Live Tests on Magma for Energy Potential

An unexpected magma overflow presented geologists with a unique opportunity to test techniques for extracting energy from the hot molten rock. The opportunity presented itself after a team of geologists drilled a 6,900-foot exploratory well in Iceland. Magma flowed unexpectedly into the well and forced the team to discontinue their drilling operation.

According to the initial project, the research team was supposed to drill a 15,000-foot well in order to look for geothermal resources in the Icelandic volcano. After magma had flown in the well, the research team turned the well into a production well, and the researchers started performing tests.

This is the third time drilling teams hit magma. The first time occurred in 1977, when magma busted out through the top of a working geothermal well in Krafka, Iceland. The second time, it happened in Hawaii, in 2005. The drilling of the well started in December 2008 and the process encountered interruptions and delays, due to technical difficulties.

The drilling became more and more difficult as the depth of the well increased. On June 25, 2009, the team reported that they had steam flashing, a phenomenon that occurred when the fluid used for drilling exploded in contact with magma. The team had found glass shards from the drill hole, evidence that they were right - they had reached magma.

The project turned from just drilling to researching the capabilities of the well. Among other things, the team inserted cold water into one borehole, which will be pushed out through other holes as super-hot steam.

Appealing Source of Green Energy

The highly-pressurized dry steam pushed to the surface from a point closer to the surface than where the magma was laying, it had a temperature of 400 degrees Celsius, or 750 degrees Fahrenheit. The research team estimated that, given its properties and if passed through an appropriate turbine, the steam could produce roughly 25 megawatts of electrical power, sufficient to power some 30,000 houses.

This estimated performance makes the well into a very appealing source of energy. Its capacity is at least three times higher than that of other geothermal well, which produce a maximum of eight megawatts of electric power, having temperatures of 300 degrees Celsius (570 degrees Fahrenheit).

Approximately one third of the electric energy produced in Iceland and 95 percent of the heating in the country’s homes comes from the hot water and steam naturally produced by the volcanic rocks.

Wilfred Elders from the University of California explained that the efficiency producing electric energy from geothermal hot water and steam increases with pressure and temperature. As the drills go deeper into a hot region, the temperature and pressure will increase. At some point, the drill should get to the point where the temperatures are very high, the fluids have higher density and temperature, and they would have low viscosity. This is called supercritical water, explained Elders.

Supercritical water is used in power plants based on coal, but it was never attempted to use naturally created supercritical water from the depths of geothermal regions.

Source : TG Daily Photo by : Micah Craig