Laboratory and field studies have proven that microbes can improve microscopic displacement efficiency and oil mobility, produce miscible gases and preferentially plug high permeability zones but these approaches have failed to satisfy valid industry concerns on their field deployment. Similar strategies have been used over a prolonged period and the same results always obtained. New users have emerged to try MEOR and then rapidly discontinued its application. After nearly one hundred years of doing the same thing, it was time to re-evaluate the fundamentals.

This presentation looks at the steps involved in developing a new microbial enhanced oil recovery concept and describes the field application and evaluation of this process. It introduces the basic characteristics of microbial life and an overview of the sequential development and assessment of this successful process. The growth of petroleum reservoir microbes, nutritional manipulation which creates cell associated hydrophobicity, organic debris removal, oil-water-bacteria interface interactions, transient stabilisation of water and oil emulsions, oil droplet coalescence and shear deformation integral to oil recovery are described. The resultant process which simply requires the addition of nutrients to a well or field is described and field data demonstrating reservoir responses and substantial increases in oil recovery are presented.