A cluster bomb in the desert by an oil well fire, Southern Iraqi oil field. Unexploded cluster bombs litter the area around the burning oil wells in Iraq's Rumaila Oil Field in Southern Iraq. The wells were set on fire with explosives by retreating Iraqi troops when the US and UK invasion began. The cluster bombs were dropped by US forces to clear the oil well area. A number of them do not explode and this unexploded ordnance is another hazard faced by the experts who have to put the fires out and restore the well heads. The Rumaila field is one of Iraq's biggest oil fields with five billion barrels in reserve. Many of the wells are 10,000 feet deep and produce huge volumes of oil and gas under tremendous pressure, which makes capping them very difficult and dangerous. Rumaila is also spelled Rumeilah.