Spiral flow

Highly paraffinic (or waxy) crude oil can cause significant problems in the pipelines due to wax–oil gel blockage resulting from the precipitation of the wax components. Once blockage of the pipeline occurs and flow ceases, the pipeline flow cannot be restarted with the original steady state operating pressure but instead requires significantly higher pressures to restart the flow. Due to this, it is important to maintain the oil at a temperature above its natural pour point. The incorporation of chemical products known as wax inhibitors and pour point depressant (PPD) reduce the pour point and viscosity of oil. This paper introduces an indigenously synthesized wax inhibitor from the hydrophobically modified polybetaines (zwitterionic) family for treating waxy crude A located in Peninsular Malaysia. The synthesized wax inhibitor had been evaluated as flow improver, crystal modifier and pour point depressant. The wax inhibitor coded CRODDA-AA, works efficiently since it can reduce th...

Paraffin deposition is a problem in producing hydrocarbons that can result in losses. Paraffin can form near a wellbore, tubing, or other production facilities. Temperature differences are one of the causes of paraffin depositions. When the temperature of a fluid starts to fall below its pour point, oil flows more slowly. The temperature at which paraffin begins to form is known as the "wax appearance temperature." The development of paraffin can reduce production rates, damage production equipment, and lead to economic losses. In many cases, paraffin can also develop near the wellbore, which can cause formation damage. As a result, when paraffin begins to form, the problem must be handled as soon as possible to minimize more severe damage. The chemical method has been proven to be effective in dealing with paraffin problems. A solvent dissolves the paraffin and reduces the oil's viscosity, allowing it to flow more easily. This study aims to discuss laboratory studies of two different solvents and analyze the best scenarios that can be applied in the field to overcome paraffin problems in the Sangasanga Field and its effect on permeability improvement. The method used in this study is laboratory testing of fluid properties, solubility tests, and permeability tests. This study shows that the Parasol solvent can dissolve paraffin up to 98.2% and improve permeability up to 94.9%.

A relatively new technology, a hybrid photovoltaic thermal (PVT) solar collector, allows for producing electrical and thermal energy.  However, the module heats up more when exposed to sunlight thanks to the PVT collector's incorporation, reducing its efficiency.  Consequently, lowering the operating temperature is crucial for maximizing the system's effectiveness.  This research aims to create a photovoltaic thermal phase change material (PVT-PCM) solar collector and evaluate its energy performance through a controlled laboratory environment.  Two different PVT collector designs, one using water and the other using a phase change material (PCM), were evaluated using a spiral flow configuration.  Under a sun simulator, the PVT solar collector was subjected to 400 W/m2, 600 W/m2, and 800 W/m2 of solar irradiation at three different mass flow rates.  The results showed that under 800 W/m2 of solar irradiation and 0.033 kg/s mass flow rate, the collector using water could only ...

A relatively new technology, a hybrid photovoltaic thermal (PVT) solar collector, allows for producing electrical and thermal energy. However, the module heats up more when exposed to sunlight thanks to the PVT collector's incorporation, reducing its efficiency. Consequently, lowering the operating temperature is crucial for maximizing the system's effectiveness. This research aims to create a photovoltaic thermal phase change material (PVT-PCM) solar collector and evaluate its energy performance through a controlled laboratory environment. Two different PVT collector designs, one using water and the other using a phase change material (PCM), were evaluated using a spiral flow configuration. Under a sun simulator, the PVT solar collector was subjected to 400 W/m 2 , 600 W/m 2 , and 800 W/m 2 of solar irradiation at three different mass flow rates. The results showed that under 800 W/m 2 of solar irradiation and 0.033 kg/s mass flow rate, the collector using water could only reach an overall maximum efficiency of 64.34 %, whereas the PVT-PCM configuration with spiral flow had the maximum performance, with an overall efficiency of 67.63%.

Wax deposition is a common problem in oil pipelines and production systems. In this study, impact of water cut, mixing rate, chemical inhibitor, and time on wax deposition were investigated in a cold finger setup. Effect of different chemical inhibitors on wax appearance temperature (WAT) was studied using viscometry and differential scanning calorimetry techniques. Results suggested that WAT reduced with increasing inhibitor concentration, with 800 ppm being the optimum. Also, chloroform-toluene-ethylene vinyl acetate (EVA) mixture with 30, 30, and 40 wt% had the highest performance and reduced the WAT to 16.7 °C. Mixtures of toluene-EVA with acetone, p-xylene, and disulfide oil (DSO), followed next. Moreover, deposition decreased with increasing temperature difference between oil and pipe at constant cold surface temperature and increased upon increasing temperature difference at constant oil temperature. Wax deposition in two-phase system was lower than in single-phase system, but increased by increasing water cut. EVA-toluene, 2 wt% DSO, 2 wt% acetone, and 2 wt% p-xylene mixtures reduced the deposition to 23.33, 21.71, 32.14, and 12.5%, but addition of 2 wt% of EVA-DSO-acetone mixture reduced deposition to 35.74%. At similar operating conditions, flow turbulence has greater impact on reducing wax deposition, and its effect is enhanced using a proper inhibitor.

