No abstract

Nanometals are useful for improving the effectiveness of in situ combustion-enhanced oil recovery. The effects of five different transition-metal nanoparticles on Colombian, Venezuelan, and Mexican crude oil samples are investigated. Experiments are used to measure the change in burning characteristics with additives at two different length scales. At the smallscale, it is shown that select nanoparticles decrease the apparent activation energy for combustion, change the gateway reaction (i.e., the reaction with the greatest activation energy), make combustion fuel more reactive, increase the fuel quality, and alter the low-temperature oxidation products. During reactive flow, the improvements as mentioned above are critical to help sustain combustion when excessive fuel deposition causes premature quenching. Copper, chromium, and titanium nanoparticles, on average, decrease the amount of fuel deposited and consumed during the process by 7%, increase the apparent H/C ratio of the coke by 15%, and increase the molar CO 2 /CO ratio of the combustion gas by 31%. These changes manifest in a decrease in water production (ΔWOR avg = −19%) and an average increase in oil production of 20%.

No abstract

We developed a novel technique based upon time-lapse infrared (IR) images to relate the effects of crude-oil oxidation kinetics on flow during one-dimensional homogeneous and heterogeneous laboratory-scale combustion tube experiments. We performed combustion tube experiments under variable conditions including different sands (i.e., grain-size distribution), air injection rate history (constant versus variable), degree of packing heterogeneity, and reaction heterogeneity. The latter is achieved by using reaction enhancing nanoparticles in controlled packing configurations. During every experiment, we obtain high-resolution IR images of the outer wall of the combustion tube that we calibrate using point-wise temperature measurements from a thermocouple. Here, a new experimental workflow that uses these images and combines knowledge obtained from kinetic cell experiments is used to isolate the spatial zones within the tube where so-called low-temperature and high-temperature oxidation (pseudoreaction regimes) occurs during combustion tube experiments for the first time. Additionally, the IR imaging technique is shown to provide new insight into the propagation of the combustion front in homogeneous and heterogeneous systems and, importantly, visualizes gravity drainage of hot oil.