Microscopic details of asphaltenes aggregation onset during waterflooding

G.Ali Mansoori; Salah Yaseen

arxiv: 1906.08105 · v2 · pith:ULMV66G2new · submitted 2019-06-19 · ⚛️ physics.chem-ph · cond-mat.soft

Microscopic details of asphaltenes aggregation onset during waterflooding

Salah Yaseen , G.Ali Mansoori This is my paper

Pith reviewed 2026-05-25 20:07 UTC · model grok-4.3

classification ⚛️ physics.chem-ph cond-mat.soft

keywords asphaltenesaggregation onsetwaterfloodingmolecular dynamicshydrogen bondingpetroleum reservoirscrude oilblockage prevention

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The pith

Asphaltene aggregation during waterflooding occurs through asphaltene-water interaction followed by water bridging and face-to-face stacking.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper uses molecular dynamics simulations to study how asphaltenes begin to aggregate when water is introduced into petroleum reservoirs at high pressure and temperature. The simulations indicate that aggregation starts with interactions between asphaltene and water molecules. This is followed by water molecules forming bridges between asphaltenes and then the asphaltenes stacking face to face. A surrounding network of hydrogen bonds then strengthens the aggregates. Such details could support efforts to predict and prevent blockages in oil reservoirs.

Core claim

Our simulation results illustrate that the aggregation onset in waterflooding generally follows three sequential steps: (i). Asphaltene-water interaction; (ii). Water bridging; (iii). Face-to-face stacking. Then, asphaltene-water and water-water hydrogen-bonding network surround every aggregate boosting the intensity of aggregation onset.

What carries the argument

The three-step sequence of asphaltene aggregation onset identified through molecular dynamics simulations of asphaltenic-oil miscibilized with water.

Load-bearing premise

The molecular dynamics model and simulation conditions accurately represent the behavior of asphaltenes in actual petroleum reservoir systems.

What would settle it

An experimental observation or alternative simulation showing asphaltene aggregation in waterflooding without the sequence of asphaltene-water interaction, water bridging, and face-to-face stacking would challenge the claim.

Figures

Figures reproduced from arXiv: 1906.08105 by G.Ali Mansoori, Salah Yaseen.

**Figure 1.** Figure 1: These molecules were also used in our previous studies (Yaseen and Mansoori 2017; 2018a; 2018b). Their molecular weights are ranged between 543 (A1) and 1197 (A4). Their molecular architectures are classified into the island (A1,A3,A4,A5,A7) and archipelago (A2,A6). Their elemental compositions are mainly composed of carbon and hydrogen atoms. However, their structures also contain heteroatoms, including … view at source ↗

**Figure 2.** Figure 2: (i) HypotheticalB molecules, having the same structures as asphaltenes in [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗

**Figure 3.** Figure 3: RDFsof asphaltenes-asphaltenes stacking as compared with RDFsof hypothetical molecules (B and C).Differencesof RDFsof asphaltenes with hypothetical molecules, B & C, are indications of the roles of heteroatoms (N, O, S) in asphaltenes aggregation. Allthe calculationsare for the centers of mass interactions.The two-coloredgraphs in Figures 3-1 and 3-5 indicate the similarityof results for asphaltenes with B… view at source ↗

**Figure 4.** Figure 4: Relative distributionsof water around various segments listed above (represented by RDFs)appearing in asphaltenes, B and C molecules [PITH_FULL_IMAGE:figures/full_fig_p005_4.png] view at source ↗

**Figure 5.** Figure 5: Relative distributionsof N-and O-segments in the stacked asphaltenes and hypothetical B molecules at their onset of aggregation. The distributionis represented by segment-segment RDFsof one molecule with respect to another [PITH_FULL_IMAGE:figures/full_fig_p006_5.png] view at source ↗

