The Research and Application of Low-Dose Inhibitors for Solid Hydrate Prevention in Multiphase Transportation Pipeline

• Systematically compile global LDHI/hybrid hydrate inhibitor industrial-scale cases in complex operational conditions. • Compare THI/KHI/AA/HHI mechanisms, limits, and application scenarios. • Define synergy pathways for combined inhibitor strategies. • Propose eco-friendly multi-inhibitor systems reducing dosage and risks. • Optimize injection, compatibility, compliance via field-data guidelines. The expansion of deep-sea oil and gas exploration into low-temperature, high-pressure environments has heightened the risk of hydrate plugging in multiphase pipelines, threatening operational safety and production continuity. Traditional thermodynamic hydrate inhibitors (THIs), such as methanol and glycols, shift hydrate phase equilibrium but require large dosages under deepwater supercooling, raising costs and harming marine ecosystems. Low dosage hydrate inhibitors (LDHIs)—including kinetic hydrate inhibitors (KHIs) that delay nucleation and anti-agglomerants (AAs) that prevent particle aggregation—offer a cost-effective alternative with minimal environmental impact. However, despite robust laboratory evidence of their effectiveness, large-scale field data and operational experience remain limited. This review systematically categorizes hydrate inhibitors by type—THIs, KHIs, AAs—and explores their mechanisms and operational boundaries. This review also compiles global field applications of inhibitor systems from offshore basins such as the Gulf of Mexico, the North Sea, and the South China Sea. It identifies practical approaches to dose optimization that balance economic and environmental considerations. A comparative analysis of inhibitor performance highlights future directions for multi-inhibitor and environmentally benign formulations. Drawing on field data, the review offers engineering guidelines covering complex mix injection, chemical compatibility, and regulatory compliance. Bridging the gap between laboratory research and industrial application, this review offers critical references for safe, economical, and sustainable deepwater flow assurance, supporting efficient deepwater oil/gas development. It further drives hydrate inhibition technology toward low-cost, low-impact industrialization, boosting the sustainable development of offshore green energy.