In traditional production environments, clay expansion in the near wellbore area may hinder drilling and completion operations. However, most of the above stabilizers cannot meet the actual requirement because the general clay stabilizer cannot migrate through small voids, and can also cause damage to the environment and be very expensive. Herein the behavior of nanoparticles in stabilizing clay particles and the condition for reducing the clay swelling and reservoir damage are investigated.
The adsorption characteristics of nanoparticles on the core surface were studied by adsorption experiments and SEM. Displacement experiments of cores was conducted to discuss the migration behavior of nanoparticle inhibitors. In addition, the Malvern Zetasizer light reflectometer was employed to measure the electrokinetic potential of nanoparticles. To obtain a nanoparticle dispersion system, the dynamic dispersion measurement information of nanoparticle size distribution was collected. In the stability, by controlling the temperature, pH, pressure and other factors, the effects of these factors on the stability of the clay are investigated to obtain the mechanism of action of the nanoparticles.
The core piece was immersed in 1g/L nano-liquid. After adsorption for a period of time, it was observed by SEM that the hydrophobic nanoparticles could form an adsorption layer on the core surface and show a strong hydrophobicity. The nano-electromotive potential is stable at +38.2mV and −36.0mV, indicating that the dispersion is very stable. The dynamic dispersion measurement surface size of nanoparticle dispersion is much smaller than the typical pore and pore channel size in most reservoirs. The microparticles are dispersed and injected through a filter device with a pore size of 200 nm and all of them are dispersed through the core. There is no residue in the filter device, thereby achieving effective migration in the core. It can be concluded that the adsorption effect is stronger under alkaline conditions when the adsorption amount is only reduced by 10% at 950 °C. This is not affected by the pressure factor and also the adsorption effect is stable.
The action of mechanism between nano-silicone material and clay is obtained, and different factors are investigated to find out the prospect of nanoparticles in improving clay stability and reducing the reservoir damage.