Enlarging hole while drilling with RRS can save money
March 5, 2008
Concurrent rotary-steerable directional drilling and hole enlargement is becoming more commonplace, Steve Jones with Pathfinder Energy Services said today at the 2008 IADC Drilling Conference.
Frank Hartley Drilling & Production Editor
ORLANDO, Florida -- Concurrent rotary-steerable directional drilling and hole enlargement is becoming more commonplace, Steve Jones with Pathfinder Energy Services said today at the 2008 IADC Drilling Conference. Enlarging the hole while drilling with a rotary-steerable system (RSS) as opposed to using a designated hole-opener run after the pilot has been drilled can save money, said Jones.
The RSS underreamer assemblies often are challenged with BHA instability, excessive vibration, and stick-slip problems when the two different cutting structures (bit and underreamer) interact with significantly different formations. He described case histories of directional wells drilled with both point-the-bit and push-the bit RSS assemblies in the North Sea, Mediterranean Sea, and Nile Delta.
He concluded that the combination of a specific RSS and underreamer with a balanced cutting structure has resulted in excellent ROP and directional control, while reducing reaming-related vibration and potential failures.
