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10 pages, 1352 KiB

Open AccessArticle

The Development of Forecasting Technique for Cyclic Steam Stimulation Technology Effectiveness in Near-Wellbore Area

by Sergey Krivoshchekov, Alexander Kochnev and Kirill Vyatkin

Fluids 2022, 7(2), 64; https://doi.org/10.3390/fluids7020064 - 3 Feb 2022

Cited by 4 | Viewed by 2380

Abstract

The analytical review has shown that the scientific inquiry for effective technologies for high-viscosity oil field development is a critical task of the present-day oil industry. The paper presents a technique for determining the expediency and effectiveness of deploying the near-wellbore cyclic steam [...] Read more.

The analytical review has shown that the scientific inquiry for effective technologies for high-viscosity oil field development is a critical task of the present-day oil industry. The paper presents a technique for determining the expediency and effectiveness of deploying the near-wellbore cyclic steam stimulation technology for oil recovery enhancement. The method involves the calculation of process parameters of the technology cycle and the comparative analysis of cumulative oil production before the treatment (base case) and after its deployment. Separately, the work focuses on studying the impact of dynamic oil viscosity over the entire temperature range on the technology effectiveness and expediency. The laboratory studies showed dynamic viscosity correlation dependencies for six different oils of the Nozhovskaya group of oil fields (Russian Federation) characterized as viscous and highly viscous. As a case study of the proposed method application, a numerical simulation of the technology deployment was carried out for six oil samples. The calculations determined inexpediency of cyclic steam stimulation for one of the samples since oil well downtime for workover operation prevailed over the time of near-wellbore cooling. Full article

(This article belongs to the Special Issue Multiphase Flow in Pipes with and without Porous Media)

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23 pages, 5972 KiB

Open AccessArticle

Effect of Geometric Configuration of the Impeller on the Performance of Liquivac Pump: Single Phase Flow (Water)

by Deepak Meerakaviyad, Tony Keville, Atma Prakash, Sajid Abdullah and Faik Hamad

Fluids 2022, 7(2), 45; https://doi.org/10.3390/fluids7020045 - 18 Jan 2022

Cited by 3 | Viewed by 3652

Abstract

Liquivac pumps, with their unique shaped twin start helical rotor, have found utility in various sectors but the major drawback limiting in their global exploitation is their low performance. This paper investigates the study of performance of the Liquivac pump produced by Tomlinson [...] Read more.

Liquivac pumps, with their unique shaped twin start helical rotor, have found utility in various sectors but the major drawback limiting in their global exploitation is their low performance. This paper investigates the study of performance of the Liquivac pump produced by Tomlinson Hall Ltd. Experimental data was used to validate a numerical model developed in Ansys Fluent 20.2 for the Liquivac pump. Four different geometric models of the rotor were tested numerically to find the optimum design using blade number and pitch length as the criteria to achieve improved efficiency. The choice of turbulence model is an important factor in the most accurate prediction with computational fluid dynamics (CFD) simulation. Four different turbulence models were validated with experimental measurements. The realizable K-ε model gave the most accurate performance predictions with a relative deviation of 3.8%. So, the realizable K-ε model was employed for further parametric optimization of the rotor. The results indicate a reasonable improvement in the head and efficiency of the Liquivac pump with a new rotor geometry of four equidistant blades in the front, back and four flights with 30 mm pitch. This is attributed to the most favourable balance between the different losses and most guided and uniform flow inside the rotor channels. Full article

(This article belongs to the Special Issue Multiphase Flow in Pipes with and without Porous Media)

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22 pages, 3738 KiB

Open AccessArticle

Analysis of a Stator-Rotor-Stator Spinning Disk Reactor in Single-Phase and Two-Phase Boiling Conditions Using a Thermo-Fluid Flow Network and CFD

by Lorenzo Mazzei, Francesco Maria Marin, Cosimo Bianchini, Riccardo Da Soghe, Cristina Bertani, Dario Pastrone, Maddalena Angelucci, Giuseppe Caggiano and Michiel de Beer

Fluids 2022, 7(2), 42; https://doi.org/10.3390/fluids7020042 - 18 Jan 2022

Cited by 1 | Viewed by 3258

Abstract

Cryogenic liquid propellants are used in liquid rocket engines to obtain high specific impulse. The flow rates are controlled by turbopumps that deliver liquid propellant to the engine at high pressure levels. Due to the very low saturation temperature of the cryogenic propellant, [...] Read more.