**Figure 6.** Figure 6: Schematic representation of sequential steps involved in asphaltenes aggregation due to waterflooding. In these figures, oil is omitted for clarity. Stage I: Asphaltene-water interaction via HBAi-W. Stage II:Formationof water bridges by HBW-W. Stage III:Face-to-facestacking configurationof asphaltenes via p–p interaction. 578 S. Yaseen and G.A. Mansoori Microscopic details of asphaltenes aggregation onset… view at source ↗

read the original abstract

We report detailed microscopic studies of asphaltenes aggregation onset during waterflooding of petroleum reservoirs. To achieve this objective, a series of simulations are performed on asphaltenic-oil miscibilized with water at high pressure and temperature through molecular dynamics. Results of this simulation onset are applicable to asphaltenes behavior in real crude oils. Our simulation results illustrate that the aggregation onset in waterflooding generally follows three sequential steps: (i). Asphaltene-water interaction; (ii). Water bridging; (iii). Face-to-face stacking. Then, asphaltene-water and water-water hydrogen-bonding network surround every aggregate boosting the intensity of aggregation onset. We intend to utilize such understanding of these details in our predictive and preventive measures of arterial blockage in oil reservoirs during waterflooding.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

The paper claims a three-step MD sequence for asphaltene aggregation in waterflooding plus an H-bond boost, but supplies none of the methods, parameters, or validation needed to check it.

read the letter

The main takeaway is that the authors ran molecular dynamics on an asphaltenic oil mixed with water and extracted a three-step aggregation path: asphaltene-water contact, water bridging, then face-to-face stacking, with an asphaltene-water and water-water hydrogen-bond network said to intensify the process. They state the results apply to real crude oils and intend to use the picture for blocking prevention during waterflooding. That sequence and the explicit H-bond role are the concrete claims on offer. The work applies an existing simulation method to a narrow industrial setting and gives a mechanistic sketch that could, in principle, suggest where to look for deposition control. Beyond that, there is little else. The manuscript reports no force-field details, no system sizes or compositions, no temperatures or pressures used, no analysis protocol for identifying the steps, and no comparison to any experimental aggregation threshold or SARA data. The applicability statement to real reservoir fluids is simply asserted. The stress-test note is therefore correct: without calibration or sensitivity checks, the transferability claim does not hold up. A reader cannot tell whether the reported steps are robust or sensitive to the particular molecular models chosen. This is the sort of short note that might interest a small group working on reservoir chemistry who are already running similar simulations and want one more data point. It is not ready for a general audience or for anyone who needs reproducible or validated results. I would not bring it to a reading group, would not cite it, and would not send it to referees; the authors would first have to supply the missing technical information before any serious evaluation is possible.

Referee Report

2 major / 1 minor

Summary. The manuscript reports molecular dynamics simulations of asphaltenic-oil systems miscibilized with water at high pressure and temperature. It claims that asphaltenes aggregation onset during waterflooding follows three sequential steps—(i) asphaltene-water interaction, (ii) water bridging, (iii) face-to-face stacking—after which asphaltene-water and water-water hydrogen-bonding networks surround aggregates and intensify the process. The authors state that the results apply to real crude oils and can inform preventive measures against reservoir blockages.

Significance. If the underlying MD trajectories are shown to be robust and transferable, the three-step sequence plus H-bond network description could supply useful microscopic insight into a process relevant to petroleum engineering. The work identifies a potential mechanistic pathway that might be exploited for blockage mitigation, but the complete absence of methodological specifics prevents any assessment of whether this pathway is actually supported by the simulations.

major comments (2)

[Abstract] Abstract: the claim that 'Results of this simulation onset are applicable to asphaltenes behavior in real crude oils' is unsupported; no calibration against experimental onset pressures, SARA fractions, or aggregation thresholds for the modeled asphaltene is reported, leaving the transferability of the three-step sequence to polydisperse reservoir fluids untested.
[Abstract] Abstract: no force-field choice, system composition, box sizes, thermostat/barostat settings, equilibration protocol, or convergence diagnostics are supplied, so it is impossible to determine whether the reported sequence (i)–(iii) is an artifact of the particular model or a general feature of the physics.

minor comments (1)

[Abstract] Abstract: the phrasing 'simulation onset' and 'this simulation onset' is non-standard and obscures the intended meaning; rephrase to 'the onset of aggregation observed in these simulations'.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive comments. Below we respond point-by-point to the major issues raised.

read point-by-point responses

Referee: [Abstract] Abstract: the claim that 'Results of this simulation onset are applicable to asphaltenes behavior in real crude oils' is unsupported; no calibration against experimental onset pressures, SARA fractions, or aggregation thresholds for the modeled asphaltene is reported, leaving the transferability of the three-step sequence to polydisperse reservoir fluids untested.

