An extra-heavy crude oil underground upgrading process is described which involves the downhole addition of a hydrogen donor additive (tetralin) under steam injection conditions. Using a batch laboratory reactor or a continuous bench scale plant (280–315°C and residence times between 24–64 h), physical simulation experiments showed an increase of at least 3° in API gravity of the treated Extra-Heavy Crude Oil, three-fold viscosity reduction and, approximately, 8% decrease in the asphaltene content with respect to the original crude. It was found that the presence of the natural formation (catalyst) and methane (natural gas) is necessary to enhance the properties of the upgraded crude oil. Compositional-thermal numerical simulations were carried out and the results showed a good match between the calculated and experimental °API gravities of the upgraded crude oil (average relative error 1–4%) for all conditions studied. Similar results were obtained with the asphaltene contents (14–23%), percentage of conversion of the >500°C fraction (12%) and tetralin (16–23%). Introduction Downhole extra-heavy crude oil upgrading processes have high potential value due to the possibility of improving crude oil quality with the concomitant higher benefits obtained by their exploitation. Underground processes leads to several advantages in comparison with aboveground counterparts. First at all, enhanced oil recovery could be obtained by adding additional oil reserves. Also, increase in the volumetric production of wells and lower lifting and transportation costs from the underground to the refining centers could be generated. Finally, the use of porous media (mineral formation) as natural chemical "catalytic reactor" will improve the upgraded crude oil properties with further reductions in expenses during down stream refining operations. Several routes for underground extra-heavy crude oil upgrading have been reported. These concepts involve the following: Physical separations (steam distillation1 or deasphalting2), underground cracking or hydrocracking (visbreaking3–4, hydrogen6 or hydrogen precursor injection6–7) and in situ combustion8–9. In this work, a different concept10 is presented (Fig. 1) involving the underground addition of a hydrogen donor additive (tetralin), which in the presence of steam, natural formation (catalyst) and methane (natural gas), leads to extra-heavy crude oil upgrading. This concept is coupled to a steam stimulation process11 with 70–80% hydrogen donor recycled as depicted in Fig. 1. Specifically, batch reactor and continuous bench scale plant physical simulations are presented under steam injection conditions (280°C, 1600 psi), and crude oil upgrading is measured in terms of its API gravity, viscosity and percentages of asphaltenes. Different extra-heavy crude oils were studied and compositional thermal simulations were carried out in order to model the upgrading process under steam stimulation conditions. Experimental Part The extra-heavy crude oils came from the Orinoco Belt (Hamaca and Cerro Negro) and their properties are listed in Table 1. The percentages of asphaltenes were measured using the ASTM D-3279 and crude oil viscosities in a Brookfield apparatus, model RVTDV-II.
The present research aims to describe a meta synthesis, the types of meta synthesis, its limitations and benefits of the application of this type of methods in research, being used mainly for qualitative studies, related to the medical area or the Branch of psychology in which the characteristics of the patients and their particular situation allows to evidence the viability of what one wants to try. It describes the procedures that must be carried out to achieve a meta-analysis, which differs from traditional research since it is necessary to detail the methodology of each study that was applied to evidence its results generating global conclusions for a given situation. The metasynthesis as a concept has been studied by different authors, coming to agree that it is a way to integrate qualitative research findings to achieve a new interpretation that explains the phenomenon with a higher level of scientific evidence
This paper aims to analyze the negotiations between the Andean Community of Nations and the European Union and the impact on the Ecuadorian trade balance from 2000 to 2010, taking into account that since Ecuador becomes a member of the then called the Andean Pact, now Community of Andean Nations, various economic benefits obtained as an increase in terms of local recognition and bargaining power, although stocks of information asymmetries and shortcomings of its productive apparatus. In the field of international negotiations, it has to be in terms of trade, the EU is the second most important partner of the Andean Community of Nations according to statistics figures of recent years, and this relative importance began from the previous decade. That is why trade relations between Ecuador and the European Union and its impact on Ecuador's trade balance will be analyzed, along with the trade balance between Ecuador and the Andean Community of Nations, where an econometric analysis using cointegration between balance is made commercial and trade balance of Ecuador Andean Community of Nations European Union, an analysis of impulse response function Ecuador's trade balance. Demonstrating empirically the impact of the agreements between these integration blocs in the trade balance of Ecuador, to propose corrective measures medium to long term.
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