Abstract
Managed Pressure Drilling(MPD)is an advanced drilling technology, featured by solving complicated drilling difficulties through precise control of bottom-hole pressure. In Block D of Myanmar field, due to the narrow mud weight window, large strata dip, and developed fractures and pores, well kick, mud leakage and well-bore collapse is likely to happen. Well Yagyi -1x is an appraisal well, and in the fifth spud of drilling, MPD is taken to precisely control the bottom hole pressure under different working conditions, such as drilling, pipe connection, and tripping. The issue of narrow mud weight window is solved successfully by applying MPD technology, and in the meantime, the chip hold down effect is decreased and the drilling rate is increased.