The ability to drill deviated and extended reach production wells is becoming an important factor in the economic assessment of remaining oil and gas reserves. However, problems associated with the weight of conventional drillpipe, such as high torques and frictional drag, can impose severe limitations on the reach which can be achieved in the horizontal section. A lightweight drillstring manufactured from composite materials can effectively ameliorate many of these problems due to the fact that loads arising through friction can be reduced by factors in excess of 3–4. Other potential advantages include reduced rig loads, or increased rig capacity, improved chemical resistance and increased fatigue performance. For certain applications, where the horizontal leg is subjected to compressive loading, there is also scope for developing an alternative to heavyweight pipe with a resistance to buckling. This paper addresses the design of a composite drillpipe and includes consideration of mechanical and dynamic loading, environmental effects and operational factors.