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Geoscience ›› 2008, Vol. 22 ›› Issue (3): 457-464.

• Engineering Geology and Environmental Geology • Previous Articles     Next Articles

Experiment of Simulation Natural Gas Migration Accompanying  Hydrate Formation in Seepage System

GUAN Jin-an1,2,3,FAN Shuan-shi2,4,LIANG De-qing1,2,ZHOU Xi-tang1,2,3,WANG Wu-chang1,2,3   

  1. 1Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou,Guangdong 510640,  China;
    2Guangzhou Center for Gas Hydrate Research, Chinese Academy of Sciences, Guangzhou,Guangdong 510640, China;
    3Graduate University of the Chinese Academy of Sciences, Beijing 100049, China;
    4Key Laboratory of Enhanced Heat Transfer and Energy Conservation of Ministry of Education,South China University of Technology,  Guangzhou,Guangdong 510640, China
  • Received:2008-01-30 Revised:2008-04-12 Online:2008-03-20 Published:2008-03-20

Abstract:

Hydrate formation is a typical phenomenon of the interface transfer, and the nature of gas migration is the decisive factor for this transfer process. Some experiments have been done by simulating in-situ hydrate formation system by gas migrating in seepage system in a glass bubble cell. The phenomena in experiments indicate that gas migration can change the quality of mass and heat transfer of the interface between gas and liguid when hydrate is forming, and it’s a moving process of equilibrium curve. There will exist a “pseudo” buffer layer which has some distance of thickness in the interface between gas and liquid, and for gas migration, as long as gas reaches its saturation in solution in this buffer layer, the hydrate can form. The overburden stress in sediments capillary will gradually breed because of continuously hydrate formation in the course of gas migration, and will cause faults or fractures of the stratum matrix. Therefore,a new hydrate phase diagram must be built up in order to adapt the new characteristic of natural hydrate system brought by gas migration.

Key words: gas migration, mass and heat transfer, buffer layer, overburden stress, new hydrate phase diagram

CLC Number: