The refining of crude oil is central to the petroleum value chain, yet Nigeria’s dependence on conventional large-scale refineries has been hindered by infrastructural and economic challenges. Modular refineries have emerged as a flexible and cost-effective alternative; however, their predominant reliance on topping technology has resulted in high residue yields and systemic inefficiencies. This study evaluates the technical and economic feasibility of hydro-skimming modular refineries for Nigerian crude oils including Bonny Light, Bonny Medium, Qua Iboe, and Nigeria Brass. This was carried out using Aspen HYSYS simulations. The hydro-skimming process was modeled to assess product yields including off gases, liquefied petroleum gas (LPG), gasoline, jet fuel, wastewater, residue, and automotive gas oil (AGO). The Economic viability was analyzed through deterministic and stochastic models incorporating capital and operational expenditures, Net Present Value (NPV), Internal Rate of Return (IRR), and payback period. The highest yield of LPG (7.10 m3/hr), and gasoline (69 m3/hr) were obtained from Nigeria Brass, and that of the jet fuel (20.10 m3/hr), and AGO (70.30 m3/hr) was produced from Bonny Medium. The least yield of off gases (5.5E-08 m3/hr), wastewater (5.40 m3/hr), and residue (30.40 m3/hr) were obtained from Bonny Light, Nigeria Brass and Qua Iboe, respectively. The result of the economic analysis shows a strong investment potential, with NPVs exceeding $300 million and IRRs above 140 % across crude types. The results demonstrate that hydro-skimming significantly reduces residue compared to topping units, enhances gasoline and diesel yields, and meets modern fuel quality standards. These findings highlight hydro-skimming modular refineries as a technically robust and financially viable pathway to strengthen Nigeria’s energy security, reduce dependence on imports, and promote sustainable refining infrastructure