Methods for improving heavy oils

A method for upgrading a heavy oil fraction in an oil well comprising:

• contacting a heavy oil in a rock formation associated with the well producing the heavy oil with a nanocatalyst for a time and under conditions sufficient for the nanocatalyst to adsorb an asphaltene in the heavy oil;
• wherein:
• the heavy oil comprises the asphaltene;
• the heavy oil fraction upgrading comprises adsorbing the asphaltene in the heavy oil onto the nanocatalyst in the well;
• said nanocatalyst comprises:
• nickel oxide nanoparticles supported on alumina nanoparticles;
• wherein:
• the alumina nanoparticle to nickel oxide nanoparticle weight to weight ratio in the catalyst is in a range of from about 99 to about 500;
• the particle size of the alumina nanoparticle is in the range of from about 30 to about 100 nanometers;
• the catalyst does not further comprise silver nanoparticles supported on the alumina nanoparticles;
• and
• the alumina nanoparticles are present in an amount of at least 99% by weight of catalyst or the SBET surface area is from about 17 to about 70 m2/g;
• and
• subsequent to the contacting, the well is maintained in a static condition for a period of time before heavy oil removal from the well is initiated.