-mag drill collars are mainly used for directional drilling where the accuracy of downhole measuring tools (such as Measurement While Drilling, MWD, and Logging While Drilling, LWD tools) can be negatively impacted by magnetic interference.
How to Use a Non-Mag Drilling Collar?– Non-mag drill collars are integrated into the BHA, typically above MWD/LWD tools and below the standard drill collars.– The non-magnetic nature of the collar provides a “magnetic-free” environment for the MWD/LWD tools, enhancing their accuracy.– In operations, the non-mag collar plays a similar role to standard drill collars: it provides weight on bit and stiffness to the drill string.
What Can Users Do With a Non-Mag Drilling Collar?– Users can conduct accurate directional drilling operations without the interference of magnetic fields.– They can obtain precise measurements from MWD and LWD tools, improving decision-making during drilling. – Non-mag collars help in maintaining the trajectory of the drill hole, which is crucial in drilling applications like offshore drilling or drilling in complex geological formations.**Benefits of Utilizing a Non-Mag Drilling Collar**– *Enhanced Measurement Accuracy:* Non-mag drilling collars reduce magnetic interference, improving the accuracy of MWD and LWD tools.– *Effective Directional Drilling:* They play a vital role in achieving accurate directional drilling, especially in complex drilling scenarios.– *Quality Control:* Non-mag drill collars are often tested for their magnetic permeability to ensure their performance, which adds another layer of quality control in drilling operations.– *Maintain Trajectory:* They help maintain the required trajectory of the drill hole, improving the overall success of the drilling operation.– *Increased Drilling Efficiency:* The improved data accuracy leads to more efficient decision-making, potentially increasing the overall efficiency and effectiveness of drilling operations.
Drill collar Number and Connection (mm)
Outside Diameter (mm)
Bore Diameter (mm)
Shoulder guide angle diameter mm
9150 or 9450