As horizontal directional drilling (HDD) celebrates its 50th year, what was once viewed as a risky and unconventional crossing method has evolved into a global multi-billion-dollar industry.
This transformation hardly occurred overnight but is instead the result of a slow but steady stream of incremental improvements to existing technologies. This has been especially true of the guidance systems that verify location of the bore within the right of way. While some early HDD jobs may have been drilled with little more than hand signals, today’s jobsite is likely to employ guidance systems utilizing advanced magnetic and gyroscopic steering, wireless communication, GPS, radar and extensive computer analysis of the resulting data. With trenchless demand showing no signs of slowing, ongoing advancements in guidance technology will be required for HDD to remain the trenchless option of choice.
HDD Finds its Roots
HDD got its start in 1971 when PG&E approached Martin Cherrington to explore the feasibility of drilling under the Pajaro River rather than trench through it. Cherrington came up with a plan to pair a road boring rig set at an angle with discarded downhole tools that had shown a disturbing habit of building angle and poking out in the middle of the street. The method was proven viable when, after some experimentation with entry angles, he successfully drilled a test bore under the Pajaro River at a length of 500 ft. Despite the success, the fact that the bit had punched out 40 ft off-line could not be ignored. Without a reliable guidance system, HDD would never become commercially viable.