Extra-Heavy Crude Oil Downhole Upgrading Process using Hydrogen Donors under Steam Injection Conditions

摘要

An extra-heavy crude oil underground upgrading processis described which involves the downhole addition of ahydrogen donor additive (tetralin) under steam injectionconditions. Using a batch laboratory reactor or a continuousbench scale plant (280-315°C and residence times between 24-64 h), physical simulation experiments showed an increase ofat least 3° in API gravity of the treated Extra-Heavy CrudeOil, three-fold viscosity reduction and, approximately, 8%decrease in the asphaltene content with respect to the originalcrude. It was found that the presence of the natural formation(catalyst) and methane (natural gas) is necessary to enhancethe properties of the upgraded crude oil. Compositional-thermalnumerical simulations were carried out and the resultsshowed a good match between the calculated and experimental°API gravities of the upgraded crude oil (average relative error1-4%) for all conditions studied. Similar results were obtainedwith the asphaltene contents (14-23%), percentage ofconversion of the >500°C fraction (12%) and tetralin(16-23%).