Attributes and behaviours of crude oils that naturally inhibit hydrate plug formation
Zachary Aman A , William G.T. Syddall B , Paul Pickering B , Michael Johns A and Eric F. May AA Fluid Science and Resources Division, The University of Western Australia.
B Woodside Energy.
The APPEA Journal 55(2) 416-416 https://doi.org/10.1071/AJ14051
Published: 2015
Abstract
The severe operating pressures and distances of deepwater tiebacks increase the risk of hydrate blockage during transient operations such as shut-in and restart. In many cases, complete hydrate avoidance through chemical management may be cost prohibitive, particularly late in a field’s life.
For a unique subclass of crude oils, however that have not been observed to form a hydrate blockage during restart, active hydrate prevention may be unnecessary.
In the past 20 years, limited information has been reported about the chemical or physical mechanisms that enable this particular non-plugging behaviour. This extended abstract demonstrates a systematic method of characterising this oil, including:
physical property analysis that includes and builds upon ASTM standards;
water-in-oil emulsion behaviour; and,
the effect of oil on hydrate blockage formation mechanics.
This last set of experiments uses a sapphire autoclave to allow direct observation of hydrate aggregation and deposition, combined with resistance-to-flow measurements. The effect of shut-ins and restarts on the oil’s plugging tendency is also studied in these experiments. The method was tested with several Australian crude oils, some of which exhibited non-plugging behaviour.
In general, these particular crude oils do not form stable water-in-oil emulsions but do form stable non-agglomerating hydrate-in-oil dispersions. The oils suppress hydrate formation rates and their resistance-to-flow does not increase significantly when the amount of hydrate present would normally form a plug.
Zachary M. Aman is an associate professor of mechanical and chemical engineering at the University of Western Australia. His research focuses on the management and prevention of gas hydrate and asphaitene blockages in subsea oil and gas pipelines, as well as the transport of oil through the water column during deepwater blowout. He holds a BSc and a PhD in chemical engineering from the Colorado School of Mines, with a research focus on the interfacial phenomena of cyclopentane hydrate at the school’s Center for Hydrate Research. Member: SPE, Australian Computer Society, the American Institute of Chemical Engineers and the Institution of Chemical Engineers. |
William G. T. Syddall is a senior flow assurance engineer at Woodside Energy Ltd. He is working as a flow assurance lead for a heavy oil development at Woodside Energy Ltd. He has had an interest in the rheology of dispersions for more than 14 years which started in the design and operation of two offshore heavy oil fields in Northern China. He holds a BSc in applied chemistry and an MEng in chemical engineering from Curtin University, Perth. |
Paul F. Pickering is a principal flow assurance engineer at Woodside Energy Ltd, where he works in the design of oil and gas production systems. He has worked with multiphase flow and modelling of fluid flow systems, most notably with the foundation of FEESA Ltd and the invention of the Maximus Integrated Production Modelling software. He holds an MEng and a PhD in chemical engineering from Imperial College, London, with a research focus on transient instabilities in multiphase flows. |
Michael L. Johns is the professor of chemical and process engineering at the University of Western Australia and is the chemical engineering discipline head. His research focuses primarily on the development and application of mobile magnetic resonance (MR) techniques with a particular focus on systems relevant to the oil and gas industry. He has previously developed and commercialised an MR method to characterise emulsions and the fouling of desalination module units. He has published more than 120 peer-reviewed publications. |
Eric F. May is the Chevron Chair in gas process engineering at the University of Western Australia (UWA). He has been conducting experimental research in fluid science for more than a decade and was awarded the Malcolm McIntosh Prize for Physical Scientist of the Year as part of the 2012 Prime Minister’s Prizes for Science. He teaches undergraduate and industry courses in thermodynamics and gas processing and has helped create a new chemical engineering degree at UWA. His research group works closely with industry and is conducting projects in LNG production, flow assurance, CO2 sequestration and fluid property prediction. |
References
Aman, Z.M., Akhfash, M., Johns, M., and May, E. (2014a). Methane hydrate bed formation in a visual autoclave: cold restart and Reynolds Number dependence. Journal of Chemical and Engineering Data 60, 409–17.Aman, Z.M., Brown, E.P., Sloan, E.D., Sum, A.K., and Koh, C.A. (2011). Interfacial mechanisms governing cyclopentane clathrate hydrate adhesion/cohesion. Physical Chemistry Chemical Physics 13, 19,796–806.
