Oil extraction method utilizing circulated heating cavity gases

The invention provides an oil extraction method utilizing circulated heating cavity gases. The method includes heating oil layer cavity gas which enters into a heating device, and extracting oil after injecting heated cavity gases into an oil layer. In this method, flue gas generated by the heating device is injected into the oil layer, and some cavity gases enter into the heating device to serve as fuel for the heating device to form a circulated heating system. By utilizing the method, the oil extraction cost is low, no water resource is needed, contaminated water processing cost is reduced, the pressure and temperature are adjustable, the oil-gas ratio of oil extraction is high, and the yield is high.