Quantifying the Transport of Superparamagnetic Nanoparticles in Porous Media Using an Acrylic Flow Cell and Integrated Magnetic Susceptibility Sensor Technique

Nanoparticle technology is starting to be explored by several groups worldwide in the petroleum industry, with potential applications of magnetic nanoparticle injection ranging from monitoring the progress of hydraulic fracturing jobs to enhancing oil recovery. However, there is currently a little published information regarding the optimum conditions for the transport of dispersed magnetic nanoparticles through reservoir material. Magnetic nanoparticles have a tendency to aggregate together, potentially blocking pore connections and degrading reservoir quality. We report results of initial experiments designed to determine the ideal conditions to transport superparamagnetic nanoparticle suspensions through simulated unconsolidated core material. We used a non-metallic flow cell and integrated magnetic susceptibility sensor technique to quantify the transport of the nanoparticle suspensions. The flow cell was made of an acrylic material and allowed simultaneous magnetic susceptibility monitoring at various positions along the cell whilst the flow experiments were taking place. Such in-line quantitative magnetic susceptibility monitoring of the nanoparticle suspensions during a fluid flow experiment represents a significant step forward in characterization techniques. Simultaneous magnetic susceptibility monitoring is not possible using traditional stainless steel flow cells. The new flow cell is also transparent, allowing visual observation of the progress of the nanoparticle suspensions. We describe the effect of different dispersants, sonications, injection rates, permeability of the porous media and nanoparticle types on the transport of the nanoparticle suspensions. The flow cell and magnetic monitoring system have several other potential applications, including simultaneous monitoring of fines migration along the length of a core plug during various fluid flow experiments.