Abstract: Daqingzijing Oilfield is a large oilfield with over 100 million tons of reserves in Jilin Oilfield discovered in recent years.However,the development of this oilfield is anyhow limited due to the formation characteristics,i.e.,loose and unconsolidated upper formation,which can be easily hydrated,while the rock in lower formation is hard and has poor drillability,and the formation is highly fractured.Drilling is difficult in this area,such problems as hole collapse,lost circulation,hole shrinkage and stuck pipe frequently occur,and the penetration rate is very low.By testing and analyzing the formation rock mechanics,optimizing casing program and drilling parameter,applying lost circulation prevention and plugging,a set of optimized and fast drilling technology have been developed for drilling operation in this area,and field application proved it to be successful.