Reservoir Souring Control: Safeguarding Asset Integrity and Operational Safety

Reservoir souring is a silent yet significant threat to oil and gas production. The increase of hydrogen sulfide (H₂S) levels in a reservoir over time, often caused by sulfate-reducing bacteria (SRB)—can severely compromise asset integrity, reduce well productivity, and expose operations to serious safety and environmental risks.

At Evasil Engineering Limited , we provide industry-leading Reservoir Souring Control solutions that combine deep microbiology expertise with real-world oilfield experience.

Our mission is clear: to help operators predict, prevent, and mitigate H₂S formation, before it becomes a problem.

The Problem with H₂S

Hydrogen sulfide is more than a nuisance gas. It is:

• Toxic to personnel and dangerous at very low concentrations,

• Corrosive to infrastructure, leading to equipment failure and expensive repairs,

• Reactive with production fluids, causing scale and emulsion issues,

• And regulatory-sensitive, leading to environmental and compliance complications.

Reservoir souring typically occurs when sulfate-containing seawater is injected into the reservoir, creating an environment for SRB activity. As these bacteria metabolize sulfate, they produce H₂S as a by-product. Without intervention, this gas spreads through the formation and surfaces through the production stream, raising safety, integrity, and economic concerns.

Our Solution: Scientific, Strategic, Scalable

Evasil takes a multi-disciplinary approach to souring control. We begin with predictive modelling of souring potential, using both microbiological and geochemical data. This helps our clients understand when and where souring is likely to occur.

From there, we design a targeted intervention strategy, which may include:

• Biocide selection and optimization to suppress SRB populations without harming beneficial microbes,

• Reservoir cooling and nutrient control to reduce SRB activity,

• Tracer studies and microbial sampling to track H₂S migration,

• And electrochemical solutions, such as chlorine dioxide generation for high-efficiency bacterial kill.

We also deploy onsite microbiology health-checks, bringing our mobile laboratory and expert team directly to the field. This allows for real-time identification, sequencing, and quantification of microbial colonies, enabling fast decision-making.