Well Unloading Technology in Gas Drilling and Its Application

To enhance the efficiency and ensure the safety and speed of gas drilling,a new unloading method named alternative unloading was put forward on the basis of conventional unloading method(gas lifting and aerated unloading).Except gas injection equipment for gas lifting unloading,drilling pump is used as liquid injection equipment for aerated unloading and alternative unloading.The paper presents the cases and results of gas lifting unloading,aerated unloading and alternative unloading.Through the comparison and analysis of their field application,it is found that gas lifting is suitable for the shallow well one-off unloading;and aerated unloading or alternative unloading is suitable for the deep well,and alternative unloading is more efficient.This technology is worthy to be promoted.