Geothermal exploration in Iceland encounters magma flowing into wellbore
A recent article in Geology and an accompanying article on the Science Daily website discusses an interesting find while drilling into the caldera of the Krafla volcano in Iceland. Dr. Wilfred Elders, professor emeritus of geology in the Department of Earth Sciences at the University of California, Riverside, led a research team as part of the Iceland Deep Drilling Project. The drillers encountered multiple problems with drilling the well, finally including a sudden increase in the rate of penetration and torque on the rotary table at 6,900 feet, which halted the drilling.
When the drill string was elevated about 30 feet (I assume, one joint) above the sticking point, then lowered, the bit became stuck at 6,875 feet. They found that magma had intruded into the borehole and filled the lowest 30 feet of the well. The drilling team then completed the hole as a geothermal production well.
Now, here is where things get interesting. According to Dr. Elders, "When the well was tested, high pressure dry steam flowed to the surface with a temperature of 400 Celsius or 750 Fahrenheit, coming from a depth shallower than the magma. We estimated that this steam could generate 25 megawatts of electricity if passed through a suitable turbine, which is enough electricity to power 25,000 to 30,000 homes. What makes this well an attractive source of energy is that typical high-temperature geothermal wells produce only 5 to 8 megawatts of electricity from 300 Celsius or 570 Fahrenheit wet steam."
That is a real-world, true source of high grade energy! Dr. Elders believes that this may show that areas with young volcanic rocks around the world may be excellent prospects for energy exploration in the future. The team is to complete another well in 2013 in Southwest Iceland.
There is more to this story, involving igneous petrology and geochemistry, but the most important factor for the interests of the general public is the fantastic amount of clean, long-lasting energy discovered by Dr. Elders and his team.
For more information:
Last updated (Thursday, 17 February 2011 11:42)