Oxygen-Controlled Dynamic Evaluation of CaCO3 Scale Inhibitors in Iron-Containing Brines
- 1Universidade Federal do Rio de Janeiro , , ,
- 2Shell Brasil Petroleo LTDA , , ,
Abstract
Scale inhibitors are widely used to control inorganic deposition in oil and gas production, but their laboratory evaluation is often performed under aerated conditions that may not adequately represent iron-containing brines. In this study, a modified Tube Block Test methodology was developed for dynamic scale-inhibition testing under controlled dissolved-oxygen conditions. Brines were prepared and transferred under a controlled atmosphere, and dissolved O2 concentrations ranging from 8500 to <10 μg/L were evaluated at 65 and 120 °C in tests lasting up to 6 h. A commercially available phosphonate-based inhibitor was used as an industry-qualified benchmark. The results indicated that dissolved oxygen strongly affected precipitation behavior and apparent inhibitor performance. At 65 °C under aerated conditions, the presence of iron substantially accelerated capillary blockage, whereas negligible differential-pressure variation was observed in the corresponding iron-free control. At 120 °C, rapid blockage also occurred in the iron-free control, consistent with an increased contribution from CaCO3 deposition. Reducing dissolved O2 to <10 μg/L delayed blockage in iron-containing brines and improved the apparent performance of the commercial inhibitor. Under oxygen-controlled conditions, the inhibitor at 250 mg/L maintained the differential-pressure increase below 1 psi throughout the 6 h test. These findings show that dissolved-oxygen control is essential for distinguishing iron-related interference from carbonate-scaling behavior during dynamic inhibitor qualification. The proposed methodology provides a reproducible approach for extended-duration evaluation of scale inhibitors in iron-containing brines under field-relevant operating conditions.
Related
- Synthesis, Biological Evaluation, and Molecular Docking of Pyridine-Containing Squaramides as DNase I Inhibitors
- New thiazole/coumarin hybrids as EGFR inhibitors with potential VEGFR-2 inhibition (design, synthesis, biological evaluation, and dynamic stimulation).
- Enantioselective sp3-sp3 cross-coupling of oxygen-containing heterocycles with cyclopropanols
- Oxygen-responsive high-efficiency orange-red room-temperature phosphorescence from chalcogen-containing dibenzo[a,c]phenazine foldamers
- Stereochemical 2D NMR Assignment of Thietane, Synthesis and Antiplatelet Activity of Novel Thietane-Containing 1-Isobutylpurine-2,6-dione Derivatives as Potential GPIIb/IIIa Inhibitors
BibTeX
@article{barros2026oxygencontrolled,
title = {{Oxygen-Controlled Dynamic Evaluation of CaCO3 Scale Inhibitors in Iron-Containing Brines}},
author = {Hugo N. S. Barros and Kaio A. B. Pereira and Matheus V. Oliveira and Aghata P. Felipe and Amaro L. G. O. A. Machado and Gustavo B. Silva and Juliana M. F. Façanha and Luiz C. M. Palermo and Claudia R. E. Mansur},
journal = {ACS omega},
year = {2026},
month = oct,
doi = {10.1021/acsomega.6c08998},
url = {https://europepmc.org/article/PMC/PMC13670308},
note = {CC BY},
}
RIS
TY - JOUR
TI - Oxygen-Controlled Dynamic Evaluation of CaCO3 Scale Inhibitors in Iron-Containing Brines
AU - Hugo N. S. Barros
AU - Kaio A. B. Pereira
AU - Matheus V. Oliveira
AU - Aghata P. Felipe
AU - Amaro L. G. O. A. Machado
AU - Gustavo B. Silva
AU - Juliana M. F. Façanha
AU - Luiz C. M. Palermo
AU - Claudia R. E. Mansur
PY - 2026
DA - 2026/10/01
JO - ACS omega
DO - 10.1021/acsomega.6c08998
UR - https://europepmc.org/article/PMC/PMC13670308
AB - Scale inhibitors are widely used to control inorganic deposition in oil and gas production, but their laboratory evaluation is often performed under aerated conditions that may not adequately represent iron-containing brines. In this study, a modified Tube Block Test methodology was developed for dynamic scale-inhibition testing under controlled dissolved-oxygen conditions. Brines were prepared and transferred under a controlled atmosphere, and dissolved O2 concentrations ranging from 8500 to <10 μg/L were evaluated at 65 and 120 °C in tests lasting up to 6 h. A commercially available phosphonate-based inhibitor was used as an industry-qualified benchmark. The results indicated that dissolved oxygen strongly affected precipitation behavior and apparent inhibitor performance. At 65 °C under aerated conditions, the presence of iron substantially accelerated capillary blockage, whereas negligible differential-pressure variation was observed in the corresponding iron-free control. At 120 °C, rapid blockage also occurred in the iron-free control, consistent with an increased contribution from CaCO3 deposition. Reducing dissolved O2 to <10 μg/L delayed blockage in iron-containing brines and improved the apparent performance of the commercial inhibitor. Under oxygen-controlled conditions, the inhibitor at 250 mg/L maintained the differential-pressure increase below 1 psi throughout the 6 h test. These findings show that dissolved-oxygen control is essential for distinguishing iron-related interference from carbonate-scaling behavior during dynamic inhibitor qualification. The proposed methodology provides a reproducible approach for extended-duration evaluation of scale inhibitors in iron-containing brines under field-relevant operating conditions.
SN - 2470-1343
ER -