부산대학교 도서관

The present study carries out the sedimentological and diagenesis impact on reservoir quality of the Early Jurassic sandstone (Datta Formation) of Trans-Indus Ranges, Pakistan. To fulfill the objectives of the present study Pezu & Abbo Wanda sections have been selected. To evaluate the reservoir characteristics the thin section analysis, scanning electron microscope (SEM), SEM, cathodoluminescence (CL), X-ray diffraction (XRD), and core plug porosity and permeability analysis have been used. Field evidence shows that there are four depositional facies six lithofacies, and three microfacies, with different sedimentary structures, were observed, which indicates that Jurassic sandstone has been deposited in a deltaic environment. Petrographic analysis and SEM show compaction is moderate to high, and grain binding calcite cement with subordinate quartz overgrowth and hematite. Feldspar dissolution and clay minerals precipitation were important diagenetic reactions that influenced the quality of the reservoir. Primary intergranular pores, fractured, and dissolution pores are present within the studied sections. Overall, pores connectivity is good, and at some places, the quality of the pores has been affected by authigenic clay minerals. SEM analysis predicts that clay minerals like kaolinite, smectite, and Illite/smectite are common pore-filling minerals that reduce the reservoir quality. Primary pores, fractures, dissolution pores, as well as core plug porosity and permeability data (porosity 15.90 to 27.01% and permeability 0.15 to 150 mD) predict that Jurassic sandstone has good reservoir characteristics. [ABSTRACT FROM AUTHOR]