渤海湾盆地博兴洼陷沙四上亚段泥页岩储层含油性与可动性评价

Oil-bearing property and mobility evaluation of shale reservoirs in upper fourth member of Shahejie Formation in Boxing subsag,Bohai Bay Basin

渤海湾盆地博兴洼陷沙四上亚段泥页岩层段中不同岩石类型的岩石物性、有机岩石学和地球化学等研究表明层状(含纹层状)泥页岩样品和非源岩夹层样品具有较好的孔、渗物性特征。前者孔隙度平均为6.7%,水平渗透率平均为0.88×10^(-3)μm^(2),后者孔隙度平均为6.46%,水平渗透率平均为0.124×10^(-3)μm^(2)。综合荧光显微镜和热解地球化学指标,认为该套地层中的砂岩类和层状-纹层状泥页岩具有良好的含油性,同时建议以S_(1)(每克岩石)为2 mg和OSI(每克TOC)高于100 mg/g作为评价沙四上亚段页岩油可动性的标准。结合研究区内页岩油生产井的原油密度与黏度等数据参数,指出研究区内西北地区的非源岩夹层和层状-纹层状泥页岩具备良好的页岩油勘探开发潜力,是未来重要目标区域。

The petrophysical properties,organic petrology,and geochemistry of different rock types in shale layers of the upper Es4 Formation in Boxing subsag of Bohai Bay Basin show that layered(laminated)shale samples and non-source rock interlayers have good pore and permeability characteristics.The former has an average porosity of 6.7%and an average horizontal permeability of 0.88×10^(-3)μm^(2),while the latter has an average porosity of 6.46%and an average horizontal permeability of 0.124×10^(-3)μm^(2).Combining fluorescence microscopy and pyrolysis geochemical indicators,it is believed that the sandstone and layered(laminated)shale in this formation have good oil-bearing properties,and it is suggested that the S_(1) is 2 mg/g(rock)and the OSI is higher than 100 mg/g(TOC)as a criterion for evaluating the mobility of shale oil in the upper Es4 Formation.Combined with the parameters of crude oil density and viscosity of shale oil production wells in the study area,it is pointed out that the non-source rock interlayers and layered-laminated shale in the northwest area have good potential for shale oil exploration and development,and it is also an important target area in the future.