Abstract Submarine lobe deposits of the upper Miocene Huangliu Formation in the Yinggehai Basin, characterised by high-temperature (132.4–141.2 °C), high overpressure (1.69–1.99), and inorganic CO2 accumulations, offer an excellent opportunity to investigate how reservoir quality is linked to sedimentary processes and diagenesis. This study examines the control on reservoir quality of submarine lobes using petrographic, geochemical, drilling test, and measured petrophysical data. Lobe axis deposits contain high-density turbidites (HDTs) that exhibit good reservoir quality, a higher degree of sandstone amalgamation, and larger grain sizes and pore-throat radii. The lobe off-axis deposits are composed of HDTs and low-density turbidites (LDTs) with moderate reservoir quality. In contrast, the lobe fringe deposits mainly comprising muddy debrites have the lowest reservoir quality. Sedimentary processes macroscopically controlled the initial grain size segregation, variation of textural properties, and reservoir quality throughout the submarine lobes. Flow transformation from turbidity currents in the lobe axis areas into muddy debris flows in the lobe fringe areas led to the high clay content of lobe fringe deposits, due to the incorporation of sediment eroded from the muddy seafloor. Mechanical compaction is the major diagenetic factor reducing reservoir properties of sandstones in the lobe axis and lobe off-axis positions. Calcite and ferrocalcite cements in the sandstones from the CO2-poor DF-B gas field were linked with thermal decarboxylation of organic matter in the adjacent mudstones. In contrast, the diagenetic processes in the CO2-rich DF-A gas field were more likely to be affected by inorganic CO2 accumulations. As a whole, the CO2-water-rock reactions in the CO2-rich DF-A area can not only lead to the precipitation of late dolomite and ankerite, and formation of authigenic clay minerals, but also cause intense dissolution of unstable compositions, resulting in an insignificant increase in porosity. In addition, the high-overpressure in both gas fields has effectively protected the primary porosity by reducing the effective stress exerted on the detrital grains. This study has implications for the assessment of reservoir potential in carbon sequestration and storage, and hydrocarbon exploration and production.

中文翻译：

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沉积过程和成岩作用对莺歌海盆地黄流组海底裂片储层质量的影响

摘要 莺歌海盆地上中新统黄流组海底叶状沉积物具有高温（132.4-141.2℃）、高超压（1.69-1.99）和无机CO2聚集特征，为研究储层质量如何提供了绝佳机会与沉积过程和成岩作用有关。本研究利用岩相学、地球化学、钻井试验和实测岩石物理数据检验了对海底叶瓣储层质量的控制。叶轴沉积包含高密度浊积岩 (HDT)，其储层质量良好，砂岩混杂程度较高，粒度和孔喉半径较大。叶离轴沉积物由 HDTs 和低密度浊积岩 (LDTs) 组成，储层质量中等。相比之下，以泥质碎屑为主的叶缘沉积物储层质量最低。沉积过程在宏观上控制了整个海底叶瓣的初始粒度偏析、结构特性的变化和储层质量。由于从泥质海底侵蚀的沉积物的掺入，叶轴区域的浊流向叶边缘区域的泥质碎屑流的流动转变导致叶边缘沉积物的高粘土含量。机械压实是降低叶轴和叶轴位置砂岩储层性质的主要成岩因素。来自贫 CO2 的 DF-B 气田砂岩中的方解石和铁方解石胶结物与相邻泥岩中有机质的热脱羧有关。相比之下，富含 CO2 的 DF-A 气田的成岩过程更可能受到无机 CO2 聚集的影响。总体来看，富CO2 DF-A区CO2-水-岩反应不仅会导致晚期白云岩和铁白云石的沉淀，形成自生粘土矿物，还会引起不稳定成分的强烈溶蚀，导致孔隙率增加不明显。此外，两个气田的高超压通过降低碎屑颗粒的有效应力，有效地保护了原生孔隙。这项研究对评估碳封存和储存以及油气勘探和生产中的储层潜力具有重要意义。富 CO2 的 DF-A 区的 CO2-水-岩反应不仅会导致晚期白云岩和铁白云石的沉淀，形成自生粘土矿物，而且会引起不稳定成分的强烈溶解，导致不显着增加在孔隙率。此外，两个气田的高超压通过降低碎屑颗粒的有效应力，有效地保护了原生孔隙。这项研究对评估碳封存和储存以及油气勘探和生产中的储层潜力具有重要意义。富 CO2 的 DF-A 区 CO2-水-岩反应不仅会导致晚期白云岩和铁白云石的沉淀，形成自生粘土矿物，还会引起不稳定成分的强烈溶蚀，导致不显着增加在孔隙率。此外，两个气田的高超压通过降低碎屑颗粒的有效应力，有效地保护了原生孔隙。这项研究对评估碳封存和储存以及油气勘探和生产中的储层潜力具有重要意义。此外，两个气田的高超压通过降低碎屑颗粒的有效应力，有效地保护了原生孔隙。这项研究对评估碳封存和储存以及油气勘探和生产中的储层潜力具有重要意义。此外，两个气田的高超压通过降低碎屑颗粒的有效应力，有效地保护了原生孔隙。这项研究对评估碳封存和储存以及油气勘探和生产中的储层潜力具有重要意义。