Steam and nitrogen composite swallowing-spitting oil extraction method

The invention provides a steam-and-nitrogen composite swallowing-spitting oil production method, comprising the following steps: a, steam injection string laying: a pipe column structure successively comprises an even steam distribution pipe column provided with an even steam distribution valve and a compensator, an injection and extraction integrated pump connected to the even steam distribution pipe column, an oil pipe arranged on the pump, and a subcritical steam injection well from bottom to top; b, N2 and steam injection: steam is injected through an oil jacket annulus, meanwhile, nitrogen is injected into an oil well through the oil pipe, nitrogen injection speed is regulated to evenly allocated and injected during the whole steam injection process; c, soaking: soaking is carried out for 2-7 days after steam injection and nitrogen injected are over; d, blowout: when the well pressure drops to 0.5Mpa/day, blowout is controlled by an oil nozzle; and e, pumping start: when open-flow liquid amount reaches 3t/d, the injection and extraction integrated pump is used to start pumping.