Abstract: In the Su-Qiao Oilfield, the flow pattern for transporting mixed oil, gas and water has been found by the pigging test on the model testing faciliy with different flowrate, water containment, oil and gas ratio and tempreture for transportation. The relationship between the resistence parameter "λ" and Renords number "Re_Lg" for mixed oil, gas and water is also found. The thermal and pressure losses of gathering system for the oil wells have been calculated based on the thermal and hydranlic formula which are mormally used for mixed oil and gas transportation in the region of North China. The results of such calculation indicates: It is suitable for the gathering system of Su-Qiao oil wells to adopt such oil thansporting processes as protecting from corrosion and heat loss with plastic foam coating (yellow Jacket), burying one meter in depth and lauching pigs at wellhead in singbe line with low tempreture and nonheating. During the production of oil wells, the climate tempreture of wellhead Was -26℃ and the tempreture in the metering station was -15℃. As aresult, the production wao successful and operation was normal. The oil flow line system with low tempreture and nonheating method which are adopted by Su-Qiao Oilfield hare saved a mount of capital construction investment and lots of energy. So it is valuable to be popularized.