台北凹陷西部七克台组油气成藏有利条件分析

台北凹陷西部七克台组自生、自储、自盖，构成良好的区域性生储盖组合。上段为大套暗色泥岩，既是生油层，也是区域性盖层；下段集中发育储集层，可分为上、下2个砂岩组，其中上砂岩组砂层单层厚度小，岩性细，排驱压力略高、孔喉半径略小，属滨湖滩坝砂和席状砂，含油气性优于下砂岩组，是今后滚动勘探的重点层系。受区域构造和沉积背景双重影响．台北西部七克台组具备形成低幅度背斜、断块和岩性多种(圈闭)油气藏的石油地质条件。火焰山构造带上盘是今后评价勘探低幅度背斜型油藏的重点领域；火焰山构造带下盘是继续滚动勘探断块型(圈闭)油藏的重点区域；古弧形带东斜坡和火焰山构造带北坡是突破岩性油藏的重点地区。

Favorable reservoir forming conditions in Qiketai formation in the west of Taibei Sag

Qiketai formation in the west of Taibei Sag has good regional assemblage of source rock, reservoir and caprock. There is a large set of dark shale in the upper section, which served as both source bed and regional caprock. Reservoir rocks were assembled in the lower section, which can be divided into upper and lower sand unit. In the upper unit, single layer thickness is thin, lithology is fine, explusion pressure is slightly high, and pore throat radius is small. It belongs to lake beach bar sand and sheet sand, with oil-bearing property better than the lower sand unit, and is the key strata of future progressive exploration. As influenced by both regional structure and sedimentary background, Qiketai formation had the geological conditions of forming low-amplitude anticline, faulted block and lithologic (traps) reservoirs. The upper wall of Huoyanshan structure belt is an important zone of exploring low-amplitude anticline reservoirs in the future; the lower wall is important for progressive exploration of faulted block reservoirs; the east slope of arc-like belt and the north slope of Huoyanshan structure are important for discovering lithologic reservoirs.