The self⁃made thermocouple, self⁃made double parallel conductivity probe, Labview programming system and IMP temperature programming system were used to obtain the phase distribution characteristics of oil⁃water two⁃phase flow, and the interaction between flow pattern and flow parameters and heat transfer coefficient was analyzed. The results show that the cooling flow process affects the flow pattern distribution, which means the range of oil⁃in⁃water and mixed interface layered flow and water⁃in⁃oil flows with cooling convection heat is smaller, but the stratified flow, water⁃in⁃oil & oil⁃in⁃water and oil⁃in⁃water & water flow types have a larger range on the flow chart, and flow pattern transition boundary between the two is higher, and the trend of higher oil velocity and water velocity is developed. The heat transfer coefficient is closely related to the flow pattern and flow velocity. The low flow velocity is mainly affected by the flow velocity, while the high flow velocity is mainly affected by the flow pattern.

The acoustic emission(AE) technique was used to measure the AE signals of gas⁃liquid slug flow in horizontal pipes with non⁃intrusive and real⁃time monitoring features. Parameters of AE signals were calculated by setting window time and Critical Time of Elongated Bubble(CTEB). The characteristics of AE signal of slug unit were analyzed simultaneously. Based on the time delay of the same liquid slug arriving at two AE sensors, the AE method was used for detecting the translational velocity of liquid slug. Also, the measurement result of AE method was compared with the parallel conductivity method and Nicklin correlation. It is found that the AE signal of slug flow is very clear. The signals of liquid slug head, liquid slug body and elongated bubble decrease gradually and the signals of elongated bubble are below the threshold. The absolute energy and count of liquid slug increase with the superficial liquid and gas velocity respectively. AE technique could be used to monitor the frequency and translational velocity of liquid slug and it is a valuable method for application in the oil and gas field.