Authors: We agree that the manuscript contains no direct calibration against experimental onset pressures, SARA data, or aggregation thresholds. The simulations employ a single model asphaltene structure, and the abstract statement therefore overreaches. We will revise the abstract to remove the claim of direct applicability and instead note that the identified mechanism supplies microscopic insight into the modeled system. revision: yes
Referee: [Abstract] Abstract: no force-field choice, system composition, box sizes, thermostat/barostat settings, equilibration protocol, or convergence diagnostics are supplied, so it is impossible to determine whether the reported sequence (i)–(iii) is an artifact of the particular model or a general feature of the physics.

Authors: These parameters are described in the Methods section of the full manuscript (force field, molecular counts, box dimensions, NPT settings, equilibration protocol, and multiple independent trajectories). Because the abstract is intentionally concise, the details are not repeated there. We will add a brief summary of the key simulation parameters to the revised abstract to allow immediate assessment of robustness. revision: partial

Circularity Check

0 steps flagged

No circularity; claims rest on MD trajectories, not self-referential construction

full rationale

The paper reports molecular dynamics simulation outcomes for asphaltene aggregation steps during waterflooding. The three-step sequence and hydrogen-bonding network are extracted directly from observed simulation trajectories under specified conditions. No equations, fitted parameters, or self-citations are invoked that would make any claimed result equivalent to its own inputs by construction. The statement of applicability to real crude oils is an interpretive assertion external to any internal derivation, leaving the core simulation-based findings self-contained against the model's own outputs.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

Based solely on the abstract; no explicit free parameters, additional axioms, or invented entities are stated. The central transferability claim rests on an unelaborated domain assumption that the simulation represents real crude oils.

axioms (1)

domain assumption The molecular dynamics simulation accurately captures asphaltenes behavior in real crude oils at reservoir conditions.
Stated directly in the abstract as applicability of results to real crude oils, without supporting evidence or validation described.

pith-pipeline@v0.9.0 · 5664 in / 1329 out tokens · 33754 ms · 2026-05-25T20:07:28.415903+00:00 · methodology

discussion (0)

Reference graph

Works this paper leans on

7 extracted references · 7 canonical work pages

[1]

SPE Production & Facilities 12 (02):116 –22

Viscometric principles of onsets of colloidal asphaltene flocculation in par- affinic oils and asphaltene micellization in aromatics. SPE Production & Facilities 12 (02):116 –22. doi: 10.2118/ 28729-PA. 579 Salah Yaseen https://orcid.org/0000-0003-0724-8044 https://orcid.org/0000-0003-3497-8720G.Ali Mansoori S. Yaseen and G.A. Mansoori Microscopic details...

work page 2019
[2]

Journal of Petroleum Science and Engineering 41 (1 –3):169–82

Measurement and correspond- ing states modeling of asphaltene precipitation in Jilin reservoir oils. Journal of Petroleum Science and Engineering 41 (1 –3):169–82. doi: 10.1016/S0920-4105(03)00151-7. Jorgensen, W. L., D. S. Maxwell, and J. Tirado-Rives

work page doi:10.1016/s0920-4105(03)00151-7
[3]

Journal of the American Chemical Society 118 (45):11225 –36

Development and testing of the OPLS all-atom force field on conformational energetics and properties of organic liquids. Journal of the American Chemical Society 118 (45):11225 –36. doi: 10.1021/ja9621760. Khalaf, M. H., and G. A. Mansoori. 2018a. Asphaltenes aggregation during petroleum reservoir air and nitrogen flooding. Journal of Petroleum Science an...

work page doi:10.1021/ja9621760 2018
[4]

Journal of Petroleum Science and Engineering 1 (3):229 –39

Asphaltene deposition: A survey of field experiences and research approaches. Journal of Petroleum Science and Engineering 1 (3):229 –39. doi: 10.1016/0920-4105(88)90013-7. Mansoori, G. A

work page doi:10.1016/0920-4105(88)90013-7
[5]

