Study On Reflux And Infusion Device Of Electric Submersible Pump Production System In CBM Wells

Coal-bed methane（CBM）is very rich in china, is ranked among the top of the world,has a good prospect of development. At present, the technology and equipment in the coalbedmethane wells are mostly come from oil wells, and the efficiency of the system is notgenerally high. The electric submersible pump equipment has the advantages in large outputvolume and high-lift, it also could be continuous work. The electric submersible pumpequipment is particularly suitable for underground water of content high in CBM exploration,and is more and more applied to the coalbed methane wells.With the electric submersible pump equipment applied to coalbed methane wells, due tothe water yield is very low in the later of CBM exploration and the limited frequency range offlow control system, the water of coalbed methane well will be empty with sharpfluctuations, then does not apply to stability requirements of exploration. Electric submersiblepump system with reflux device, not only to prevent the underground fluid is evacuated, butaslo the coal in the oil can be smoothly discharged into the ground to prevent electricsubmersible pump being blocked, and improves the reliability and applicability of the electricsubmersible pump drainage method.Based on the analysis of the subsidence mechanism of pulverized coal, this paper makesan analysis on the movement of coal group with different diameters, and the size distributionof coal in the tubing was obtained. Compare the CBM exploration method, such as gas liftdrainage method, rod pump drainage method, screw pump drainage method, electricsubmersible pump drainage method and so on. The parameters of submersible pump drainageand reflux are analyzed, this paper aslo provide a calculation method of the minimumdischarge of pulverizing coal from the tubing with the basis of simulation results.This paperalso proposes a set of reflux scheme of ESP with the analysis of existing reflux scheme, anunderground reflux valve is designed according to the proposed scheme, and does simulationresearch of reflux valve with software.