The tools and techniques discussed in earlier chapters are normally used to drill directional wells whose maximum inclination is about 60°. Highly deviated wells may be described as those wells whose inclination exceeds 60° for most of their length. It is possible to extend directional drilling techniques to increase the inclination to 60–90°, although alterations may have to be made to drilling practices. Modifications to standard rig equipment may also be necessary to drill these high-angled wells successfully. A horizontal well may be defined as a well which is drilled to an inclination of 90°, and maintains this inclination for a significant distance. Owing to the need for special equipment and the longer drilling times that must be expected, horizontal wells are considerably more expensive than conventional deviated wells.
Weitere Kapitel dieses Buchs durch Wischen aufrufen
- Highly Deviated and Horizontal Wells
T. A. Inglis
- Springer Netherlands
- Chapter 11