Converting Static Friction to Kinetic Friction to Drill Further and Faster in Directional Holes

Abstract

Abstract Since the dawn of directional drilling with downhole mud-motors, Operators and Directional Drillers (DD’s) have been continuously frustrated by the difficulties encountered during "sliding" operations. The challenge has always been how to overcome static friction between the drill pipe and the hole wall while the pipe is not rotating. Overcoming this static friction becomes more and more difficult as the DD leaves 0° inclination and works toward 90°. Some of the challenges to overcome are weight stacking, sinusoidal and helical buckling of the drill pipe, stick slipping, inability to hold tool face, slow ROP, etc. The good news is that static friction while sliding can now be greatly reduced by effectively converting it to kinetic friction; kinetic friction being much less inhibitive to drilling operations. The following paper introduces a drilling tool that breaks static friction while sliding. This tool has repeatedly shown to break this friction without detriment to other downhole drilling tools or operations. Drilling with kinetic friction instead of static friction saves time, money and frustration. The Introduction of the following paper demonstrates the stated problem by showing the basics of friction resistance in the drill string while directionally drilling. The paper then describes this downhole tool and how it cures symptoms that frustrate the DD. The final section will present a Case Study conducted in a Barnett Shale horizontal drilling application in Tarrant County, Texas. It will strive to graphically illustrate and emphasize the effect of the tool on drilling operations.