Reservoir pores characteristics of Sha3 member of Mian120 area in Bamianhe oilfield

According to the analysis of lithology and porosity feature of Sha3 member of Mian 120 area in Bamianhe oil- field,sandbodies are found to be arkoses with low compo- sitional maturity.The authigenic minerals include illite, montmorillonite,calcite cement,quartz,kaolinite,chlo- rite and dolomite.Secondary pore system is developed. The main pore types are dissolved pores between grains, dissolved pores in grains and moldic pores.The pore structure is characterized by medium porosity and medium pore throat,and the ones with bigger throat than 2.5μm are good to permeability.Pore development is mainly af- fected by diagenesis and sedimentation.The secondary pore system formed by dissolution can be used as main reservoirs space.