The hydrocarbon charge history of the Silurian bituminous sandstone reservoirs in the Yingmaili area was investigated using an integrated approach by combining detailed petrographic analysis (thin section and SEM ), clay mineral XRD characterization, and the modeling of authigenic clay minerals and subsequent K-Ar dating of authigenic illites. The result was correlated within the basin. The ordered mixed-layer illite/smectite (I/S) is dominant in the clay assemblages of the Silurian bituminous sandstones in the Yingmaili area except in local areas. They are authigenic in origin. The authigenic illite ages of the Silurian bituminous sandstone reservoirs range from 255 Ma to 293 Ma, mainly from 277 Ma to 293 Ma, corresponding to the Late Carboniferous to Early Permian, indicating that the primary Silurian oil pools were formed mainly during the late phase of the Early Hercynian to the Late Hercynian. The authigenic illite ages of the Silurian bituminous sandstone reservoirs in the Yingmaili area are consistent with the general characteristics of the age distribution within the basin. The palaeo structural framework and the distribution of hydrocarbon supply center might be one of the key controlling factors for the difference in accumulation times within different areas. The long distance of the Yingmaili area from the hydrocarbon supply center might be one of the main controlling factors for the relatively late accumulation in this area.%利用沉降、离心和微孔滤膜真空抽滤相结合的综合分离提纯技术,分别提取不同粒级的自生伊利石进行K-Ar年龄测定,据此对塔里木盆地英买力地区志留系沥青砂岩油气藏的成藏年代进行分析与研究,并在盆地内进行对比.除局部地区外,英买力志留系沥青砂岩中的黏土矿物均主要为伊利石/蒙皂石(I/S)有序间层,具明显的自生成因特征,属自生伊利石.英买力志留系沥青砂岩自生伊利石年龄为255～293 Ma,主要集中在277～293 Ma,相当于晚石炭世-早二叠世,表明志留系古油藏成藏时间主要为早海西晚期-晚海西期.英买力地区志留系沥青砂岩的自生伊利石年龄符合盆地内的整体分布规律.古构造格局和生烃中心可能是导致不同地区成藏时间差异的主要因为之一.荚买力地区成藏时间相对较晚,可能与其距生烃中心相对较远有关.图4表1参27
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