Unsaturated water flow-induced the structure variation of gas hydrate reservoir and its effect on fluid migration and gas production

Bingbing Chen, Huiru Sun, Kehan Li, Tao Yu, Lanlan Jiang, Mingjun Yang and Yongchen Song

Energy, 2023, vol. 282, issue C

Abstract: Multi-phase (gas, saturated water, and unsaturated water) seepage is bound to exist in natural gas hydrates (NGHs) production process. The effect of water flow, especially for unsaturated water flow, on the permeability variation of hydrate reservoir and gas production behavior do not appear well understood. In this study, the unsaturated water flow in hydrate-bearing sediment and hydrate-free sediment is simulated by controlling water flow velocity. The hydrate phase distribution was monitored using visualization magnetic resonance imaging system. The variation of temperature, pressure, and gas production rate during the unsaturated water flow were analyzed. The results show that the changing trend of the pressure difference presented the three stages for the hydrate-free sediment. In contrast, the pressure difference followed a five-stage change for the hydrate-bearing sediment in the unsaturated water flow process due to the hydrate dissolution. The hydrate dissolution caused an increase in permeability (maximum of log10(Kr) was 0.5) and formed the obvious unsaturated water flow channel. Moreover, the higher water flow velocity, which increased the chemical potential difference between hydrate phase and water phase, accelerated the MH dissolution, and further induced the faster increase rate of permeability and gas production. Surprisingly, when the unsaturated water flow velocity was improved to 15 mL/min from 0.5 mL/min, the gas production rate increased by 35 times. Furthermore, the average gas production rate was mainly determined by the unsaturated water flow velocity, it was changing in a linear fashion with the increasing water flow velocity. The findings could provide new knowledge on the strategy design on NGHs production with high efficiency.

Keywords: Methane hydrate; Unsaturated water flow; Permeability; Phase transition; Gas production rate (search for similar items in EconPapers)
Date: 2023
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (6)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0360544223022375
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:energy:v:282:y:2023:i:c:s0360544223022375

DOI: 10.1016/j.energy.2023.128843

Access Statistics for this article

Energy is currently edited by Henrik Lund and Mark J. Kaiser

More articles in Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().