ENG  Vol.8 No.6 , June 2016
Gas Production from Offshore Methane Hydrate Layer and Seabed Subsidence by Depressurization Method
Abstract: Numerical simulations on consolidation effects have been carried out for gas production from offshore methane hydrates (MH) layers and subsidence at seafloor. MH dissociation is affected by not only MH equilibrium line but also consolidation (mechanical compaction) depended on depressurization in the MH reservoir. Firstly, to confirm present model on consolidation with effective stress, the history matching on gas production and consolidation has been done to the experimental results using with synthetic sand MH core presented by Sakamoto et al. (2009). In addition, the comparisons of numerical simulation results of present and Kurihara et al. (2009) were carried out to check applicability of present models for gas production from MH reservoir in field scale by depressurization method. The delays of pressure propagation in the MH reservoir and elapsed time at peak gas production rate were predicted by considering consolidation effects by depressurization method. Finally, seabed subsidence during gas production from MH reservoirs was numerically simulated. The maximum seabed subsidence has been predicted to be roughly 0.5 to 2 m after 50 days of gas production from MH reservoirs that elastic modulus is 400 to 100 MPa at MH saturation = 0.
Cite this paper: Matsuda, H. , Yamakawa, T. , Sugai, Y. and Sasaki, K. (2016) Gas Production from Offshore Methane Hydrate Layer and Seabed Subsidence by Depressurization Method. Engineering, 8, 353-364. doi: 10.4236/eng.2016.86033.

[1]   Fuji, T., Saeki, T., Kobayashi, T., Inamori, T., Hayashi, M., Takano, O., Takayama, T., Kawasaki, T., Nagakubo, S., Nakamizu, M. and Yokoi, K. (2008) Resource Assessment of Methane Hydrate in the Eastern Nankai Trough, Japan. Offshore Technology Conference, Paper Number OTC 19310.

[2]   Pooladi-Darvish, M. (2004) Gas Production from Hydrate Reservoirs and Its Modelling. Journal of Petroleum Technology (JPT), 56, 65-71.

[3]   Kurihara, M., Sato, A., Ouchi, H., Narita, H., Masuda, Y., Saeki, T. and Fuji, T. (2009) Prediction of Gas Productivity from Eastern Nankai Trough Methane-Hydrate Reservoirs. SPE Reservoir Evaluation and Engineering, 12, 477-499.

[4]   Yang, M., Fu, Z., Zhao, Y., Jiang, L., Zhao, J. and Song, Y. (2016) Effect of Depressurization Pressure on Methane Recovery from Hydrate-Gas-Water Bearing Sediments. Fuel, 166, 419-426.

[5]   Moridis, G.J., Pooladi-Darvish, M., Santamarina, J.C., Kneafsey, T.J., Rutqvist, J., Reagan, M.T., Sloan, E.D., Sum, A. and Koh, C. (2010) Challenges, Uncertainties and Issues Facing Gas Production from Hydrate Deposits in Geologic Systems. SPE Unconventional Gas Conference, Pittsburgh, 23-25 February 2010, SPE131792.

[6]   Sasaki, K., Sugai, Y. and Yamakawa, T. (2014) Integrated Thermal Gas Production from Methane Hydrate Formation. SPE/EAGE European Unconventional Resources Conference and Exhibition, Vienna, 25-27 February 2014, 1-9.

[7]   Sasaki, K., Ono, S., Sugai, Y., Ebinuma, T. and Narita, H. (2009) Gas Production System from Methane Hydrate Layers by Hot Water Injection Using Dual Horizontal Wells. Journal of Canadian Petroleum Technology, 48, 58-63.

[8]   Singh, P., Panda, M. and Sokes, J.P. (2008) Full Scale Reservoir Simulation Studies for the East Pool of the Barrow Gas Field and the Walakpa Gas Field-Petrotechnical Resources of Alaska. DOE Report, Project Number DE-FC26-06NT42962.

[9]   Sloan, E.D. (1998) Clathrate Hydrates of Natural Gases. 2nd Edition, Marcel Dekker, Inc., New York.

[10]   Sakamoto, Y., Shimogawara, M., Ohga, K., Kumamoto, K., Miyazaki, K., Tenma, N., Komai, T. and Yamaguchi, T. (2009) Numerical Study on Dissociation of Methane Hydrate and Gas Production Behavior in Laboratory Experiments for Depressurization: Pert3—Numerical Study on Estimation of Permeability in Methane Hydrate Reservoir. International Journal of Offshore and Polar Engineering, 19, 124-134.

[11]   Sakamoto, Y., Komai, T., Miyazaki, K., Tenma, N., Yamaguchi, T. and Zyvoloski, G. (2010) Laboratory-Scale Experiments of the Methane Hydrate Dissociation Process in a Porous Media and Numerical Study for the Estimation of Permeability in Methane Hydrate Reservoir. Journal of Thermodynamics, 2010, Article ID 452326.

[12]   Masui, A., Haneda, H., Ogata, Y. and Aoki, K. (2005) Effects of Methane Hydrate Formation on Shear Strength of Synthetic Methane Hydrate Sediments. ISOPE: Paper-I-05-056.

[13]   Miyazaki, K., Masui, A., Yamaguchi, T., Sakamoto, Y., Haneda, H., Ogata, Y. and Aoki, K. (2005) Strain-Rate Dependency of Peak and Residual Strength of Sediment Containing Synthetic Methane Hydrate in Triaxial Compression Test. ISOPE: Paper-I-09-344.

[14]   Aoki, K., Ogata, Y. and Esaki, T. (1991) On the Surface Subsidence in Natural Gas Fields. Proceedings of 7th ISRM Congress, Aachen, 16-20 September 1991, 134.

[15]   Nishida, T., Saeki, T., Aoki, K. and Kameda, N. (1981) On the Surface Subsidence in Natural Gas Fields. Proceedings of the International Symposium on Weak Rock, Tokyo, 21-24 September 1981, 701-705.

[16]   Kurihara, M., Sato, A., Funatsu, K., Ouchi, H., Narita, H. and Collet, T.S. (2011) Analysis of Formation Pressure Test Results in Mount Elbert Methane Hydrate Reservoir through Numerical Simulation. Marine and Petroleum Geology, 28, 502-516.

[17]   Yoneda, J. (2013) Prediction of Stress and Strain for the Seabed and Production Well during Methane Hydrate Exploitation in Turbidite Reservoir. Proceedings of the 18th International Conference on Soil Mechanics and Geotechnical Engineering, Paris, 2-6 September 2013, 861-864.