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: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=709119
• 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.

尽管在过去的二十年中对涉及白云石化的成岩流体的起源进行了大量的研究，但关于白云岩形成的过程/机制的争论仍在进行中，特别是关于流体流动的时间和这些流体的化学性质以及大块白云岩在近地表环境中形成的程度，而不是通过热液和埋藏过程在不同埋藏深度形成的程度。目前的建议是一个正在进行的研究计划的一部分，概念和实验，在沉积盆地的化学，成岩流体的来源和流体流动事件的时间。它的目的是把特别强调断层和裂缝成岩作用，因为断层和裂缝往往是成岩流体的主要通道，无论是被动还是主动。这些流体不仅导致断裂成矿作用，而且还可能对寄主碳酸盐岩产生重要的成岩改造作用，如溶解作用、重结晶作用和结晶石化作用。 利用综合的野外、构造、岩相学和地球化学工具对流体流动进行量化，也可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年的研究目标是：（1）更好地量化沉积盆地中的主要成岩事件及其相应的起源流体;（2）确定断裂与变形或构造事件之间的关系（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（5）研究Mg同位素和块状同位素在成矿流体来源和温度-流体成分关系方面的应用;（6）阐明成岩事件对孔隙演化的影响。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。从碳酸盐岩储层及其来自不同地质背景（稳定克拉通内区域与盆地内构造更活跃的区域）的露头类似物中取样，将有助于更好地了解和量化每个背景中的碳酸盐岩和其他成岩阶段的起源、时间和空间分布。还将在加拿大西部沉积盆地（WCSB）、密歇根盆地和中东盆地之间进行古流体流动和成岩作用的比较研究。