Cryogenic liquid propellants are used in liquid rocket engines to obtain high specific impulse. The flow rates are controlled by turbopumps that deliver liquid propellant to the engine at high pressure levels. Due to the very low saturation temperature of the cryogenic propellant, in the first phases of the transient operation, in which the engine is at ambient temperature, its surfaces are subject to boiling conditions. The effect of boiling on the heat transfer between the solid and the fluid needs to be well characterized in order to correctly predict the cryopump metal temperature temporal evolution and the necessary amount of propellant. With the aim of benchmarking numerical tools against experimental data, a representative test case was chosen. This consists of a stator-rotor-stator spinning disc reactor studied under single-phase and two-phase heat transfer conditions. The numerical approaches used are represented by a 1D network solver, where the pressure drop and heat transfer are calculated by correlations, and Computational Fluid Dynamics (CFD) simulations, carried out with ANSYS Fluent. Both the numerical tools returned a reasonable agreement in single-phase conditions, also thanks to the use of adequate correlations in the flow network solver and typical conditions for the CFD simulations. Two-phase conditions on the contrary are more challenging, with underpredictions up to 20% and 80%, respectively. The issues are ascribable to the use of correlations that are inadequate to capture the two-phase phenomena occurring in the srs reactor and numerical limitations in the actual implementation of the boiling model in the CFD solver. Full article

(This article belongs to the Special Issue Multiphase Flow in Pipes with and without Porous Media)

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14 pages, 3620 KiB

Open AccessArticle

Air Entrainment in Drop Shafts: A Novel Approach Based on Machine Learning Algorithms and Hybrid Models

by Francesco Granata and Fabio Di Nunno

Fluids 2022, 7(1), 20; https://doi.org/10.3390/fluids7010020 - 1 Jan 2022

Cited by 7 | Viewed by 2129

Abstract

Air entrainment phenomena have a strong influence on the hydraulic operation of a plunging drop shaft. An insufficient air intake from the outside can lead to poor operating conditions, with the onset of negative pressures inside the drop shaft, and the choking or [...] Read more.

Air entrainment phenomena have a strong influence on the hydraulic operation of a plunging drop shaft. An insufficient air intake from the outside can lead to poor operating conditions, with the onset of negative pressures inside the drop shaft, and the choking or backwater effects of the downstream and upstream flows, respectively. Air entrainment phenomena are very complex; moreover, it is impossible to define simple functional relationships between the airflow and the hydrodynamic and geometric variables on which it depends. However, this problem can be correctly addressed using prediction models based on machine learning (ML) algorithms, which can provide reliable tools to tackle highly nonlinear problems concerning experimental hydrodynamics. Furthermore, hybrid models can be developed by combining different machine learning algorithms. Hybridization may lead to an improvement in prediction accuracy. Two different models were built to predict the overall entrained airflow using data obtained during an extensive experimental campaign. The models were based on different combinations of predictors. For each model, four different hybrid variants were developed, starting from the three individual algorithms: KStar, random forest, and support vector regression. The best predictions were obtained with the model based on the largest number of predictors. Moreover, across all variants, the one based on all three algorithms proved to be the most accurate. Full article

(This article belongs to the Special Issue Multiphase Flow in Pipes with and without Porous Media)

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20 pages, 6832 KiB

Open AccessArticle

Machine Learning Augmented Two-Fluid Model for Segregated Flow

by Ayush Rastogi and Yilin Fan

Fluids 2022, 7(1), 12; https://doi.org/10.3390/fluids7010012 - 29 Dec 2021

Cited by 5 | Viewed by 3016

Abstract

Segregated flow, including stratified and annular flows, is commonly encountered in several practical applications such as chemical, nuclear, refrigeration, and oil and gas industries. Accurate prediction of liquid holdup and the pressure gradient is of great importance in terms of system design and [...] Read more.

