Feasibility Study Of Nano-catalyst Assisted Heavy Oil In-situ Combustion

During conventional in-situ combustion,improper production method and inadequate reservoir knowledge increase the amount of fuel burned during the process and reduce the production efficiency.Meanwhile,more carbon oxides are produced,and it causes greater pollution to the environment.In this paper,the variation of activation energy,combustion front propagation characteristics and fuel amount are studied in laboratory during heavy oil in-situ combustion with and without adding nano-catalysts,which provides a reference for solving the problems in heavy oil fire flooding production.Firstly,the variations of activation energy for heavy oil without and with different catalysts were compared by linear heating experiment in combustion cell.The activation energy of heavy oil during in-situ combustion decreases with the addition of different catalysts.The activation energy of heavy oil decreases by a relatively large extent with the addition of nano-alumina aqueous solution and nickel-cyclopentadiene toluene solution.Then,the dynamics of the two kinds of catalysts with different concentration on the combustion front propagation characteristics were studied through the combustion tube experiment.The results show that the addition of catalyst not only improves the combustion temperature,reduces the fuel amount and the residual coke,but also improves the speed of combustion front propagation.Also,it is found that the addition of oil-soluble catalyst will cause difficulties for ignition.The addition of nano-alumina aqueous solution reduced the production of COx by about 10%.PY-GC-MS results showed that the addition of nano-alumina solution resulted in the increase of pyrolysis products.Above all,nano-catalyst assisted heavy oil in-situ combution not only reduces the fuel amount of heavy oil,improves the recovery efficiency,but also improves the speed of combustion front propagation.Therefore,this idea has certain feasibility in field implementation.