WorldOil

Extreme drilling pushes RSS application to a new Alaskan limit

In one of the most remote and demanding drilling environments in the world-in the Alpine Development Field on the Western North Slope of Alaska-ConocoPhillips Alaska, Inc. and partner Anadarko continue to extend the reach of the small-bore well design using rotary steerable drilling assemblies. Refining drilling techniques and practices that have maximized reach and increased horizontal length since 2004 (World Oil, June 2007), the team has delivered four more horizontal wells using only three hole sizes, including a recent well exceeding 25,000-ft MD-a new Alaskan depth/departure record. By building on previous experience while accumulating an extensive database of more than 100 wells, the team has been able to drill these new, complex wellbores with 4¾-in. small-bore Rotary Steerable System (RSS) tools in the horizontal production section, thus avoiding upsizing the entire well design. However, it has required continuous optimizations in RSS and PDC bit design, torque and drag modeling...