Experimental study on severe slugging mitigation by applying wavy pipes

Xing, Lanchang; Yeung, Hoi; Shen, J.J.S.; Cao, Yi

doi:10.1016/j.cherd.2012.06.020

Cited by 18 publications

(3 citation statements)

References 11 publications

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“…The details of the experimental flow rig design including the parameters of straight and bend pipeline test section, velocity trend profile along the longitudinal cross-section around the straight and 45 0 bend, and the capacity of the flow rig are reported in a study by Makwashi et al (2019). The flow rig was designed based on the work by Adeyanju and Oyekunle (2013) and Theyab and Diaz (2016) for the straight pipe, whereas, studies by Xing et al (2013) and Rashidi et al (2016) were used to design the bend pipe test section with modifications. The straight pipe test section is jacketed in a copper pipe material, while, the bend pipe is installed in an open polypropylene feed and expansion cistern tank (40 gallons capacity).…”

Section: Experimental Flow Rig and Test Configurationsmentioning

confidence: 99%

Depositional Behaviour of Highly Macro-Crystalline Waxy Crude Oil Blended with Polymer Inhibitors in a Pipe with a 45-Degree Bend

Makwashi

Barros

Sarkodie

et al. 2019

Day 4 Fri, September 06, 2019

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Production, transportation and storage of highly waxy crude oil is very challenging. This is because they are usually characterised by high content of macro-crystalline waxes, predominantly consisting of n-alkanes (C 18 to C 36) that which could cause costly deposition within the wellbore and production equipment. The accumulation of deposited wax can decrease oil production rates, cause equipment breakdown, and clog the transport and storage facilities. Currently, different polymeric inhibitors have been utilised in the oil and gas field to mitigate and prevent wax deposition. However, as of today, there is no distinctive wax inhibitor that could work effectively for all oil fields. One of the objectives of this work is to study the efficacy of a blended commercial wax inhibitor-pour point depressant on wax deposition mitigation in a flow rig designed with 0 and 45-degree bends in the pipeline. Standard laboratory techniques using high-temperature gas chromatography (HTGC), rheometer rig, polarized microscope and elution chromatography were employed to obtain n-paraffin distribution, oil viscosity, WAT, pour point and SARA fractions. Series of experimentation were carried out with and without the inhibitor in a straight pipe test section. The severity of wax deposition in the pipeline built-in with a 45-degree bend is compared with a straight pipe. The blended inhibitor was tested at concentrations of 500, 1000, and 1500-ppm, under laminar and turbulent conditions. The crude oil sample was found to be naturally waxy with wax content of 19.75wt%, n-paraffin distributions ranges from C 15-C 74 , WAT and pour point of 30°C and 25°C respectively. The severity of wax deposition in the test section is 43% higher in 45-degree bend compared to straight pipe. However, the severity of the deposition was reduced to 12.3% at extremely low temperature and flow rate. Nonetheless, better inhibition performance was achieved at 25 and 30°C. The wax thickness was reduced from δ wax ≈ 0.36mm at 5 l/min to δ wax ≈ 0.132mm at 7 l/min at constant coolant temperature (25°C) and 1500-ppm, whereas, no wax deposition was observed at 11 l/ min. Mechanisms such as molecular diffusion due to frictional pressure losses, shear dispersion and gravity settling due to momentum change and hydrostatic, alongside with thermal difference are the main drivers for wax deposition in both straight and bend pipe. Whereas, the interaction mechanisms such as the nucleation, alongside with adsorption, co-crystallization, and solubilisation between the new blended inhibitor and the wax crystals provide an improved inhibition performance in the system even at extreme cases.

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Section: Experimental Flow Rig and Test Configurationsmentioning

confidence: 99%

Depositional Behaviour of Highly Macro-Crystalline Waxy Crude Oil Blended with Polymer Inhibitors in a Pipe with a 45-Degree Bend

Makwashi

Barros

Sarkodie

et al. 2019

Day 4 Fri, September 06, 2019

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“…Alimonti et al (2010) investigated the characteristics of two-phase flows through a "Willis-type" multiple orifice valve (MOV), while Azzi and Friedel (2005), Chen et al (2006) and Kim et al (2010) evaluated the use of 90 • elbows as primary elements to estimate the total mass flow-rates. Additionally, Xing et al (2013) performed a study comprising wavy pipe sections to mitigate slug flow regimes. Gourma and Verdin (2016) investigated the influence of helical pipes on slugs while Athulya and Miji Cherian (2016) numerically studied multiphase flows in a T-junction.…”

Section: Introductionmentioning

confidence: 99%

The hydrodynamics of two-phase flows in the injection part of a conventional ejector

