One of the fundamental aspects of petroleum exploitation and production is that of petroleum engineering, ie the assessment and recovery of oil from the various types of oil 'reservoirs'. The importance of effective petroleum engineering has increased dramatically due to a number or of varying reasons. Firstly, recoverable oil reserves should be capable of extended life by application of efficient reservoir depletion methods. Secondly, the average recovery factor does not appear to have increased over the last three decades. Thirdly, the behaviour of reservoirs is still unpredictable in spite of the fact that the principles of oil recovery are better understood. Finally, there has been an enormous growth in the number of computer-based analysis techniques available to the engineer. These factors, taken in conjunction with the fact that many developments have been presented as unpublished papers, have highlighted the need for a series of volumes which will give the engineer a starting point for the collection of up-to-date information. This new series of volumes, Developments in Petroleum Engineering, is intended to fill this gap and will contain reviews of recent developments. The chapters are written by specialists at a level which summarises the progress, but does not necessarily cover every facet and detail, of a particular subject. Rather, they direct the reader to the most useful of the original sources.