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.