岐口凹陷侏罗系微晶石英包壳特征及形成机制

自生微晶石英包壳、石英次生加大是渤海湾盆地岐口凹陷侏罗系储集层砂岩中重要的自生矿物，在深埋藏条件下，储集层拥有较多的与微晶石英有关的原生孔隙。应用铸体薄片、扫描电镜、阴极发光、电子探针、X射线衍射等分析测试手段，对研究区微晶石英包壳硅的来源、生长方式和形成机制、对原生粒间孔隙的保护作用及对石英次生加大的抑制机理进行了研究，明确了自生微晶石英包壳砂岩的成岩演化序列。微晶石英形成时间较早，平行于宿主颗粒生长，并沿C轴方向任意旋转，与其相关的原生孔隙较为发育。分析自生微晶石英包壳成因及其成岩演化序列，对渤海湾盆地深层和超深层优质储集层的形成机制研究和油气勘探开发具有重要意义。

Characteristics and Formation Mechanism of Jurassic Microcrystalline Quartz Coating in Qikou Sag

Authigenic microcrystalline quartz coating and quartz secondary overgrowth are the most important authigenic minerals in the Jurassic sandstones of the Qikou sag, Bohai Bay basin. Primary pores related to microcrystalline quartz are well developed in the reservoir with deep burial depth. Based on the analysis of thin section, SEM, cathode luminescence, electronic probe and X-ray diffraction, the paper studies the source, growth pattern and formation mechanism of microcrystalline quartz coating, protection of primary intergranular pores and inhibitory mechanism of quartz secondary overgrowth in the study area, and verifies the diagenetic evolution sequence of the authigenic microcrystalline quartz coating sandstone. The microcrystalline quartz formed in early time, grew parallel to host grains and could rotate arbitrarily along the C axis. The associated primary pores are well developed. The analysis of the genesis of the authigenic microcrystalline quartz coating and its diagenetic evolution sequence is of great significance for the research on forming mechanisms of high-quality deep and ultra-deep reservoirs and petroleum exploration and development in Bohai Bay basin