Oil-reservoir and pipeline souring (H2S) control by nitrate injection (biocompetitive exclusion by nitrate-reducing bacteria) — instead of continuous biocide dosing
Glutaraldehyde, THPS (tetrakis(hydroxymethyl)phosphonium sulfate), quaternary ammonium biocides, acrolein and other biocides injected into water-flooded reservoirs, pipelines and produced-water systems
Water-flooded oil fields (Russia: West Siberia, Volga-Ural; North Sea, Canada, Middle East), produced-water re-injection, pipelines
Suppliers 1
| Yara | Norway | active |
Route into Russia / EAEU SERV
- Regulator
- — (operator: Rosprirodnadzor, Rostechnadzor)
- Typical time
- none for the service; operator permits (integrated environmental permit ~1 month)
- Legal basis
- No product registration; operators of category I facilities need an integrated environmental permit (Federal Law 7-FZ Art. 31.1) and, where relevant, Rostechnadzor licences
Information, not legal advice — confirm the procedure for your product.
Proof 4 claims
Continuous biocide dosing (e.g., glutaraldehyde, THPS).
Nitrate injection to control sulfate-reducing microorganisms and prevent biogenic H2S production.
- Displaced at scale?
- partly
- Caveats
- The evidence does not show a global or industry-wide displacement of biocides by nitrate injection; rather, it indicates that nitrate treatment is used on many installations in a variety of environmental conditions, with success and effects on corrosion varying considerably and appearing to be specific to operating conditions.
- Hand review
- D2 Field level: nitrate injection replaced glutaraldehyde at Veslefrikk and Gullfaks (North Sea, 1999).
- checked
- 2026-10-06
| Continuous injection of nitrate replaced glutaraldehyde as the corrosion and souring control method at the Veslefrikk and Gullfaks oil fields in the North Sea in 1999. “Continuous injection of a low nitrate concentration (0.25-0.33 mM) replaced glutaraldehyde as corrosion and souring control at the Veslefrikk and Gullfaks oil Weld (North Sea) in 1999.” North Sea · 1999 · large measured reduction of the old process | peer-reviewed ✓ exa.ai |
| At the Gullfaks field, a reduction in corrosion of up to 40% was observed after switching from biocide treatment to nitrate treatment. “At the Gullfaks Weld, a reduction in corrosion of up to 40% was observed after switch to nitrate treatment.” North Sea · 2008 · | peer-reviewed ✓ exa.ai |
| Field-wide nitrate injection in an Alberta oil field resulted in a 70% drop of aqueous sulphide within the first 5 weeks of treatment. “Field-wide nitrate injection gave a 70% drop of aqueous sulphide within the first 5 weeks, after which the concentration recovered somewhat for the next 20 weeks.” Alberta, Canada · 2009 · | peer-reviewed ✓ exa.ai |
| In one well pair in the Skjold field, nitrate injection achieved an 80% reduction in H2S production. “In one well pair with a short breakthrough time a reduction in H2S production of some 80 % was achieved.” Danish sector of the North Sea · 2002 · | peer-reviewed ✓ exa.ai |
References 3
- Gieg LM, Jack TR, Foght JM (2011). Biological souring and mitigation in oil reservoirs. *Applied Microbiology and Biotechnology* 92: 263–282. VERIFIED DOI · cited by 312
- Voordouw G, Grigoryan AA, Lambo A, et al. (2009). Sulfide remediation by pulsed injection of nitrate into a low temperature Canadian heavy oil reservoir. *Envir VERIFIED DOI · cited by 122
- Hubert C, Voordouw G (2007). Oil field souring control by nitrate-reducing *Sulfurospirillum* spp. that outcompete sulfate-reducing bacteria for organic electro VERIFIED DOI · cited by 277
Details
Replaces: continuous biocide dosing · Scope: oil production · Evidence: high
The chemical problem#
Seawater or produced-water injection feeds sulfate-reducing microorganisms (SRM) in reservoirs. They produce H₂S: “souring”, which is deadly to workers, corrodes pipes and lowers oil value. The standard countermeasure is continuous biocide dosing (glutaraldehyde, THPS). Biocides penetrate poorly into the reservoir, select tolerant microbes, and reach the sea in produced-water discharges.
