Inhibition of methane hydrate re-formation in offshore pipelines with a kinetic hydrate inhibitor
Methane gas from marine hydrate deposits can be produced by one or a combination of three methods; depressurization, thermal stimulation, and the injection of hydrate inhibitors. Because residual hydrate structures known as hydrate precursors will exist in the liquid water phase after dissociation,...
Published in: | Journal of Petroleum Science and Engineering |
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Language: | English |
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Online Access: | http://hdl.handle.net/10203/104305 https://doi.org/10.1016/j.petrol.2011.11.001 |
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ftkoasas:oai:koasas.kaist.ac.kr:10203/104305 2023-05-15T17:11:45+02:00 Inhibition of methane hydrate re-formation in offshore pipelines with a kinetic hydrate inhibitor Seo, Y Seo, Yutaek Kang, SP Kang, Seong-Pil 201206 http://hdl.handle.net/10203/104305 https://doi.org/10.1016/j.petrol.2011.11.001 ENG eng ELSEVIER SCIENCE BV ARTICLE A 2012 ftkoasas https://doi.org/10.1016/j.petrol.2011.11.001 2015-04-16T23:52:55Z Methane gas from marine hydrate deposits can be produced by one or a combination of three methods; depressurization, thermal stimulation, and the injection of hydrate inhibitors. Because residual hydrate structures known as hydrate precursors will exist in the liquid water phase after dissociation, the risk of methane hydrate re-formation has to be evaluated during the production and transportation of methane gas through offshore pipelines. New experimental procedures composed of three stages are designed to simulate the dissociation of marine hydrates and the transportation of produced fluids. The obtained experimental results have shown that methane hydrates are rapidly re-formed when the temperature of dissociated water falls into the hydrate formation region during the cooling down process. The subcooling for three different dissociation pressures of 80, 70, and 60 bar were 1.3, 1.2 and 1.6 degrees C, respectively. One viable option to avoid hydrate re-formation is injecting hydrate inhibitors before transporting the fluids through pipelines. Among various hydrate inhibitors, Poly(N-vinylcaprolactam) (PVCap) was selected as a possible candidate for a Kinetic Hydrate Inhibitor (KHI) and injected into dissociated water before cooling down the fluids. The concentration of PVCap was varied from 0.5 to 3.0 wt.%. With an increase in the PVCap concentration, the subcooling increased to 7.8 degrees C at a dissociation pressure of 80 bar, which suggests that the risk of hydrate re-formation can be reduced by injecting PVCap. Moreover it is observed that the subcooling increased to 8.8 degrees C at the PVCap concentration of 3.0 wt.% in the presence of NaCl in the water phase. Although the use of KHI in conventional gas production has become common, its applicability to methane hydrate production has not yet been studied thoroughly, especially in the presence of residual hydrate structures. In this work, the application of KHI to methane hydrate production is discussed. (c) 2011 Elsevier B.V. All rights reserved. Article in Journal/Newspaper Methane hydrate Korea Advanced Institute of Science and Technology: KOASAS - KAIST Open Access Self-Archiving System Journal of Petroleum Science and Engineering 88-89 61 66 |
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Open Polar |
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Korea Advanced Institute of Science and Technology: KOASAS - KAIST Open Access Self-Archiving System |
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ftkoasas |
language |
English |
description |
Methane gas from marine hydrate deposits can be produced by one or a combination of three methods; depressurization, thermal stimulation, and the injection of hydrate inhibitors. Because residual hydrate structures known as hydrate precursors will exist in the liquid water phase after dissociation, the risk of methane hydrate re-formation has to be evaluated during the production and transportation of methane gas through offshore pipelines. New experimental procedures composed of three stages are designed to simulate the dissociation of marine hydrates and the transportation of produced fluids. The obtained experimental results have shown that methane hydrates are rapidly re-formed when the temperature of dissociated water falls into the hydrate formation region during the cooling down process. The subcooling for three different dissociation pressures of 80, 70, and 60 bar were 1.3, 1.2 and 1.6 degrees C, respectively. One viable option to avoid hydrate re-formation is injecting hydrate inhibitors before transporting the fluids through pipelines. Among various hydrate inhibitors, Poly(N-vinylcaprolactam) (PVCap) was selected as a possible candidate for a Kinetic Hydrate Inhibitor (KHI) and injected into dissociated water before cooling down the fluids. The concentration of PVCap was varied from 0.5 to 3.0 wt.%. With an increase in the PVCap concentration, the subcooling increased to 7.8 degrees C at a dissociation pressure of 80 bar, which suggests that the risk of hydrate re-formation can be reduced by injecting PVCap. Moreover it is observed that the subcooling increased to 8.8 degrees C at the PVCap concentration of 3.0 wt.% in the presence of NaCl in the water phase. Although the use of KHI in conventional gas production has become common, its applicability to methane hydrate production has not yet been studied thoroughly, especially in the presence of residual hydrate structures. In this work, the application of KHI to methane hydrate production is discussed. (c) 2011 Elsevier B.V. All rights reserved. |
format |
Article in Journal/Newspaper |
author |
Seo, Y Seo, Yutaek Kang, SP Kang, Seong-Pil |
spellingShingle |
Seo, Y Seo, Yutaek Kang, SP Kang, Seong-Pil Inhibition of methane hydrate re-formation in offshore pipelines with a kinetic hydrate inhibitor |
author_facet |
Seo, Y Seo, Yutaek Kang, SP Kang, Seong-Pil |
author_sort |
Seo, Y Seo, Yutaek |
title |
Inhibition of methane hydrate re-formation in offshore pipelines with a kinetic hydrate inhibitor |
title_short |
Inhibition of methane hydrate re-formation in offshore pipelines with a kinetic hydrate inhibitor |
title_full |
Inhibition of methane hydrate re-formation in offshore pipelines with a kinetic hydrate inhibitor |
title_fullStr |
Inhibition of methane hydrate re-formation in offshore pipelines with a kinetic hydrate inhibitor |
title_full_unstemmed |
Inhibition of methane hydrate re-formation in offshore pipelines with a kinetic hydrate inhibitor |
title_sort |
inhibition of methane hydrate re-formation in offshore pipelines with a kinetic hydrate inhibitor |
publisher |
ELSEVIER SCIENCE BV |
publishDate |
2012 |
url |
http://hdl.handle.net/10203/104305 https://doi.org/10.1016/j.petrol.2011.11.001 |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_doi |
https://doi.org/10.1016/j.petrol.2011.11.001 |
container_title |
Journal of Petroleum Science and Engineering |
container_volume |
88-89 |
container_start_page |
61 |
op_container_end_page |
66 |
_version_ |
1766068510004346880 |