Application of Sidetracking to Well Yuanlu-1 during Air Drilling

Air drilling is widely popularized and has been applied to more than one hundred wells in Puguang and Yuanba areas. It is the major technology of drilling-speed increasing for con tinental strata. But, tool broken and wall sloughing often occur. So,sometimes sidetracking is very necessary. Compared with air drilling sidetracking, the conventional one with drilling-fluid changing has some problems of low penetration rate and operating efficiency. Therefore,sidetracking without mud changing can increase efficiency for solving complicated accidents, extend well sections of sidetracking application and raise drilling speed a lot. It has been implemented successfully in well Yuanlu-1. Good results of drilling-speed increasing and economic benefits have been obtained.