Product overview#
Nitrate injection (calcium nitrate or sodium nitrate added to the injection water) stimulates nitrate-reducing bacteria (NRB) and nitrate-reducing sulfide-oxidizing bacteria (NR-SOB):
- NRB outcompete SRM for electron donors (organic acids, oil components).
- NR-SOB oxidize existing H₂S.
- Nitrite, an intermediate, inhibits the sulfate-reduction enzymes of SRM. Nitrate is used in the North Sea (e.g. Statoil/Equinor fields since the late 1990s), in Canadian heavy-oil fields, and in pipelines. It is a microbial-ecology solution, not a toxin.
Active ingredient / Composition#
Calcium nitrate or sodium nitrate (fertilizer-grade chemicals), sometimes with low doses of molybdate or perchlorate (partial).
Key facts#
| Parameter | Value |
|---|---|
| Class | Biocompetitive exclusion (microbial ecology management) |
| Dose | Typically tens to hundreds of mg/L nitrate in injection water (field-specific) |
| Effect | Large H₂S reductions in produced gas/water reported in field studies |
| Toxicity | Nitrate is far less toxic to aquatic life than biocides at use concentrations; manage the discharge |
Advantages#
- Reaches deep into the reservoir (nitrate is transported with the water), unlike biocides.
- Treats the cause (the microbial community) instead of killing everything.
- Lower toxicity in produced-water discharges.
Mode of action#
Changing the electron acceptor makes nitrate reduction energetically favourable, so NRB take over. NR-SOB remove sulfide, and nitrite inhibits dissimilatory sulfite reductase in SRM.
Application#
| System | Measure | Specifics |
|---|---|---|
| Seawater-flooded reservoirs | Continuous or batch nitrate injection from early flooding | Better as prevention than after heavy souring |
| Produced-water re-injection | Nitrate treatment | Monitor sulfide, nitrate, nitrite |
| Pipelines, tanks | Nitrate dosing (partial) | Corrosion monitoring (nitrite can affect corrosion in some cases) |
Limitations#
- Efficacy varies by reservoir (temperature, water chemistry); in some fields souring moves deeper into the reservoir.
- Nitrate discharge in produced water must be managed (eutrophication potential).
- Not a sterilant; some systems still need occasional biocide.
Evidence of displacement — D2: measurable displacement (minority share)#
Assessment (hand-reviewed): Field level: nitrate injection replaced glutaraldehyde at Veslefrikk and Gullfaks (North Sea, 1999).
Verified figures (the number is in the quoted sentence and the sentence is on the source page):
- displacement — Continuous injection of nitrate replaced glutaraldehyde as the corrosion and souring control method at the Veslefrikk and Gullfaks oil fields in the North Sea in 1999. (North Sea, 1999; peer-reviewed: exa.ai)
- performance — At the Gullfaks field, a reduction in corrosion of up to 40% was observed after switching from biocide treatment to nitrate treatment. (North Sea, 2008; peer-reviewed: exa.ai)
- performance — Field-wide nitrate injection in an Alberta oil field resulted in a 70% drop of aqueous sulphide within the first 5 weeks of treatment. (Alberta, Canada, 2009; peer-reviewed: exa.ai)
- performance — In one well pair in the Skjold field, nitrate injection achieved an 80% reduction in H2S production. (Danish sector of the North Sea, 2002; peer-reviewed: exa.ai)
Suppliers — real products and services (from the vendor index)#
Honest finding: the vendor index has no reservoir-souring (nitrate injection) service supplier. This is recorded as a supplier gap.
