Energy & Fuels, Vol.31, No.3, 2765-2770, 2017
Reliable Evaluation of Oil-Water Two-Phase Flow Using a Method Based on Terahertz Time-Domain Spectroscopy
Oil water two-phase flow widely exists in the petroleum industry, such as crude oil production and transportation. The flow pattern and slip phenomenon of oil water two-phase flow have an important impact on the rational design and management of oil wells and pipelines. Because of the extremely high sensitivity of the terahertz wave to hydrogen bonding, terahertz time-domain spectroscopy (THz-TDS) is used to study oil water two-phase flows with the input water fraction ranging from 0.5 to 5.0%. The flow rate is controlled in the range of 0.6-0.0 m(3)/h, and the flow pattern transition and slip phenomenon in horizontal circular pipes have been studied experimentally and theoretically. In a word, the flow pattern and critical flow rate for the flow pattern transition can be distinguished by amplitudes of THz-TDS of the oil water two-phase flows. The work indicates that, at a low Qvalue, the flow pattern is an oil layer over a dispersion of water-in-oil (O & DW/O) flow and the ratio of in situ oil to water velocity is smaller than those at a high Qvalue, where the flow is a water-in-oil (W/O) flow.