Study on Low-Temperature Coated Sand Technology for Gas Hydrate Reservoirs

To address the challenges of insufficient consolidation strength and instability in conventional coated sand under low-temperature conditions in hydrate-bearing formations, this study systematically evaluated compressive strength and permeability under varying operational parameters (5–15 ℃ temperature, 0–70000 mg/L salinity, and 24–48 h curing time) to select an optimized low-temperature coated sand (RCS-1). Experimental results demonstrate that the consolidated sand body achieved a compressive strength exceeding 5.34 MPa and permeability up to 2533 mD through controlled compaction. Rapid mechanical stabilization was observed within 8 h of curing, with performance parameters stabilizing after 24 h. The optimized coated sand exhibited exceptional resistance to formation water (3-day compressive strength loss: 1.23%) and moderate alkali tolerance (24.50% strength reduction), though significant degradation occurred in acidic environments (67.23% strength loss). Additionally, it demonstrated superior resistance to formation water scouring. These findings confirm that the optimized coated sand RCS-1 meets critical performance requirements for hydrate reservoir engineering applications, providing reliable maintenance of formation integrity and effective permeability control in low-temperature environments.