| This study deals with the Upper part of Kongdian formation of dating from Paleocene-Eocene age in the south slope of Dongying depression. The main principle problems in the study area include, the diagenetic history, the type of sandstone, the source of the sandstone type, the source of cement, the source rocks for generation petroleum, the formation of secondary porosity, the oil migration, and reservoir quality. The methods of the studies involve stratigraphic analysis and cores samples analysis. Various types of techniques have been applied to study the main principle problem. These techniques involve petrography, X-ray diffraction (XRD), scanning electron microscope (SEM), carbon isotope, Cathodoluminescence (CL), fluid inclusion, and epoxy-resin casts.The stratigraphic analysis reveals that the Upper part of Kongdian formation is characterized by thickness range from 461-744 m and average of thickness of 602.5 m. The number quantity of sandstone increased to the north and northwest, indicating more sand bodied are found at these directions. The formation consists of an abundance of purple to red mudstone, suggesting a week possibility of mudstone to be as a source rock. The thickness of the formation increased to the north and northeast. The general thickening from the southwest towards the northeast and north, combined with increasing of fine clastic to the northeast and north, indicate principle source of the Upper Kongdian formation from the southwest and south.The Upper part of Kongdian formation of Paleocene-Eocene age consists mainly of fine to medium sandstones. Samples analyzed are from depths of 1572.55 to 2298 m, representing temperature range of 60.5癈 to 88.5癈, and geothermal gradient of 3.7-4.0 癈/100 m. The petrographic and XRD analysis reveals that the reservoir of the Upper part of Kongdian formation mainly consists of feldspathic and minor amount of lithic sandstone. The feldspar is consisting mainly of Na. Feldspar and K. feldspar. The feldspar of the reservoir sandstone in the study area consists of a higher percentage of Na feldspar that of K. feldspar. The sandstone is composed of certain little rock fragments such as pyrite, mica, siltstone, mudstone, chert, and volcanic fragments. The sandstone contains lesser amount of heavy minerals such as zircon, garnet, tourmaline, and staurolite. The cement material consists mainly of calcite, clay, and minor amount of dolomite and pyrite. The Cathodoluminescence (CL) analysis shows the quartz reflects an abundance of brown color, blue-purple, dark blue, dull color, and no CL color for quartz overgrowth, while feldspar shows light blue, yellow-green, yellow-brown, green and brown CL colors. The calcite reflects bright orange-yellow for non-ferroan calcite and dull orange-brown CL colors for ferroan calcite. The feldspathic sandstones belong to this formation of composite sources metamorphic, sedimentary, and igneous sources, but mainly from metamorphic source due to the high abundance of brown CL colors of quartz.The Upper part of Kongdian formation represents shallow diagenesis ranges in depth from 1572.55 to 2298 m. The XRD and SEM indicate that the types clay consists of I/S mixed layer, illite and kaolinite. The I/S mixed layer is the most abundant mineral in the clay samples. Thechlorite clay mineral has not been detected in the formation. The I/S mixed layer and illite occur as pore lining and pore filling, while kaolinite occurs as pore filling. The illite in the study area is characterized by, occurs as irregular flakes with short lath-like projection and this growth form can be confused with the mixed layer I/S, and formed in an alkaline environment .The I/S mixed layer in the study area occurs as irregular flakes with short lath-like projection. Its formation is due to conversation of smectite to mixed layer illite-smectite with increase in depth and temperature. The morphology of kaolinite occurs as pseudohexagonal plates and pseudohexagonal-staked plates. The authigenic kaolinite in the study area may be formed by...
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