Circulating heating system for pumping well

The utility model relates to a circulating heating system for a pumping well, which belongs to the field of oil production industry. The technical scheme of the utility model is as follows: the circulating heating system consists of a heater, a high temperature delivery pump, a wellhead delivery hose, a return hose, an adapter, a pumping unit, a polished rod eye, a wellhead device, an oil pipe, an oil well pump, a hollow sucker rod and a borehole delivery pipe, and the outer wall of the borehole delivery pipe is provided with a heat-preserving layer, which is wrapped on the whole outer wall of the borehole delivery pipe or the outer wall except the bottom part of the outer wall from the top down. A heat-preserving composite metal pipe is adopted as the borehole delivery pipe in order to effectively deliver heat down to the bottom of the well. The main body of the borehole delivery pipe is a continuous steel pipe (better matched with the continuous hollow sucker rod), and is characterized by high temperature r