Transocean and Santos Achieve MPD First

In an industry first, Transocean and Santos have combined the use of surface BOP technology and managed pressure drilling (MPD) methods on a semisubmersible rig working offshore Indonesia in a water depth of 2,240 feet. The achievement on the Transocean semisubmersible rig, the Sedco 601, was the first use of a rotating control head (RCH), which was produced by Weatherford, to control annulus pressure while drilling with a surface BOP from a floating rig. This innovative combination of technologies enabled better control of the well while drilling through formations prone to total losses of circulation when drilled conventionally.

Previously the Sedco 601 crews and Santos utilized this method in conjunction with a conventional subsea BOP and marine riser to drill an abnormally pressured well in a water depth of 145 feet.

The Sedco 601 has drilled more offshore wells in surface BOP mode than any other rig in the industry. Since June 1998, this rig has constructed some 110 wells in this manner in water depths ranging from 30 feet to 6,722 feet.

MPD, which has been pioneered onshore, is now making notable advances offshore, where it is expected to significantly improve the safety and efficiency of well construction.