Building Integrated Photovoltaic thermal solar collector (BIPVT) with Spiral flow absorber design is a collector not only used to generate electricity and thermal energy simultaneously but also can be integrated with the roof. Due to it characteristic as a roof, the collector is exposed to the direct sunlight resulting from a higher temperature on it surfaces. The temperature increased will simultaneously decrease it efficiency. An experiment has been conducted outdoor at Universiti Kebangsaan Malaysia to examine and evaluate the efficiency of the collector. Data for the experiment has been collected and gathered from 08:00 to 17:00 respectively. Results from the experiment recorded the best total efficiency of 65.10% (53.64% thermal efficiency and 11.46% electrical efficiency from the PV panel) at mass flow rate of 0.041kg/s and solar radiation of 1148W/m2. The effect of mass flow rates on open circuit voltage (Voc) and the modules short circuit current (Isc) are also presented.

Highly paraffinic (or waxy) crude oil can cause significant problems in the pipelines due to wax–oil gel blockage resulting from the precipitation of the wax components. Once blockage of the pipeline occurs and flow ceases, the pipeline flow cannot be restarted with the original steady state operating pressure but instead requires significantly higher pressures to restart the flow. Due to this, it is important to maintain the oil at a temperature above its natural pour point. The incorporation of chemical products known as wax inhibitors and pour point depressant (PPD) reduce the pour point and viscosity of oil. This paper introduces an indigenously synthesized wax inhibitor from the hydrophobically modified polybetaines (zwitterionic) family for treating waxy crude A located in Peninsular Malaysia. The synthesized wax inhibitor had been evaluated as flow improver, crystal modifier and pour point depressant. The wax inhibitor coded CRODDA-AA, works efficiently since it can reduce th...

Wax deposition in production pipelines and transportation tubing from offshore to onshore is critical in the petroleum industry due to low-temperature conditions. The most significant popular approach to solve this issue is by inserting a wax inhibitor into the channel. This research aims to reduce the amount of wax formation of Malaysian crude oil by estimating the effective parameters using Design-Expert by full factorial design (FFD) method. Five parameters have been investigated, which are rotation speed (A), cold finger temperature (B), duration of experimental (C), the concentration of poly (stearyl acrylate-co-behenyl acrylate) (SABA) (D), and concentration of nano-silica SiO2 (E). The optimum conditions for reducing the amount of wax deposit have been identified using FFD at 300 rpm, 10 ℃, 1 h, 1200 ppm and 400 ppm, respectively. The amount of wax deposit estimated is 0.12 g. The regression model’s variance results revealed that the R2 value of 0.9876, showing 98.76% of the ...

Building Integrated Photovoltaic thermal solar collector (BIPVT) with Spiral flow absorber design is a collector not only used to generate electricity and thermal energy simultaneously but also can be integrated with the roof. Due to it characteristic as a roof, the collector is exposed to the direct sunlight resulting from a higher temperature on it surfaces. The temperature increased will simultaneously decrease it efficiency. An experiment has been conducted outdoor at Universiti Kebangsaan Malaysia to examine and evaluate the efficiency of the collector. Data for the experiment has been collected and gathered from 08:00 to 17:00 respectively. Results from the experiment recorded the best total efficiency of 65.10% (53.64% thermal efficiency and 11.46% electrical efficiency from the PV panel) at mass flow rate of 0.041kg/s and solar radiation of 1148W/m2. The effect of mass flow rates on open circuit voltage (Voc) and the modules short circuit current (Isc) are also presented.

The flow of fluid confined between a heated rotating cylinder and a cooled stationary cylinder is a canonical experiment for the study of heat transfer in engineering. The theoretical treatment of this system is greatly simplified if the cylinders are assumed to be of infinite length or periodic in the axial direction. In these cases heat transfer in the laminar regime occurs only through conduction as in a solid. We here investigate numerically heat transfer and the onset of turbulence in such flows by using both periodic and no-slip boundary conditions in the axial direction. The influence of the geometric parameters is comprehensively studied by varying the radius ratio (0.1 ≤ η ≤ 0.99) and the length-to-gap aspect ratio (5 ≤ Γ ≤ 80). Similarly, a wide range of Prandtl, Rayleigh, and Reynolds numbers is explored (0.01 ≤ σ ≤ 100, Ra ≤ 30000, and Re ≤ 1000, respectively). We obtain a simple criterion, Ra a(η)Γ, which determines whether the infinite-cylinder assumption can be employed. The coefficient a is well approximated by a cubic fit over the whole η-range. Noteworthy the criterion is independent of the Prandtl number and appears robust with respect to Reynolds number even beyond the laminar regime.

