Propagation of Polymer Nanospheres in Outcrop Cores

作者：Nikita S. Lenchenkov, Michiel Slob, Gerard Glasbergen, Cor van Kruijsdijk · 发表于：SPE Journal · 年份：2019 · DOI：10.2118/194489-pa · 被引用次数：12 · 研究领域：Enhanced Oil Recovery Techniques、Hydraulic Fracturing and Reservoir Analysis、Hydrocarbon exploration and reservoir analysis

Summary When nanospheres are used for in-depth diversion in heterogeneous reservoirs, it is desired that spheres propagate deep into the reservoir along highly permeable zones with a resistance-factor (RF) buildup over time. This results in the reduced permeability of these reservoir zones and the diversion of subsequently injected water into unswept areas with higher oil saturation. Theoretically, a good propagation of the spheres can be achieved if their size is significantly smaller than the radius of pore throats. However, because of the interaction of nanospheres with each other and their swelling behavior, they can be retained without further propagation. Depending on the characteristics of the reservoir, the required deep propagation might not be realistic. Hence, it is important to study the influence of essential reservoir characteristics, such as brine salinity, saturation, and rock mineralogy, on the retention of the spheres in porous media. In this work, a series of coreflood experiments in Berea, Bentheimer, and Boise outcrop cores were performed to experimentally study the flow of nanospheres in porous media with different mineralogy and permeability. Complementary to that, the dynamic of the pressure drop over cores and the carbon content in the effluent were also analyzed at different injection flow rates. Dynamic light–scattering (DLS) tests indicated the size of nanospheres in different types of brine and helped to better understand their influence on the pr...