Impacts of hydrate on the lateral stress in sediments

¹ Geosystems Engineering, Georgia Institute of Technology, 790 Atlantic Drive, Atlanta, GA, USA
² School of Naval, Ocean and Architecture Engineering, Shanghai Jiao Tong University, Shanghai China
³ National Energy Technology Laboratory, Morgantown WV, USA

^* Corresponding author: sheng.dai@ce.gatech.edu

Abstract

The ratio between the horizontal and the vertical effective stresses is defined as the coefficient of earth pressure at rest K_o. K_o in hydrate-bearing sediments is critical in understanding the stress states in hydrate-bearing sediments, yet has not been previously understood. An oedometer cell equipped with vertical and horizontal stress measurement sensors is used to measure the evolution of K_o in tetrahydrofuran hydrate- bearing sands during hydrate formation and dissociation and vertical stress changes. The results show that the response of K_o in hydrate-bearing specimens reflects the combined effects of hydrate cementation, the viscous nature of hydrate crystals, and the stress levels. These results can enhance the understanding of stress anisotropy and geomechanical behaviors of hydrate reservoirs during gas production.