Signatures of Bioactivity in Petroleum Reservoirs

Microbial life is not restricted to the Earth’s surface and the upper few meters of its crust but also occurs in deep subsurface environments, like petroleum reservoirs. Progressing biological degradation of crude oil under anaerobic conditions leads to a tremendous reduction of petroleum quality, which is caused by a quasi-sequential removal of certain compound classes. Due to undesirable effects, such as biofouling of steel material or plugging of wells, the costs for petroleum production are considerably higher in oil fields with significant microbial activity. While the consequences of the compositional change caused by ongoing biodegradation are well-known, much lesser information is available about the involved microorganisms and their metabolism. To fully assess microbial activity in oil fields it would be very valuable to have, in addition to molecular microbiological tools, other parameters based on independent approaches. This project investigates signatures of bioactivity based on geochemical parameters in petroleum reservoirs. Therefore, the following approaches are pursued in the framework of this project:

  1. Characterization of crude oil alteration due to microbial degradation and abiotic processes.
  2. Identification of metabolites as marker for certain metabolic processes. 
  3. Analysis of specific organic molecules as life markers for variable microorganisms. 
  4. Determination of stable isotope fractionation of individual oil constituents as tracers of microbial degradation.


  • Dr. Kai Mangelsdorf
  • Andrea Gruner


  • Dow Microbial Control