Showing posts with label fracking. Show all posts
Showing posts with label fracking. Show all posts

Friday, August 2, 2013

Positives of fracking

"Geothermal is homegrown, reliable and clean," says Rohit Khanna, program manager at the World Bank for its Energy Sector Management Assistance Program. That is a big part of the reason it is being pursued in developing countries such as Chile, Indonesia, Kenya and the Philippines.
Australia's first enhanced geothermal system, spicily named Habanero, began producing power in May, and Europe has brought three such power plants online. A geothermal power plant in Larderello, Italy, has churned out electricity this way in Tuscany for more than a century, and big power plants can be built this way.
By some estimates, the U.S. could tap as much as 2,000 times the nation’s current annual energy use of roughly 100 exajoules (an exajoule equals a quintillion, or 1018 joules) via enhanced geothermal technologies. With respect to electricity, the DoE concludes at least 500 gigawatts of electric capacity could be harvested from such EGS systems. Even better, hot rocks underlie every part of the country and the rest of the world. The Geysers in California can produce 850 megawatts of electricity alone.
The idea is simple: pump water or other fluids down to the hot rocks beneath the surface. Heat from the rocks turns the water to steam. The steam rises and turns a turbine that spins a magnet to make electricity.
Some places have the natural bounty of hot rocks and cracks in them. But such sites are not plenty.  That's where fracking, the controversial practice of pumping fluid underground to shatter shale and release oil or gas, can help. Fracking “enhances” geothermal by making cracks in hot rocks where none existed, allowing heat to be harvested from Earth’s interior practically anywhere, although this reduces the total power produced because of the need to pump water through the system.
Yet, geothermal’s abundant, renewable, clean potential for making electricity largely languishes, producing "less than 1 percent of global energy," according to a recent perspective in Science. Indeed, only 6 percent of naturally occurring geothermal resources have been tapped to date, according to Bloomberg New Energy Finance (BNEF).
The reason is simple: money. In addition to the $6-million to $8-million risk of drilling a dry hole or a well that does not produce steam as it should there is the multimillion-dollar expense of building a power plant on top of those wells that do produce steam as they should. That adds up to a total cost for a geothermal power plant of roughly $90 per megawatt-hour,
Gradient holes have to be drilled to explore a particular area. Explosions need to be set off at the surface to send seismic waves through the rock that allow for surveying the underground landscape—a technique familiar from the oil and gas industry. It can take years and millions of dollars to do this exploration with the prospect of earning that money back slowly via electricity sales—or all those funds could be lost.
 BNEF puts the odds of successfully completing a geothermal well at 67 percent, which means one third of all geothermal projects fail. The analyst outfit has called for a "global geothermal exploration drilling fund" of some $500 million provided by investment agencies like the World Bank.


Another problem: some EGS projects have been associated with small earthquakes, much like oil and gas drilling and wastewater disposal. That has caused some projects to be abandoned.

Wednesday, March 27, 2013

Water injection induced quake, says study

With all the environment concerns around fracking, a new study may just be sounding another alarm. It says that wastewater injection was the major trigger for the Prague earthquake of 2011.

Wastewater injection is the removal of water from fossil-fuel energy production into the ground — whether for hydrofracking, which uses the pressure of the water to crack open rocks to release natural gasses, or using the water to force petroleum out of conventional oil wells. In both cases the water has to be disposed of somewhere away from drinkable and habitable water supplies, so it is often pumped underground somewhere.

Geologically sedate areas of Arkansas, Texas, Ohio, and Colorado have recently become relatively earthquake-prone, with quakes in the middle of the US jumping 11-fold over the past four years when compared to the previous three decades. The risk is such that the National Academy of Sciences in a report last year called for further research to “understand, limit and respond” to induced seismic events.

The present study looked at the evidence for the Prague quake November 6, 2011, when a 5.7 magnitude and found that as wastewater refilled now-empty oil wells the pressure to continue filling the holes with water had to be increased which caused the Wilzetta fault to jump. The amount of wastewater injected into the well was relatively small, yet it triggered a cascading series of tremors that led to the main shock, said study

The study’s authors believe that water injection should be kept away from known fault locations, and that companies involved in wastewater injection should be compelled to provide accurate measurements of the amount of water that is being pumped into the ground and at what pressure. They also recommend that sub-surface monitoring of fluid pressure for earthquake warning signs.

Thursday, July 7, 2011

What's good for you is bad for another

Well, the debate over fracking for shale gas continues. The French parliament voted on June 30 to ban the controversial technique for extracting natural gas from shale rock deposits known as hydraulic fracturing, or fracking. This, even as the New York state in US considers revoking a ban!

Companies that currently own permits for drilling in oil shale deposits on French land will have two months to notify the state what extraction technique they use. If they declare to be using fracking, or if they fail to respond, their permits will be automatically revoked.

Fracking requires the injection of vast quantities of water and potentially hazardous chemicals into the ground to force the release of natural gas. The U.S. government is investigating the environmental impact of the technique, which critics say produces toxic waste and pollutes water wells.

A UK panel had found that fracking does not cause damage to the surroundings, especially to water. But not everyone is convinced.

And as though to commemmorate the BP oil spill, we have yet another spill as a pipeline ruptured and sent oil into the Yellowstone river!

Looks like we humans are hell bent on messing up the place - digging up muck, throwing our waste around, making gashes and ravines on the surface as we go searching for all the things we need. Or rather, believe we need! Any opinions on that?