Hydrate Formation: Considering the effects of Pressure, Temperature, Composition and Water

Jerome Rajnauth, Maria Barrufet, Gioia Falcone

Abstract


The main components in producing natural gas hydrate (whether for gas storage or for transportation), are water and natural gas, at low temperatures and high pressures. Each variable has a significant effect on the formation of gas hydrate. It is therefore critical to analyze the effect of each variable on hydrate formation to ascertain the best conditions required for a successful gas hydrate formation process.
This research evaluates the effect of these critical elements: temperature, pressure, gas composition, and water upon gas hydrate formation. This paper summarizes the findings of a sensitivity analysis using varying natural gas compositions. Results show that the composition of the natural gas can affect the temperature and pressure required for formation of the hydrate. Even more significant is the effect of impurities in the natural gas on the pressure temperature (PT) curves of the hydrate. Carbon dioxide, hydrogen sulfide and nitrogen are the main impurities in natural gas affecting the hydrate formation. At a particular temperature, nitrogen increases the required hydrate formation pressure while both carbon dioxide and hydrogen sulfide lower the required hydrate formation pressure.
The quantity of water required for hydrate formation is an important variable in the process. The water to gas ratio vary depending on the composition of the natural gas and the pressure. Generally the mole ratio of water to natural gas is about 6:1; however, to achieve maximum hydrate formation an incremental increase in water or pressure may be required. This is an interesting trade-off between additional water and additional pressure in obtaining maximum volume of hydrate and is shown in this analysis.

Key words: Hydrate formation; Temperature; Pressure; Gas composition; Water


Keywords


Hydrate formation; Temperature; Pressure; Gas composition; Water

Full Text:

PDF

References


[1] Ministry of Energy and Energy, Trinidad (2007). Resource Management Report.

[2] Calsep (2008). PVTSim Software (18th ed.).

[3] Masoudi, R., & Tohidi, B. (2005). Gas Hydrate Production Technology for Natural Gas Storage and Transportation and CO2 Sequestration. In Proceedings of the SPE Middle East Oil & Gas Show and Conference, Bahrain, 12-15 March 2005.

[4] Gudmundsson, J., Andersson, V., Levik, O., & Parlaktuna, M.H. (1998). Concept for Capturing Associated Gas. In Proceedings of the SPE European Petroleum Conference held in Hague, Netherlands, 20-22 October 1998.

[5] Gudmundsson, J., Parlaktuna, M., & Khokhar, A.A. (1994). Storing Natural Gas as a Frozen Hydrate. SPE Production & Facilities, 9(1), 69-73.

[6] Makogon, Y., & Holditch, S. (2002). Gas Hydrate as a Resource and a Mechanism for Transmission. In Proceedings of the SPE Annual Technical Conference and Exhibition, San Antonio, Texas, 29 September-2 October 2002.

[7] Makogon, Y. (1981). Hydrates of Natural Gas. Tulsa: Penn Well Pub. Co.

[8] Makogon, Y. (1997). Hydrates of Hydrocarbon. Tulsa: Penn Well Pub. Co.

[9] Sloan, E.D. (1997). Clathrate Hydrate of Natural Gas. New York: Marcel Dekker.

[10] Okutani, K., Kuwabara, Y., & Mori, Y. (2008). Surfactant Effects on Hydrate Formation in an Unstirred Gas/Liquid System: An Experimental Study Using Methane and Sodium Alkyl Sulfates. Chemical Engineering Science, 63, 183-194.




DOI: http://dx.doi.org/10.3968%2Fj.est.1923847920120401.397

Refbacks

  • There are currently no refbacks.


Reminder

If you have already registered in Journal A and plan to submit article(s) to Journal B, please click the CATEGORIES, or JOURNALS A-Z on the right side of the "HOME".


We only use three mailboxes as follows to deal with issues about paper acceptance, payment and submission of electronic versions of our journals to databases: caooc@hotmail.com; est@cscanada.net; est@cscanada.org

Copyright © 2010 Canadian Research & Development Centre of Sciences and Cultures
Address: 730, 77e AV, Laval, Quebec, H7V 4A8, Canada

Telephone: 1-514-558 6138
Http://www.cscanada.net Http://www.cscanada.org

E-mail: est@cscanada.net est@cscanada.org