This five-day comprehensive course is designed to provide in-depth knowledge and practical skills in well test analysis and interpretation for petroleum engineers. It covers key concepts, methodologies, and advanced techniques required to evaluate reservoir performance, characterize reservoir properties, and optimize production. The course combines theoretical instruction with hands-on exercises, enabling participants to interpret real-world well test data and apply their knowledge to complex reservoir scenarios. Reservoir flow behavior is influenced by a wide range of scales, from microscopic to field scale. At the microscopic level, key parameters include mineralogy, clay content (Vshale), pore space geometry, porosity, horizontal and vertical permeability (Kh and Kv), water saturation (Sw), and capillary pressure (Pc). At the larger scale, factors such as depositional environments, reservoir architecture, trapping mechanisms, field geometry, and fault systems govern connectivity and overall flow performance. These elements must be integrated into a geologically consistent grid-based model capable of accurately replicating well and field-scale flow behavior. Particular emphasis is placed on fluid contacts and transition zones. The course is structured with morning lectures followed by afternoon tutorials. During the practical sessions, participants work in teams of three to four to build a static reservoir model from scratch, which is then tested using a flow simulator. Based on their models, teams will estimate hydrocarbons in place and recoverable reserves. On the final afternoon, each team will deliver a 20-minute presentation summarizing their methodology, results, and conclusions.