1. The Role of Clay Minerals in Drilling and Drilling Fluids 2. Application of Bentonite in Water-Based Drilling Fluids 3. Application of Nanofibrous Clay Minerals in Water-Based Drilling Fluids 4. Clay-Nanoparticle Interactions and their Influence on the Properties of Water-Based Drilling Fluids 5. Borehole instability related to clay minerals 6. Clay Stabilization by Inorganic Inhibitors 7. Clay Stabilization by Organic Inhibitors 8. Organic modification of montmorillonite and its use in oil-based drilling fluids 9. Application of Nanofibrous Organoclays in Oil-Based Drilling Fluids 10. Interfacial interactions between organoclays and invert emulsion drilling fluids 11. Industrial Clay Products for Drilling Fluids 12. Challenges and Perspective of Drilling and Drilling fluids related to Clay Science