Paleofluid Flow, Fracturing and Reservoir Implications in dolostone reservoirs in foreland and intracratonic tectonic settings

前陆和克拉通内构造环境中白云岩储层的古流体流动、压裂和储层意义

• 批准号: RGPIN-2017-04570
• 负责人: AlAasm, Ihsan
• 金额: $ 1.6万
• 依托单位: University of Windsor
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=633818
• 关键词: Paleofluid; Flow; Fracturing; Reservoir; Implications

Despite considerable research over the last two decades on the origin of diagenetic fluids involving dolomitization, the debate about the process/ mechanism of dolomite formation is still is ongoing, especially regarding timing of fluid flow and chemistry of these fluids and the extent to which massive dolostones formed in near surface environments as opposed to formation at variable burial depths by hydrothermal and burial processes. The present proposal is part of an ongoing research program, both conceptually and experimentally, on the chemistry, source(s) of diagenetic fluids and timing of fluid flow events in sedimentary basins. It is aimed to put special emphasis on fault and fracture diagenesis, because faults and fractures are often the primary conduits for diagenetic fluids, whether passively or actively. These fluids do not only result in fracture mineralization but may also induce important diagenetic modifications to the host carbonate rocks, such as dissolution, recrystallization and dolomitization. Quantification of the fluid flow using integrated field, structural, petrographic and geochemical tools can be also used to develop conceptual models for the spatial and temporal distribution and connectivity of reservoir porosity and permeability on a regional basinal scale. The proposed research program for the next 5 years will have the following objectives: (1) a better quantification of the main diagenetic events and their responsible originating fluids in sedimentary basins; (2) determination of the relationship between the fractures and deformational or tectonic events (i.e. fracture diagenesis); (3) geochemical simulation of fluid/rock interaction (e.g. using reactive transport modeling); (4) determination of patterns of paleo-fluid flow (e.g. numerical and geochemical modeling); (5) investigate the application of Mg-isotopes and clumped isotopes on source(s) for dolomitizing fluids and temperature-fluid composition relationship; and, (6) unravel the impact of diagenetic events porosity evolution. These objectives can be achieved through careful examination of textural parameters, mapping of regional and local distribution of diagenetic and structural components, geochemistry (stable and radiogenic isotope measurements, fluid inclusions), burial and thermal history curves and quantitative basin modeling techniques. Sampling from carbonate reservoirs and their outcrop analogs from different geologic settings (stable intracratonic areas vs. tectonically more active areas within the basin) will allow a better understanding and quantification of the origin, timing and spatial distribution of dolomites and other diagenetic phases within each setting. Comparative studies on paleo-fluid flow and diagenesis will also be carried out between the Western Canada Sedimentary Basin (WCSB), Michigan Basin and Middle East basins.

尽管过去二十年对涉及白云石化的成岩流体的起源进行了大量研究，但关于白云石形成过程/机制的争论仍在继续，特别是关于流体流动的时间和这些流体的化学性质以及块状白云岩的程度在近地表环境中形成，而不是通过热液和埋藏过程在不同埋藏深度形成。本提案是正在进行的概念性和实验性研究计划的一部分，该研究计划涉及化学、成岩流体的来源以及沉积盆地中流体流动事件的时间。它的目的是特别强调断层和裂缝的成岩作用，因为断层和裂缝通常是成岩流体的主要通道，无论是被动还是主动。这些流体不仅会导致裂缝矿化，还可能引起宿主碳酸盐岩的重要成岩作用改变，例如溶解、重结晶和白云石化。使用集成的现场、结构、岩石学和地球化学工具对流体流动进行量化还可以用于开发区域盆地尺度上储层孔隙度和渗透率的时空分布和连通性的概念模型。未来5年的拟议研究计划将有以下目标：（1）更好地量化沉积盆地中的主要成岩事件及其负责的起源流体； (2) 确定裂缝与变形或构造事件（即裂缝成岩作用）之间的关系； (3)流体/岩石相互作用的地球化学模拟（例如使用反应输运模型）； (4) 确定古流体流动模式（例如数值和地球化学模型）； (5) 研究镁同位素和团簇同位素在白云石化流体来源及温度-流体成分关系中的应用； (6)揭示成岩事件对孔隙度演化的影响。这些目标可以通过仔细检查结构参数、绘制成岩和结构成分的区域和局部分布图、地球化学（稳定和放射性同位素测量、流体包裹体）、埋藏和热历史曲线以及定量盆地建模技术来实现。从不同地质环境（稳定的克拉通内区域与盆地内构造更活跃的区域）的碳酸盐储层及其露头类似物进行采样，将有助于更好地了解和量化每个环境中白云岩和其他成岩阶段的起源、时间和空间分布。还将对加拿大西部沉积盆地（WCSB）、密歇根盆地和中东盆地进行古流体流动和成岩作用的比较研究。