Increase Heavy-Oil Production in Combustion Tube Experiments through the Use of Catalyst

Abstract

In this research a catalyst was evaluated in a combustion tube using heavy oil from Gulf of Mexico. The underlying objective is to increase the mobility of the oil inside the reservoir by effect of the catalyst during the combustion. The catalyst, used in the experiments was previously mixed with heavy crude oil of 12.5 °API. The catalyst, in liquid phase, is based in Molybdenum, Cobalt, Nickel and Iron. This organometallic catalyst is highly soluble and ultradispersed, and it was mixture with heavy crude oil with a concentration of 750 ppm wt. The porous media used in the combustion tube was a triturated dolomite carbonated rock with a 41.9% of porosity, and a particle size of 0.42 mm. This rock was used for two experiments at the same saturation conditions: heavy crude oil (23.79%), and water (25.26%). The results obtained shown the advantages of use of catalyst in relationship of a conventional combustion as follows:oil production increases,faster combustion front,higher efficiency in the combustion, andhigher temperatures at the beginning of the combustion. The use of this kind of organometallic catalyst at low concentrations is a potential application in order to upgrade the oil properties in-situ, saving the cost of facilities on surface required for the same purpose. Introduction Exploitation of reservoirs in the world is steadely moving inexorably towards large reserves of heavy crude oil. Producing, transporting and marketing this heavy oil represents a lot of problems, including almost inability of most refineries to accept heavy crude oils. Heavy crude oils could be more accceptable if they can be upgraded prior to send it to refineries. One of the techniques in which heat is purposely introduced into an oil-bearing formation primarily to reduce oil viscosity is the process called in-situ combustion. However, there is the idea of combination of this process with the use of catalysts as alternative to upgrade the heavy oil prior to production and prior to reaching the surface stock tank, either in an oil-bearing reservoir, near a producing well, or in the producing wellbore: in-situ catalytic upgrading process. Several experimental investigations have been considered studies of combustion front behavior in porous media with catalytic agents following different routes: Downhole physical separations such as steam distillation 1, and deasphalting 2–4, thermal conversion as v.gr. visbraking 5,6, underground hydrogen 7–12, hydrogen precursor injection 13 and, in-situ combustion 14,15. It was reported previously that metallic additives increased fuel deposition, although the mechanism is not well understood 16–19. Examples of comprehensive studies about enhancing the combustion process by addition of metallic salts have shown that for some crude oils there is a modification of the reaction kinetics in a favorable way: salts such as tin chloride or ferric nitrate, promote combustion of light oils, being that combustion more uniform and occurs at higher temperature. However, in another study was not possible to obtain a sustained combustion of light oil without the addition of metallic salts 20. There are more works reported on mechanistic studies about upgrading extra heavy crude oil, and even with heavy oil residues using hydrogen sources and the addition of metallic catalyst without consider any air injection in the process 21–23.

Catalytic Effect of Transition Metallic Additives on the Light Oil Low-Temperature Oxidation Reaction

“…Studies of catalytic low-temperature oxidation (CLTO) technologies applied on light oil at reservoir temperatures and pressures have seldom been reported in the published literature. The procedures and results of the previous studies ,− of crude oil catalytic oxidation technology are summarized in Table .…”

Crude Oil Oxidation in an Air Injection Based Enhanced Oil Recovery Process: Chemical Reaction Mechanism and Catalysis

“…Compared with metal oxide particles and water-soluble metallic salts, oil-dispersed metal-based catalysts started to be studied relatively late (see Table ). In 2007 and 2008, Ramírez-Garnica et al , reported Ni, Mo, Fe, and Co-based acetylacetonate or alkylhexanoate as oil-dispersed organometallic catalysts for increasing oil production in ISC processes. They indicated that these organometallic catalysts accelerated the combustion front propagation velocity, improved the combustion efficiency of oils, and increased oil recovery.…”

Effect of Different Water Content and Catalyst on the Performance of Heavy Oil Oxidation in Porous Media for In Situ Upgrading

“…Because of these unpleasant aspects of metals, metal oxides, and water-soluble metal salts as a catalyst or a precursor, ISC technology has tended to emphasize the need for other species of catalysts or precursors that are widely distributed and readily soluble in heavy oil continue . Using metal catalysts with a high valence electronic state and being oil-soluble or oil-dispersed in heavy crude oil in the ISC process dramatically improves stability of the combustion front. ,,, Recently, oil-soluble and oil-dispersed catalysts, due to their high distribution in the crude oil environments, have been considered as an option for oil oxidation in porous media to improve the enhanced oil recovery and reduced the viscosity of the produced oil. ,,− Previous work by our group has shown that oil-dispersed iron oxide is highly distributed in heavy oil environments, including both liquid and porous forms, resulting in lower ignition temperatures and oxidation temperatures in both stages of heavy oil combustion (LTO and HTO) …”