Advances and Future Prospects of Temperature and Salt-Resistant Gel Materials for Downhole Plugging Applications

The exploitation of deep hydrocarbon resources in extreme environments, particularly high-temperature and high-salinity (HTHS) carbonate reservoirs, poses unprecedented challenges for downhole plugging operations. This review provides a critical analysis of the development of gel-based plugging materials designed to withstand these harsh conditions. It systematically examines three primary material categories-polymers, inorganic composites, and nanocomposites-dissecting the fundamental relationships between their molecular architectures and their resulting performance, including the pervasive trade-offs between mechanical strength, stability, and controllable degradation. While highlighting promising advances, such as bio-derived polymers and self-healing mechanisms, the review explicitly identifies the limitations of current technologies, most notably their inadequate long-term durability under synergistic HTHS stress and lack of industrial scalability. This forward-looking perspective emphasizes the integration of nano-reinforcements and stimuli-responsive chemistries as a critical pathway toward achieving the next generation of high-performance, deployable, and environmentally considerate plugging materials, thereby ensuring the efficient and sustainable development of challenging oil and gas assets.