Injection of aqueous fluids into reservoirs as an enhanced oil recovery (EOR) tool has been of great interest in petroleum engineering. EOR using viscous polymer solutions improves the volumetric sweep efficiency. However, significant polymer adsorption on reservoir rock surfaces is one of the greatest challenges in polymer-flooding EOR. We have synthesized and characterized five zwitterionic copolymers and studied their static adsorption on limestone surfaces in seawater at high temperatures and salinities. Our results indicate that polymer adsorption directly correlates to a small percentage of functional co-monomers on the polymer backbone. One particular copolymer shows negligible static adsorption on limestone surfaces.
The injection of aqueous polymer solutions into reservoirs for enhanced oil recovery has attracted considerable interest in the petroleum industry. Polymers increase the viscosity of the fluids and thereby improve the volumetric sweep efficiency. However, significant polymer retention in reservoirs by adsorption to surfaces limits the propagation through the reservoir and can reduce the efficiency of the polymer flooding. To explore the structure−property relationships that can direct improvements in future polymer designs, we have investigated the dynamic adsorption of a model system of five zwitterionic copolymers using a quartz crystal microbalance with dissipation and core-flooding experiments at high temperatures and salinities. The results indicate that the degree of dynamic polymer retention is sensitive to a low percentage of functional comonomers on the polymer backbone. The concept of using a small fraction of comonomers to tune the adsorption of polymers is an attractive cost-effective method for modifying the properties of the polymers employed in the oil and gas industry.
Understanding
the interactions of surfactants and wettability alteration
of surfaces is important for many fields, including oil and gas recovery.
This work utilizes the quartz crystal microbalance with dissipation
to study the interaction of stabilized linear and branched alkylbenzene
sulfonates (ABSs), among the most cost-efficient industrial surfactants,
with water- and oil-wet calcite surfaces under high-salinity and high-temperature
conditions. Confocal laser scanning microscopy is also used to study
the effect of the type of ABS on their interaction with oil-wet calcite
surfaces. Experiments demonstrate that vesicles made of linear and
branched ABSs interact differently with both water- and oil-wet surfaces.
Therefore, surfactant formulations made of ABSs for high-salinity
applications can further be improved for advantageous wettability
properties by varying the hydrophobic chain of the surfactants. When
interacting with a water-wet surface, both types of vesicles adsorb
onto the surface as is. Upon dilution, however, vesicles made of linear
ABS stay adsorbed as is, and vesicles made of branched ABSs disassemble
and produce a layered structure with altered wettability. Linear ABSs
show greater efficiency in desorbing oil from the oil-wet calcite.
The results of this study demonstrate an improved method for studying
and understanding the interaction of surfactant formulations with
water- and oil-wet surfaces. This approach could significantly benefit
applications in which wettability alteration of surfaces is of great
interest and facilitate the implementation of low-cost surfactants
based on petroleum sulfonates.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.