Segregated flow, including stratified and annular flows, is commonly encountered in several practical applications such as chemical, nuclear, refrigeration, and oil and gas industries. Accurate prediction of liquid holdup and the pressure gradient is of great importance in terms of system design and optimization. The current most widely accepted model for segregated flow is a physics-based two-fluid model that treats gas and liquid phases separately by incorporating mass and momentum conservation equations. It requires empirically derived closure relationships that have the limitation of being applicable only under a narrow range of input parameters under which they were developed. In this paper, we proposed a more generalized machine learning augmented two-fluid model, using a database that spans the range of various flowing conditions and fluid properties. Machine learning algorithms such as random forest, neural networks, and gradient boosting were tested for the best performing data-driven predictive model. The new model proposed in this work successfully captures the complex, dynamic, and non-linear relationships between the friction factor and flowing conditions. A comprehensive model evaluation against nineteen existing correlations shows the best results from the proposed model. Full article

(This article belongs to the Special Issue Multiphase Flow in Pipes with and without Porous Media)

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9 pages, 2426 KiB

Open AccessArticle

Development of a Methodology and Software Package for Predicting the Formation of Organic Deposits Based on the Results of Laboratory Studies

by Pavel Ilushin, Kirill Vyatkin and Alexander Menshikov

Fluids 2021, 6(12), 446; https://doi.org/10.3390/fluids6120446 - 10 Dec 2021

Cited by 3 | Viewed by 2115

Abstract

One of the main problems in the oil industry is the fallout of asphaltene–resin–paraffin deposits (ARPDs) during oil production and transportation. The formation of organic deposits leads to reduced equipment life and reduced production. Currently, there is no single methodology for the numerical [...] Read more.

One of the main problems in the oil industry is the fallout of asphaltene–resin–paraffin deposits (ARPDs) during oil production and transportation. The formation of organic deposits leads to reduced equipment life and reduced production. Currently, there is no single methodology for the numerical simulation of the ARPD dropout process. The aim of our work was to obtain a correlation dependence characterizing the rate of wax growth over time for oils in the Perm Krai, depending on temperature, pressure, and speed conditions. Experimental data for 20 oil samples were obtained using a Wax Flow Loop installation that simulates fluid movement in tubing. The developed correlation was tested in 154 wells. The results of numerical modeling of the paraffin precipitation process made it possible to correct the inter-treatment period of scraping for 109 wells (71%), indicating the high accuracy of the developed approach. Full article

(This article belongs to the Special Issue Multiphase Flow in Pipes with and without Porous Media)

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21 pages, 10454 KiB

Open AccessFeature PaperArticle

Klinkenberg-Corrected and Water Permeability Correlation for a Sarawak Carbonate Field

by Izzat Ahmad, Maqsood Ahmad and Imtiaz Ali

Fluids 2021, 6(10), 339; https://doi.org/10.3390/fluids6100339 - 27 Sep 2021

Cited by 2 | Viewed by 3571

Abstract

Klinkenberg-corrected permeability (k_∞) or water permeability (k_w) is an important input parameter for hydrocarbon reservoir simulation studies. The theoretical concept that a core sample’s k_∞ is comparable to its k_w is flawed and has to be verified, [...] Read more.

Klinkenberg-corrected permeability (k_∞) or water permeability (k_w) is an important input parameter for hydrocarbon reservoir simulation studies. The theoretical concept that a core sample’s k_∞ is comparable to its k_w is flawed and has to be verified, since experimental evidence indicates that k_∞ and k_w are clearly different. Thus, a series of gas and water permeability measurements were conducted on eight carbonate core plug samples from Sarawak, Malaysia to develop a correlation between both permeability values. The new k_∞ vs. k_w correlation clearly proved the differences between both permeability values for all samples. The findings were in agreement with FESEM-EDX and total suspended solids (TSS) analysis, which proved the migration of fines and clay particles that blocked the pore throats, thus reducing k_w values. The new k_∞ vs. k_w correlation was validated using four different samples from the PETRONS-2 well using its k_∞ values and comparing them with the respective measured k_w values. The new correlation will reduce the amount of time and cost needed to obtain absolute liquid permeability values but may be further improved by conducting permeability measurements on more samples from the PETRONS field, which will improve the accuracy of hydrocarbon reservoir simulation of the PETRONS field. Full article

(This article belongs to the Special Issue Multiphase Flow in Pipes with and without Porous Media)

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24 pages, 8332 KiB

Open AccessArticle

Study of Heat Pipe Thermal Performance with Internal Modified Geometry

by Alaa A. B. Temimy, Adnan A. Abdulrasool and F. A. Hamad

Fluids 2021, 6(7), 231; https://doi.org/10.3390/fluids6070231 - 22 Jun 2021

Cited by 6 | Viewed by 3810

Abstract

The aim of this study was to investigate the effect of inserting a new internal tube packing (TP) on the thermal performance of a thermosyphon heat pipe (THP). The THP pipe was made from copper with an inner diameter of 17.4 mm and [...] Read more.

