【摘要】 以组作为岩石地层单元又作为年代地层单元的作法已存在多年，其主要弊端是地层界线不统一和单元过大，未能适应寻找地层圈闭或复杂圈闭类型油气田的需要。本文结合珠江口盆地的实例，总结了从应用岩石地层单元到层序地层学的年代地层单元的生产实践，认为层序地层学最重要的贡献是它能够提供统一的和比阶（或本区的组）更细的年代地层单元，从而提高年代地层对比的精度和预测岩相的能力。更多还原

【Abstract】 The“formation” has been used as both rock-stratigraphic unit and time-stratigraphic unit over the past several dozen years.The evil result lies in that the unit istoo big to fine stratigraphic or subtle traps,and the boundaries are always contradictoryfrom place to place. Sequence stratigraphy provides a unified and smaller time-stratigraph-ic unit-sequence,and will increase the possibility to predict sedimentary facies on bothregional and reservoir scale.更多还原