Heavy oil accounts for a large portion of new oil being produced around the world today. It is known as heavy oil due to its high viscosity which makes it difficult to extract. Steam is usually pumped underground at high temperatures to heat up the oil and improve its liquidity to make it easier to pump to the surface. The steam is generally produced by burning natural gas to heat water.
At the Coalinga oil field in California, Chevron has decided to try and use solar energy to heat the water in an attempt to reduce the reliance on natural gas. The oil major partnered with BrightSource Energy, who design and build solar towers, to build a similar version of the technology at the oil field. They have erected 7,000 heliostat mirrors which will focus the sun’s rays on a solar tower to produce heat and boil the water into steam to be sent underground and free up the heavy crude. The solar tower system will still be used in conjunction with traditional natural gas boilers to provide power 24 hours a day.
Jerry Lomax, vice president of emerging energy at Chevron said that, “it’s operating and providing the bulk of the steam generated to support enhanced oil recovery.”
As 2012 progresses Chevron will determine how reliable and useful the solar steam is, and whether it could be feasibly used to run an oil field entirely on solar steam. If the California test is successful the idea could be implemented at oil fields in Saudi Arabia, Kuwait or Indonesia. As Lomax says, “all three locations have sites with ample sunlight and ample amounts of flat acreage near oil fields where you could include a solar field of this scale.”
Chevron are also looking to determine whether this technology could be used in oil refineries and petrochemical plants, both of which use lots of heat.
By. Joao Peixe of Oilprice.com
Joao is a writer for Oilprice.com