Practical reservoir engineering techniques have been adequately described in various publications and textbooks, and virtually all useful techniques are suit able for implementation on a digital computer. Computer programs have been written for many of these techniques, but the source programs are usually not available in published form. The purpose of this book is to provide a central source of FORTRAN-coded algorithms for a wide range of conventional reservoir engineering techniques. The book may be used as a supplementary text for courses in practical reservoir engineering. However, the book is primarily intended for practicing reservoir engineers in the hope that the collection of programs provided will greatly facil itate their work. In addition, the book should be also helpful for non-petroleum engineers who are involved in applying the results of reservoir engineering analysis. Sufficient information is provided about each of the techniques to allow the book to be used as a handy reference. ix INTRODUCTION This book provides many of the useful practical reservoir engineering (conven tional) techniques used today in the form of FORTRAN codes. The primaI:y objectives have been to provide the simplest possible method for obtaining reli able answers to practical problems. Unfortunately, these codes can usually be applied by simply following a cookbook approach. However, if at all possible, the solutions obtained should be verified and cross-checked by some other means and, most important, should be checked for reasonability.