MANAGED-PRESSURE DRILLING; TECHNIQUES AND OPTIONS FOR IMPROVING OPERATIONAL SAFETY AND EFFICIENCY

In the most of the drilling operations a considerable amount of money is spent for drilling related problems; including stuck pipe, lost circulation, and excessive mud cost. In order to decrease the percentage of non-productive time (NPT) caused by these kind of problems, the aim is to control annular frictional pressure losses especially in the fields where pore pressure and fracture pressure gradient is too close which is called narrow drilling window. By solving these problems, drilling cost will fall, therefore enabling the industry to be able to drill wells that were previously uneconomical. Managed pressure drilling (MPD) is a new technology that enables a driller to more precisely control annular pressures in the wellbore to prevent these drilling related problems.As the industry remains relatively unaware of the full spectrum of benefits, this paper involves the techniques used in Managed Pressure Drilling with an emphasis upon revealing several of its lesser known and therefore less appreciated applications.