Study And Application Of Self-Excited Pulsed Eddy Current Drainage Gas Recovery Technology

Under the situation that a large number of gas wells have entered the general late stage of exploitation in China,the phenomenon of bottom hole fluid accumulation is becoming more and more serious,and the demand for drainage and gas production technology is increasing.A series of dra inage and gas recovery technologies have been developed at home and abroad for gas wells,such as piston gas lift drainage,gas drainage,gas production,gas drainage,gas drainage,gas drainage and gas recovery.However,the traditional drainage and gas production process consumes a lot of energy in the process of lifting,handling and injection,which greatly increases the cost of gas extraction and may cause serious environmental pollution.Therefore,we need to develop new efficient and energy-saving eddy current drainage technology.Aiming at the problem of liquid accumulation at the bottom of natural gas wells,Helmholtz nozzle is introduced into the field of drainage gas production to provide pulse energy for eddy current drainage gas production tools.The flow field characteristics of eddy current drainage gas recovery tool and Helmholtz nozzle were studied by numerical simulation method,and their structures were optimized.Compared with the traditional eddy current drainage gas recovery tool,the applicable gas-liquid ratio range of the self-excited pulsed eddy current drainage gas recovery device is studied.The results of numerical simulation,laboratory test and field test show that under the same conditions,compared with the traditional eddy current drainage gas production tools,the pressure and velocity field nephogram of gas-liquid two-phase flow passing through the self-excited pulse eddy current drainage gas production tools are better,the average velocity of outlet increases by more than 40%,the liquid holdup increases by 28%,and the pressure drop decreases greatly,which can be more effective and slower.The occurrence of bottom hole fluid accumulation.The results of structural optimization and application of self-excited pulsed eddy current drainage gas recovery tool show that the self-excited pulsed eddy current drainage gas recovery tool has the best drainage effect when the helix angle is 45 degrees and the diameter ratio of upper and lower nozzles in resonant cavity is 1.2.The suitable gas-liquid ratio is between 400 and 1600,the depth of tool dropping is about 1720 meters,and the working distance is 1923 meters.