Firefighters from the Kuwait Oil Company (called KWWK: Kuwait Wild Well Killers) pray at noon by the first oil well fire they were working on in Iraq's Rumaila Oil Field. Later in the day they extinguished this smoky fire and the next day stopped the flow of gas and oil with drilling mud using what is called a "stinger", a tapered pipe on the end of a long steel boom controlled by a bulldozer. Drilling mud, under high pressure, is pumped through the stinger into the well, stopping the flow of oil and gas. The Rumaila field is one of Iraq's biggest with 5 billion barrels in reserve. The burning wells in the Rumaila Field were ignited by retreating Iraqi troops when the US and UK invasion began in March 2003. Rumaila is also spelled Rumeilah.