An aeronautical engineer may have solved the problem of the huge cost of drilling geothermal wells, or any kind of well for that matter. Conventional drilling can cost anywhere from five to twenty million dollars depending on the depth of the well and the geology.
Mark Russell of Spokane Washington USA, who heads up the company Hypersciences has applied for a patent on a new type of ramjet style gun that fires projectiles into the ground. The projectile is loaded into the ram accelerator and then the gas is ignited through what appears to be in the patent diagram a series of boosters, much like a rail gun that uses electromagnetic acceleration. By the time the projectile exits the acceleration chamber into the earth it is travelling at a speed of 4,500 miles per hour. On contact with the geology the projectile simply vapourises the rock and is vaporised itself leaving only a gaseous pulverised by product which is sucked or flushed out of the hole.
It is not revealed how deep each projectile could blast into sedimentary rock, but Mark states that; “I think I’m solving a huge energy problem, and we are going to drill 10 times faster than anyone else has drilled before, which means you can access energy faster than ever before,” he said. Russel further expects to be able to drill, or more correctly punch wells to about two miles depth. This is really not deep enough to tap into geothermal energy in most parts of the world, except volcanically active places like Iceland, but if the cost of operation is less than the wastage on diamond drill bits then punching a hole to two miles and finishing off with conventional drilling becomes quite feasible.
The whole project has received about one million dollars from the Shell Game Changer programme, so they obviously see some value in pursuing this line of investigation. Russel has raised a further $880,000 and is about to go out for a further $370,000 in the near future.
Some concerns have been raised on the localised effects on the rock strata. It is not known how much fracturing in the surrounding rock will occur or how the system handles aquifers it encounters and effects that will have on groundwater. Extensive testing needs to be done until all interested parties can be satisfied that the environmental and localised geological effects are acceptable. But if indeed it proves viable then at ten times the drilling rate and an expected significantly lower cost, this gun will bring geothermal energy closer to many communities.
Watch a video brief here.