The Research Of Reservoir Geochemistry Characteristics Of Upper Permian And Lower Triassic In The NE Sichuan Basin

The research of reservoir geochemistry characteristics of Upper Permian and Lower Triassic in the NE Sichuan Basin are guided by the theories of geochemistry and gas/oil reserve ,and based on analysis of the rock structure, combing with analysis of trace element and stabilization isotopes and the geochemistry characteristics of inclusion .The author systems research the characteristics of the Changxing Formation of Upper Permian and of the Feixianguan Formation of Lower Triassic in the NE Sichuan Basin.On the basis of analysis of the rock structure ,combining with analysis of strontium isotopes and microelement strontium and the oxygen isotope of calcite and the geochemistry characteristics of inclusion .The author consider that the diagenetic fluids of dolostones of he Changxing Formation of Upper Permian and of the Feixianguan Formation of Lower Triassic in the NE Sichuan Basin has notable homogeny , which is the high-salinity intergranular water and its form of setting was occlude comparatively.The dolomite of Feixianguan has two types genesis, penecontemporaneous alternation and buried alternation, the high-quality reservoirs was the products of buried alternation rock-forming. The temperature of sea was 29℃～36℃which beneficial for formation of he high-quality reservoirs. The paleotemperature of ancient oil reservoir and reservoir of Permian and Triassic main concentrated 120℃-170℃, exceeded 80℃,which is the critical temperature of yield oil of our country. The range 120℃-170℃is broadaly consistent with the emergence of a large number of liquid hydroca?? condensate oil to moisture phase of the temperature range (100 ~ 180℃). The author calculated the era of immitting oil-gas is Early Jurassic to Late Jurassic by the theories of Sm-Nd isochrone lines and the oxygen isotope of calcite and the homogenization temperature of inclusion.