Any latest development in the world of asphaltene inhibitor and asphaltene in general?
Ahmed Helmi
Adjunct Professor at Pharos University
Gents: I appreciate the initiator of this discussion Mike Davis and all the Commentators for extending my vision of Asphaltenes from the macro-scale to the micro-scale. Appreciate Win for a deeper vision beyond the micro-scale, I may call it the Sub-MicroScale. I wrote in a previous comment the need for a joint R&D research program by the Biggies of the O&G Industry to have a universal solution for the Asphaltenes depositional problems. Thanks to the last comment of Win as the Search engine lead me to a valuable published academic report authored by a researcher from the University of Illinois that digs in finding a Universal Solution. Here, I post the Abstract of this report hoping for your comments: G. Ali Mansoori Departments of BioEngineering, Chemical Engineering & Physics, University of Illinois at Chicago, Chicago, IL 60607-7052, USA E-mail: mansoori@uic.edu Abstract: We present a coherent and unified group of general explanations for the various phase transitions, which may occur in the seven naturally occurring petroleum fluids with emphasis on their heavy organics. The seven petroleum fluids include, in the order of their fluidity, natural gas, near-critical gas-condensate, light crude, intermediate crude, heavy oil, tar sand and oil shale. At first the nature of every petroleum fluid is presented including their constituents and their heavy fractions. Then their main families of constituents are presented. The generalised petroleum fluid phase behaviour is introduced in light of the well-known theory of phase transitions. The effects of variations of composition, temperature and pressure on petroleum fluids phase behaviour are introduced. Their 11 distinct phase-transition points are presented and their relation with state variables and constituents are identified. This report is the basis for development of a unified phase behaviour prediction model of all the petroleum fluids. Keywords: asphaltene; diamondoid; heavy oil; heavy organic; hydrocarbon; oil shale; phase transition points; polydisperse fluid; resin; tar sand. Reference: Mansoori, G.A. (2009), ‘A unified perspective on the phase behaviour of petroleum fluids’, Int. J. Oil,Gas and Coal Technology, Vol. 2, No. 2, pp.141–167.
If you read in this report, please see Fig. 8, as I suspect a printing error that spoils my interpretation of this particular valuable data presentation/plot. What do you think?
Win Robbins
Advanced Characterization - petroleum at Carmagen Engineering
Ahmed,
Mansoori makes a valiant effort to come up with a universal model based on phase transitions; however, his references to asphaltene composition and structure is 10-20 years out of date. The only recent reference that he cites for the "continental" model is Mullins (2006). Over the past 20 years the consensus has grown to prefer a mixed model with both continental and "archipelago"( model with a maximum of 6 fused aromatic rings linked by short C-C bonds or naphthenes.) Rodgers (FSU) and Qian (Exxon) have separately used different MS techniques to demonstrate the latter is the dominant structure in most cases. The more open structure is supported by Exxon asphaltene models (Siskin, 2006) and Exxon papers by Freund supporting a patented model for the fragmentation of kerogen and asphaltenes.(US 7,334,889). As for Mansoori's Figure 8, GCP or SEC is not adequate for determining the MW of asphaltenes, it only reveals the apparent molecular size for the asphaltene aggregates at the concentration and in the solvent used for the test.
Ahmed Helmi
Adjunct Professor at Pharos University
Win: I was about to shutdown my Laptop, take a break, then I made a visit to the Group to see if any comment. I am now fully alert and thanks again and again for your generous information about the latest updates in Asphaltenes' research. Mansoori is depending on the PT diagram and its Gas Envelope to characterize the separation of different phase/s per given change in PT and I was about to consider the extension of his approach when it comes to Asphaltenes as exaggeration; but I recalled a scene during a visit to the Lab of a Gas Separation plant west of Alexandria a couple of years ago. An experimentalist chief chemist of that Lab showed me his separated Asphaltenes out of Natural Gas Condensates with Gas Oil at its tail end. He managed to concentrate these Asphaltenes by several consequent distIllations starting with a Large quantity of Condensates. I was shocked as I used to tell my students that Asphaltenes can be found only in Crudes/Residues. Could these separated Asphaltenes precipitated out of the Condensates according to the PT Diagram? Rephrasing; could this support Mansoori's claim? Win: it seems that I always manage to drag you for deeper insights, will this one work?
