Abstract
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.
Highlights
Along with profound exploration and exploitation (Figure 1), the oilfield at the No.1 area Yaojia formation reservoir in Daqing has come into the ultra-high water-containing phase(Fan & Ma, 2011; Ma et al, 2015; Lin, Shan, & Chen, 2017b; Yang et al, 2017)
Description and depositional analysis of the eleven coring holes of PI2 individual reservoir at the Putaohua reservoir formation in Daqing oilfield, we find that meandering channel micro-facies generally develop at the individual reservoir, which can be further divided into PI2a snaking stream (Figure 2b) and PI2b winding stream (Figure 2a) sublevel micro-facies(Figure 3)
In process of sedimentary diagenesis, along with depth increasing which results in the temperature increasing and pressure build-up, the organic thermal evolution will release plenty of CO2, which will be combined with a Ca2+、Mg2+ ion of reservoir water to form density interlayer of carbonate cementation
Summary
Along with profound exploration and exploitation (Figure 1), the oilfield at the No. area Yaojia formation reservoir in Daqing has come into the ultra-high water-containing phase(Fan & Ma, 2011; Ma et al, 2015; Lin, Shan, & Chen, 2017b; Yang et al, 2017). In the initial and middle stages of oilfield development, researches on oil layer emphasize the distribution, scale, connectedness and macro-heterogeneous of monosandbody, which plays an important part in the layout of the well network and oil-water dynamic and so on. Through the practice of oilfield, the thin interlayer in the reservoir plays an important role in fluid seepage of each layer(Wang, Xu, & Zhong, 2010; Miall, 2014; Lin, 2017; Lin, Shan, & Chen, 2017a; Matapour & Karlsen, 2017)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have