The nonlinear analysis of horizontal oil-water two-phase flow in a small diameter pipe

Abstract

Horizontal oil-water two-phase flows are frequently encountered in many industrial processes but the understanding of the dynamic behaviour underlying the different flow patterns is still a challenge. In this study, we first conduct experiments of horizontal oil-water flows in a small diameter pipe, and collect the fluctuation signals from conductance probes. The multiscale power-law correlations of the oil-water flow structures are investigated using Detrended Fluctuation Analysis (DFA) based on the magnitude and sign decomposition of the raw signals. The analysis reveals the scaling behaviour of different flow structures; five conductive flow patterns are indentified based on the magnitude and sign scaling exponents at different time scales. In addition, the transfer entropy (TE) in a state space is used to study the information transferring characteristics of the oil-water mixture flowing past a conductance crosscorrelation velocity probe. The results of TE indicate that the transferring information depends on the flow conditions and can be used to show changes in the flow patterns.

Multifractal magnitude and sign correlations in multiphase flows

“…The sensor measurements contain copious amounts of dynamic information pertaining to fluid flow [9,[12][13][14][15][16]. As a result, there is a lot of interest in using sensor outputs to clarify the dynamics of multiphase flow systems, which has led to an increase in the demand for a data-driven understanding of flow patterns [17][18][19][20][21][22]. Currently, methods based on hydrodynamic models [14], Shannon entropy [20], time-frequency analysis [17], complex networks [18], and fractal theory [22] are used to study gas-liquid two-phase flow.…”

“…It demonstrates that a time series with identical correlation properties could have completely different characteristics of fluctuation, which can be characterized by different scaling exponents for the magnitude and sign series. Furthermore, the magnitude series inherits the linear characteristics in the long-range correlations of the initial series, while the sign time series is responsible for nonlinear part [19,31,32].…”

Simulation research on a new method of phase-regulated single-phase flow measurement for low production horizontal well

“…The application of this fracturing technology makes horizontal wells also show multi-segment and multi-cluster fluid production after fracturing. However, because the single well capacity of horizontal wells in low permeability reservoirs is generally low [4][5] [6], for example, the horizontal production of a single well in Daqing oil field is around 20 m 3 /d [7][8] so the single section production may be lower than 0.1 m 3 /d under the horizontal well multi-segment multi-cluster fracturing condition [9] [10]. In this low fluid production situation, there is no corresponding flow testing technique in China to meet this flow range and lower flow limit [11].…”

The Influence on Response of a Combined Capacitance Sensor in Horizontal Oil–Water Two-Phase Flow

“…As an efficient production logging technology, horizontal well development plays an important role in improving single well productivity and oil recovery [1,2]. In recent years, most oil fields were in the high water cut stage due to the long-term water injection development of horizontal wells in China [3].…”