Certus SRB

SRB in oil and gas production

Sulfate-reducing bacteria (SRB) drive a significant share of corrosion damage in oilfield, industrial, and aging municipal water systems. The challenge has never been knowing that SRB causes problems. The challenge has been detecting it fast enough to act.

SRB are found from reservoir to refinery. They cause:

Reservoir souring
Production of hydrogen sulfide (H₂S), which is highly toxic
Microbiologically influenced corrosion (MIC) of piping and equipment

The traditional API RP 38 serial dilution method takes 7-28 days because it relies on bacterial reproduction in growth media. You wait for colonies to multiply enough to register as a positive. Other culture-based field kits take around 8 days for the same reason. qPCR runs faster but detects DNA, including from non-viable organisms, which produces well-documented false positives that drive unncessary biocide treatment.

Retego Certus SRB works differently. The cuvette chemistry detects SRB metabolic activity directly and returns a quantitative result in 1 to 24 hours. A two-part assay confirms both the SRB enzyme and the H₂S it produces, which reduces the false positives that affect culture methods. No 28-day wait while the colony doubles. No lab. No shipping.

Contents

Field Case with Tray
Sterile Transfer Pipettes
Disposable Gloves
Comparator Light Box
SRB Control Cuvette
H₂S Control Cuvette
White Cuvette Holder
Test Instructions
SRB Sample Cuvettes
H₂S Sample Cuvettes

Click here to watch a video on how to conduct the Certus SRB test

Method	Time to Result	Location	Key drawback
Retego Certus™ SRB	1–24 hours	Field	SRB-specific; does not detect acid-producing bacteria.
API serial dilution	Weeks	Lab	Too slow to inform treatment
ATP	Minutes	Field	Measures total microbial activity, not SRB specifically
qPCR	Hours	Lab	Documented false positives

FAQ

How are SRB quantified?

SRB concentration is determined by the time it takes the SRB test to exceed the fluorescence intensity and color of a comparator. A positive result for H₂S test is also required to confirm the presence of H₂S. The tests are observed at 1, 4, 8 and 24 hours, with the concentration of SRBs estimated by the time taken for the SRB test sample to change color as follows:

0-1 hour≥ 1,000,000 CFU/ml
4 hours ≈ 100,000 CFU/ml
8 hours ≈ 10,000 CFU/ml
24 hours ≈ 1,000 CFU/ml

How long should the test take?

The test should run between 1 and 24 hours. If the test cuvettes have not turned color after 24 hours, then any SRB present are below the limit of detection of the test.

What type of SRB does the method detect?

The method will detect SRBs that utilize either sulfate (including desulfovibrio) or thiosulfate and ultimately produce H₂S.

Does the test detect other bacteria or archaea?

The SRB component of the test can detect other bacteria and archaea (although much more slowly) since the enzyme substrate used may react with other enzymes. However, this happens if the test is left for more than 24 hours, which is why the samples are only observed for 24 hours.

Does the method only detect living SRB?

The method preferentially detects living SRBs, with this effect being more pronounced at lower SRB concentrations.

For a positive SRB result, do both the H₂S and SRB test need to be positive?

Yes, both the SRB and H₂S tests are required to be positive for the method to definitively predict the presence of SRBs.

How frequently do you need to observe the sample?

The samples should be observed as frequently as practicably possible. Ideally, the samples should be inspected at 1, 4, 8 and 24 hours.

What is included in Retego Certus SRB?

Retego Certus SRB contains everything needed to analyze 20 water samples for SRB. The kit contents are itemized above. Additional SRB and H₂S test cuvettes are available separately, all tests are packaged in sets of 10.

Where has the SRB test been used to date?

The SRB test has been used to analyze water from potable water supplies in domestic, industrial and commercial facilities in the USA. The method has been used to analyze oilfield waters throughout the Texas oilfields, Alaska, Egypt, Ecuador and Oman.

Is the SRB test included in any recognized standard including AMPP or ASTM?

We are currently pursuing approvals

What is the weight of the kit?

Shipping weight is 6.5 pounds or 3 kilograms

Retego Certus^™ SRB

SRB results in
1–24 hours.
Not weeks.

All the specs

SRB in oil and gas production

FAQ

Stop waiting weeks for an answer that should have arrived yesterday.

Water is universal, so is corrosion.

Retego Certus™ SRB

SRB results in 1–24 hours. Not weeks.

All the specs

SRB in oil and gas production

FAQ

Stop waiting weeks for an answer that should have arrived yesterday.

Water is universal, so is corrosion.

Retego Certus^™ SRB

SRB results in
1–24 hours.
Not weeks.