Fundamental and Applied Investigations in Rock Physics and Mechanics

岩石物理与力学的基础与应用研究

• 批准号: RGPIN-2014-04014
• 负责人: Schmitt, Douglas
• 金额: $ 3.13万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=664494
• 关键词: Fundamental; Applied; Investigations; Rock; Physics

The Experimental Geophysics Group (EGG) investigates the factors that control the physical properties of earth materials and applies this knowledge in next generation interpretation of geophysical observations. Investigations are carried out both in controlled laboratory conditions and in the field with surface and borehole measurements. A major interest focusses on measurement of the stresses in the earth, both their directions and their strength. The students working with EGG have the opportunity to participate in the field activities that are increasingly rare. This proposal seeks support to allow us to continue collaboration in scientific drilling programs and to carry out novel rock physics laboratory experiments. *We are part of the science team for two upcoming scientific drilling programs. In the first, a 1.5 km deep borehole will be drilled through the Alpine Fault on the South Island in New Zealand. The Alpine Fault bounds the Pacific and the Australian plates and is a significant crustal feature accommodated by significant uplift, it is feared that this fault can produce a major earthquake with devastating. The borehole, with drilling expected to begin in late 2014, is slated to intersect the fault at a depth of about 1 km. EGG will take significant responsibilities for the logging program that provides baseline physical property data along the borehole that will be used by the entire science team to correlate core and to assist in understanding in situ conditions. This work will have implications for the understanding of plate boundary fault motions leading to large earthquakes.*We are also in the science team for drilling at Coulman High, a seafloor area that has collected sediments from Antarctica for much of the Cenozoic. Again, we are tasked with logging operations and we expect to send a trained Ph.d. student to carry out this work. In this case, the logging data will be key to locating in proper depth the core materials. The logs will look for patterns in sedimentation that switch from open ocean to ice covered; this information reveals patterns of past climate changes as indicators of open ocean in this part of the world strongly suggest that when the sediment was deposited the planet was generally warmer everywhere. Our primary interest, however, will focus on determination of stress states in the borehole. *Our laboratory studies will concentrate on two topics. The first examines seismic reflections from anisotropic layers. While this work is of a more fundamental nature, having a good understanding of how the reflections change with both angle of incidence and azimuth is necessary for the proper interpretation of industrial seismic surveys that seek to indicate the patterns of in situ fracturing. Such knowledge is key to the planning of drilling for hydrocarbons in low permeability formations and for long term injection of geologically sequestered greenhouse gases. We will use a specialized instrument called an acoustic goniometer to measure the variations in the amplitudes of ultrasonic pulses reflected from anisotropic blocks of materials in order to simulate in situ conditions. *Finally, we will continue laboratory research on seismic dispersion, i.e. the changes in the seismic wave speeds and attenuation with frequency. The purpose is to determine how to reconcile laboratory measurements taken at very high frequencies of 1 MHz with field seismic observations acquired at frequencies of 100 Hz. We are currently developing new instrumentation to measure directly the bulk modulus at low frequencies. This differs from all other measurements in the and as such the new instrumentation should provide a new tool for studying frequency dispersion.

实验地球物理小组(EGG)研究控制地球材料物理性质的因素，并将这一知识应用于下一代地球物理观测的解释。调查既是在受控的实验室条件下进行的，也是在野外通过地面和井眼测量进行的。一个主要的兴趣集中在测量地球上的应力，包括它们的方向和强度。从事鸡蛋工作的学生有机会参加越来越难得的野外活动。这项提议寻求支持，以使我们能够继续在科学钻探计划和开展新的岩石物理实验室实验方面进行合作。*我们是即将到来的两个科学钻探计划的科学团队的一部分。首先，将在新西兰南岛的阿尔卑斯断层上钻一个1.5公里深的钻孔。阿尔卑斯断裂以太平洋和澳大利亚板块为界，是一个重要的地壳特征，具有显著的隆升作用，人们担心该断裂会引发毁灭性的大地震。钻井预计将于2014年底开始，预计将在约1公里深的地方与断层相交。EGG将为测井计划承担重大责任，该计划将提供井筒沿线的基线物性数据，整个科学团队将使用这些数据来对比岩心并帮助了解现场条件。这项工作将对理解导致大地震的板块边界断层运动产生影响。*我们还在库尔曼高中钻探的科学团队中，库尔曼高中是一个海底区域，在新生代的大部分时间里从南极洲收集了沉积物。同样，我们的任务是记录操作，我们希望派遣一名训练有素的博士。学生进行这项工作。在这种情况下，测井数据将是在适当深度定位岩心材料的关键。日志将寻找从开阔海洋转变为冰盖的沉积模式；这些信息揭示了过去气候变化的模式，因为这一地区的开阔海洋指示强烈表明，当沉积物沉积时，地球各地普遍较暖。然而，我们的主要兴趣将集中在确定钻孔中的应力状态上。*我们的实验室研究将集中在两个主题上。第一种是研究各向异性地层的地震反射。虽然这项工作具有更基本的性质，但对反射如何随入射角和方位变化有很好的了解，对于寻求指示现场压裂模式的工业地震调查的正确解释是必要的。这些知识对于在低渗透率地层中钻探碳氢化合物和长期注入地质隔离的温室气体的计划至关重要。我们将使用一种名为声学测角仪的专门仪器来测量各向异性材料块反射的超声波脉冲幅度的变化，以便模拟现场条件。*最后，我们将继续在实验室研究地震频散，即地震波速和衰减随频率的变化。其目的是确定如何使在1兆赫甚高频下进行的实验室测量与在100赫兹频率下获得的实地地震观测相一致。我们目前正在开发新的仪器，以便在低频下直接测量体积弹性系数。这不同于所有其他测量，因此，新的仪器应该为研究频率色散提供一个新的工具。