Talk:Asphaltenes
Please post below any questions you have on asphaltenes.
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| Thread title | Replies | Last modified |
|---|---|---|
| Any latest development in the world of asphaltene inhibitor and asphaltene in general? | 31 | 04:51, 4 December 2013 |
Any latest development in the world of asphaltene inhibitor and asphaltene in general?
Last time I checked, asphaltene inhibitors are not that very effective (60 -70% effective in a good case) and hence a lot of asphaltene problems in the industry.
Does anyone have any new info to share on the latest development in the world of asphaltenes and asphaltene inhibitor?
Scott Lamb
Corrosion Inhibitor Chemical Manufacturer
As long as they could identify the value of the opportunity, then anyone with the funding could find a Universal Solution, regardless of national affiliation. My suspicion is that the costs associated with this solution have been weighed against the costs of the status quo, and the consensus may be that the less expensive option is to simply continue dealing with the asphaltene deposition problem using established methods.
Titus Sobisch
Senior Application Specialist at LUM seeking for new opportunity in R&D and customer support
Fully agree that the asphaltene problem is strongly associated with the solvent, i.e. crude oil composition. @Humberto I would assume that filtration efficiency based on compatibility of the filter (absorption) media to asphaltenes and the remaining crude oil would be more promising, i.e. finding out on which media or surfaces asphaltene deposition is strongest. Of course in any case problem of clogging would be the most serious one. Good luck.
Win Robbins
Advanced Characterization - petroleum at Carmagen Engineering
Humberto, Because asphaltenes precipitate as a function of solvent composition, there is no single size to remove by filtration. Although there are wide variations in detail, consensus analytical definition of asphaltenes is hepane insolubles toluene solubles. Numerous processes have been proposed for asphaltene removal, only a few have been found economic either due to filter plugging, energy costs or loss of "good" HC's. One such process is ROSE. Note that this process uses supercritical CO2 as a precipitating solvent (liquid CO2 is equivalent to nC6 in solvent power). Because asphaltenes are surface active they stabilize emulsions and foams. The latter is now used in froth processing Canadia tats sands. Rather than diluting with a "good solvent " like toluene, the tars sands are diluted with a paraffinic naphtha (solvency like heptane), frothed with gas vapor, and the froth enriched with asphaltenes and fine particulated skimmed away See.
Ahmed Helmi
Adjunct Professor at Pharos University
Win: The literature states that the molecular size of Colloidal Particles range from as small as 1 nanometer upto 1 micrometer. The consequent logic tells me that Humberto "should" use a filtration device having pores of 1 nanometer, ie. the smallest diameter for retaining the smallest particle. There is no role for any solvent in this rationale. But the logic tells me one further step: How Humberto would tackle / avoid plugging his filtration device in the very moment of the initial start up of his pilot plant?? Is it the role of high pressure? if so it may work in the beginning of a run but shortly the "high" pressure may cause getting the retained Asphaltenes as a compact layer on the surface of the filtration device. If Humberto could rely on intermittent operation meaning periodically stopping the run to skim the Asphaltene layer off his filtration device, could this be practically acceptable? I doubt. Humberto: Appreciate your elaboration.
Win Robbins
Advanced Characterization - petroleum at Carmagen Engineering
Ahmed,
Asphaltenes have no specific composition, rather the event of precipitation brought on by a change in solvent power (pressure drop, mixed crudes, or solvent addition) crashes a complex mixture of structures out solution. The precipitate includes not only insoluble compounds but a variety of trapped (occluded) solvent molecules. TWhereas the precipitated asphaltenes have a generic discotic (disk-like) character, the molecules within the precipitate slowly re-arrange. Kilpatrick has recently referred to the precipitates as "molecular velcro". In separate papers, Kilpatrick and Gray have published useful hypothetical models showing his type of aggregated material. Analytically, the size of the precipitate is a function of solvent composition and diluent volume; but no analytical technique has been able characterize a monomer of asphaltene. Most analytical methods use solvent/oil ratios >10, preferably >30, and allow the precipitate to age for several hours before filtration on disposable paper filters followed by extensive solvent washing. Such conditions are not economically feasible for a process. The ROSE process mentioned earlier is exception because the CO2 doesn't have to be recycled to be economic.
