Pore fluid evolution in sedimentary basins: integrated sedimentology and geochemistry of carbonate reservoirs

尽管过去二十年来对成岩流体起源的大量研究涉及石灰岩成岩作用和白云石化作用，但关于这些流体的时间和化学性质以及块状白云岩在近地表环境中形成的程度，而不是在不同埋藏深度通过热液和埋藏过程形成的白云岩体，仍存在争议。这些白云岩和伴生的灰岩层序具有重要的油气聚集以及广泛的铅锌矿床。目前的建议是一个正在进行的研究计划的一部分，从概念上和实验上，研究沉积盆地中成岩流体的化学、来源和流体流动事件的时间。它的目的是特别强调裂缝成岩作用，因为裂缝通常是成岩流体的主要管道。这些流体不仅导致裂缝矿化，而且可能对宿主碳酸盐岩产生重要的成岩改造作用。利用场、构造、岩石学和地球化学工具对流体流动进行量化，也可用于在区域盆地尺度上建立储层孔隙度和渗透率时空分布和连通性的概念模型。今后5年的研究目标是：(1)更好地量化沉积盆地主要成岩事件及其成因流体；(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/岩石相互作用的数值模拟（例如使用反应输运模型）；(4)确定古流体流动模式（如数值模拟）；(5)揭示成岩事件对孔隙演化的影响。这些目标可以通过仔细检查构造参数、绘制成岩和构造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。

Despite considerable research over the last two decades on the origin of diagenetic fluids involved limestone diagenesis and dolomitization, the debate about timing and chemistry of these fluids and the extent to which massive dolomites formed in near surface environments as opposed to formation of dolomite bodies at variable burial depths by hydrothermal and burial processes. These dolostones and associated limestone sequences host significant accumulations of oil and gas as well as extensive lead and zinc deposits. 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 fracture diagenesis, because fractures are often the primary conduits for diagenetic fluids. These fluids do not only result in fracture mineralization but may also induce important diagenetic modifications to the host carbonate rocks. Quantification of the fluid flow using 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) numerical simulation of fluid/rock interaction (e.g. using reactive transport modeling); (4) determination of patterns of paleo-fluid flow (e.g. numerical modeling); and, (5) 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.