Covers the purpose and planning of a well using different types of bits. Expertly written, this updated book explains why certain bits are selected and how they are used. Also covers bit wear and tear and replacing bits as well as the effects of weight and rotary speed. Additional discussions focus on drilling fluid use, bit hydraulics, and formation properties, demonstrating the importance of maintain-ing bit performance and functionality. Includes detailed illustrations, review questions, answers, and a complete glossary. pp. xiii, 137 Illusts #0517