Reservoir Description And Remaining Oil Distribution Study Of Thin-interbedded Reservoirs In Fault Block Shen 67 Of Liaohe Oilfield

With the proceeding of oil production,oilfields of the world have come into high water-cut stage. But for old oilfields, there are still large amounts of remaining oil stored in place. How to characterize the distribution of remaining oil and enhance oil recovery is the main purpose of the current exploration and exploitation activities. Reservoir geologic modeling and distribution of remaining oil, not only the main contents of reservoir description,but also the basis of developing reservoir, plays an important role in the overall exploration and exploitation.After collecting and re-processing of the data related with geological background, drilling, logging, lab analysis as well as seismic interpretation, starting from single sandbodies, this paper uses a multi-discipline theories and research methods such as stratigraphy, sedimentology, reservoir engineering, and well logging geology to study the structural framework, mico-structures, sedimentary facies, reservoir heterogeneity and flow units of the thin-interbedded reservoirs. In this way, this paper establishes one reservoir geological model under dense well pattern and analyzes the elements and mechanism that control the remaining oil accumulation in thin-interbedded reservoirs from views of both geological genesis and development influences. Taking Fault block Shen 67 as a case study, this paper studies the way for reservoir numerical simulation and remaining oil prediction methods for thin-interbedded reservoirs in both qualitative and quantitative ways. The main conclusions can be summarized as follows:1) The key for thin-interbedded sandstone reservoir correlation is the determination of the single sand body assemblage pattern. The correlation principle is determined after the determination of the assemblage pattern, ensuring a more effective beds correlation, which is more reasonable and close to the in-site geological conditions.2) The foundation for remaining oil study is fine geological modeling of the reservoirs under dense well pattern. For thin-interbedded sandstone reservoirs, the process includes the establishment of fine stratigraphical framework model, mico-structures model, sedimentary facies and micro-facies models, logging data interpretation model, reservoir heterogeneous model, as well as reservoir flow unit model. 3) The elements controlling the distribution of remaining oil include reservoir micro-structures, distribution of semdimentary facies, characteristics of reservoir heterogeneity, horizontal percolation difference, percolation baffle between different units, as well as the effective degree of water injection-production system. 4) The premise for the production of remaining oil is the determination of its distribution law and favorable regions, while the key point is the comprehensive evaluation of remaining oil potential.To sum up, this paper takes Fault block Shen 67 as an example and summarizes the methods and techniques to establish geological model for thin-interbedded sandstone reservoirs. During the research, static characters and dynamic features are both taken into account to combine both the static reservoir characteristics and the dynamic reservoir changes in the development stages. Finally, this paper develops a set of comprehensive prediction methods for remaining oil distribution, determines the favorable accumulation areas for remaining oil, thus provides practical direction and targets for further-step development procedures modification and potential-tap of remaining oil reserves in thin-interbedded sandstone reservoirs.