You are absolutely right about the filtration. Filtration through nano-porous ceramic membranes will remove some of the asphaltenes but at the expense of extreme pressure. After a few hours the pressure drop becomes excessive, recovery of precipitated material by backflush with a good solvent (toluene) is partially successful because the pressure has de-aggregated the asphaltene within the membrane pores leaving some insoluble deposit. After a few cycles, initial pressure drop is too high. In general, filtration is not a practical method for petroleum processing. If phase separation can be achieved predictably, then physical property separations( distillation, centrifugation, liquid/liquid extraction, etc) are more acceptable, especially if the phases can flow. Batch type operations like filtration are only practical for high value products.
Manfred Eigner
Owner, ME Consultancy Services (MECS) and Oil & Energy Consultant
Hi Mike, During my active career with Shell we did excellent research into the phenomena of asphaltenes and what they actually are. Lately, I did some work for Maersk Angola for developing a new oil field offshore Angola comprising an extensive literature study. What resulted was rather disappointing in terms of availability of suitable asphaltene inhibitors. They are not available yet, mainly because the chemical industry does not look for suitable products. All what is available is based on suitable surfactants but non of them based on the principle properties of asphaltenes. Having said this, to find a solution will be difficult anyway: asphaltenes vary a lot in composition. I reckon that the industry discovered that as well and are now aiming at quantifying the phase behavior of asphaltenes under a variety of production conditions, even commingling. In that way may be operators will be able to manage troublefree production when asphaltenes are present. Sorry for the bleak picture, but these are the facts, unless the chemical industry will make a dedicated effort.
Manfred
Tom McCartney
Director of Chemical Development
Hello Mike. The work on asphaltene inhibitor and dispersants have been ongoing for a number of companies. Not to blow my own horn (but if I don't who will) we have an excellent dispersant product that is highly effective in suspension of asphaltenes. Check out Paratene S627 on my website paratene.com - we have a number of case studies you may find interesting available.
Humberto Miguel Mejía Pérez
New Business Development IOS Group / Independent BD + Technologist + Systems Thinker
Tom is it possible to send me infor on the Paratene S627, I cannot access the website.
Manfred- excellent insight.
By any chance do you have a particle size distributions of the asphaltenes?
Manfred Eigner
Owner, ME Consultancy Services (MECS) and Oil & Energy Consultant
Humberto, Particle size of asphaltenes is difficult to give. Their size depends very much of their state of flocculation, so their original size in crude oil is very much different from when the precipitate from crude oil. To overcome this problem we started to mimic actual field conditions in coreflow experiments. There were a few surprises, mainly in the area of plugging phenomena. Can you me tell what you need the size distribution for.
Cheers Manfred
Humberto Miguel Mejía Pérez
New Business Development IOS Group / Independent BD + Technologist + Systems Thinker
Thanks Manfred- I am designing a filtration device to capture the asphaltenes, I have powdered particle distribution of asphaltenes that are free of resid, however, I want to have the "real" particle size distribution of the asphaltenes + resid, in the clean up process I need to recover as much resid as I can and therefore a chemical that can take on this problem is highly desirable
Prof. Dr. Hans-Jörg Oschmann
Prof. II Colloid and polymer chemistry at NTNU
@Humberto
If you are precipitating the asphaltenes + dry them to generate a powder you are very much moving away from the original colloidal system...
Manfred Eigner
Owner, ME Consultancy Services (MECS) and Oil & Energy Consultant
Dear professor Oschmann, It is good that the scientific world takes part in the discussions. I must point out that the chemical solutions offered to-day are not fully suitable. Especially not for offshore applications where we have to operate underwater completions, remotely operate valves etc., hence we can not accept a product that is will eliminate the problem of deposition for 60-70%. This is a no go as the deposition will take place and will hamper operation of underwater completions. In the field of scale inhibitors the world looks different as there are very effective products available. Moreover, there chemistry differs from what is being offered to counteract asphaltene precipitation.