The aim of this study was to investigate the effect of inserting a new internal tube packing (TP) on the thermal performance of a thermosyphon heat pipe (THP). The THP pipe was made from copper with an inner diameter of 17.4 mm and length of 600 mm. The new internal tube packing (TP) had a central copper disc with two copper tubes soldered onto both sides to transport vapor and condensate. The upper tube or riser had an inner diameter of 8.3 mm and was 300 mm long; it was connected to a hole in the disc from the upper side to transport the steam to the condenser section. The lower tube or downcomer had an inner diameter of 5 mm, was 225 mm long and was connected to the lower side of the disc to collect the condensate and transport it to the evaporator. The TP was inserted inside the THP to complete the design of the improved heat pipe (TPTHP). Experimental results showed that the TPTHP reduces the transit time from 16 to 11 min and the thermal resistance by 17–62% based on the input power and depending on the conditions of the THP. The results also showed that the inclination angle and filling ratio have no effect on the thermal resistance of the TPTHP. Full article

(This article belongs to the Special Issue Multiphase Flow in Pipes with and without Porous Media)

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21 pages, 9974 KiB

Open AccessArticle

Low Pressure Experimental Validation of Low-Dimensional Analytical Model for Air–Water Two-Phase Transient Flow in Horizontal Pipelines

by Hamdi Mnasri, Amine Meziou, Matthew A. Franchek, Wai Lam Loh, Thiam Teik Wan, Nguyen Dinh Tam, Taoufik Wassar, Yingjie Tang and Karolos Grigoriadis

Fluids 2021, 6(6), 220; https://doi.org/10.3390/fluids6060220 - 11 Jun 2021

Cited by 1 | Viewed by 2844

Abstract

This paper presents a low-pressure experimental validation of a two-phase transient pipeline flow model. Measured pressure and flow rate data are collected for slug and froth flow patterns at the low pressure of 6 bar at the National University of Singapore Multiphase Flow [...] Read more.

This paper presents a low-pressure experimental validation of a two-phase transient pipeline flow model. Measured pressure and flow rate data are collected for slug and froth flow patterns at the low pressure of 6 bar at the National University of Singapore Multiphase Flow Loop facility. The analyzed low-dimensional model proposed in comprises a steady-state multiphase flow model in series with a linear dynamic model capturing the flow transients. The model is based on a dissipative distributed parameter model for transient flow in transmission lines employing equivalent fluid properties. These parameters are based solely on the flowing conditions, fluid properties and pipeline geometry. OLGA simulations are employed as an independent method to validate the low-dimension model. Both low-dimensional and OLGA models are evaluated based on the estimated two-phase pressure transients for varying gas volume fraction (GVF). Both models estimated the two-phase flow transient pressure within 5% mean absolute percent error of the laboratory data. Additionally, an unavoidable presence of entrained air within a pipeline is confirmed for the case of 0% GVF as evidenced by the pressure transient estimation. Thus, dampened oscillations in the simulated 0% GVF case exists owing to an increase in the fluid compressibility. Full article

(This article belongs to the Special Issue Multiphase Flow in Pipes with and without Porous Media)

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17 pages, 9606 KiB

Open AccessArticle

Study on the Law of Pseudo-Cavitation on Superhydrophobic Surface in Turbulent Flow Field of Backward-Facing Step

by Xuecheng Lv, Wei-Tao Wu, Jizu Lv, Ke Mao, Linsong Gao and Yubai Li

Fluids 2021, 6(6), 200; https://doi.org/10.3390/fluids6060200 - 27 May 2021

Cited by 12 | Viewed by 3122

Abstract

Superhydrophobic surface is regarded as important topic in the field of thermal fluids today due to its unique features on flow drag reduction and heat transfer enhancement. In this study, the pseudo-cavitation phenomenon on the superhydrophobic surface in the backward-facing step turbulent flow [...] Read more.

