Drilling Data Handbook

New Specifications and Recommended Practices have been published by the American Petroleum Institute. Meanwhile, manufacturers have also greatly improved their equipement. In particular, remarkable progress has been achieved in the following fields: horizontal displacements have reached a distance of over ten kilometers in directional and horizontal drilling, with the use of more complex bottom hole assemblies and drill strings; coiled tubing units are now being used almost systematically during workover, and occasionally during drilling; the range of drilling bits has been entirely renewed, and the classifications and Used Bit Dull Grading System Format and Codes of the IADC have been modified accordingly; new dimensions and weights for casings have appeared with the drilling of HP-HT wells; wellhead equipment and control systems were modified to keep up with deep offshore drilling.