Abstract: When producing from offshore extended-reach wells using conventional dual-tank dual-pump technology, externally routed cables are prone to damage. Additionally, the dual-pump dual-tank configuration creates excessive projection area, increasing risks of flow restriction and erosion. In the dual Y-joint structure, the combined projection area of the bypass tubing and high-capacity electric submersible pumps (ESPs) exceeds the casing's inner diameter, with the bypass tubing also facing erosion risks. To address these challenges, a novel artificial lift design featuring a single-tank dual-ESP configuration was developed through comparative analysis of design software simulations and actual equipment structures. By employing specialized tools such as in-tank packers and expandable rotating subs to internalize cables and pipelines within the tank, a single-tank dual-ESP technology was created. Research results demonstrate this innovation reduces the tank's projected outer diameter to 193.7 mm, significantly smaller than the 215.9 mm ESP diameter of dual-Y configurations. This solution effectively mitigates cable damage risks and severe equipment erosion inherent in traditional external ESP arrangements. Successful field application has been achieved in the South China Sea's Enping 21-4 oilfield. This technological approach provides new insights for ESP deployment design in similar extended-reach wells.