As you may already know, Drillstar is involved in the ORCHYD project, funded by the European Union, which aim to develop an innovative drilling technology, combining percussive drilling and high-pressure water jetting. The objective is to improve the drilling rate in hard rocks such as granite that are generally found in depths greater than 3 km, when drilling deep geothermal wells.

The high-pressure water jet (between 1000 and 2000 bars) creates a peripheral groove on the rock surface (up to 2 cm deep), which releases the rock from the surrounding confining stresses and facilitates the drilling action in the center with percussion. For ORCHYD prototyping, Drillstar’s MUDHammer is used to generate high power percussive action on the drill bit, adapted with a high-pressure line ended by a specific nozzle. Throughout this project, various phenomena such as bit rock interaction or jetting action are studied both through numerical simulations and experimental works. Preliminary results already demonstrated more than two times improvement on the drilling rate of percussive drilling when using the jet action.

In 2023, during the last year of the project, several full-size prototypes will be built – combining an intensifier to generate the high-pressure, the MUDHammer and specifically optimized drill bits – and tested on a bench from our partner Armines, in Pau (Mines-ParisTech).

More information about the project can be found on the dedicated website at www.orchyd.eu, with reports, papers and deliverables now available for consultation and download on the repository tab.