Chem. Engg. Seminar Series: Ateeque Malani

Molecular-Level interactions of Rock-Crude Oil interfaces: Fundamentals to Enhance Oil Recovery

Crude oil is a dirty mixture of organic molecules (of varying size, structure and affinity) which interacts with rock of sub-surface. For the extraction of this crude oil, several approaches are used from water to chemical/polymer/gas based flloding. The efficiency of enhanced oil recovery (EOR) is strongly influenced by the molecular-level interactions between crude oil components and reservoir rock surfaces. The deposition of heavy fractions such as asphaltenes leads to wettability alteration, pore blockage, and reduced oil mobility, posing significant technical and economic challenges. 

In our work,[1-6] molecular dynamics simulations are employed to systematically investigate the structural and energetic behavior of crude oil components—including saturates, aromatics, heavy oil, and model asphaltenes—on representative mineral surfaces such as calcite, silica, and mica. We have calculated Potential of mean force calculations (PMF) which reveal that asphaltenes exhibit significantly stronger adsorption than saturates, primarily due to heteroatom-mediated interactions. Polar functional groups (oxygen- and nitrogen-containing) enhance adsorption via electrostatic and hydrogen-bonding interactions, whereas sulfur-containing species show weaker affinity. The nature of the mineral surface plays a critical role: calcite exhibits the highest adhesion, followed by mica and silica.  Interfacial structuring reveals the formation of a dense adsorbed layer near the surface, with preferential adsorption of aromatic components on calcite and mica, and aliphatic components on silica. Molecular orientation is governed by the interplay between aromatic core interactions and steric effects of aliphatic chains. We also probed the free-energy of crude oil delamination from rock surface by the penetrating CO2 gas for both light and heavy oils[7]. We observe that CO2-EOR is favoruable for light-oil whereas a thermodynamic barrier exist for heavy oil which will affect the kinetics of CO2-EOR process for heavy-oil system. The delamination process is governed by the enthalpy (of oil-rock) and entropy of CO2 gas molecules. These insights provide a mechanistic framework for designing targeted solvents and additives to improve oil displacement and enhance EOR efficiency.

Biography: Dr. Ateeque Malani is a Professor in the Department of Chemical Engineering at the Indian Institute of Technology (IIT) Bombay, where he leads the Materials Modeling and Simulation Laboratory (MMSL). He holds an M.Tech. from IIT Bombay and a Ph.D. from IISc, Bangalore. Prior to joining the faculty at IIT Bombay, he advanced his expertise as a Postdoct at the UMASS, Amherst, and MIT. At IIT Bombay, his research group utilizes a multiscale simulation approach—combining Quantum Mechanics, Molecular Dynamics, Monte Carlo techniques, and continuum modeling—to tackle critical energy, environment, and industrial challenges.