The need for this book has arisen from demand for a current text from our students in Petroleum Engineering at Imperial College and from post-experience Short Course students. It is, however, hoped that the material will also be of more general use to practising petroleum engineers and those wishing for aa introduction into the specialist literature. The book is arranged to provide both background and overview into many facets of petroleum engineering, particularly as practised in the offshore environments of North West Europe. The material is largely based on the authors' experience as teachers and consultants and is supplemented by worked problems where they are believed to enhance understanding. The authors would like to express their sincere thanks and appreciation to all the people who have helped in the preparation of this book by technical comment and discussion and by giving permission to reproduce material. In particular we would like to thank our present colleagues and students at Imperial College and at ERC Energy Resource Consultants Ltd. for their stimulating company, Jill and Janel for typing seemingly endless manuscripts; Dan Smith at Graham and Trotman Ltd. for his perseverence and optimism; and Lesley and Joan for believing that one day things would return to normality. John S. Archer and Colin G. Wall 1986 ix Foreword Petroleum engineering has developed as an area of study only over the present century. It now provides the technical basis for the exploitation of petroleum fluids in subsurface sedimentary rock reservoirs.

The analysis of well tests constitutes one of the most powerful tools for the effective description of a petroleum reservoir and its subsequent management. This requires that the well test be placed in the proper context of related disciplines, especially geoscience, production and reservoir engineering. Modern methods of automated data processing can conceal mathematical limitations and overlook the need for realistic physical and geologic models. This book emphasizes the plausible physical contexts and mathematical models and limitations, and also the importance of realistic geologic models in analysis.Although the book is clearly targeted at petroleum engineers, the approach taken by the authors will no doubt find favour with practitioners in other areas of fluid flow in porous media, such as hydrology and the flow of pollutants. Scattered throughout the book are worked examples of the use of the methods described in the text. It also contains extensive appendices on permeability, application of Laplace transforms to flow equations valid for single and multi-layered systems, convolution and deconvolution, dimensionless parameters and P-theorems, and physical and thermodynamic properties of gases. This book should appeal to students as well as practitioners in industry; many in the latter group may have benefited before from formal exposure to the underlying theory and its limitations in real reservoir environments.