Pressure drop, flow pattern and local water volume fraction measurements of oil–water flow in pipes

Abstract

Abstract. Oil-water flow in horizontal and slightly inclined pipes was investigated. The experimental activities were performed using the multiphase flow loop at Telemark University College, Porsgrunn, Norway. The experiments were conducted in a 15 m long, 56 mm diameter, inclinable steel pipe using Exxsol D60 oil (density of 790 kg/m 3 and viscosity of 1.64 mPa s) and water (density of 996 kg/m 3 and viscosity of 1.00 mPa s) as test fluids. The test pipe inclination was changed in the range from 5° upward to 5° downward. Mixture velocity and inlet water cut varies up to 1.50 m/s and 0.975, respectively. The time averaged cross sectional distributions of oil and water were measured with a single-beam gamma densitometer. The pressure drop along the test section of the pipe was also measured. The characterization of flow patterns and identification of their boundaries are achieved via visual observations and by analysis of local water volume fraction measurements. The observed flow patterns were presented in terms of flow pattern maps for different pipe inclinations. In inclined flows dispersions appear at lower mixture velocities compared to the horizontal flows. Smoothly stratified flows observed in the horizontal pipe disappeared in upwardly inclined pipes and new flow patterns, plug flow and stratified wavy flow were observed. The water-inoil dispersed flow regime slightly shrinks as the pipe inclination increases. In inclined flows the dispersed oil-in-water flow regime extended to lower mixture velocities and lower inlet water cuts. The present experimental data were compared with results of a flow pattern dependent prediction model, which uses the area averaged steady state two-fluid model for stratified flow and the homogeneous model for dispersed flow. The two-fluid model was able to predict the pressure drop and water hold-up for stratified flow. The homogeneous model was not able to predict the pressure profile of dispersed oil-water flow at higher water cuts. The two-fluid model and homogeneous model over-predicts the pressure drop for dual continuous flow.

Performance of a drag-reducing polymer in horizontal and downward-inclined oil–water flow

“…The ST flow barely appeared at -5 0 as it was only observed at flow condition of = 0.1 m/s and = 0.3 -0.6 unlike at 0 0 where the it is clear that the introduction of the downward inclination caused higher mixing of the two phase which results in having dispersion occurring at lower mixture velocities at -5 0 .Similar observation was made byCox (1985),Abduvayt et al (2004),Lum et al (2006) andKumara et al (2009). In addition, the Do/w&w flow pattern that was observed at 0 0 disappeared and replaced by o/w flow pattern at -5 0 .…”

“…Finally, oil-in-water emulsion flow region was also found to extend to higher input oil fractions when compared with the one in horizontal flow but the water-in-oil emulsion flow region was not significantly affected. The introduction of downward inclinations similarly affected the flow patterns observed by Kumara et al (2009). The stratified smooth flow regime that was observed at 0.25 m/s mixture velocity from 0.1 to 0.9 inlet water cuts in the horizontal flow only appeared from 0.2 to 0.6 inlet water cuts at -1 0 while it completely disappeared and replaced by stratified flow with mixing at the interface at -5 0 .…”

“…Such works include Cox (1985) at -15 0 and -30 0 ; Vedapuri et al (1997) at -2 0 ; Alkaya (2000) at -0.5 0 , -1 0 , -2 0 and -5 0 ; Oddie et al(2003) at -2 0 ; Abduvayt et al (2004) at -0.5 0 and -3 0 ; Lum et al (2006) at -5 0 ; Rodriguez and Oliemans (2006) at -1.5 0 , -2 0 and -5 0 ; and Kumara et al (2009) at -1 0 and -5 0 . All these studies, with the exception of Oddie et al(2003), observed that the introduction of downward inclinations resulted in higher mixing such that transitions from separated flows to dispersed flows occurred at lower mixture velocities than in horizontal flows.…”

“…The resurgence of interest in the study of oil-water flow is prompted by the increasing amount of water produces from maturing oil fields (Kumara et al, 2009). Hence, the simultaneous flow of oil and water through horizontal, inclined or even vertical pipelines has become a common occurrence during production and transportation of oil in the petroleum industries.…”

Heat transfer to immiscible liquid mixtures in a spiral plate heat exchanger

“…Trallero (1995) identified flow patterns for oil-water flows in horizontal pipes and developed a liquid-liquid flow pattern prediction model. Among the organic phases studied in the literature are kerosene (Zhao et al, 2006;Huang et al, 2007), Exxsol D140 (Lum et al, 2004;Lum et al, 2006), Exxsol D60 (Kumara et al, 2009), cyclohexane (Kashid and Agar, 2007), MACROL82 mineral oil (Salim et al, 2008), glycerine-water mixture (Lozano et al, 2008), diesel (Rodriguez and Oliemans, 2006) and Shell Vitrea 10 (Xu et al, 2010). Tap water and brine have been used as the aqueous phase.…”