GAS-FIRED STEAM-INJECTION BOILER FOR OILFIELD

Disclosed in the present invention is a gas-fired steam-injection boiler for an oilfield, the gas-fired steam-injection boiler comprising a flue and a water supply pipeline, wherein the flue is provided with a radiation section (1) and a convection section (2), which are arranged in a flue gas flow direction. The water supply pipeline comprises a first pipe section, a second pipe section, and a third pipe section, wherein in the flue gas flow direction, the first pipe section is located at an upstream portion of the convection section (2), the second pipe section is located at a downstream portion of the convection section (2), and the third pipe section (3) is arranged between the first pipe section and the second pipe section; and in a water flow direction of the water supply pipeline, the second pipe section, the first pipe section and the third pipe section (3) are arranged in sequence. By using a flue gas condenser, the temperature of flue gas can be further reduced, and the latent heat of vaporization o