厄瓜多尔Oriente盆地南部区块Napo组层序地层模式与岩性地层圈闭预测

应用经典层序地层学方法,通过不整合面、钻测井等标志将厄瓜多尔Oriente盆地南部区块Napo组划分为5个三级层序;以地层叠置样式、岩性、岩相的变化细分出陆架边缘、海侵和高位体系域。陆架边缘体系域以潮汐水道沉积为特征;海侵体系域以广泛分布的陆棚相泥岩沉积为特征;高位体系域发育加积式陆棚相灰岩沉积。最后识别出潮汐水道砂体、水下浅滩和M1岩性尖灭带3种有利的岩性地层圈闭,综合预测Oriente盆地南部区块Napo组的潮汐水道砂体发育区是最有利的勘探方向。

Sequence Stratigraphy Mode and Lithologic Traps Prediction of Napo Formation in South Block of Oriente Basin,Ecuador

Napo Formation in south block of Oriente basin can be divided into 5 sequences according to sequence boundaries,such as unconformity and seismic reflective characteristics.Shelf margins systems tracts,marine transgressive and highstand systems tracts can be subdivided by the stacking patterns of stratigraphy,changes of lithology and lithofacies.Shelf margin systems tract is characterized by the tidal flat,lacustrine transgressive systems tract is charaterized by the wide spread of marine mudstone sedimentation,and highstand systems tract is featured by the subaqueous shoal sandstone.It is identified that tide channel sandstone is the high quality reservoirs in south block,tide channel sandstone,M1 lithologic pointout zones,subaqueous shoal sandstone are the favorable lithologic traps.The oil shale of the Napo Formation marine shale can offer platitudinous hydrocarbon.The south block locates in the favorable directional zone of oil and gas migration.Hydrocarbon accumulation is in condition of pool-forming.Tide channel sandstone growing area is the beneficial exploration directions by integrated forecasting.