A Novel Technique for Monitoring Hydrate Safety Margin
- Jinhai Yang (Heriot-Watt University) | Antonin Chapoy (Heriot-Watt University) | Saeid Mazloum (Heriot-Watt University) | Bahman Tohidi (Heriot-Watt University)
- Document ID
- Society of Petroleum Engineers
- SPE Production & Operations
- Publication Date
- November 2012
- Document Type
- Journal Paper
- 376 - 381
- 2012. Society of Petroleum Engineers
- 4.1.5 Processing Equipment, 4.1.2 Separation and Treating, 4.2 Pipelines, Flowlines and Risers, 4.3.1 Hydrates
- 0 in the last 30 days
- 472 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 5.00|
|SPE Non-Member Price:||USD 35.00|
A novel technique has been developed for optimizing hydrate-inhibitor dose rates by monitoring the actual hydrate safety margin. The technique is based on measuring acoustic velocity and electrical conductivity in an aqueous sample taken from the pipeline/separator. The developed system then determines salt and organic inhibitor concentration (e.g., methanol, monoethylene glycol, and kinetic hydrate inhibitors). In the case of thermodynamic inhibitors, the information is then fed to a thermodynamic model determining the hydrate stability zone (HSZ). Superimposing the pipeline operating conditions (e.g., pressure and temperature profile), the developed system can determine the hydrate safety margin. The system can provide warning if the operating conditions are inside the HSZ or if too much inhibitor is being injected.
The technique can be used in optimizing inhibitor-injection rates, reducing the impact on the environment and operational costs. It can also improve production-system reliability by constant monitoring the hydrate safety margin and protecting the system against pump malfunction and/or changes in process variables (e.g., water cut).
This technique has been developed through a joint-industry project, and its performance has been intensively evaluated using synthetic samples and real produced-water samples by the authors and the project sponsors in field trials. The results demonstrate that this system can be used for different inhibitor systems, including methanol (MeOH)/NaCl, monoethylene glycol (MEG)/NaCl, and kinetic-hydrate-inhibitor/salt systems, with good accuracy.
The developed system can have a major impact on reducing the inhibitor-injection rates and environmental impact and improving the reliability of production systems against risks associated with hydrate formation. The developed system can be laboratory-based, a mobile unit, or online, with near-real-time samples taken from live pipelines/separators.
|File Size||467 KB||Number of Pages||6|
Argo, C.B., Blain, R.A., Osborne, C.G.,and Priestley, I.D. 2000. Commercial Deployment of Low-Dosage HydrateInhibitors in a Southern North Sea 69 km Wet-Gas Subsea Pipeline. SPE Prod& Oper 15 (2): 130-134. SPE-63017-PA. http://dx.doi.org/10.2118/63017-PA.
Barker, J.W. and Gomez, R.K. 1989. Formation of Hydrates During DeepwaterDrilling Operations. J Pet Technol 41 (3): 297-301.SPE-16130-PA. http://dx.doi.org/10.2118/16130-PA.
Broten, G.S. and Wood, H.C. 1993. A neural network approach to analysingmulti-component mixtures. Meas. Sci. Technol. 4 (10):1096-1105. http://dx.doi.org/10.1088/0957-0233/4/10/012.
Brustad, S., Løken, K.-P., and Waalmann, J.G. 2005. Hydrate Prevention usingMEG instead of MeOH: Impact of experience from major Norwegian developments ontechnology selection for injection and recovery of MEG. Paper OTC 17355presented at the Offshore Technology Conference, Houston, 2-5 May. http://dx.doi.org/10.4043/17355-MS.
Clay, C.S. and Medwin, H. 1977. Acoustic Oceanography: Principles andApplication. New York: Ocean Engineering, John Wiley & Sons.
Cowie, L., Bollavaram, P., Erdogmus, M., Johnson, T., and Shero, W. 2005.Optimal Hydrate Management and New Challenges in GoM Deepwater Using "Best inClass" Technologies. Paper OTC 17328 presented at the Offshore TechnologyConference, Houston, 2-5 May. http://dx.doi.org/10.4043/17328-MS.
Fu, B., Neff, S., Mathur, A., and Bakeev, K. 2002. Application of Low-DosageHydrate Inhibitors in Deepwater Operations. SPE Prod & Oper 17 (3): 133-137. SPE-78823-PA. http://dx.doi.org/10.2118/78823-PA.
Henning, B., Daur, P.-C., Prange, S., Dierks, K., and Hauptmann, P. 2000.In-line concentration measurement in complex liquids using ultrasonic sensors.Ultrasonics 38 (1-8): 799-803. http://dx.doi.org/10.1016/s0041-624x(99)00190-0.
Kelland, M.A. 2006. History of the Development of Low Dosage HydrateInhibitors. Energy Fuels 20 (3): 825-847. http://dx.doi.org/10.1021/ef050427x.
Lavallie, O., Al Ansari, A., O'Neill, S., Chazelas, O., Glenat, P., andTohidi, B. 2009. Successful Field Application of an Inhibitor ConcentrationDetection System in Optimising the Kinetic Hydrate Inhibitor (KHI) InjectionRates and Reducing the Risks Associated with Hydrate Blockage. Paper SPE 13765presented at the International Petroleum Technology Conference, Doha, Qatar,7-9 December. http://dx.doi.org/10.2523/13765-MS.
Lederhos, J.P., Long, J.P., Sum, A., Christiansen, R.L., and Sloan, E.D. Jr.1996. Effective kinetic inhibitors for natural gas hydrates. Chem. Eng.Sci. 51 (8): 1221-1229. http://dx.doi.org/10.1016/0009-2509(95)00370-3.
Mitchell, G.F. and Talley, L.D. 1999. Application of Kinetic HydrateInhibitor in Black-Oil Flowlines. Paper SPE 56770 presented at the SPE AnnualTechnical Conference and Exhibition, Houston, 3-6 October. http://dx.doi.org/10.2118/56770-MS.
Notz, P.K., Bumgardner, S.B., Schaneman, B.D., and Todd, J.L. 1996.Application of Kinetic Inhibitors to Gas Hydrate Problems. SPE Prod &Oper 11 (4): 256-260. SPE-30913-PA. http://dx.doi.org/10.2118/30913-PA.
Sloan, E.D. Jr. 2000. Hydrate Engineering, No. 21. Richardson, Texas:Monograph Series, SPE.
Sloan, E.D. Jr. 2008. Clathrate Hydrates of Natural Gases, thirdedition. Boca Raton, Florida: CRC Press.
Sundgren, H., Winquist, F., Lukkari, I., and Lundstrom, I. 1991. Artificialneural networks and gas sensor arrays: quantification of individual componentsin a gas mixture. Meas. Sci. Technol. 2 (5): 464-469. http://dx.doi.org/10.1088/0957-0233/2/5/008.
Tohidi, B., Chapoy, A., and Yang, J. 2009. Developing a Hydrate-MonitoringSystem. SPE Proj Fac & Const 4 (1): 1-6. SPE-125130-PA.http://dx.doi.org/10.2118/125130-PA.
Tohidi, B., Danesh, A., Burgass, R.W., and Todd, A.C. 1996. Measurement andPrediction of Hydrate-Phase Equilibria for Reservoir Fluids. SPE Prod &Oper 11 (2): 69-76. SPE-28884-PA. http://dx.doi.org/10.2118/28884-PA.
Willmon, J.G. and Edwards, M.A. 2006. From Precommissioning to Startup:Getting Chemical Injection Right. SPE Prod & Oper 21(4): 483-491. SPE-96144-PA. http://dx.doi.org/10.2118/96144-PA.