Reservoir Souring: A Review on Mechanisms, Mitigation/Reduction Methods with Updating Souring Screening Criteria

Sulphate reducing bacteria (SRB) have been identified in oil reservoirs since 1920s. They reduce sulphate to sulphide resulting in production of hydrogen sulphide. H2S is a corrosive, toxic and flammable gas which causes operational and capital costs for oil industry. Classification of microbial activity as the main source of H2S generation in flooded reservoirs is followed by the increasing number of water-based EOR projects in the few last decades. Failure in precise prediction of reservoir souring onset in the reservoir may lead to severe health and safety issues. Once the prediction and simulation phase is accomplished, appropriate mitigation method should be selected. However, many simulators capable of considering the reservoir souring are available, urgent need to quick prediction of this phenomenon looks necessary. A novel souring screening approach is presented to investigate the souring potential using simple information. Comparing the reservoir conditions with the required criteria for microbial activity is the main idea of this method. In addition, some new methods to mitigate the souring effects are proposed. The most inspiring method is to utilize (per) chlorate group to inhibit bacterial activity.