body to surround, to complete this objectives Shock Absorber test Rig was constructed. Most of shock absorber contains the air gap inside the shock absorber between internal cylinder and outer body, Air gap has lower heat transfer rate, and so Problem of overheating will be effect of damping fluid characteristics and decrease shock absorber performance, to improve heat transfer air gap is filled by fluid substance like ethylene glycol, propylene glycol and glycerol and collect Required data of improved Heat Transfer into Shock Absorber, Finally ethylene glycol as a substance can be increased heat transfer inside absorber up to 52%, And propylene glycol as a substance can be increase heat transfer inside shock absorber up to 39 but glycerol give maximum heat transfer rate up to 64 %. With increase heat transfer rate from inside absorber to surroundings problem of overheating of damper fluid should be decrease and maintain shock absorber performance for long time.

A newly synthesized pour point depressant (PPD) was used to decrease the wax deposition thickness and drag force during a waxy crude oil flow in two horizontal pipes of length 2.5 m each and inner diameters 1 inch and 2 inches. The flow rates of 80-120 LPM were used. 1,000-ppm PPD reduced the thickness of wax deposited by 31% and 72% at 120 LPM and 30°C in 1-inch and 2-inch pipes, respectively. There was about 15% drag reduction in both the pipes at 30°C and 120-LPM flow rate after adding 1,000-ppm PPD.

Conning tower’s use in the submarine is increasing due to its excellent underwater operation characteristics. Therefore, this investigation aims to investigate fluid flow characteristics at different conning tower position on the submarine in order to obtain the conning tower position that generates lower drag coefficient, which results in lower energy consumption of the submarine. The conning tower was placed in 5 different positions on submarine’s cylindrical middle portion and thereby determining the position of the conning tower in a submarine at which lowest drag coefficient occurs.

body to surround, to complete this objectives Shock Absorber test Rig was constructed. Most of shock absorber contains the air gap inside the shock absorber between internal cylinder and outer body, Air gap has lower heat transfer rate, and so Problem of overheating will be effect of damping fluid characteristics and decrease shock absorber performance, to improve heat transfer air gap is filled by fluid substance like ethylene glycol, propylene glycol and glycerol and collect Required data of improved Heat Transfer into Shock Absorber, Finally ethylene glycol as a substance can be increased heat transfer inside absorber up to 52%, And propylene glycol as a substance can be increase heat transfer inside shock absorber up to 39 but glycerol give maximum heat transfer rate up to 64 %. With increase heat transfer rate from inside absorber to surroundings problem of overheating of damper fluid should be decrease and maintain shock absorber performance for long time.

Paraffin wax deposition causes severe operational problems in oil fields. The major problem is the blockage of flow passage of the transportation lines and increase in the apparent viscosity of crude oil. This leads to decreased production rates, equipment breakdown and production shutdown. Tremendous energy and labour is utilized in pumping this waxy crude and maintenance of the flowlines which further affects the economics of the process. Hence timely control and removal of wax deposition is of prime importance. A number of treatment methods are available that have their own relative advantages and disadvantages. Chemical methods are mostly used. But they have their own limitations like being highly crude specific and environmentally hazardous. Mechanical methods like pigging although used widely suffer the drawback of requiring a lot of downtime, thereby affecting the production. This paper discusses briefly the various treatment methods and focuses on the method of magnetic fiel...

Highly paraffinic (or waxy) crude oil can cause significant problems in the pipelines due to wax–oil gel blockage resulting from the precipitation of the wax components. Once blockage of the pipeline occurs and flow ceases, the pipeline flow cannot be restarted with the original steady state operating pressure but instead requires significantly higher pressures to restart the flow. Due to this, it is important to maintain the oil at a temperature above its natural pour point. The incorporation of chemical products known as wax inhibitors and pour point depressant (PPD) reduce the pour point and viscosity of oil. This paper introduces an indigenously synthesized wax inhibitor from the hydrophobically modified polybetaines (zwitterionic) family for treating waxy crude A located in Peninsular Malaysia. The synthesized wax inhibitor had been evaluated as flow improver, crystal modifier and pour point depressant. The wax inhibitor coded CRODDA-AA, works efficiently since it can reduce th...

