Abstract:With the exploration region expanding, the main problems facing to leakage plugging in Shaanxi and Gansu work areas are the complexity and uncertainty of the geological conditions. Simple, convenient and intuitive real-time monitoring on the leakage layer; in-time evaluation to formation pressure, strength and leakage possibility and the implementation of simple and effective plugging measures have become the key to solve these difficult problems. The bridging mud technology widely used at present can not completely meet the requirements of leakage plugging and reservoir protection. Analysis was made on the drilling leakage causes in Shaanxi and Gansu work areas with the technical measures of lost circulation control.