Next Generation Drill Pipe for Extended Reach, Deepwater and Ultra-deep Drilling

Abstract

Abstract A new drill pipe size, 5-7/8 in. OD, represents enabling technology for Extended Reach Drilling (ERD), deepwater and other deep well applications. Most world-class ERD and deepwater wells have traditionally been drilled with 5-1/2 in. drill pipe or a combination of 6-5/8 in. and 5-1/2 in. drill pipe. The hydraulic performance of 5-1/2 in. drill pipe can be a major limitation in substantial ERD and deepwater wells resulting in poor cuttings removal, slower penetration rates, diminished control over well trajectory and more tendency for drill pipe sticking. Hydraulic pressure losses are minimized with 6-5/8 in. drill pipe, but 6-5/8 in. drill pipe is an "over-design" solution in many cases. The 6-5/8 in. drill pipe is difficult to handle, requires excessive physical space on the rig, can limit setback capacity and generally requires significant rig handling equipment modifications. In addition, 6-5/8 in. drill pipe cannot be used to drill inside of 9-5/8 in. casing and 8-1/2 in. hole sections. The 5-7/8 in. drill pipe provides a significant improvement in hydraulic efficiency compared to 5-1/2 in. drill pipe and does not suffer from the disadvantages associated with use of 6-5/8 in. drill pipe. It represents a drill pipe assembly that is optimized dimensionally and on a performance basis for casing and bit programs that are commonly used for ERD, deepwater and ultra-deep wells. Realizing the full potential of 5-7/8 in. drill pipe requires a high performance tool joint connection. A second-generation double-shoulder tool joint connection, optimized for 5-7/8 in. drill pipe, provides exceptional torsional strength combined with a streamline configuration. Configured with a 7 in. OD tool joint the connection permits fishing inside of 9-5/8 in. casing or 8-1/2 in. open hole sections. The first string of 5-7/8 in. drill pipe went to work on a Gulf of Mexico project in July 1999. Since that time more than 830,000 ft of 5-7/8 in. drill pipe comprising over 40 drill strings has been manufactured and put into the field. The drill pipe has been successfully used to drill ERD, deepwater and ultra deep HPHT wells in the South China Sea, Gulf of Mexico, Offshore Trinidad, Onshore Wyoming and Onshore Colombia. The 5-7/8 in. drill pipe has improved penetration rates with large diameter bits and significantly shortened drilling curves to total depth in established fields. Drilling engineers are currently evaluating 5-7/8 in. drill pipe for use on major ERD, deep directional and deepwater projects in various parts of the world. The paper discusses the engineering philosophy behind 5-7/8 in. Extreme Reach (XR) drill pipe, the design challenges associated with development of the product and reviews the features and capabilities of the second-generation double-shoulder connection. The paper provides drilling case history information on significant projects where the pipe has been used and details results achieved with the pipe.