Humberto Miguel Mejía Pérez
New Business Development IOS Group / Independent BD + Technologist + Systems Thinker
Dear Prof. Hans- Thanks for the note. Since Mike's post also inquires about asphaltene in general, I take the opportunity to interact with the Group in order to see if the conceptual design I am working on is valid. I am planning to deasphalt via mechanical filtration, the idea is not new, once the asphaltene flocs are trapped in the porous structure the idea is to see how to remove the resid content that binds to the asphaltene core in order to have recover as much resid as possible and mix with the DAO, this is where chemistry would come into play, I am considering Supercritical CO2 solvent extracting, ideally after that I would have "pure" asphaltenes granules trapped in the porrous stucture that I would oxidize to then afterward recover V and Ni from the water.
Mike Davis
Senior Technical Writer/Editor at OilfieldWiki.com
@Prof. Dr. Hans-Jörg Oschmann
The 60-70% reduction comes from experience as well. I agree, asphaltene is a little easier to treat than wax because wax inhibitor can also have poor performance, never 100%. asphaltene is also easier to dissolve than wax. A lot of times, asphaltene deposition is saved by high flow rate while wax doesn't benefit from it as much.
Prof. Dr. Hans-Jörg Oschmann
Prof. II Colloid and polymer chemistry at NTNU
Thanks Mike, I may have been lucky as I have a lot of cases where we had 100% efficiency (confirmed by monitoring/pigging inspection). All of them however are via continuous treatment below bubble point or early injection into incompatible crude (aliphatic condensate / black oil). Good point rgds the high flow rate / shear! This matches others experience as well and was one of the points brought up in the asphaltenes discussion at the recent SPE workshop on flow assurance in Norway (Tackling Tomorrow's Challenges 13 - 14 November 2013).
@Manfred - totally agree that 60-70% efficiency would be a killer for many subsea applications. That was why I was a bit surprised as many GoM projects rely on highly effective asphaltenes inhibition. Nobody can nowadays afford a "Prinos" asphaltenes disaster with wells blocking up quicker then you can look.
Prof. Dr. Hans-Jörg Oschmann
Prof. II Colloid and polymer chemistry at NTNU
Hi Humberto,
just to get this correct- do you want to focus primarily on the recovery of the metals? If yes you may be better of using iso-octane or similar medium mol. weight aliphatics as you will separate a lot of lower molecular weight colloids with the supercritical CO2. Also if you go with supercritical CO2 as opposed to liquid CO2 you will partially break down asphaltene agglomerates changing their properties.
Humberto Miguel Mejía Pérez
New Business Development IOS Group / Independent BD + Technologist + Systems Thinker
Thanks Prof Hans-
Actually v and Ni recovery is just an added bonus operation that has to be considered depending on the site economics.
The process would be run batch type
1- HO would cycle though a filtration media to capture the asphatenes.
2- Once asphaltenes are "trapped" a DAO (deasphalted oil) is obtained and removed.
3- The filtration media would be regenerated via SCCo2, other solvents to recover resid.
4- At this stage we should have solid asphaltene granules in the porous structure, that would be oxidized, if in water media the water would have the V and the Ni + other compunds such as S, etc.
Hope this helps
Win Robbins
Advanced Characterization - petroleum at Carmagen Engineering
Asphaltenes are not a compound or a class of compounds, they are an event cuased by solvent incompatibility. A solvent strength change can occur by pressure drop in the production tubing in the upstream or by blending with oils with different composition, i.e. both upstream and downstream. Asphaltene aggregation and precipitation causes problems in areas as diverse as emulsions in oil water separators/desalters, deposits & fouling in heat exchangers, poisoning& plugging hydroprocessing catalysts, and even creating hotspots in cokers. The "composition" and occurrence of asphaltenes has been studied extensively both academically and by the refining industry. Over my 30+ years working for Exxon, I followed processes have proposed for asphaltene and metals removal, including some of my own. In the past decade, more characterization has been achieved, but the problems remain.
Search the literature for papers by Mullins (Schlumberger) for discussions of size and pressure drop, Kilpatrick (Notre Dame) Rodgers (FSU-NationalHigh Field Magnet Lab) for compostion, Chapman (Rice) and Folger (U MIchigan) on phase behavior, Buckley(New Mexco Tech) and Jeff Creek (Chervon) on flow assurance, and Wiehe (Soluble Solutions) for discussion of solvent compatibility. All these individuals have been working closely with chemical service vendors in addressing asphaltene deposition. As Manfred has indicated, success is limited to specific cases because the "asphaltene event" can be induced by so many variables that there is no universal solution.
