Evaluation of silicone fluids and resins as CO2 thickeners for enhanced oil recovery using a computational and experimental approach

GALLO, GONZALO; ERDMANN, ELEONORA; CAVASOTTO, CLAUDIO N

ACS Omega

American Chemical Society

Año: 2021 vol. 6 p. 24803 - 24813

2470-1343

CO2 thickeners have the potential to be a game-changer forenhanced oil recovery (EOR), carbon capture utilization and storage,and hydraulic fracturing. Thickener design is challenging due topolymers´ low solubility in supercritical CO2 (scCO2)and the difficulty of substantially increasing the viscosity of theCO2. In this contribution, we present a framework todesign CO2 soluble thickeners, combining calculationsusing a quantum mechanical solvation model with direct laboratoryviscosity testing The Conductor-like Polarizable Continuum Model forsolvation free energy calculation was used to determine functionalsilicones and silsesquioxanes solubilities in scCO2. Thismethod allowed for a fast and efficient identification of CO2soluble compounds, revealing silsesquioxanes as more CO2-philicthan linear polydimethylsiloxane (PDMS), the most efficientnon-fluorinated thickener know to date). The rolling ball apparatuswas used to measure the viscosity of scCO2 with both PDMSand silicone resins with added silica nanoparticles. Methyl siliconeresins were found to be stable and fast to disperse in scCO2while having a significant thickening effect. They have a largereffect on the solution viscosity than higher molecular weightpolydimethylsiloxane and are able to thicken CO2 even athigh temperatures. Silicone resins are thus shown to be promisingscCO2 thickeners, exhibiting enhanced solubility and goodrheological properties, while also havingmoderate cost and being easily commercially attainable.p { margin-bottom: 0.1in; direction: ltr; line-height: 115%; text-align: left; orphans: 0; widows: 0 }p.western { font-family: "Times New Roman", serif; font-size: 12pt; so-language: en-US }p.cjk { font-family: "Times New Roman"; font-size: 12pt; so-language: en-US }a:link { color: #0000ff }