A visual glance at energy terms and technologies - Article Photos 1/9

FILE -In this Wednesday, May 9, 2012, file photo, a drilling rig using horizontal drilling is seen near Kennedy, Texas. Companies used to drill wells straight down into the earth to tap pools of oil and gas. Now they can drill down and then change the angle to follow thin layers of source rock, reaching more oil and gas with each well. (AP Photo/Eric Gay,File)