Superhydrophobic surface is regarded as important topic in the field of thermal fluids today due to its unique features on flow drag reduction and heat transfer enhancement. In this study, the pseudo-cavitation phenomenon on the superhydrophobic surface in the backward-facing step turbulent flow field is observed through experiments. The underlying reason for this phenomenon is studied with experimental observation and analysis, and the time variant mechanisms of this phenomenon with various Reynolds number is summarized. The research results indicate that the superhydrophobic surface and the backward-facing step provide the material basis and dynamic condition for the generation of pseudo-cavitation. The pseudo-cavitation induces a large bubble on the superhydrophobic surface below the backward-facing step. The size, position, shape, oscillation amplitude, detachment, and splitting of the large bubble show regularity with the changes of Reynolds number. Meanwhile, the bubble growth, oscillation, detachment, split, and regeneration over time also show regularity. The study of bubble generation and development laws can be used to better control the perturbation of the flow field. Importantly, the present study has meaning in better understanding the flow mechanisms and gas coverage of superhydrophobic surface under condition of backward-facing step, paving the way for studying the flow drag reduction effect of superhydrophobic surface. Full article

(This article belongs to the Special Issue Multiphase Flow in Pipes with and without Porous Media)

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14 pages, 3429 KiB

Open AccessArticle

Three Steps Mixed (Fire Tube–Water Tube) Vertical Boiler to Optimize Thermal Performance

by Duilio Aguilar Vizcarra, Doris Esenarro and Ciro Rodriguez

Fluids 2021, 6(3), 93; https://doi.org/10.3390/fluids6030093 - 25 Feb 2021

Cited by 4 | Viewed by 8537

Abstract

The research aims to design and construct a new mixed vertical boiler (fire tube – water tube) with three gas passes. The strength of this technological innovation is in the best use of the thermic transmission receiving fluid (hot water, steam, thermal oil), [...] Read more.

The research aims to design and construct a new mixed vertical boiler (fire tube – water tube) with three gas passes. The strength of this technological innovation is in the best use of the thermic transmission receiving fluid (hot water, steam, thermal oil), this due to its multipurpose function of three steps using alternative fuels (Diesel, Liquid Petroleum Gas LPG, natural gas), by improving the thermal efficiency of the boiler its temperature is reduced with gases at low temperatures, which in turn also reduce environmental pollution. The methodology focuses on calculating the transfer area with the calculation method that will allow dimensioning the boiler, considering the calculation of losses and the fluid speed, with two defined procedures, the first for fire tube and water tube boilers. And another alternative. The results obtained allowed optimizing the thermal efficiency level, achieving very significant thermal efficiency results: With LPG 92.4% for hot water and 92.42% to generate steam in the same way with natural gas 90.25% for hot water and 90.24% to generate steam as well with Diesel 2; 89.21% for hot water and 89.31% to generate steam. Full article

(This article belongs to the Special Issue Multiphase Flow in Pipes with and without Porous Media)

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Review

Jump to: Research

29 pages, 11613 KiB

Open AccessReview

A Review on Process and Practices in Operation and Design Modification of Ejectors

by Ravi Koirala, Quoc Linh Ve, Baoshan Zhu, Kiao Inthavong and Abhijit Date

Fluids 2021, 6(11), 409; https://doi.org/10.3390/fluids6110409 - 11 Nov 2021

Cited by 8 | Viewed by 4424

Abstract

This work reviews the current operational condition and activities on design modification for different applications of ejectors. Ejectors being a simple mechanical system capable of performing multiple fluid related functions (vacuum generation, pumping, mixing, condensing and heat exchanging), have been an essential part [...] Read more.

This work reviews the current operational condition and activities on design modification for different applications of ejectors. Ejectors being a simple mechanical system capable of performing multiple fluid related functions (vacuum generation, pumping, mixing, condensing and heat exchanging), have been an essential part of several industrial processes. Two areas have been emphasized; internal flow and application-based modifications in components of ejectors. The geometry and inlet flow conditions were found to be the prime influencing factor of its performance. The objective and application-based modifications were performed on the primary nozzle, secondary nozzle, mixing chamber, throat and diffuser. The resultant performance was found to be dependent on operational condition and fluid type. This emphasizes the requirement of application-based design selection of the technology. In addition, the flow dynamics of condensing, non-condensing, particle and slurry flow has been studied based on available literatures. The one-point final objective is to identify the usability of primary water jet ejectors for active vapor transport and condensation, to replace vacuum pump and condenser in compact domestic water desalination system. Full article

(This article belongs to the Special Issue Multiphase Flow in Pipes with and without Porous Media)

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