内蒙古西部额济纳旗及邻区石炭系—二叠系的储集条件——石炭系—二叠系油气地质条件研究之二

    Reservoir conditions of Carboniferous- Permian strata in Ejin Banner and its vicinities, western Inner Mongolia: a study of Carboniferous-Permian petroleum geological conditions (part 2)

    • 摘要: 通过对研究区石炭系—二叠系碎屑岩沉积相纵向演化与平面展布特征、岩石学特征、成岩作用、孔隙类型的研究,认为研究区石炭系—二叠系碎屑岩砂砾岩的发育程度、成分成熟度、结构成熟度等均受阿拉善古陆和马鬃山-拐子湖中间隆起带2个沉积物源的控制。南部以阿拉善古陆为主要沉积物源,砂砾岩发育,成分成熟度和结构成熟度均较高。由南向北阿拉善古陆作为物源的影响逐渐降低,砂砾岩发育程度逐渐变差,成分成熟度和结构成熟度亦逐渐变差。以粘土矿物及其相对含量、自生矿物特征等为主要依据,对成岩作用阶段进行划分,多数剖面以中成岩A期为主,研究区北部、北山地区和受阿尔金走滑断裂影响的雅干一带,受构造动力变质作用或岩浆热接触变质作用的影响进入中成岩B期。碎屑岩储集层孔隙演化受成岩作用的控制,多数以溶蚀孔(缝)为主,少数具有残余粒间孔,总体来看孔隙发育较差。除碎屑岩储集层外,各类碳酸盐岩、火山岩,以及华力西期风化壳的各类岩石均可能成为重要的储集层类型。

       

      Abstract: Based on the characteristics of vertical variation and plane distribution of Carboniferous-Permian clastic rock sedimentary facies, petrological features, diagenesis and pore types, the authors hold that the development degree and compositional and structural maturity of Carboniferous-Permian glutenite are controlled by two sedimentary derivations of Alxa ancient land and Mazongshan-Guaizihu central uplift belt. The sedimentary derivation in the south is Alxa ancient land, with the development of glutenite, and the compositional and structural maturities are both high. The effect of Alxa ancient land central uplift as the material source is decreased from south to north, with the gradual worsening of the glutenite development and the compositional and structural maturities. Based on clay mineral content and authigenic mineral characteristics, the authors divided the diagenesis into stages: most sections belong mainly to A stage of middle diagenesis, and the diagenesis of northern study area, Beishan area and Yagan area affected by Altun fault belongs to B stage of middle diagenesis, affected by tectonic dynamometamorphism or magmatic-thermal contact-metamorphism. Because pore evolution of the clastic rock reservoir is controlled by diagenesis, the pores are mostly dissolved pores (fractures), with only a few residual intergranular pore, and the pores are on the whole poorly-developed. Carbonate, volcanics and Variscan Stage weathering crust are likely to become important reservoir types.

       

    /

    返回文章
    返回