Polymer treatments are an efficient and cost-effective technique to control water and oil flow in order to reduce water production significantly, leading to an enhanced oil recovery. Traditional PPGs are polyacrylamide-based hydrogel compositions which can withstand neither temperatures greater than about 80 °C nor high salinity conditions that are typical for many oil reservoir environments. For instance, there are many deep oilfield reservoirs worldwide which demand use of products that provide long term hydrolytic and thermal stability, e.g., at temperatures equal to or higher than 130 °C. In this paper, we describe a systematic approach to develop hydrogel compositions which can withstand temperatures of at least 150 °C. A unique high temperature-resistant hydrogel composition (HT-PPG) was developed with exceptional thermal stability for greater than 18 months in different brine environments. HT-PPG described herein can swell more than 30 times its initial volume in brines of different ionic strengths. We will present the effects of salinity, pH, temperature, and multivalent ions on swelling, swelling rate, and rheological behavior. HT-PPG compositions discussed herein are shown stable under conditions of high pressure and supercritical CO<sub>2</sub> conditions. We will demonstrate the effectiveness of HT-PPGs in reducing the permeability of open fractures by core flooding model results. Owing to its characteristic features, HT-PPG is a candidate for conformance control of reservoirs with harsh temperature and salinity environments.

Ultra-high temperature resistant preformed particle gels for water production control and enhanced oil recovery

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.