ANALYSIS ON THE CHARACTERISTICS OF PERMO-CARBONIFEROUS SANDSTONE RESERVOIR AND ITS GEOLOGICAL CONTROLLING FACTORS IN NORTH CHINA

According to plenty of experimental data and regional geology informations,the depositional history of Permo-Carboniferous sandbodies in North China are studied.It is pointed out the petrophysics perperties of sandstone reservoirs are controlled by geological factors,such as the maturity of lithologic texture,mineral composition and evolution,epigenetic reworks,the intensity of faulting and fracturing.In the newly depressing with the central uprise,it is better to search for the sandbodies in high energy zone with moderate compositional maturity,particularly for the sand beds within the range of 350 m beneath an unconformity,where the secondary porosity is well developed and is favourable for coal gas reservior.In structurally subsiding areas,the sandbody traps in high energy zone formed in early stage are the best site for the accumulation of coal gas.