@article{Xue2026, 
author = {Yan Xue and Xiao-Feng Zhao and Qiu-Lu Yin and Jing-Yang Gu and Bing Wei and Jun Lu},
title = {Thermally activated self-adhesive flexible granules for sealing fractures in high-temperature and high-salinity reservoirs: Synthesis, tunability, and performance evaluation},
year = {2026},
journal = {Petroleum Science},
volume = {23},
number = {9},
pages = {5757-5769},
keywords = {Fracture sealing, Self-adhesion, Response surface methodology, High-temperature and high-salinity reservoir},
url = {https://www.sciopen.com/article/10.1016/j.petsci.2026.06.019},
doi = {10.1016/j.petsci.2026.06.019},
abstract = {To overcome the limitations of conventional preformed particle gels in ultra-high-temperature and high-salinity fractured reservoirs, this study developed a novel self-adhesive flexible granule (SAFG). SAFG is synthesized through a two-step process involving the hydrophobic modification of polyvinyl alcohol, followed by chemical cross-linking with terephthalaldehyde, resulting in a stable granular structure. Comprehensive characterization confirmed the successful synthesis, tunable granule size controlled by stirring speed, and exceptional long-term thermal stability in high-salinity brine (2.1 × 105 mg/L, 130℃ for 180 d). Response surface methodology (RSM) optimization determined the optimal synthesis parameters, yielding granules with superior comprehensive performance. SAFG exhibits a unique, tunable self-adhesion mechanism activated by elevated temperature in high-salinity brine, transforming into a cohesive bulk gel. Core-flooding experiments demonstrated effective migration and dynamic plugging in simulated fractures (fracture widths of 0.5 and 1.0 mm), with optimal performance observed at injection rates of 1.5–2.5 mL/min and SAFG concentrations of 5.0 wt%. Critically, after thermally assisted adhesion aging, the adhered SAFG structure achieved a breakthrough pressure of 3080 kPa, approximately 6.3 times the initial stabilization pressure, confirming its robust sealing capability. This work demonstrates SAFG as a robust and tunable conformance control agent for extreme reservoir conditions, offering a viable solution to enhance oil recovery in challenging fractured formations.}
}