吐哈盆地托克逊凹陷中、上三叠统含油砂岩形成条件

The formation factorsof the oil-bearing sandstone in the Middle and Upper Triassic in Tuokexun depression of Turpan-Hami basin

采用岩石学、矿物学、X射线衍射分析技术及镜质体反射率等方法 ,分析了吐哈盆地托克逊凹陷含油砂岩特征及其形成条件。结果表明 ,沉积相、构造运动、地层水的性质及地温梯度等都是促成含油砂岩形成的重要因素。由此认为 :伊拉湖构造带与乌苏构造带具有不同的地质特征 ,前者为水下分流河道砂体 ,储集性能优良 ,且经历了后期酸性地层水与燕山运动的改善 ,后者为辫状河道砂体 ,物性较差 ;两构造带距主力生油区的距离不同 ,乌苏构造带距有效生油层远 ,而伊拉湖构造带距离生烃中心近 ,油源充足 ,生储盖组合匹配 。

By meansof petrology,mineralogy,X- ray diffraction analysis and vitrinite reflectance,the character and formation of the oil- bearing sandstone are studied in Tuokexun depression of Turpan- Hami basin. It may be concluded thatthe sedimentary facies,tectogenetic movement,the formation water and geothermic gradient are allimportantfactorsto form the oil- bearing sandstone.Itispossible thatthe Yilahu structuralbeltand Wusu structural belt have different geological feature.The former is subaqueous channel sandstone whose reservoir property is good and lately improved by acid formation waterand Yanshan movement.The laterisbraided river channel sandstone whose reservoir property is poor. In addition,the distance from the main source area is different. Wusu structural belt is far from the valid source bed,while the Yilahu structural beltis close to the source bed and can capture enough petroleum atthe good tectonic position.