The influence of sedimentary rock fabrics on subsurface fluid flow: origin of quartz cement distribution in sandstones

该研究旨在研究沉积岩中的构造对流体流动的影响。沉积岩不是规则的颗粒或晶体块。相反，它们是异质的，在多个尺度上包含各种结构，包括颗粒的微观排列和厘米到米尺度的层，构成岩石的结构。颗粒之间充满流体的孔隙空间的几何形状同样是不均匀的，因此岩石中的流体不会在所有方向上均匀流动。例如，穿过沉积层的流体流量通常小于沿沿着流动的流量，但为什么会这样并不总是很清楚。孔隙和颗粒组构定量描述应用显微镜图像分析和统计技术的岩石切片，在不同的方向取向。还可以在这些方向上进行流动测量，然后可以将流动的质量或岩石的渗透性与岩石组构联系起来。重点将放在砂岩上，这些砂岩在不同程度上被围绕颗粒结晶的石英胶结，在这个过程中填充了以前开放的孔隙。由于孔隙空间可以被流体（油、气、水）占据，因此石英胶结物的分布对于建立地下流体储层的概念和应用模型具有极大的意义。这项研究对于更多地了解地下流体流动的控制因素具有根本的重要性，例如水通过含水层的流动，富含矿物质的溶液通过沉积岩的迁移，或者石油和天然气如何在油气藏中运输。特别是石英水泥被认为是砂岩油气藏（包括加拿大的许多油气田）中最有效的替代孔隙空间的水泥，增加对其分布的了解直接适用于改善这些资源的利用和管理。

The proposed research aims to investigate the influence of the structures in sedimentary rocks on fluid flow. Sedimentary rocks are not regular masses of grains or crystals. Instead, they are heterogeneous, containing a variety of structures at multiple scales, including the microscopic alignment of grains and cm- to metre-scale layers, making-up the fabric of rocks. The geometry of fluid-filled pore spaces in between the grains is similarly heterogeneous, and therefore fluids within the rocks will not flow equally in all directions. As an example, fluid flow across sedimentary layers is typically less than flow along layers, but it is not always clear why this is so. The pore and grain fabric is described quantitatively by applying microscope image analysis and statistical techniques to sections of rock that are oriented in various directions. Flow measurements in these directions are also made, and the quality of flow, or permeability of the rock, can then be related to the rock fabric. The focus will be on sandstones that are cemented to varying degrees by quartz that crystallizes around grains, filling formerly open pores in the process. Since that pore space could otherwise be occupied by fluids (oil, gas, water), the distribution of quartz cement is of great interest to build conceptual and applied models of subsurface fluid reservoirs. This research is of fundamental importance to learn more about the controls on fluid flow in the subsurface, such as the flow of water through aquifer layers, the migration through sedimentary rocks of mineral-rich solutions, or how oil and gas is transported in hydrocarbon reservoirs. Quartz cement in particular is considered to be the most effective cement replacing pore space in sandstone hydrocarbon reservoirs (including many oil&gas fields in Canada), and increased understanding of its distribution is directly applicable to improve the utilization and management of these resources.