Diagenesis and reservoir quality analysis in the Lower Cretaceous Qishn sandstones from Masila oilfields in the Sayun-Masila Basin, eastern Yemen

摘要: Lower Cretaceous sandstones of the Qishn Formation have been studied by integrating sedimentological, petrological and petrophysical analyses from wells in Masila oilfields eastern Yemen. These were used to define origin, type diagenesis its relation reservoir quality. The are predominately quartz arenite subarkose with sublitharenite wackes displaying a range porosities, averaging 22.33%. Permeability is likewise variable an average 2844.2 mD. Cementation coupled compaction had important effect on porosity destruction after sedimentation burial. widespread occurrence early calcite cement suggests that lost significant primary at stage diagenetic history. In addition poikilotopic calcite, several different cements including kaolinite, illite, chlorite minor illite–smectite occur as pore-filling pore-lining cements, which either accompanied or followed development cement. Secondary occurred due partial complete dissolution feldspar grains. new data presented this paper suggest quality strongly linked their history; hence, reduced clay minerals, silica but enhanced unstable grains, Copyright © 2015 John Wiley & Sons, Ltd.