ROP Enhancement of Hydro-Efflux Hammer in Hard and Abrasive Formations

This paper introduces the hydro-efflux hammer - a rotary percussion drilling tool that is developed to improve ROPs in hard and abrasive formations. Hydro-efflux hammer is a hydro-mechanical tool which utilizes drilling fluid to power its continuous percussion motion. The tool’s rock-breaking capability is achieved by the high unit load and unique breaking methods. The periodic impact generated by the tool excites strong pulsating stress waves, which strengthens the concentrated stress in internal rocks, and speeds up the rock breaking process. For the design of the tool, improved system integrity is achieve by implementing optimized actuating mechanism, sealing components, and anticorrosion materials. The optimization also involves fine tuning the tool including its percussion stroke and impact energy based on the formation characteristics. Recent field test results in challenging formations are presented and analyzed. In this work, based on the testing result, a number of approaches to extend the life time of the tool for higher performances are also proposed.