Accurate measurement of inclined oil-water two-phase flows is vital for guiding reservoir management. Internal waves in such flows present a major challenge to production logging in oil wells. This study combines an electromagnetic flowmeter and a differential pressure sensor to measure the inclined oil-water flows in a 20-mm pipe. To address the problem that the Flores flow pattern map is unsuitable for predicting flow patterns in the small diameter pipe, recurrence plots based on differential pressure signals are used for effective identification of the experimental flow patterns. The ideal water holdup is measured by correlating the two-phase friction factor and the Reynolds number of the mixture fluid. Based on the water holdup and the flow pattern classification, a new meter factor model is developed to correct the electromagnetic flowmeter. Then, the individual phase superficial velocity is predicted in combination with the drift-flux model. These contributions provide a new perspective on the combined measurement of inclined oil-water flows.