通过对右江盆地二叠系生物礁古油藏流体包裹体的研究,探讨含油气流体的物理化学性质和油气演化程度。结果表明,含油气流体是一种多成分、多相态的不混溶体系,主要组分是有机质、CO2和H2O。成藏流体的温度变化于73-200℃,主要集中于90-160℃,与我国碳酸盐岩生油最佳温度或生油高峰温度一致。含油气流体的盐度低(多小于6%NaCl),密度中等(0.90-1.02 g/cm^3),压力为4.2-65.4 MPa,有机组分中CH4占绝对优势,次为C2H6。从含油气流体的演化程度和物理化学特征来看,生物礁型油气藏应是右江盆地油气勘探的重点对象。
Fluid inclusion study was performed on the Permian biohermal type paleo-oil reservoirs in the Youjiang basin,in order to understand the physicochemical characteristics of hydrocarbon-bearing fluids and the evolutionary degree of oil and gas.It is indicated that the hydrocarbon fluid is a multicomponent and multiphase immiscible system composed mainly of hydrocarbon,CO2,and H2O.The fluid temperature varies between 73℃ and 200℃(mostly 90~160℃),consistent with the peak oil generation temperature of carbonates in China.The hydrocarbon fluid has a low salinity(typically less than 6% NaCl) and a medium density(0.90~1.02 g/cm3),with fluid pressure varying between 4.2 MPa and 65.4 MPa.The organic components are dominated by CH4 and less commonly C2H6.On the viewpoint of hydrocarbon evolution and physicochemical properties of the fluid,it is suggested that biohermal type oil-gas reservoirs should be the key exploration object in the Youjiang basin.