By OGJ editors
HOUSTON, May 1 -- Shell UK Exploration & Production and Schlumberger Oilfield Services claim to have achieved a world first for the successful field test of a 4 ¾-in. slimhole rotary steerable drilling system in the North Sea. The field test was performed for Shell Expro, which operates in the UK North Sea on behalf of Shell and ExxonMobil Corp. subsidiary Esso, in Brent Delta field.
On its first field test in the North Sea, Schlumberger's system successfully drilled 2,377 ft in 43.5 hr, with an average rate of penetration of 67 fph, making it the first known rotary steerable system to drill this size hole section successfully.
"With the introduction of this new technology, we can now consider drilling wells previously deemed too complex," said Klaas van der Plas, senior well engineer, new technology, for Shell Expro. "In this particular project, [the drilling system] saved 8.42 days compared to drilling a typical 6 1/8-in. section."
The system was composed of Schlumberger's proprietary steering unit with a telemetry system for transmitting data and a specially designed bit. According to van der Plas, the well profile was complex, which required three-dimensional steerability to intersect multiple targets. "We experienced excellent steering response and hole quality and were able to complete the job in a single run instead of several," said van der Plas.
Using the system, a well can be designed with a 6-in. hole as the primary reservoir section, Schlumberger said, and reservoir profiles can be drilled in a single run.
Using this capability in conjunction with real-time drilling and geological data offers an advantage to oil and gas operators by reducing well construction costs, said Imran Kizilbash, president, drilling and measurements, for Schlumberger Oilfield Services.
