ORCHYD

ORCHYD’s new drilling technology will increase hard rock drilling rates from the current range of 1-2m/h to up to 4-10 m/h. The novelty is to combine two, previously separate, mature technologies: High Pressure Water Jetting (HPWJ) and Percussive Drilling, in a system customised for hard rock geothermal reservoirs to depths of 6 km.

Planned experiments and solid-fluid coupled models designed to reveal the critical fragmentation mechanisms under in-situ stress conditions will be used to design, build and validate, with pilot drilling tests, the new system for field operations.

The hybrid development requires optimisation of: i) release of high stress concentrations on the hole bottom while drilling, ii) slotting circumferential relieving grooves on the hole bottom using HPWJ (up to 200 MPa), iii) in-hole production of the HPWJ using a down-hole pressure intensifier activated by the drilling vibrations, hence damping out harmful drilling system vibrations and iv) an advanced down-hole percussive rotating mud hammer for drilling to derive the maximum benefit from the modified bottom-hole stress regime.

ORCHYD ambition is to cut by 65% the drilling cost in hard rock sections. This will result in 30% reduction of the total cost of deep geothermal well construction. In addition, the new coupled Intensifier-HPWJ-Hammer system has the potential to drill and steer multi-lateral wells which greatly increase thermal connectivity, are cheaper, use far less water and are more controllable than conventional fracking stimulation.