Aman, Z.M., Joshi, S.E., Sloan, E.D., Sum, A.K., and Koh, C.A. (2012). Micromechanical cohesion force measurements to determine cyclopentane hydrate interfacial properties. Journal of Colloid and Interface Science 376, 283–8.
Aman, Z.M., Olcott, K., Pfeiffer, K., Sloan, E.D., Sum, A.K., and Koh, C.A. (2013). Surfactant adsorption and interfacial tension investigations on cyclopentane hydrate. Langmuir 29, 2,676–82.
Aman, Z.M., Pfeiffer, K., Vogt, S.J., Johns, M.L., and May, E.F. (2014b). Corrosion inhibitor interaction at hydrate–oil interfaces from differential scanning calorimetry measurements. Colloids and Surfaces A: Physicochemical and Engineering Aspects 448, 81–7.
Barnes, B.C., Knott, B.C., Beckham, G.T., WU, D.T., and Sum, A.K. (2014). Reaction coordinate of incipient methane clathrate hydrate nucleation. Journal of Physical Chemistry B 118, 13,236–43.
Boxall, J.A., KOH, C.A., Sloan, E.D., Sum, A.K., and Wu, D.T. (2012). Droplet size scaling of water-in-oil emulsions under turbulent flow. Langmuir 28, 104–10.
Creek, J.L., Subramanian, S., and Estanga, D., 2011—New Method for Managing Hydrates in Deepwater Tiebacks. Society of Petroleum Engineers Offshore Technology Conference. Houston, Texas, 2–5 May.
Dieker, L.E., Aman, Z.M., George, N.C., Sum, A.K., Sloan, E.D., and Koh, C.A. (2009). Micromechanical adhesion force measurements between hydrate particles in hydrocarbon oils and their modifications. Energy and Fuels 23, 5,966–71.
Erstad, K., Hoiland, S., Fotland, P., and Barth, T. (2009). Influence of petroleum acids on gas hydrate wettability. Energy and Fuels 23, 2,213–9.
Grasso, G.A., Lafond, P.G., Aman, Z.M., Zerpa, L.E., Sloan, E.D., Koh, C.A., and Sum, A.K., 2014—Hydrate Formation Flowloop Experiments. 8th International Conference on Gas Hydrates, Beijing, China. July 28–August 1.
Johns, M.L. (2009). NMR studies of emulsion. Current Opinion in Colloid and Interface Science 14, 178–83.
Lafond, P.G., Gilmer, M.W., Koh, C.A., Sloan, E.D., Wu, D.T., and Sum, A.K. (2013). Orifice jamming of fluid-driven granular flow. Physical Review E 87, 1–8.
Rasband, W., 2013—ImageJ, National Institute of Health. Accessed 1 February 2013. <http://imagej.nih.gov/ij/>.
Sjoblom, J., ’Afvrevoll, B., Jentoft, G., Lesaint, C., Palermo, T., Sinquin, A., Gateau, L., Barre, L., Subramanian, S., Boxall, J., Davies, S., Dieker, L., Greaves, D., Lachance, J., Rensing, P., Miller, K., Sloan, E.D., and Koh, C.A. (2010). Investigation of the hydrate plugging and non-plugging properties of oils. Journal of Dispersion Science and Technology 31, 1,100–19.
Skiba, S., Aman, Z.M., Joshi, S., Sum, A.K., Sloan, E.D., and Koh, C.A., 2011—Measurements to Characterise the Plugability of Crude Oils. 7th International Conference on Gas Hydrates. Edinburgh, United Kingdom. 17–21 July.
Sloan, E.D., and Koh, C.A., 2007—Clathrate Hydrates of Natural Gases. Boca Raton, Florida: CRC Press, Taylor & Francis Group.
Sloan, E.D., Koh, C.A., and Sum, A.K., 2011—Natural Gas Hydrates in Flow Assurance. Houston: Gulf Professional Publishing, Elsevier Inc.
Taylor, C.J., Miller, K.T., Koh, C.A., and Sloan, E.D. (2007). Macroscopic investigation of hydrate film growth at the hydrocarbon/water interface. Chemical Engineering Science 62, 23,6524–33.
Turner, D., Miller, K., and Sloan, E. (2009). Methane hydrate formation and an inward growing shell model in water-in-oil dispersions. Chemical Engineering Science 64, 3,996–4004.
Walsh, M.R., Koh, C.A., Sloan, E.D., Sum, A.K., and Wu, D.T. (2009). Microsecond simulations of spontaneous methane hydrate nucleation and growth. Science 326, 1,095–8.