Companies below are active vendors in the vendor index whose own card (profile / official website) shows this product or service — matched 2026-10-05 by keyword and checked by hand against the card text. Being listed is not an endorsement; open each card for evidence, contacts and status.
Update 2026-10-05: the new Europe dataset supplies this product — rows marked Europe below. For the other regions the gap noted above still stands unless a row says otherwise.
| Company | Region · Country | What the index shows | Card |
|---|---|---|---|
| Yara | Europe · Norway | nitrate products for reservoir-souring control | card |
Government funding signals#
Public grants for a specific technology are a leading indicator: governments fund what regulators want to replace and what is close to practical adoption. Searched on 2026-09-27 in: EU CORDIS (FP7, Horizon 2020, Horizon Europe), US federal awards (USAspending: USDA NIFA/ARS/APHIS/Forest Service, EPA, DOE, NOAA, USAID; plus NSF and NIH), UK UKRI Gateway to Research, Australian Research Council. Each grant below was reviewed by hand for relevance. China, Brazil and India are covered in the subsection below (publication-acknowledged grants). Not covered: Russia (RSF, FASIE — not reachable from the research environment) and national agencies outside these databases. Amounts are the funder’s contribution as recorded (US NIH/UKRI: per award or fiscal year).
Signal: Weak. 2 relevant grant(s) · about €0.1M in total · jurisdictions: UK.
| Funder / programme | Project | Lead organisation | Start | Amount | Link |
|---|---|---|---|---|---|
| UKRI — Innovate UK | Hydrocarbon Reservoir Souring Control | (UK) | 2015 | 63,660 GBP | link |
| UKRI — EPSRC | Brimstone and Treacle: Understanding Oil-Driven Microbial Souring In Petroleum Reservoirs | School Of Natural And Environmental Sciences (UK) | 2018 | n/a | link |
China, Brazil, India — national research grants acknowledged in publications#
Chinese, Brazilian and Indian funders have no open grant databases reachable here, so this measures scientific papers published since 2015 that acknowledge national government grants, taken from the grant numbers publishers deposit with Crossref. Only papers whose title contains this article’s key terms are counted (a conservative lower bound; “100+” = search window full). It shows research-funding intensity, not budgets. Funders: China — NSFC, National Key R&D Program, China Agriculture Research System; Brazil — CNPq, CAPES, FAPESP, Embrapa, FAPEMIG; India — DBT, DST, ICAR, SERB, CSIR, BIRAC. Rating per country: Strong ≥50 papers · Moderate 10–49 · Weak 1–9.
| Country | Papers funded (2015–2026) | Signal | Main funders (grant acknowledgements) | Example grant → funded paper |
|---|---|---|---|---|
| China | 4 | Weak | NSFC (5) | NSFC 42473082 → A new control strategy of sulfate-reducing microorganisms and corrosion rate from a high-temperature oil… (2025) doi |
| Brazil | 1 | Weak | CAPES (1), CNPq (1) | – |
| India | 2 | Weak | SERB (1), DST (1) | SERB IMP/2018/000589 → Control of reservoir souring by incomplete nitrate reduction in Indian oil fields (2023) doi |
Scientific evidence#
- Gieg LM, Jack TR, Foght JM (2011). Biological souring and mitigation in oil reservoirs. Applied Microbiology and Biotechnology 92: 263–282.
- Voordouw G, Grigoryan AA, Lambo A, et al. (2009). Sulfide remediation by pulsed injection of nitrate into a low temperature Canadian heavy oil reservoir. Environmental Science & Technology 43: 9512–9518.
- Hubert C, Voordouw G (2007). Oil field souring control by nitrate-reducing Sulfurospirillum spp. that outcompete sulfate-reducing bacteria for organic electron donors. Applied and Environmental Microbiology 73: 2644–2652.
Bioeconomy value#
Steering reservoir microbiology replaces toxic biocides: an applied microbial-ecology technology for Russia’s oil industry.