Molecular Design of the Amphiphilic Polymer as a Viscosity Reducer for Heavy Crude Oil: From Mesoscopic to Atomic Scale

Abstract

The use of an appropriate viscosity reducer is the key during the process of heavy crude oil exploitation. To design a new amphiphilic polymer as an efficient viscosity reducer, we combined the dissipative particle dynamics (DPD) simulation and allatom simulation in this work to reveal the viscosity reduction mechanism. Nine primary polymers were added into the oil−water system, in which the oil−water volume ratio was 4:1, by comparing the mean-square displacement (MSD) of asphaltene, aggregation ratio, the oil−water interfacial tension value, and the effects of nitrogen type, benzene ring morphology, and the alkyl side-chain length of the polymers on the properties of the system. The interaction mechanism was further revealed by analyzing the interaction energy between the asphaltene and the polymer molecules at the atomic scale. Finally, three kinds of polymers, P12, P22, and P31, which used polyacrylamide as a skeleton and were modified by pyrrolidone, a naphthalene ring, and the alkyl side chain without a −CH 2 group, respectively, were selected to design a new amphiphilic polymer as a viscosity reducer. This work combined the advantages of the mesoscopic and atomic simulation methods to design the amphiphilic polymer, shedding light on the development of the novel heavy-oil viscosity reducer.

Preparation of Temperature-Sensitive SiO2–PSBMA for Reducing the Viscosity of Heavy Oil

“…The modeling process was briefly described as follows. An oil–water system box (13.0 nm × 13.0 nm × 15.0 nm), containing saturates (74), aromatics (482), asphaltenes (30), resins (140), and water (15 177), was constructed, and the remaining molecular models used in the simulation were consistent with our previous studies. , Molecular dynamics simulations were then performed with GROMACS software. GROMOS-54A7 was chosen as the atomic force field. , The equilibrium phase simulation of 10 ns was performed under the NPT ensemble.…”

Chemical Additives as Flow Improvers for Waxy Crude Oil and Model Oil: A Critical Review Analyzing Structure–Efficacy Relationships

“…There have been studies on the strength reduction of selfaggregation of asphaltenes. Xu et al 136 chose nine polyacrylamide-based polymers of different chemical structures which could be grouped into three classes: nitrogen variants, aromatic ring variants, and alkyl chain variants. They combined the mesoscopic-scale and atomistic-scale simulations to obtain different parameters to estimate a better reduction in viscosity.…”

A Polycyclic–Aromatic Hydrocarbon-Based Water-Soluble Formulation for Heavy Oil Viscosity Reduction and Oil Displacement

“…56 Additionally, the naphthyl group was reported to be the most efficient in IFT reduction and reducing heavy oil viscosity among several functional groups covalently attached onto the PAM polymer backbone. 57 The solution viscosity of DDG/PAP can be significantly enhanced upon addition of the terpolymer PAAN. The ternary DDG/ PAP/PAAN system possessed a large viscosity in brine.…”

“…Naphthalene modified PAM has been demonstrated to be a qualified associative polymer for solution viscosity enhancement . Additionally, the naphthyl group was reported to be the most efficient in IFT reduction and reducing heavy oil viscosity among several functional groups covalently attached onto the PAM polymer backbone . The solution viscosity of DDG/PAP can be significantly enhanced upon addition of the terpolymer PAAN.…”