Electro-pulse-boring (EPB): Novel super-deep drilling technology for low cost electricity

Abstract

The inexhaustible heat deposit in great depths (5–10 km) is a scientific fact. Such deposit occurs around the globe. Thereby, everybody is enabled to generate autonomously clean and renewable energy, ample electricity and heat. The economical exploration and exploitation of this superdeep geothermal heat deposit requires a novel drilling technique, because the currently only deep drilling method (Rotary) is limited to about 5 km, due to the rising costs, depending exponentially on depth. Electro-pulse-boring (EPB) is a valuable option to Rotary drilling. EPB, originally investigated in Russia, is ready to be developed for industrialization. The feasibility of EPB is proven by many boreholes drilled up to 200 m in granite (crystalline). Estimates show outstanding low costs for drilling by EPB: 100 zs/m for a borehole with a large diameter (Ø) such as 20″ (50 cm), independent on depth and applicable likewise for sediments and crystalline rocks, such as granite. The current rate of penetration (ROP) of 3 m per hour is planned to be augmented up to 35 m per hour, and again, irrespective whether in sedimentary or crystalline formations. Consequently, a 10 km deep borehole with Ø 50 cm will ultimately be drilled within 12 days. EPB will create new markets, such as: (i) EPB shallow drilling for geotechnics, energy piles, measures in order to mitigate natural hazards, etc., (ii) EPB deep drilling (3–5 km) for hydro-geothermics, exploration campaigns etc. and (iii) EPB super-deep drilling (5–10 km) for petro-geothermics, enabling the economic generation of electricity. The autonomous and unlimited supply with cost efficient electricity, besides ample heat, ensures reliably clean and renewable energy, thus, high supply security. Such development will provide a substantial relief to cope with the global challenge to limit the climate change below 2 °C. The diminution of fossil fuels, due to the energy transition in order to mitigate the climate change, implies likewise the decrease of air pollution.