构造运动、沉积作用和气候变化具有一定的周期性 ,导致沉积物在时间、空间上具有旋回性 ,垂向上具有分段性和周期性 ,平面上具有分带性 ,因此 ,沉积地层是具有层次的。依据这一原理 ,层次的划分由低级到高级划分为 9级层次。根据盆地演化、古生物、同位素及地质年代资料 ,将盆地基底或盖层作为 1级层次 ,界、系、统为2、3、4级层次 ,这是进行油气储层划分的基础。根据露头、岩芯、地震、测井资料在第 4级层次内划分出第 5级层次 (层序 ) ;继而根据高分辨率层序地层学原理在第 5级层次内可划分出第 6、7级层次 (中、短期旋回 )。最后 ,根据储层建筑结构层次分析原理和方法在第 7级层次内再划分出 8、9级层次 (单一成因砂体、复合成因砂体 )。层次的解释应在充分运用事件地层学、泥砂运动力学、现代沉积、露头调查、模拟实验的基础上 ,对沉积过程和层次成因作出合理解释。层次对比应遵循先低级后高级、先区域后局部及等时对比的原则 ,力求使各种地层对比、划分方法有机结合起来 ,取长补短 ,达到精细研究储层的目的 Tectonic movement, sedimentation and climate change have certain periodicity, resulting in cyclonicity in time and space, subdivision and periodicity in the vertical direction and zonality in the plane. Therefore, of. According to this principle, the level of division from low to high divided into nine levels. According to basin evolution, paleontology, isotope and geochronology, the basal or caprock of the basin is regarded as a first level, boundary, system and system as a 2,3,4 level, which is the basis for the division of oil and gas reservoirs. Based on outcrops, cores, earthquakes and logging data, the 5th level (sequence) is divided into 4 levels; then, according to the principle of high resolution sequence stratigraphy, the 6th, 7 levels (medium and short term cycle). Finally, according to the theory and method of AHP, the grade 8 and 9 (single genetic sand body and composite genetic sand body) are further divided into seven levels. The explanation of the level should give a reasonable explanation to the deposition process and the reason of the level on the basis of making full use of event stratigraphy, mechanics of sediment movement, modern sedimentation, outcrop investigation and simulation experiment. The comparison of levels should follow the principle of “prior to low-level senior”, “prior to regional” and “isochronous comparison”, so as to make the comparison and division of various stratums organically combine and complement each other to achieve the purpose of fine study of reservoirs