Research on Performance Evaluation and Mechanism Analysis of a Novel Nano Oil-Displacement System

Abstract

Abstract The heterogeneity of reservoirs in Offshore Oilfields is severe. There is a large amount of remaining oil exists in interlayer, intra layer, or microscopic pores after water flooding, which is difficult to be displaced efficiently. Therefore, a novel dispersion system has been developed in recent years. Due to its excellent performance and advanced mechanism, it can achieve the goal of deep fluid diversion and expanding swept volume. The dispersion system consists of particles and its carrier fluid. After coming into porous media, it shows the motion feature of "temporary plugging and good migration". In this paper, the preparation method, reservoir adaptability evaluation, and plugging characteristics of dispersion system is firstly studied. Then, by adopting the microfluidic technology, its oil displacement mechanism is further explored. On this basis, oil displacement evaluation is carried out through the CT technology. Results show that, by changing the type and amount of modifiers, spherical silicon-based nanomaterials ANS and flake silicon-based nanomaterials ALP were synthesized. The two nanofluids show a good ability to change the wettability of cores and strip oil droplets. On the other hand, through the migration performance test, ANS and ALP have temporary plugging characteristics and good migration performance, which can realize deep fluid diversion and expand swept volume. 3D macro physical simulation experiment shows that, dispersion system can achieve the goal of enhance oil recovery. In this paper, through the regulation of nanofluid conformation, the multiple effects of oil film stripping, emulsification, dispersion, temporary plugging, and oil displacement has been developed, which solves the bottleneck problem of potential application of new oil displacement agents. This lays a theoretical foundation for nanofluids flooding technology.