Abstract:

According to the comprehensive analysis of the regional geology, logging, sandstone thin section, casting lamella, scan electronmicroscope,X-ray diffractions and other means, the sedimentary facies and reservoir features of Chang 2 Formation in Hanqu-Zhangtianqu region of Ordos basin have been studied.The results show that the sand bodies of the Chang 2 oil reservoir are mainly deltaic plain deposits,and the distributary channel sand bodies in Chang 2 Formation are the advantageous places for Petroleum accumulation of this area. The main porosity type of reservoir is primary interparticle pore. The porosity and permeability of reservoir are about 15 % and 5×10^-3μm² separately, which belong to low porosity and low permeability reservoir. Located in the flat Shanbei slope with weak tectonic activities,Chang 2 oil pool belongs to the tectonic-lithologic pool. Channel sand bodies,lithologic lateral bareier and the shale cap rock of Chang 1 Group are the main dominant factors for the petroleum accumulation in Chang 2 sand bodies.

Key words: Ordos basin；Hanqu-zhangtianqu area；sedimentary facies；reservoirs