Coalbed Gas Jet Pump Gas Production Technology Research

Drainage is the key part and also the weakest part in the development and utilization of coalbed methane at present.The main production means for coalbed methane are beam pumping unit combine with mechanical pump,progressive cavity pump, electric submersible pump and air lift.This production means are often used in oil and gas exploration.However, practice shows that it often happens the phenomenon of eccentric wear of tube or rod and holddown of pump,so that it needs frequent workover,pump inspection and replace pipepole to ensure the return to normal production.These problems seriously restrict the continuity of CBM production and gas production effect.In this paper,Pumping technology of concentric tube jet pump is successfully introduced into the drainage of coal bed methane. The research purpose of jet pump technology is to solve the problems of the eccentric wear of tube or rod and holddown of pump in the tube pump, crew pump,electric submersible pump.So as to ensure the continuity of CBM production and the gas production effect.Through the study of the master’s period,the paper achieved the following main research results.(1) Based on the mechanism and principles of coal bed methane drainage,the CBM adaptability research technology are carried out,and the applicable conditions of CBM production technology are summarized.finally the optimization scheme of Coal bed methane drainage technology is proposed.(2) According to the basic theory on dynamics of jet pump and the experimental research of fluid carrying solid particles,the method to calculate key parameters of jet pump are provided in this paper.(3) The subsidence regularity of pulverized coal in the static fluid and flow fluid is studied,so thecorrelation formula between the initiated flow velocity and the settling velocity of the pulverized coal in the liquid、the settling velocity and the liquid velocity are got.Finally based on the correlation formula,the theory of jet pump technology is perfected and according to the characteristic actual situation of the coal seam gas drainage,the core components of the jet pump are optimized.(4) Base on the characteristics of the dual channel production of gas and water in coal bed methane wells,the process of the downhole string and wellhead are designed optimally.Based on the conventional oil and gas well automatic control system,the automatic control system of jet pump is developed, which can realize the automatic data collection and intelligent control of the function of the coal bed gas jet pump.(5) According to the characteristics of Coal bed gas well drainage,the optimal design method of the efflux pump is formed.16 wells are applied in field,it prove that the application effect is well.