A fishing neck is a specially designed protrusion or groove on downhole tools (e.g., gas lift valves, packers) that allows retrieval tools (overshots, spears) to latch onto and pull the tool out of the wellbore. Application Highlights •Deepwater Recovery: Retrieved fractured drill collars at 6,800m in Tarim Basin, reducing operation time by 60% •H₂S Resistance: Hastelloy slips operated corrosion-free in Sichuan Basin sour gas wells. •Marginal Field Economics: Modular design cuts single-job cost by 35% with payback <3 months.