Nari Formation is considered as one of the most important oil and gas exploration targets. These fine-grained tight sandstone reservoirs face enormous challenges due to their extremely low matrix porosity and permeability. Hence, in this regard, the study was carried out to collect the high-quality data on petrophysical properties along with mineralogy and microstructural characteristics and diagenesis. The experiments performed includes the petrographic study and scanning electron microscopy, and X-ray diffraction analyses. Besides, the measurement of petrophysical properties was carried out to assess the likely influence of the reservoir quality. The petrographic analysis shows predominantly fine- to medium-grained grey samples along with calcite, clay, lithic fragments and iron oxides. Further, the thin-section observations revealed that the quartz is a principal mineral component in all the analysed samples ranging from 52.2 to 92.9%. The bulk volume of clay minerals that range from 5.3 to 16.1% of. The porosity and permeability measured range from 5.08 to 18.56% (average 7.22%) and from 0.0152 to 377 mD (average 0.25 mD), respectively. The main diagenetic processes that affected the sandstones of Nari Formation are mechanical compaction, grain deformation, cementation and quartz dissolution and have played a significant role in influencing the quality of the reservoir rock. Overall, it appears that the primary petrophysical properties (porosity and permeability) were decreased due to the mechanical compaction, lithification, cementation, and framework grain dissolution. Based on the integrated mineralogical, microstructural analysis, and the laboratory-based petrophysical properties, the samples exhibited poor porosity, permeability, and moderate clay content, which indicate that the Nari Formation is a poor quality reservoir.

中文翻译：

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巴基斯坦下印度河盆地渐新统地层细粒岩的成岩特征对其岩石物性的影响

纳里组被认为是最重要的油气勘探目标之一。这些细粒致密砂岩储层由于其基质孔隙度和渗透率极低而面临巨大挑战。因此，在这方面，进行了这项研究以收集有关岩石物性的高质量数据以及矿物学，微观结构特征和成岩作用。进行的实验包括岩石学研究和扫描电子显微镜以及X射线衍射分析。此外，对岩石物性进行了测量，以评估储层质量的可能影响。岩石学分析显示，主要是细粒至中粒的灰色样品以及方解石，粘土，石屑和氧化铁。更多，薄层观察表明，石英是所有分析样品中的主要矿物成分，范围从52.2％到92.9％。粘土矿物的总体积为5.3％至16.1％。测得的孔隙率和渗透率分别为5.08％至18.56％（平均7.22％）和0.0152至377 mD（平均0.25 mD）。影响纳里组砂岩的主要成岩作用是机械压实，晶粒变形，胶结作用和石英溶解，在影响储集岩质量方面发挥了重要作用。总体而言，由于机械压实，石化，胶结和骨架颗粒溶解，看来主要的岩石物理性质（孔隙度和渗透性）降低了。基于综合的矿物学，微观结构分析，