A New, Fast, and Efficient Method for Evaluating the Influence of Catalysts on In-Situ Combustion Process for Heavy Oil Recovery

The use of catalysts has been considered as an effective method to improve the efficiency of in-situ combustion (ISC) process for heavy oil recovery. In this work, we present a new small-scale combustion tube to quickly and effectively evaluate the effect of catalysts on ISC process. Different oil-soluble metal-based catalysts were evaluated for ISC process for heavy oil recovery using this small-scale combustion tube. These experiments can provide the information about the stability of combustion front, oil recovery, and in-situ oil upgrading information. Using this device, ISC process was successfully simulated. It turned out that the ISC process itself can effectively improve heavy oil recovery up to about 70 % and simultaneously achieve an in-situ oil upgrading evidenced by a significant viscosity reduction and an API increase. The presence of oil-soluble iron-based, nickel-based and copper-based catalysts can achieve a further oil upgrading to the level of medium oil from heavy oil with a more significant reduction in the content of resins and asphaltenes. However, the in-situ oil upgrading in ISC process yielded by iron-based and nickel-based catalysts at the expense of an unstable combustion front and a lower oil recovery (about 10 % lower than that without catalysts). The presence of copper-based catalysts not only achieved a further oil upgrading, but also improved the stability of combustion front and yielded a higher oil recovery (about 5 % higher than that without catalysts). The obtained results indicated that oil-soluble copper-based catalyst has a great potential for improving the efficiency of ISC processes for heavy oil recovery. The new small-scale combustion tube was proven to have the ability for a fast and effective evaluation of the influence of catalysts on ISC processes.