The geomechanical behaviour of natural and synthetic gas hydrate bearing sediments

* 从天然水合物积累中生产甲烷气体提供了大量环境可持续的非常规天然气，这是一种有前途的未来能源。天然气水合物是由氢键水分子组成的晶体化合物，形成由笼状甲烷分子稳定的刚性晶格。这些“冰状”固体是在高压和低温下形成的;因此，它们存在于北极永久冻土下或大陆斜坡和大陆边缘海底下的沉积物孔隙中。在天然气水合物钻探和表征考察过程中使用的技术最近发生了巨大的变化，其结果是我们对天然气水合物系统的理解发生了质的飞跃。由于天然气水合物在用常规取芯法回收时会迅速分解，因此开发了压力取芯技术，以“锁定”现场静水压力和压力室转移和分析系统，随后建立该系统以表征未扰动沉积物芯。 利用这些系统，最近在今年夏天收集的综合数据集可能会为天然气水合物承载系统提供改变游戏规则的见解。这项研究计划研究了天然水合物沉积物及其合成构建的实验室类似物的新信息之间的联系，进一步加深了我们对这两个系统的理解，并最终提高了我们在天然水合物积聚过程中模拟储层地质力学的能力。* 研究方法包括实验室测试、数值模拟和与天然气水合物岩心最新数据的关键比较/分析相结合。 我们对天然水合物性质的认识的一个新的基线将通过仔细审查在最近的北极和海洋天然气水合物考察中积累的数据集来建立。 创造力，创新和合作将是开发高度新颖的实验室工艺的动力，以生产模拟天然样品的合成水合物样品。 重点实验计划的目的是定义基本属性和检查细观水平的响应，并最终提供输入，校准和验证数据的本构模型。 将模拟比例放大到水合物级，可以探测、理解和预测水合物聚集产气过程中的沉积物响应（储层稳定性、沉降和相关地质灾害）。*天然气水合物是加拿大非常规能源供应的重要组成部分;这种前沿天然气的研究和开发符合我们的优先事项，即增加北方发展，行使北极主权权利，优化能源回收，同时减少经济和环境影响。**

***Production of methane gas from naturally occurring hydrate accumulations offers a vast supply of environmentally sustainable unconventional gas, a promising future energy resource. Gas hydrates are crystalline compounds comprised of hydrogen-bonded water molecules forming a rigid lattice stabilized by encaged methane molecules. These “ice-like” solids form at high pressures and low temperatures; hence they are found within the pore space of sediments located below the permafrost in the Arctic or beneath the seafloor on the continental slopes and margins.***The technology used during gas hydrate drilling and characterization expeditions has recently undergone colossal change, the result of which has been a quantum leap in our understanding of natural gas hydrate systems. Because gas hydrate dissociates rapidly when recovered with conventional coring, pressure-coring techniques were developed to “lock in” the in-situ hydrostatic pressures and pressure chamber transfer and analyses systems built to subsequently characterize the undisturbed sediment core. Utilizing these systems, comprehensive datasets, gathered as recently as this summer, may offer game-changing insights into natural gas hydrate bearing systems. This research program examines the link between this newly available information on natural hydrate bearing sediments and their synthetically constructed laboratory analogs, furthering our understanding of both systems, and ultimately our ability to model reservoir geomechanics in natural hydrate accumulations during methane gas production. ***The research approach involves a combination of laboratory testing, numerical modeling, and critical comparison/analysis with the most up-to-date data from natural gas hydrate core. A new baseline of our knowledge of natural hydrate properties will be established through careful scrutiny of the datasets amassed during recent arctic and marine gas hydrate expeditions. Creativity, innovation, and collaboration will be the instigation for developing highly novel laboratory processes to produce synthetic hydrate-bearing specimens that mimic natural samples. Focused experimental programs aim to define fundamental properties and examine the meso-level response, and to ultimately provide the input, calibration, and verification data for constitutive models. Up scaling to reservoir-level simulations enables probing, understanding, and prediction of the sediment response (reservoir stability, subsidence, and associated geohazards) during gas production from hydrate accumulations.***Gas hydrates are an important component of Canada's unconventional energy supply; research and development of this frontier gas aligns with our priorities to increase northern development, exercise arctic sovereign rights, and optimize energy recovery while reducing economic and environmental impacts. **