JpGU-AGU Joint Meeting 2017

Presentation information

[JJ] Poster

M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS16] [JJ] Gas hydrates in environmental-resource sciences

Mon. May 22, 2017 3:30 PM - 5:00 PM Poster Hall (International Exhibition Hall HALL7)

convener:Hitoshi Tomaru(Department of Earth Sciences, Chiba University), Akihiro Hachikubo(Environmental and Energy Resources Research Center, Kitami Institute of Technology), Sumito Morita(Institute for Geo-Resources and Environment, Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology), Atsushi Tani(Graduate School of Human Development and Environment, Kobe University)

[MIS16-P04] Gas hydrate dissociation behavior from temperature monitoring data

*Koji Yamamoto1, Xiaoxing Wang2, Takayuki Kanno2, Xiaowei Wang3 (1.Japan Oil, Gas, and Metals National Corporation, 2.Schlumberger K. K., 3.Baker Hughes Inc.)

Keywords:Gas hydrate, Thermal behavior, Depressurization, Downhole measurement

Because the gas hydrate dissociation is an endothermic process, temperature measurement is an important way to know the response of gas hydrate reservoir to the application of some gas production techniques. Furthermore, a heat source, and how efficiently the heat is supplied form the formation are critical knowledge to evaluate effectiveness of the depressurization method as a practical gas production technique that depends on natural heat supply from formations.

The program of the 2013 first offshore production test of methane hydrate in the Eastern Nankai Trough included temperature monitoring in the production hole (AT1-P) and monitoring holes (AT1-MT1/MC). In all wells, some degree of temperature drop was observed.

During the six-days of the depressurization operation, maximum 5 K and 0.5 K in P and MT1 wells respectively. The vertical profiles of the temperature drop show high degree of heterogeneity, and the dissociation process reached in a localized region of the monitoring well. The water production zone in the production well was also concentrated at a specific depth.

Rapid temperature changes were observed in every well when the sand production event happened and terminated the flow in the seventh day of the test. The data show that the sanding occurred at a specific depth with strong water flow, and effect of it reached the monitoring hole location of 20 to 30 m far away.