Reservoir souring often occurs as a result of secondary recovery using water-flood. Until recently, the mechanisms of souring were poorly understood but it is now possible to quantify and profile the development of sour gas production. The latest understanding of the mechanisms of reservoir souring have been used to model the souring potential of North Kuwait reservoirs, undertaken as part of a process of risk management in field development planning. The Kuwait Oil Company has taken this one step further by interfacing the souring model to a proprietary, state-of-the-art, steady state process simulation package, as part of a wider process of integrated field development. Interfacing a sub-surface souring model to a process facilities compositional simulation has resulted in the ability to assess, with an unusual degree of confidence, the technical and economic effects of reservoir souring on facilities design and operation. This knowledge has been used for the preliminary assessment of options for controlling souring in the future. To assure accuracy, the proprietary process simulation software thermodynamic generator, chosen for its ability to handle hydrogen sulphide, was independently validated by the thermodynamics section of BP Research Centre. This paper reviews the basis of the reservoir-souring model and shows the results obtained in terms of sour gas profiles predicted over a period of time. It then goes on to show in more detail how these results were linked into a process simulation model which was constructed to emulate both existing and future facilities configurations. The paper concludes by showing how the knowledge gained has allowed optimum decision making regarding the materials and equipment of the non-sour service facilities and the safety of operation. In addition, how this knowledge has been used for providing assurance and guidance for the planning of future production facilities.