塔里木盆地塔中隆起志留系油气聚集控制因素

塔中隆起志留系中沥青及可动油气显示十分丰富。油气聚集的基本特征是多油气源、多成藏期、多油气藏类型、多油气产状。纵向上志留系油气分布受盖层控制,沥青和稠油分布在塔塔埃尔塔格组下段红色泥岩段以下,而现今可动油则集中分布在柯坪塔格组上二亚段灰色泥岩之下。平面上,志留系油气聚集受构造背景控制,继承性发育的古隆起决定各个时期油气运移指向,塔中地区油气基本上是自北西向南东方向运移。潮坪相沉积决定了薄砂层单个砂体规模不大,一系列砂体靠断层沟通。塔中地区志留系形成了油气丰度不高、在空间上叠置连片、大面积分布、受多种圈闭类型控制的油气聚集特征。

Controlling Factors on Petroleum Accumulation in Silurian Reservoir in Tazhong Uplift of Tarim Basin

The asphalt, movable oil and gas shows are quite abundant in the Silurian reservoir in the Tazhong uplift. Hydrocarbon accumulations of the Silurian are characterized by multiple sources of oil and gas, multiple stages of reservoir formation, multiple types of pools, and multiple occurrences of oil and gas. Vertically, hydrocarbon distributions of the Silurian are controlled by the cap beds. The asphalt and heavy oil of the Silurian are distributed under the red mudstone of the lower member of Tataaiertage Formation, while the movable oils are distributed under the gray mudstone of the second upper sub-member of Kepingtage Formation. Hydrocarbon accumulations of the Silurian are plainly controlled by structural background, paleo-uplift of inherited development determines the migration directions of hydrocarbon, and hydrocarbon of the Tazhong area basically migrated from northwest to southeast. The single sandstone body formed in tide environment is thin and its scale is small. A series of sandstone body were communicated by faults. The Silurian hydrocarbon accumulation of Tazhong area is characterized by no highness in abundance of hydrocarbon accumulation, coincidence of thin layers with large distributive area, and control of several types of traps.