scholarly journals Flow Pattern and Pressure Drop for Oil-Water Flows in and around 180° Bends

Author(s):  
Paul Onubi Ayegba ◽  
Lawrence C. Edomwonyi-Otu ◽  
Abdulkareem Abubakar ◽  
Nurudeen Yusuf

Pressure drop and flow pattern of oil-water flows were investigated in a 19 mm ID clear polyvinyl chloride pipe consisting of U-bend with radius of curvature of 100 mm. The range for oil and water superficial velocities tested were and respectively. Measurements were carried out under different flow conditions in a test section that consisted of four different parts: upstream of the bend, at the bend and at two redeveloping flow locations after the bend. The result indicated that the bend had limited influence on downstream flow patterns. However, the shear forces imposed by the bend caused some shift flow pattern transition and bubble characteristics in the redeveloping flow section after the bend relative to develop flow before the bend. Generally, pressure gradient at all the test sections increased with both oil fraction and water superficial velocity and there was a sharp change of pressure gradient profile during phase inversion. The transition point where phase inversion occurred was always within the range of . Pressure losses differed at the various test sections and the difference was strongly linked to the superficial velocity of the phases and the flow pattern. At high mixture velocity, pressure losses at the redeveloping section after the bend were higher than that at the bend and that for fully developed flows. At low mixture velocity, pressure losses at the bend are higher than in the straight sections. Pressure drop generally decreased with level of flow development downstream of the bend.

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Paul Onubi Ayegba ◽  
Lawrence C. Edomwonyi-Otu ◽  
Abdulkareem Abubakar ◽  
Nurudeen Yusuf

AbstractPressure drop and flow pattern of oil–water flows were investigated in a 19-mm ID clear polyvinyl chloride pipe consisting of U-bend with radius of curvature of 100 mm. The range for oil and water superficial velocities tested was $$0.04 \le U_{{{\text{so}}}} \le 0.950 \;{\text{m/s}}$$ 0.04 ≤ U so ≤ 0.950 m/s and $$0.13 \le U_{{{\text{sw}}}} \le 1.10 \;{\text{m/s}}$$ 0.13 ≤ U sw ≤ 1.10 m/s , respectively. Measurements were carried out under different flow conditions in a test section that consisted of four different parts: upstream of the bend, at the bend and at two redeveloping flow locations after the bend. The result indicated that the bend had limited influence on downstream flow patterns. However, the shear forces imposed by the bend caused some shift flow pattern transition and bubble characteristics in the redeveloping flow section after the bend relative to develop flow before the bend. Generally, pressure gradient at all the test sections increased with both oil fraction and water superficial velocity and there was a sharp change of pressure gradient profile during phase inversion. The transition point where phase inversion occurred was always within the range of $$0.4 \le U_{{{\text{sw}}}} \le 0.54 \;{\text{m/s}}$$ 0.4 ≤ U sw ≤ 0.54 m/s . Pressure losses differed at the various test sections, and the difference was strongly linked to the superficial velocity of the phases and the flow pattern. At high mixture velocity, pressure losses at the redeveloping section after the bend were higher than that at the bend and that for fully developed flows. At low mixture velocity, pressure losses at the bend are higher than in the straight sections. Pressure drop generally decreased with level of flow development downstream of the bend.


2020 ◽  
Vol 24 (6) ◽  
pp. 1-10
Author(s):  
Lawrence Chukwuka Edomwonyi-Otu ◽  
Muhammed Muhammed Gimba ◽  
Nurudeen Yusuf

The search for lower cost materials that reduce pressure drop in fluid transport systems in oil and gas industries to conserve pumping energy is of paramount importance. Polymers are known to reduce pressure drop in pipeline oil-water flows in a process referred to as drag reduction (DR). The effect of partially hydrolysed polyacrylamide, polyethylene oxide, Aloe Vera mucilage and their mixtures as drag reducing polymers (DRPs) on pressure gradient (pressure drop; Δp) in pipeline oil-water flows were studied. The experiment was carried out in flow rig with 0.02-m diameter straight unplasticised polyvinylchloride (uPVC) pipe, two centrifugal pumps, control valves and two storage tanks. Tap water (ρ = 997 kg/m3 and µ = 0.89 cP) and diesel (ρ = 832 kg/m3 and µ = 1.66 cP) were used as the test fluid at ambient condition. The polymer mixture total concentration (MTC) of 30 and 400 ppm at different mixing proportion, mixture Reynolds number (Remix) and oil input volume were investigated. The results show increase in pressure gradient with increase in oil input volume in both single-phase water flow and oil-water flow before adding drag reducing polymers (DRPs). However, Δp decreased after adding DRPs with increase in Reynolds number (Re) or Remix and decrease in the oil-phase Re, and vice versa. The results further showed higher reduction in pressure drop by the polymer mixture than in each of the polymer used at the same conditions. The rigidness of the biopolymer was improved by adding synthetic polymers which resulted to increase in DR efficiency.


