【摘要】 通过精细岩芯描述、单井沉积微相分析与地震相、测井相综合研究,认为在塔里木盆地满加尔凹陷西缘奥陶系柯坪塔格组下段顶部含油气砂体中,发育3种类型的准层序:①粒级由底部粗—中下部细—上部粗的、反映整体向上变浅的海侵滞留沉积—海泛泥岩—滨岸沉积准层序,羊屋2井5460～5468m含油气段位于该准层序内;②粒级向上变粗的滨外泥岩—临滨-前滨沉积,顶部受风暴影响的准层序,跃南2井6503～6512m含油气段位于该准层序内;③粒级向上变细的潮下带—潮间带沉积的准层序,吉南1井5465～5486m含油气段属于此准层序。发育于羊屋2井中的第一种准层序内含油气砂体在时间上属于较早的准层序3,发育于跃南2井、哈得13井中的第二种准层序与吉南1井中的第三种准层序内的含油气砂体属于稍晚的准层序4。早期沉积的、发育于羊屋2井顶部的第一种准层序是有利储层发育段,该井区以北靠近柯坪塔格组下段顶面尖灭线附近的准层序3时期沉积的临滨相储层是油气聚集成藏的有利部位。更多还原

【Abstract】 Based on core facies sequence,sedimentary microfacies,seismic facies and logging facies,this study recognized three types of parasequence developed within oil-bearing sandstone of top Lower-Kepingtage Formation in the western margin of the Manjiaer Depression of Tarim Basin during the Ordovician. 1) Grain changes from coarse and medium grain at the bottom,fine-grained in the lower middle to coarse grain in the upper middle reflects a sedimentary parasequence from a shallow transgressive sedimentation,ingression mudstone to littoral deposition,in which oil-bearing section in Yangwu 2 well is located at the depth of 5460~5468 m; 2) Gradually-coarsened sedimentary sequences from offshore mudstone,shoreface and foreshore environments,with the top section influenced by storm,belong to the parasequence,and oil-bearing section was found to be at the depth of 6503~6512 m. 3) Parasequence depositing in sublittoral and intralittoral zones has fine grains upwards,in which oil-bearing section of Jinan No. 1 well was developed at the depth of 5465~5486 m. Oil-bearing sandstone of the first type of parasequence (Yangwu No. 2 well) is earlier that that of the third type,while Oil-bearing sandstones of the second type Grain (Yuenan No.2 and Hade No. 13 well) and of the third type (Jinan No. 3 well) is later than the fourth parasquence. The first-type parasequence developed at the top of Yangwo No. 2 well at the early stage is favorable zone to development of reservoirs layers. To the north of the well and close to the ower Kepingtage Formation,shoreoff reservoirs depositing at stage of the third-type parasequence is also favorable position for oil-gas accumulation.更多还原