Mifsud

Cao

Verdin

et al. 2019

International Journal of Multiphase Flow

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The characteristics of two-phase flow through a 'conventional' convergent-nozzle in an entrainment chamber of an ejector apparatus are described in this paper. A unique data set comprising 350 data points was generated in an air-water horizontal test-rig. Two sets of flow conditions were established, the first one including high liquid-low gas fluids with void fractions less than 0.55, and the second one involving high gas-low liquid fluids with void fractions greater than 0.75. All considered flow-rates lied within the sub-critical flow region. Two-phase flow pressure drop multiplier based empirical correlations were developed to estimate the total mass flow-rates. In the high liquid region, Morris (1985) correlation was modified, resulting in less than 10 % error. In the high gas region, two new correlations were proposed, showing less than 10 % and 15 % of errors, respectively. The established empirical correlations were related to other available multipliers for different geometric configurations including a Venturi, an orifice plate, a gate valve, and a globe valve and were compared to 20 other void fraction correlations. The Chisholm (1983) and Huq and Loth (1992) correlations showed the highest similarities to the ones proposed for the high liquid and high gas regions, respectively.

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“…Severe slugging in an offshore field was first reported by Yocum (1973) where he identified the threat of severe slugging to production facilities and the different approaches for severe slug elimination. Typical approaches includes installing flow conditioners (Xing et al, 2013a(Xing et al, , 2013b(Xing et al, , 2013cGonçalves, 1999, 2000;Adedigba, et al,, 2006;Adedigba, 2007) , intermittent absorber (Ehinmowo et al, 2016), multiple risers (Kaasa, 1990;Prickaerts et al, 2013), slug catchers (McGuinness and Cooke, 1993), using fixed or permanent choking (Schmidt et al, 1979(Schmidt et al, , 1980Taitel, 1986;Taitel et al, 1990;Farghaly, 1987;Jansen et al, 1996) and using different intrusive devices (Schrama and Fernandes, 2005;Brasjen et al, 2013). Xing et al (2013aXing et al ( , 2013b carried out experimental studies and numerical study (Xing et al, 2013c) to investigate the effects of the wavy pipe on the flow behaviour in a pipeline-riser system and to verify its effectiveness in severe slugging mitigation.…”

Section: Introductionmentioning

confidence: 99%

Severe slug mitigation in an S-shape pipeline-riser system by an injectable venturi

Inok

Lao

Cao

et al. 2019

Chemical Engineering Research and Design

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Severe slugging is a cyclic flow regime that causes pressure, flow and temperature oscillations which leads to an intermittent delivery of liquid (oil and water) and gas to processing facilities during hydrocarbon extraction and transportation. These oscillations can cause separator flooding, production reduction, platform trips and plant shutdown. This paper presents a novel method for severe slug mitigation in a pipeline-riser system which use an injectable venturi coupled to the pipeline-riser system upstream of the topside test separator for severe slug mitigation. Injectable venturi is a venturi tube that has an opening at its throat and a pipe inclined at 45°is inserted into this opening. Gas is injected through the pipe counter to the flow coming from upstream of the injectable venturi to choke the working fluid passing through the throat of the injectable venturi. Flow regimes maps, stability maps, severe slug envelopes and Hopf bifurcation maps were generated and used to demonstrate the performance of the injectable venturi in mitigating severe slugging in a pipeline-riser system. A similar experiment was conducted with the injectable venturi with no gas injection and the plain riser (without the injectable venturi coupled). The results from the experiment show that with the injectable venturi coupled to the pipeline-riser system, severe slugging was mitigated, the severity of severe slugging was reduced, the operating region of severe slugging (severe slug envelop) was reduced and stability was achieved at a larger valve opening. Practically, these results imply that oil and gas production can proceed more smoothly, thus, enhancing flow assurance. The injectable venturi with gas injection gave a better performance than with no gas injection. Thus, the effectiveness of the injectable venturi is not due to the venturi itself, but due to gas injection at the throat of the venturi.

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Experimental study on severe slugging mitigation by applying wavy pipes

Cited by 18 publications

References 11 publications

Depositional Behaviour of Highly Macro-Crystalline Waxy Crude Oil Blended with Polymer Inhibitors in a Pipe with a 45-Degree Bend

Depositional Behaviour of Highly Macro-Crystalline Waxy Crude Oil Blended with Polymer Inhibitors in a Pipe with a 45-Degree Bend

The hydrodynamics of two-phase flows in the injection part of a conventional ejector

Severe slug mitigation in an S-shape pipeline-riser system by an injectable venturi

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