This book dealt comprehensively with reservoir simulation model, to be precise, water and polymerflood at a varying mobility ratio. The ideal of using the wide range of mobility ratio was use used to identify a limit of mobility ratio be young which the floods operations becomes economically unattractive. The cornerstone of our work hinges on the vertical heterogeneity in the reservoir formation: effect of vertical communication between the reservoir layers on the oil recovery. The book is design to be useful guide for those aspiring to water and polymerflood or mobility control experts but not gas or WAG injection. As you read through this book, you will come across a section that dealt scolarly with the use of horizontal well injectors as against vertical well injectors in the floods operation.Furthermore, among many valuable set of information you can fine is this book is the answer to the controversial question: Is polymerflood operations economically viable when oil viscosity becomes increasingly higher (150 cp)?. The 1990 polymer screening test show that polymerflood operations will be economically feasible when the oil viscosity is less than 150 cp. So looki