Experimental investigation of the shear strength of gas hydrate-bearing sediments

含天然气水合物沉积物抗剪强度实验研究

• 批准号: 238267-2011
• 负责人: Grozic, Jocelyn
• 金额: $ 2.11万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=478783
• 关键词: Experimental; investigation; shear; strength; gas

Interest in methane gas production from hydrate accumulations has increased dramatically in the last decade, with this vast supply of unconventional gas offering a promising future energy resource. Hydrates also pose a geohazard in exploration and production of conventional offshore hydrocarbon reserves; hydrate dissociation has been linked to submarine slope instability, gas blowouts, and near well failures. Environmental implications of hydrate deposits can be negative owing to potential methane release to the atmosphere, or positive as prospective storage of carbon dioxide in hydrate form. Gas hydrates are solid crystalline compounds comprised of hydrogen-bonded water molecules forming a rigid crystal lattice stabilized by encaged gas molecules, predominately methane. Although our knowledge of the geomechanical properties of hydrate bearing sediments is immature, experimental and theoretical models demonstrate that the presence of hydrate will increase strength and stiffness and decrease permeability; however, dissociation of hydrate induces fluid and gas production, loss of strength and stiffness, and elevated pore pressures.

在过去的十年中，对从水合物积聚中生产甲烷气体的兴趣急剧增加，这种大量的非常规天然气供应提供了一种有前途的未来能源。 水合物还在常规海上油气储量的勘探和生产中造成地质灾害;水合物分解与海底斜坡不稳定、气体井喷和近井故障有关。 水合物沉积对环境的影响可能是负面的，因为可能会向大气中释放甲烷，也可能是正面的，因为二氧化碳可能以水合物形式储存。 气体水合物是由氢键水分子组成的固体晶体化合物，形成由笼状气体分子（主要是甲烷）稳定的刚性晶格。 尽管我们对含水合物沉积物的地质力学性质的认识还不成熟，但实验和理论模型表明，水合物的存在会增加强度和刚度并降低渗透率;然而，水合物的分解会导致流体和气体的产生、强度和刚度的损失以及孔隙压力的升高。