2017 ◽  
Vol 10 (1) ◽  
pp. 69-78 ◽  
Author(s):  
Wang Shou-long ◽  
Li Ai-fen ◽  
Peng Rui-gang ◽  
Yu Miao ◽  
Fu Shuai-shi

Objective:The rheological properties of oil severely affect the determination of percolation theory, development program, production technology and oil-gathering and transferring process, especially for super heavy oil reservoirs. This paper illustrated the basic seepage morphology of super heavy oil in micro pores based on its rheological characteristics.Methods:The non-linear flow law and start-up pressure gradient of super heavy oil under irreducible water saturation at different temperatures were performed with different permeable sand packs. Meanwhile, the empirical formulas between start-up pressure gradient, the parameters describing the velocity-pressure drop curve and the ratio of gas permeability of a core to fluid viscosity were established.Results:The results demonstrate that temperature and core permeability have significant effect on the non-linear flow characteristics of super heavy oil. The relationship between start-up pressure gradient of oil, the parameters representing the velocity-pressure drop curve and the ratio of core permeability to fluid viscosity could be described as a power function.Conclusion:Above all, the quantitative description of the seepage law of super heavy oil reservoir was proposed in this paper, and finally the empirical diagram for determining the minimum and maximum start-up pressure of heavy oil with different viscosity in different permeable formations was obtained.


1981 ◽  
Vol 103 (1) ◽  
pp. 56-66 ◽  
Author(s):  
H. Mukherjee ◽  
J. P. Brill ◽  
H. D. Beggs

Pressure loss and water holdup data were measured for oil-water flow in 1.5-in-dia inclined pipe with inclination angles from ± 30 deg to ± 90 deg from horizontal. Pressure losses were higher than calculated with available techniques, with maximum values near the phase inversion. Effects of input liquid fraction and inclination angle on friction pressure gradient are presented. Water holdup correlations for predicting in-situ liquid fractions are given.


Author(s):  
Jie Cui

Pneumatic conveying pipelines are widely employed in many industries to transport granular solids. Use of bends with various turning radii in these pipelines is mandatory and it is well known that the bends cause a loss of energy which results in an additional pressure drop. The pressure loss associated with various bends in pneumatic conveying pipelines was studied numerically. The numerical modeling results were validated against laboratory measurements, and parametric studies were performed to examine various factors that affect the pressure loss caused by bends in pneumatic conveying pipelines. Since the numerical results supply flow information at every location in the pipeline, the flow pattern and pressure field of air and pellet were resolved in detail to investigate the mechanism of the pressure loss in such systems.


2011 ◽  
Vol 402 ◽  
pp. 816-819
Author(s):  
Hai Qin Wang ◽  
Yong Wang ◽  
Lei Zhang ◽  
Jin Hai Gong ◽  
Zhen Yu Wang

The experiments were conducted in a horizontal multiphase flow test loop (50mm inner diameter, 40m long) and the cross-correlation technology was used for the study of the characteristics of the interfacial wave velocity about two types of annular flow regimes (AN║DO/W and AN║DW/O) for gas-oil-water three-phase flow. The results show that the interfacial wave velocity on the liquid film of AN║DO/W flow pattern and AN║DW/O flow pattern all increases with the increase of gas superficial velocity and liquid superficial velocity on the condition of fixed ratio of oil and water flow rates, but the difference is that the increase is a linear monotonic increase for AN║DO/W flow pattern and a non-linear increase for AN║DW/O flow pattern, and the liquid superficial velocity makes a larger contribution than the gas superficial velocity. The interfacial wave velocity also increases with the increase of input water cut in liquid at different gas superficial velocities under the conditions of liquid superficial velocity fixed.


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