Experimental and numerical investigation of polymer pore-clogging in micromodels

Antonia Sugar; Maged Serag; Ulrich Buttner; Marwan Fahs; Satoshi Habuchi; Hussein Hoteit

doi:10.1038/s41598-023-34952-9

Experimental and numerical investigation of polymer pore-clogging in micromodels

Sci Rep. 2023 May 22;13(1):8245. doi: 10.1038/s41598-023-34952-9.

Authors

Antonia Sugar¹, Maged Serag², Ulrich Buttner³, Marwan Fahs⁴, Satoshi Habuchi², Hussein Hoteit⁵

Affiliations

¹ Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
² Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
³ Nanofabrication Core Lab, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
⁴ Institut Terre et Environnement de Strasbourg, Université de Strasbourg, CNRS, ENGEES, Strasbourg, France.
⁵ Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia. Hussein.hoteit@kaust.edu.sa.

Abstract

Polymers have been used effectively in the Oil & Gas Industry for a variety of field applications, such as enhanced oil recovery (EOR), well conformance, mobility control, and others. Polymer intermolecular interactions with the porous rock, in particular, formation clogging and the associated alterations to permeability, is a common problem in the industry. In this work, fluorescent polymers and single-molecule imaging are presented for the first time to assess the dynamic interaction and transport behavior of polymer molecules utilizing a microfluidic device. Pore-scale simulations are performed to replicate the experimental observations. The microfluidic chip, also known as a "Reservoir-on-a-Chip" functions as a 2D surrogate to evaluate the flow processes that take place at the pore-scale. The pore-throat sizes of an oil-bearing reservoir rock, which range from 2 to 10 nm, are taken into consideration while designing the microfluidic chip. Using soft lithography, we created the micromodel from polydimethylsiloxane (PDMS). The conventional use of tracers to monitor polymers has a restriction due to the tendency of polymer and tracer molecules to segregate. For the first time, we develop a novel microscopy method to observe the dynamic behavior of polymer pore-clogging and unclogging processes. We provide direct dynamic observations of polymer molecules during their transport within the aqueous phase and their clustering and accumulations. Pore-scale simulations were carried out to simulate the phenomena using a finite-element simulation tool. The simulations revealed a decline in flow conductivity over time within the flow channels that experienced polymer accumulation and retention, which is consistent with the experimental observation of polymer retention. The performed single-phase flow simulations allowed us to assess the flow behavior of the tagged polymer molecules within the aqueous phase. Additionally, both experimental observation and numerical simulations are used to evaluate the retention mechanisms that emerge during flow and how they affect apparent permeability. This work provides new insights to assessing the mechanisms of polymer retention in porous media.