Characteristics of Chang 2_1 Sandstone Reservoir in Jiyuan Region of Ordos Basin and Its Influence Factors

Characteristics of Chang 21 sandstone reservoir in Jiyuan region of Ordos Basin were investigated by the data of core analysis,log,scanning electron microscope,porosity and permeability analysis,acoustic emission test and mercury injection test.The results show that pore space of the reservoir mainly includes primary residual intergranular pores,secondary intergranular pores and crack..The reservoir physical properties is not well and it belongs to the typical reservoir of low porosity and low permeability.There are three types of pore.They are secondary pore,millipore and microfissure,intergranular pore which is the most important in the three types.The quality of reservoir was affected by sedimentary microfacies and diagenesis.