"I would like to thank those of you who bought the first edition. I hope you found it helpful. Thanks also to those who gave me feedback, nearly all of which was positive and was encouragement enough to provide you with this update. This second edition contains literature references up until mid-2013. Even though this is only 4.5 years since the first edition, a huge amount of research and field applications have taken place since then. For example, the number of references in this book has increased by almost 50%, almost none of which pre-date 2009. Other changes and trends I have observed within the development of oilfield production chemicals I have reported (M.A. Kelland, 'Production Chemicals and Their Future,' Chemistry in the Oil Industry XIII--New Frontiers, Manchester, UK, November 2013). So, apart from updating each chapter, what's new in this second edition? First, I have expanded and separated out the section on foamers for gas well deliquification and given this subject its own chapter (Chapter 19). I have also included a new chapter (Chapter 18) on hydrotesting, as requested by a number of you. In addition, I have added a section on chemical injection in Chapter 1. These new additions are undoubtedly not exhaustive, so I would welcome your feedback on these. I have also been asked to add other chapters, such as surfactant and/or polymer flooding for enhanced oil recovery, heavy oil transportation, fracturing fluids, and tracers. Owing to size constraints by the publisher and my own time constraints, I have not been able to add these other topics. Since the first edition was published, some new and useful websites have surfaced. Oilfieldwiki has become a useful Internet site to find basic information on some oilfield chemicals,"--