Oliver C. Mullins & Alan
G. Marshall talk with ScienceWatch.com and answer
a few questions about this month's Fast Breaking Paper in
the field of Engineering. The authors have also sent
along images of their work.
Oliver C. Mullins
Alan G. Marshall
Article Title: Contrasting perspective on
asphaltene molecular weight. This comment vs the overview
of A. A. Herod, K. D. Bartle, and R.
Journal: ENERG FUEL
Year: MAY-JUN 2008
* Schlumberger Doll Res Ctr, Cambridge, MA 02139 USA.
* Schlumberger Doll Res Ctr, Cambridge, MA 02139 USA.
* Univ Pablo De Olavide, Dept Sistemas Fisicos Quim
& Nat, Seville 41013, Spain.
* Florida State Univ, Natl High Magnet Field Lab,
Tallahassee, FL 32310 USA.
Why do you think your paper is highly
Per its title, our paper addresses one of the most basic properties of
asphaltenes—the most aromatic component of crude oil—their
molecular weight. Published differences of this property ranged over at
least a factor of 1000, with some reports having even larger disagreements.
Without resolution of this most basic property, the fields of petroleum and
asphaltene science become severely limited precluding new efficiencies in
the multi-trillion dollar petroleum industry.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
In our paper, we utilize many different techniques to obtain a robust value
of asphaltene molecular weight. In particular, we show the four different
techniques of measuring molecular diffusion and six different methods of
mass spectroscopy are now all yielding comparable results for asphaltene
deepwater gulf of
Moreover, recent work shows that aggregation of asphaltenes in both
solutions and in the laser desorption processes causes apparent molecular
weights to greatly exceed actual molecular weights. Unfortunately, there
had previously been greater reliance on techniques which were quite
susceptible to the unrecognized aggregation problems of asphaltenes.
Would you summarize the significance of your paper in
The most important property of chemical compounds is their elemental
composition. For asphaltenes, there was no uncertainty here. The second
most important property of chemical compounds is molecular weight.
For more than a generation, there had been orders of magnitude debate about
this property of asphaltenes. Because of the importance of this property,
every lab tried to measure it. However, many labs were ill-equipped to do
so, and the controversy raged.
There have been many recent advances in asphaltene science using very
sophisticated methods to resolve this issue. For example, the highest
resolution mass spectrometer on earth, at the National High Magnetic Field
Laboratory, Florida State University, has been used for exhaustive studies
on this topic, showing what is correct, confirming other studies, and why
previous results were in error.
How did you become involved in this research, and were
there any problems along the way?
The authors of this paper are building a new field called "petroleomics,"
which is defined as the characterization of petroleum at the molecular
level. The foundation of this field is to understand the chemical
constituents and interactions of petroleum.
The objective of the field is to optimize resource
utilization—including production, transportation, refining, heavy-end
upgrading, and asphaltic paving and coating materials.
The reach of the industry is enormous. Chemists can play a decisive role in
resource optimization, but only with the proper foundation. Petroleomics,
while still rather young, is already proving its mettle.
Where do you see your research leading in the
This research is already having enormous impact. For example, with newfound
knowledge of the molecular and colloidal structures of
asphaltenes—coupled with new technology—new solutions have been
demonstrated for the largest uncertainty in multibillion dollar oil
production projects, predicting the size of the subsurface oil reservoirs.
Ultrahigh resolution mass spectroscopy is pointing the way to identifying
deleterious oil components, previously undetected until after costly
problems had arisen.
Do you foresee any social or political implications for
Energy will remain one of the most important concerns of countries and
peoples around the world and petroleum will be in the mix long into the
future. In addition, for many countries mired in poverty, petroleum
represents their best hope for a better life.
The vision of petroleomics is to codify petroleum science as a proper
predictive science based on solid scientific and technical foundations.
This is mandated for improving efficiency in the increasingly expensive
arena of energy production. In addition, environmental concerns also
mandate efficiency in order to minimize impact.
Moreover, it is now recognized that the world's oceans contain an enormous
quantity of chemically altered asphaltenes from natural sources; likely a
sufficient quantity to be of concern for the global carbon cycle.
We are now merging scientific disciplines and treating the world's
hydrosphere and petroleosphere within a single fluid sphere. A single
scientific leadership impacting both environment and industry is our goal.
Oliver C. Mullins, Ph.D.
Reservoir Domain Champion for Wireline Headquarters
Cambridge, MA, USA
Alan G. Marshall, Ph.D.
Robert O. Lawton Professor of Chemistry & Biochemistry
Director, Ion Cyclotron Resonance Program
National High Magnetic Field Laboratory
Florida State University
Tallahassee, FL, USA Web