International Journal of Oil, Gas and Coal Technology 2 (2):141 –67

A unified perspective on the phase behaviour of petroleum fluids. International Journal of Oil, Gas and Coal Technology 2 (2):141 –67. doi: 10.1504/IJOGCT.2009.024884. Mohammed, S., and G. A. Mansoori

work page doi:10.1504/ijogct.2009.024884 2009
[6]

Journal of Petroleum Science and Engineering 26 (1 –4):49–55

Identification and measurement of petroleum precipitates. Journal of Petroleum Science and Engineering 26 (1 –4):49–55. doi: 10.1016/S0920-4105(00)00020-6. Yaseen, S., and G. A. Mansoori

work page doi:10.1016/s0920-4105(00)00020-6
[7]

Journal of Petroleum Science and Engineering 156 :118–24

Molecular dynamics studies of interaction between asphaltenes and solvents. Journal of Petroleum Science and Engineering 156 :118–24. doi: 10.1016/j.petrol.2017.05.018. Yaseen, S., and G. A. Mansoori. 2018a. Asphaltenes aggregation due to waterflooding (A molecular dynamics simu- lation study). Journal of Petroleum Science and Engineering 170:177–83. doi:...

work page doi:10.1016/j.petrol.2017.05.018 2017

[1] [1]

SPE Production & Facilities 12 (02):116 –22

Viscometric principles of onsets of colloidal asphaltene flocculation in par- affinic oils and asphaltene micellization in aromatics. SPE Production & Facilities 12 (02):116 –22. doi: 10.2118/ 28729-PA. 579 Salah Yaseen https://orcid.org/0000-0003-0724-8044 https://orcid.org/0000-0003-3497-8720G.Ali Mansoori S. Yaseen and G.A. Mansoori Microscopic details...

work page 2019

[2] [2]

Journal of Petroleum Science and Engineering 41 (1 –3):169–82

Measurement and correspond- ing states modeling of asphaltene precipitation in Jilin reservoir oils. Journal of Petroleum Science and Engineering 41 (1 –3):169–82. doi: 10.1016/S0920-4105(03)00151-7. Jorgensen, W. L., D. S. Maxwell, and J. Tirado-Rives

work page doi:10.1016/s0920-4105(03)00151-7

[3] [3]

Journal of the American Chemical Society 118 (45):11225 –36

Development and testing of the OPLS all-atom force field on conformational energetics and properties of organic liquids. Journal of the American Chemical Society 118 (45):11225 –36. doi: 10.1021/ja9621760. Khalaf, M. H., and G. A. Mansoori. 2018a. Asphaltenes aggregation during petroleum reservoir air and nitrogen flooding. Journal of Petroleum Science an...

work page doi:10.1021/ja9621760 2018

[4] [4]

Journal of Petroleum Science and Engineering 1 (3):229 –39

Asphaltene deposition: A survey of field experiences and research approaches. Journal of Petroleum Science and Engineering 1 (3):229 –39. doi: 10.1016/0920-4105(88)90013-7. Mansoori, G. A

work page doi:10.1016/0920-4105(88)90013-7

[5] [5]

International Journal of Oil, Gas and Coal Technology 2 (2):141 –67

A unified perspective on the phase behaviour of petroleum fluids. International Journal of Oil, Gas and Coal Technology 2 (2):141 –67. doi: 10.1504/IJOGCT.2009.024884. Mohammed, S., and G. A. Mansoori

work page doi:10.1504/ijogct.2009.024884 2009

[6] [6]

Journal of Petroleum Science and Engineering 26 (1 –4):49–55

Identification and measurement of petroleum precipitates. Journal of Petroleum Science and Engineering 26 (1 –4):49–55. doi: 10.1016/S0920-4105(00)00020-6. Yaseen, S., and G. A. Mansoori

work page doi:10.1016/s0920-4105(00)00020-6

[7] [7]

Journal of Petroleum Science and Engineering 156 :118–24

Molecular dynamics studies of interaction between asphaltenes and solvents. Journal of Petroleum Science and Engineering 156 :118–24. doi: 10.1016/j.petrol.2017.05.018. Yaseen, S., and G. A. Mansoori. 2018a. Asphaltenes aggregation due to waterflooding (A molecular dynamics simu- lation study). Journal of Petroleum Science and Engineering 170:177–83. doi:...

work page doi:10.1016/j.petrol.2017.05.018 2017