The Shaybah oilfield has estimated 'extra light' crude oil reserves of over 14 billion barrels (2.2×109 m3) and 25 trillion cubic feet (710 km3) of natural gas. The field is about 64 km long and 13 km wide, with production from a depth of about 2 km. Water occurs below and gas above the oil zone, so horizontal drilling extending up to 12 km were employed to increase production efficiency up to 12,000 barrels per day.