A Study of Architecture of Thin Interlayer within Meandering River Monosandbody of Thick-Bedded Oil Layers

This paper investigates the reservoir architecture of thin interlayer within meandering river monosandbody in the thick-bedded oil layers. The thin interlayer within the monosandbody of the terrestrial reservoir is one of the dominant factors which form the reservoir heterogeneity of fluid motion. It is of equal importance in comparison with the rhythmic distribution of permeability, and it is also the important content of the elaborate representation of reservoirs. However, previous researches of the heterogeneity of reservoir focus mostly on the theory of distribution disparity of the permeability and neglect the influence of thin interlayer on the heterogeneity. Therefore, taking the PⅠ2 individual reservoir at the Putaohua reservoir formation in Daqing oilfield as an example, this paper analyzes the distribution, formation, and the three-dimensional construction of the internal thin interlayer of the monosandbody from a new point of view, on the basis of which a set of cycle research technique about it is put forward. With the method of configuration parameter extraction, which is most important before establishing interlayer configuration in three dimensions, this study clarifies the classification, causes of formation and the differences of distinct monosandbodies. Ultimately, four categories of thin interlayer according to the characteristics of the studied area is divided and two dominate causes for thin interlayer formation is discussed: argillaceous and arenaceous rock interlayer through deposition and interlayer in process of sedimentary diagenesis.For the convenience of the study, here mainly focuses on the thick - thin interlayer. Techniques are taken the use of determining the obliquity of the thin interlayer superface based on the configuration of paired wells and abandoned channel surface. The causes for thin interlayer and their classification, distribution and the three-dimensional construction are entirely revealed, which would possess important geologic meaning for taking affective engineering measures in the aspects of the elaborate representation of oil reservoir, and the research of remaining oil formation and distribution.