Evaluation of the Thermal, Chemical, Mechanical, and Microbial Stability of New Nanohybrids Based on Carboxymethyl-Scleroglucan and Silica Nanoparticles for EOR Applications

Abstract

Scleroglucan (SG) is resistant to harsh reservoir conditions such as high temperature, high shear stresses, and the presence of chemical substances. However, it is susceptible to biological degradation because bacteria use SG as a source of energy and carbon. All degradation effects lead to viscosity loss of the SG solutions, affecting their performance as an enhanced oil recovery (EOR) polymer. Recent studies have shown that nanoparticles (NPs) can mitigate these degradative effects. For this reason, the EOR performance of two new nanohybrids (NH-A and NH-B) based on carboxymethyl-scleroglucan and amino-functionalized silica nanoparticles was studied. The susceptibility of these products to chemical, mechanical, and thermal degradation was evaluated following standard procedures (API RP 63), and the microbial degradation was assessed under reservoir-relevant conditions (1311 ppm and 100 °C) using a bottle test system. The results showed that the chemical reactions for the nanohybrids obtained modified the SG triple helix configuration, impacting its viscosifying power. However, the nanohybrid solutions retained their viscosity during thermal, mechanical, and chemical degradation experiments due to the formation of a tridimensional network between the nanoparticles (NPs) and the SG. Also, NH-A and NH-B solutions exhibited bacterial control because of steric hindrances caused by nanoparticle modifications to SG. This prevents extracellular glucanases from recognizing the site of catalysis, limiting free glucose availability and generating cell death due to substrate depletion. This study provides insights into the performance of these nanohybrids and promotes their application in reservoirs with harsh conditions.

Expansion of Nanotechnology-Based Chemically Enhanced Oil Recovery Field Applications in Colombia: An Approach from Laboratory Experiments, Effluent Follow-Up, and Machine Learning

“…Regarding CEOR applications, nanomaterials have been developed mainly to optimize the performance of polymers and surfactants, among others. In the case of polymer systems, special attention has been paid to the inhibition of polymer degradation and improvement of the solution stability in polymers of different chemical nature with several types of nanoparticles. − However, polymer application under real conditions is limited due to the robust facilities that are required for polymer preparation in the field, which makes the development and expansion of field trials using nanoparticle-enhanced polymer solutions. On the other hand, when nanoparticles are added to surfactant-based solutions, there is no need of robust surface facilities for the injection , and several mechanisms can be impacted, including (i) reduction of the surfactant adsorption on the rock, (ii) reduction of interfacial tension, (iii) less amount of chemistry used in CEOR processes, and (iv) promotion of water-wettable surfaces. − In this sense, several studies have been developed under laboratory and field conditions to enhance surfactant-based processes with nanotechnology, including raw nanoparticles, ,− composite/functionalized/grafted nanomaterials, ,− Janus nanoparticles, − bionanofluids, − solvent-based nanofluids, , among others.…”