When we drill the formation in ocean where the gas deposits, the natural gas breaks into the well bore and circle space and generates hydrate with water in drilling mud under certain condition.

• 海洋钻井过程中如果遇到含气地层,地层气窜入井筒及环空中,与钻井液中水在一定条件下易形成天然气水合物,堵塞井简、环空及防喷器,使钻井无法正常进行。