Oil and gas companies are continually seeking and applying new technologies, processes, and methods to reduce their cost of finding and producing hydrocarbons while remaining competitive in the current and changing global economy. Improving the efficiency of business processes and maximizing the productivity of the workforce will help to reduce the associated costs and should ultimately increase profitability.

Although technology has helped companies to better evaluate the prospects, lack of trained geoscientists and engineers and the absence of proper vehicles for training and technology transfer may jeopardize oil- and gasfield-development efforts. An efficient and effective way to help develop core competencies for different jobs is to design tools and training actions to address these needs. In this book, workflows have been developed that apply key technology independently by analyzing the processes and solving example problems, thereby addressing the importance of integration of subsurface disciplines related to oil and gas exploration and production.

Traditional Arp’s models exist that are based on graphical extrapolation of production data, and they have been regarded in our industry as one of the preferred and commonly-used tools for estimating future performance in oil and gas wells. However, the practical aspects of analyzing production performance have changed as a result of the increased exploitation efforts in unconventional reservoirs. The complexities of these types of reservoirs were not adequately covered in the initial work Analysis of Production Decline Curves, published by the Society of Petroleum Engineers in October 2008. In the current book, the scope has been broadened, and we provide many more field examples, including problems that cover the specific subjects of developing well-evaluation procedures and best practices for new areas of shale and tight formation reservoirs.

Advances in horizontal well drilling and multistage hydraulic fracturing have allowed industry to develop unconventional nano-Darcy permeability reservoirs (shale oil and shale gas). These highly-heterogeneous multiphase systems do not lend themselves to typical analytical solutions to predict future performance. Boundary conditions applied to such systems are based on ideal geometrical configurations and idealized flow theory. This approach implies important and sometimes faulty assumptions concerning geological heterogeneity and multiphase flow in the physical system. Aspects of production forecasting in unconventional resources are now covered in this book. The sections discussing type curve and two phase flow have been expanded and revised completely, and an additional section on types of equations replicating different flow conditions encountered in the oil field is presented. The most useful plotting and interpretive methods have been added, and a method for estimating ultimate recovery is included.

This book is intended for engineers, geologists, and anyone working in the oil and gas industry with an interest in production forecasting of conventional and unconventional resources for evaluation and development. The majority of the book is concerned with commonly observed oilfield practice and practical solutions to the problems encountered therein. Each chapter begins with a workflow diagram that, in essence, provides the reader with the learning objectives of the chapter. A primary focus of the book is to instill each reader with the competency to solve typical operational problems with minimal exposure to the complexity of the underlying mathematics and equations. The basics and utility of each equation are discussed; however, the focus is on the practical application of the underlying technology to real-life problems. There are numerous illustrations and solutions to typical field problems included for the reader.