Formation evaluation of a petroleum reservoir is the practice of finding out the amount of hydrocarbon and its productivity. The volume of hydrocarbon can be found out by determining reservoir parameters such as porosity, hydrocarbon saturation, reservoir thickness etc. Lithology of the reservoir should be known precisely to determine above mentioned parameters as well as permeability to predict its productivity. These parameters can be known indirectly from well logs. Because of the multi-discipline approach required, the analyst must maintain a web of communication with many seemingly unrelated functions within the organization. The analyst must be sensitive to the vibrations coming along each strand of the network and respond accordingly. That response might be in the realm of geophysics, geology, reservoir engineering, petroleum economics or corporate managements. This book explains in detail about the various logging techniques involved in finding Oil and Gas in place. It also covers the easy and best way of interpretation of logs. Further it explains about latest technological advancements in Logging.