Evaluation of Gas Production from Methane Hydrate Sediments with Heat Transfer from Over-Underburden Layers

详细信息    查看全文

• 作者：Chuanxiao Cheng ; Jiafei Zhao ; Mingjun Yang ; Weiguo Liu ; Bin Wang ; Yongchen Song
• 刊名：Energy & Fuels
• 出版年：2015
• 出版时间：February 19, 2015
• 年：2015
• 卷：29
• 期：2
• 页码：1028-1039
• 全文大小：782K
• ISSN：1520-5029

文摘

To clarify the dissociation characteristics by depressurization with heat flow rate from over-underburden layers (Q_ov), the effects of different Q_ov levers on gas production by depressurization were analyzed with various initial hydrate saturations in a 5 L pressure vessel. The ratio of sensible heat of the hydrate sediments to hydrate dissociation latent heat (螖H_Sen/螖H_L), the accumulated volume of gas production, the percentage of gas production, and the rate of gas production were obtained and compared. The effects of 螖H_Sen and Q_ov on gas production in the fast depressurization stage and the stable temperature stage were analyzed separately during the gas production process. A sharp increase of temperature and pressure was observed which was caused by the latent heat of ice formation during the fast depressurization stage. It is concluded that the Q_ov has a positive influence on gas production during the stable temperature stage after the total consumption of 螖H_Sen. The Q_ov effectively increased the production temperature, rate of gas production, and percentage of gas production under these experimental conditions. With increased Q_ov, the promotion effects are different depending on 螖H_Sen and S_hi. High Q_ov had a remarkable influence on the rate of gas production and the percentage of gas production for the high S_hi sample. In this experiment, v_a increased from 1.33 to 2.24 SL/M depending on the Q_ov, an increase of 68.42%. In addition, with high Q_ov, the upward migration of free water decreased the thermal conductivity of the hydrate sediments, which would decrease the rate heat flow from Q_ov.