It’s an uneasy alliance to be sure, but in an age when diminishing sources of fossil fuels mean the cost of even getting the stuff out of the ground is at times almost not worth the effort and expense, the idea of using solar power to “drill” for oil makes a strange kind of sense. At least, that’s the idea one of the world’s biggest crude oil producers is selling.
With oilfields around the world being sucked dry and the gushers of yesteryear becoming a distant memory; oil companies are turning to an extraction process called steam flooding that forces superheated steam down into old wells containing semi-solidified bitumen-crude, the leftovers from once-prime oilfields. The hot steam breaks down the viscosity of the oil, allowing it to be pumped to the surface more easily.
Currently, natural gas is use to heat massive boilers to produce the vast amount of steam needed in what is termed “enhanced oil recovery”. Chevron Technology Ventures, a division of Chevron U.S.A Inc., has begun trials of solar thermal steam production system, a project we first reported on in 2009, to test the viability of using solar energy to produce oil.
At a test site on one of America’s oldest Californian oilfields, the Coalinga, Chevron has built a solar thermal facility using over 3000 heliostat sun-tracking mirror systems to focus sunlight onto a a receiver at the peak of a 327-foot-tall solar tower. The receiver heats a boiler in the tower which in turns produces steam used for steam flooding the Coalinga field. After several days “soaking”, the steam cools and is returned to the surface as water via pipes and recycled.
According to Chevron, the solar demonstration generates about the same amount of steam as one gas-fired steam generator.
“Through this demonstration, we want to determine the feasibility of using solar power for enhanced oil recovery,” says Desmond King, president of Chevron Technology Ventures. “This technology . . . may provide an additional resource in areas of the world where natural gas is expensive or not readily available.”
Chevron isn’t the only company harnessing solar power for enhanced oil recovery. Earlier this year, GlassPoint Solar unveiled the world’s first commercial solar power enhanced oil recovery project in Kern County, California.
