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 renew- able energy, ample electricity and heat. The economical exploration and exploitation of this super- deep 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 €/m for a borehole with a large diameter (O) such as 20" (50 cm), independent on depth and applicable likewise for sediments and crystalline rocks, such as granite. The current rate of pene- tration (ROP) of 3 m per hour is planned to be augmented up to 35 m per hour, and again, irrespec- tive whether in sedimentary or crystalline formations. Consequently, a 10 km deep borehole with O 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 renew- able 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 oC. The diminution of fossil fuels, due to the energy transition in order to mitigate the climate change, implies likewise the decrease of air pollution.