Drill ing Techniques of Improving Drilling Rate in Exploration Wells in Xihu Trough, the East China Sea

Based on the analysis of nine exploration wells'drilling rate drilled in Xihu Trough, the East China Sea, the paper puts forward some suggestions of improving drilling rate and reducing drilling cost by such drilling techniques as well structure simplification, drilling parameter optimized, drill bit selected and used reasonably, BHA made up properly and drilled in approximate balance, as well as provides good experiences for exploration and development in the area in the future.