This book comprehensively introduces the drilling theory and practice behind CCSD-1 well drilling, the first stage of a key national scientific engineering project of China. In addition to access to variety of data and information accumulated decade during the project decade-long operation, readers also gain insight into state-of-the-art techniques and most recent achievements in China scientific drilling industry. Specifically, this work introduces the drilling engineering design, well site construction, and equipment and construction situation. It also provides a minute description on the new techniques that were developed for tackling the technical difficulties, expounds in detail the core drilling techniques for hard rock deep well, and treats diamond core drill bits, reaming drilling techniques in hard crystalline rocks, well-deviation control techniques for strong dipping strata, and much more. In summary, this book offers a valuable resource for engineers and technicians who engage in scientific drilling and a variety of resource drilling engineering; teachers and students who are interested in this field will also gain plentiful information. Prof. Da Wang, the former deputy director of China Geological Survey, was the director of the Engineering Centre, chief engineer and drill-site general director of China Continental Scientific Drilling Project.