Modelling Approaches to Assess Biogenic Souring During Waterflooding and EOR Operations

Injection of water for pressure maintenance of reservoirs or injection of EOR solutions for enhanced oil recovery (EOR) may result in biogenic H2S production, which creates additional challenges in waterflood and EOR applications. In addition to serious health and safety concerns, this can cause significant production problems such as reduced quality of sales gas and crude, degraded productivity of wells, increased corrosion or enhanced scaling. Therefore, the realistic assessment of the magnitude of biogenic souring is of highest importance when it comes to project development to be able to mitigate and inhibit. However, physical and numerical estimation of the souring related parameters is highly unsatisfying in most of the cases due to significant uncertainties when making a deterministic assessment. The objective of the paper is to assess biogenic souring based on two different techniques using a commercial reservoir simulator as tool. Previous studies as well as the outcome of on-going field projects are used to develop the assessment concept and required input parameters. The results are provided as uncertainty analysis with their potential implications on field applications.