关键词: 飞仙关组, 圈闭, 含油气性, 主控因素, 热化学硫酸盐还原作用, 构造运动, 原油裂解型气藏, 川东北地区

Abstract: The observation of core and thin section and analyses of organic geochemistry and statistics showed that oil-bearing quality of paleo-oil reservoirs and gas-bearing quality of present-gas reservoirs in Feixianguan Formation were different.The micro-facies were very important factors for controlling oil-bearing quality of paleo-oil reservoirs.The traps in Jinzhuping Field had bad oil-bearing or no oil at all,because the porosity was close to the petrophysical threshold limit of 3.5%.The present-gas fullness degree of bituminous oolitic beach deposit trap was controlled by the oil richness of paleo-oil reservoirs and thermochemical sulfate reduction(TSR).The corrosion-volume depression effectiveness for the reservoirs and the consumption of H₂S resulted from TSR production were the main reasons for making the gas-bearing fullness of reservoirs lower in Feixianguan Formation.The tectonic movement in the later period resulted in the readjustment of fluid and the redistribution of gas and water in the pools,which made the parts of the oil-cracking gas pools with good oil-bearing into the reservoir with bad gas-bearing property at present.

Key words: Feixianguan Formation, trap, hydrocarbon-bearing property, main controlling factor, thermochemical sulfate reduction, tectonic movememt, oil-cracking gas poots, northeastern Sichuan Basin