Transport of Non-Aqueous Nano-Dispersed Catalyst Suspensions in Porous Media.

摘要

Vast heavy oil and bitumen resources and the current environmental challenges associated with their exploitation beckon new ideas for improved production technology. One promising new idea is the proposed in-situ upgrading of heavy oil during thermal recovery by catalytic hydrogenation using nanometer size dispersed catalysts. This requires placement of the ultra-dispersed catalysts deep into the formation where it can accelerate the high temperature upgrading reactions.;Propagation of ultra-dispersed catalysts suspended in oil with and without commercial surfactant through the sand beds was examined. Effects of several parameters, including connate water salinity, absolute permeability, system temperature, and particle concentration were also evaluated. At the end, the propagation behavior of ultra-dispersed catalyst particles in Athabasca reservoir sand was examined at two different flow rates.;The results show that it is possible to propagate the ultra-dispersed catalyst suspensions through sand beds. However, the catalyst particles deposit along the sand pack in a way that much higher retention occurs in the entrance region of the bed. Particles appear to be deposited on sand surfaces by an attachment mechanism deep inside the bed but larger particles appear to be strained by mechanical trapping near the inlet face. The deposition of particles was found to be almost irreversible.;A phenomenological approach was used to model the macroscopic propagation behavior of suspended particles in the porous medium. The model was used to history match the effluent composition profile observed in the experiments and the deposition profile obtained from post-mortem analysis.;This dissertation presents the results of several experiments that were carried out to systematically examine the propagation of nano-dispersed catalyst suspensions in sand packs at simulated reservoir conditions. These experiments involved injection of nano-size catalyst particles suspended in oil into a sand pack. The concentration and size distribution of the particles injected at the inlet and produced at the production end were measured. The pressure drops in different segments along length of the sand pack were monitored continuously. The retention behavior of particles in the sand was examined by measuring the catalyst concentration in the bed as a function of the distance from the injection end.