About This Course

Temperature is the barrier that technology is trying to break. Above roughly two hundred degrees Celsius, measurement while drilling tools, motors, elastomers and conventional fluids become unreliable or unavailable, which forces blind drilling, frequent cooling circulations and slow progress. Most of the technology development in geothermal drilling is aimed at that barrier.

Rate of penetration in hard crystalline rock is the other cost driver. Geothermal wells are drilled through granite and basalt where conventional bits wear quickly and penetration rates are low, so bit technology, including impregnated and hybrid designs and alternative rock destruction methods, is where significant cost reduction is sought.

Stimulation brings its own issue. Enhanced geothermal systems require fractures to create permeability, and injecting at pressure into crystalline rock has induced seismicity in several projects, some of which were stopped as a result. Managing that risk, through protocols, monitoring and operating limits, is now part of the engineering rather than an afterthought.