建立高精度的等时地层格架、定量研究储层成因单元划分对比、为油田开发小尺度流动单元提供基础,是开发地质研究的目标,本文指出目前面临两种储层划分对比方法—基准面旋回与沉积旋回,说明高分辨率层序划分对比的精髓是基准面旋回的对比,大庆油田储层描述对比的关键是沉积旋回的对比,从而阐述了二者在划分对比的原则、方法及理论上异同。研究表明,这两种地层划分方法的理论基础皆为旋回 (自旋回或异旋回 )和层次、研究目标皆为地层格架及沉积地层单元的规模尺度。基准面旋回对比关键是旋回的组合分析,其方法在湖相 (异旋回 )中可行,在冲积相 (自旋回 )中基准面旋回划分困难,而且随意性很大;沉积旋回对比方法在河湖相对比中存在穿时现象,但应用广泛。不同级别基准面周期性的运动,使沉积旋回在周期性和规模上产生不同,形成层序的分级现象,所以说,沉积旋回和基准面旋回地层对比方法是从不同的角度对同一事物进行研究。进而讨论了旋回对比的两个关键问题—层次和界面,提出了存在的问题,对流动单元和剩余油分布研究具重大意义。
It is the research goal of the development geology to build up high-resolution isochronous sequence framework, quantitatively study the division and correlation of the reservoir genetic units and provide the basis for developing small-scale flow-units in Daqing oilfield. The paper points out that there are currently two methods on reservoir division and correlation, i.e. base-level cycle and sedimentary cycle, and the marrow of the high-resolution sequence division is the correlation of the base-level cycle. The key of the detailed geological description and correlation of Daqing oilfield is the correlation of sedimentary cycle. Thus, the author expounds the similarities and differences between the high-resolution sequence stratigraphy and detailed geological description and correlation of Daqing oilfield on such aspects as principles, methods and theory. This research also indicates that the theoretic basis of the two methods is cycle and sequence, and their research object is sequence framework and the scale of sedimentary sequence units. The combination of different cycles is very important in correlation of base-level cycle. It can be used in lacustrine facies analysis, but difficult in fluvial facies analysis and with some uncertainties. Sedimentary cycle exists diachronism in fluvial facies and lacustrine facies, but it can be used widely. The movement of base-level cycles of the different grades makes the difference in cycles and scales of sedimentary cycle, resulting in the grade of the sequence, therefore, base-level cycle and sedimentary cycle approach the same object from different ways. Furthermore, the paper discusses two key problems about cycles and correlation, i.e., sequence and boundaries, and their relevant questions. Finally, the author points out their important significances in studying the flow units and distribution of remnant oil.