This paper presents the industry's first application of balanced pressure drilling to drill a difficult well section with continuous circulation using jointed pipe. Previous attempts to drill the section in 2004 failed and balance pressure drilling was identified as the only safe and practical drilling technique to use. The paper will present the reasons for employing a new drilling technique, together with the associated changes to conventional drilling and well control procedures. In the Port Fouad Marine Deep-1 (PFMD-1) well below 4000m, there exists a critical pressure gradient zone with pore pressures exceeding 2.0 sg EMW, with the difference between pore and fracture pressure gradients as low as 0.10 sg EMW. The dynamic hydrostatic pressure difference between the Equivalent Circulating Density (ECD) and the mud weight was equivalent to about 0.07 sg during drilling operations. The well was reentered in June 2005 using the Continuous Circulation System (CCS?) and the problem zone drilled maintaining constant ECD. Drilling difficulties resulting in the earlier suspension were successfully overcome. Balance Pressure Drilling (BPD) with uninterrupted circulation and revised drilling and well control procedures significantly improved drilling performance and operational safety in the critical gradient zone. This resulted in adding significant new hydrocarbon reserves that could not previously be drilled.
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