Conformance control evaluation of the of cellulose nanocrystals based CO2 foams stabilized in synergy with surfactant

Abstract

Using biomass-derived materials for oil production is not a new concept but using them to stabilize foam via synergistic interactions is new for oil production. There is a lack of research and technology showing the advantage of biomass-derived nanomaterials at reservoir conditions for CO2 Enhanced oil recovery processes. Cellulose nanocrystal (CNC) is an Alberta based wood-derived nanomaterial. In this work, we are testing the feasibility of CNC based CO2 foam synergistically stabilized by CNC and surfactant. We first design a composition of CNC/surfactant for stable CO2 foam on the concept of synergy between nanoparticles and surfactant. Then we evaluate the conformance control of CNC-enabled foam in dynamic tests and view how foam evolves over time using computed tomography imaging. Ultra-stable foam is achieved with surfactant concentration as low as 0.05 wt%. Foam potential in limiting the CO2 pathways is shown and its conformance control ability is confirmed visually. This study demonstrates a cost-effective and simple way of surface modification by using a cationic surfactant via electrostatic interactions. Instead of bringing modified CNCs to the interface for the stabilization, the synergism between DTAB and native CNCs is exploited to obtain Pickering foams with superior stabilities. The results provide baseline information for other research on CNC based fluids for underground applications.