The prediction of reservoir souring requires assessment of three key factors:

• Microbial generation of H 2S
• Transport and scavenging of microbially generated H 2S in the reservoir
• Partitioning of H 2S between the oil, gas and water phases.

Generic computer-based predictive models currently exist which, although based on the same fundamental principals, take different approaches to assessing the level of H 2S generation. Each model has its own strengths and weaknesses.

As a result of many years research and extensive experience of reservoir souring investigations throughout the world, CAPCIS has developed a model for reservoir souring that incorporates all of the key factors.

Our approach to reservoir souring studies is unique in that it combines the scientific knowledge to understand the causes and extent of souring with the engineering knowledge required to address the consequences of souring.

Through a combination of site surveys and fluid chemistry assessments with mathematical modelling, validated by specialised laboratory testing, we are able to provide field specific souring models. The consequences of souring can then be evaluated in terms of:

• Equipment and material risks
• Safety and environmental hazards
• Possible process modifications
• Reservoir management options, including nitrate injection

The economic impact of the different options.