Cause Analysis and Treatment Measures of Differential Pressure Sticking in a Well in the East China Sea

The high-pressure and low-permeability characteristics are prominent in the oil and gas fields of the East China Sea.The lower density of drilling fluid is not conducive to well control safety. However, the higher density of drilling fluid will lead to high pressure difference and induce engineering accidents such as pressure differential sticking of pipe and cable. This paper explores the causes of the pressure differential sticking in the φ215.9 mm well section in the East China Sea from the well structure, the formation pressure,the density of drilling fluid,the borehole trajectory,etc., then briefly describes the unfreezing processes,eventually put forward some valuable suggestions for drilling operation in high-pressure and low-permeability formations and for preventing and treating differential pressure sticking. It can provide a reference for drilling in the same formation in the East China Sea and effectively avoiding or relieving the pressure differential sticking.