High-Temperature Stable Dispersed Particle Gel for Enhanced Profile Control in Carbon Capture, Utilization, and Storage (CCUS) Applications

CO2-responsive gels, which swell upon contact with CO2, are widely used for profile control to plug high-permeability gas flow channels in carbon capture, utilization, and storage (CCUS) applications in oil reservoirs. However, the use of these gels in high-temperature CCUS applications is limited due to their reversible swelling behavior at elevated temperatures. In this study, a novel dispersed particle gel (DPG) suspension is developed for high-temperature profile control in CCUS applications. First, we synthesize a double-network hydrogel consisting of a crosslinked polyacrylamide (PAAm) network and a crosslinked sodium alginate (SA) network. The hydrogel is then sheared in water to form a pre-prepared DPG suspension. To enhance its performance, the gel particles are modified by introducing potassium methylsilanetriolate (PMS) upon CO2 exposure. Comparing the particle size distributions of the modified and pre-prepared DPG suspension reveals a significant swelling of gel particles, over twice their original size. Moreover, subjecting the new DPG suspension to a 100 degrees C environment for 24 h demonstrates that its gel particle sizes do not decrease, confirming irreversible swelling, which is a significant advantage over the traditional CO2-responsive gels. Thermogravimetric analysis further indicates improved thermal stability compared to the pre-prepared DPG particles. Core flooding experiments show that the new DPG suspension achieves a high plugging efficiency of 95.3% in plugging an ultra-high permeability sandpack, whereas the pre-prepared DPG suspension achieves only 82.8%. With its high swelling ratio, irreversible swelling at high temperatures, enhanced thermal stability, and superior plugging performance, the newly developed DPG suspension in this work presents a highly promising solution for profile control in high-temperature CCUS applications. (c) 2025 THE AUTHORS. Published by Elsevier LTD on behalf of Chinese Academy of Engineering and Higher Education Press Limited Company. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).