Reliable Evaluation of Oil–Water Two-Phase Flow Using a Method Based on Terahertz Time-Domain Spectroscopy

Abstract

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 m3/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 Q value, 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 Q value, where the flow is a water-in-oil (W/O) flow.

The Detection of Water Flow in Rectangular Microchannels by Terahertz Time Domain Spectroscopy

“…The signals transmitting through the chip show the presence of peak trough intensity features at different Re . As expected, the signal loss increases with the increase of Re , but it seems to occur in two-phases which is consistent with the results in our previous research [ 14 ]: a first fast phase until Re reaches about 250, and next a second phase showing a slower signal loss. Then the question arises why, although the flow seems to be in the laminar range, there is such an inversion point in the E P changing along with Re .…”

“…However, there is still little research on understanding the characteristics and affecting factors of the flow in microchannels by terahertz time-domain spectroscopy (THz-TDS). Preliminary studies on the flow pattern and the slip phenomenon for oil-water two phase flow in macroscale pipes based on THz-TDS have been made previously [ 13 , 14 ]. Owing to the sensitivity of THz waves to the fluctuations of water dipole moments occurring on the picosecond (ps) timescale, THz technology can detect the subtle changes of water [ 15 , 16 ], so attempts have been made to predict the flow pattern transition of single phase flow in a rectangular microchannel using a method based on THz-TDS in this work.…”

Thermal Terahertz Analysis for the Detection of Trace Organic Matter

“…As a practical method exploited in petroleum geology and biology to characterize the structural and compositional properties, THz-TDS has a high signal-to-noise ratio and great sensitivity to polar molecules. − A THz wave segment corresponds to molecular rotation, molecular low-frequency vibration, crystal lattice motion, and hydrogen-bond extension . The results of previous studies revealed that THz-TDS technology has become a widely used OM detection method .…”

Laser-Induced Voltage Application for Identification of Crude Oils

“…Optical technology plays an important role in probing crude oils. Laser-induced ultrasonic technique is here proposed to characterize the process of pyrolysis in the oil shale, and it is also used to measure the full-range water content up to 100%. , In addition, terahertz technology was used to characterize the water content and distribution in high-water-cut crude oil, , probe disaggregation of crude oil in a magnetic field, − and evaluate pattern transitions of oil-water two-phase flow. , …”