The problems of three-dimensional computer models of geological oil and gas fields are discussed. Methodological and technological approaches to model creation in the different stages of modelling are described taking into account the exploration maturity, amount and quality of the initial geological and geophysical data. Different aspects of building the models are explained with a large number of illustrative material. The results of building the models for numerous hydrocarbon fields in the different software systems are presented. The book will be interesting to professionals of the companies involved in building geological models of oil and oil and gas fields and also for the students and high school graduates with a specialization in petroleum and geology.