T HIS work was focused on an investigating of flow ability of waxy crude oil by nontraditional polymer compound. For this propose, a spirocompound consisted of benzaldehyede and triethanolamine 6,6'-(((phenylmethylene) bis (oxy)) bis (ethane-2,1-diyl)) bis (2-phenyl-1,3,6dioxazocane) [SB1] was synthesized using zeolite as a catalyst. The chemical structure of the [SB1] was investigated by FT-IR, TGA,GPC, H1NMR and Mass spectroscopy. The rheological behavior and pour point depression of waxy crude oil were also studied different dosages and temperatures. The results showed a significant reduction in the viscosity at different temperatures and dosages. Moreover, it was noticed a decrease in the apparent viscosity and the Bingham yield value for [SB1] 437.7, 367.1, and 307.1 cp and 0.48, 0.39 and 0.31 Pa at 15 ºC, 20 ºC and 30 ºC and concentration 1000 ppm respectively. While the blank experiment displayed 743.1, 694.2 and 607.2 cp and 0.74, 0.69 and 0.60 Pa at the same temperatures. This study included blends between [SB1] and the acrylate based polymers abbreviated as (B1, B2, B3 and B4). Furthermore, the rheological behavior and the pour point for these blends exhibited that the blend [B4] shew more reduction in the apparent viscosity than [SB1] being alone. The apparent viscosity and yield value for [B4] were; 267.8, 249.2 and 212.7 cp and 0.22, 0.11 and 0.09 Pa at 15ºC, 20ºC and 30ºC and concentration 1000 ppm respectively. The pour point depression (Δpp) of [SB1] was 9ºC while the blank pour point was 27 º C and the B4 was achieved the maximum depression in the pour point (Δpp= 18 º C) at a concentration of 1000 ppm. This result means that the addition of [SB1] to [B4] showed the most positive synergistic effect.

Paraffin deposition within petroleum reservoir during crude oil production can cause a decrease in reservoir performance, consequently the need to predict wax deposition is a major concern to all petroleum producers. The paper presents the development processes of a numerical simulator to model the deposition of Paraffin in the reservoir and it also shows the effects of the Paraffin (wax) deposition on the skin factor in the reservoir. A one-dimensional, three-phase and four-pseudo-component model for paraffin deposition was developed. The paraffin retention by static and dynamic pore surface depositions and pore throat plugging were considered. A fully implicit finite difference numerical scheme was developed and solved by a double iteration procedure. The model when applied to a typical field condition showed that the wax precipitation and consequently deposition to be a near well-bore phenomenon where the pressure gradient is relatively higher than those attainable far in the res...

A variety of techniques have been used in order to reduce problems caused by the crystallization of paraffin during the production and/or transportation of waxy oils. Flow improvers are used extensively to increase the mobility of waxy oils. In this work, the influence of different concentrations of polymeric flow improver such as dodecyl polymethacrylate and tetradodecyl polymethacrylate on pour point of waxy oils has been investigated. The results show that the polymeric flow improver improves the pour point of the waxy oils, but the relation between pour point decrease and polymeric flow improver concentration is not linear. It was also found that the performance of the polymeric flow improver dissolved in isooctane was better than the effect of pure flow improver. Also, the results indicate that the higher molecular weight flow improver (tetradodecyl polymethacrylate) has better efficiency on pour point of waxy oils.

Expansion of potato cropping on lowland is an alternative for increasing potato production in Indonesia. Aeroponics cultivation system with limited cooling at root zone is one of the solutions in obtaining quality potato seed in tropical lowland. Problems in fluids flow for supplying nutrition need to be understood, either fluids movement inside a pipe or inside an aeroponics chamber. One of the methods to understand the distribution of air tem- perature in a chamber is by analyzing it by means of Computational Fluid Dynamic (CFD). The objective of this research was to find out the temperature distribution in an aeroponics system. Two treatments were applied, i.e., application of root zone cooling at 10 °C and no cooling as control. The tempera- ture distribution inside the aeroponics chamber was analyzed using the CFD. The size of the aeroponics chamber used was 1.5 m length, 1.0 m width and 1.0 m height. The outer wall of the aeroponics chamber was made of plywood material of 12 m...

Deposition wax is one of the chronic flow assurance problems that continue to attract attention in the oil and gas field, particularly as the hydrocarbon explorations and productions in recent years move into a colder environment. The accumulation of the wax deposit in the pipeline reduced or interrupted the production, and in the worst-case completely clogged the pipeline, resulting in equipment failure or field abandonment. Although significant progress has been made in mitigating the problem, many questions about the full understanding of the factors and the physical process mechanisms of deposition remain unanswered. Predominant researches are being conducted in straight pipes. The impact of pipe curvatures such as pipe bends, elbows, and inclinations (found in production and transportation systems) on the increased severity of the deposition is not well studied, only very limited studies being reported. In this thesis, the deposition of wax was studied in a single-phase flow us...

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 (C18 to C36) 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), rheomet...

PVT solar systems are recently emerging solar technology that allows the simultaneous conversion of solar energy into both electricity and heat. The aim of these systems PVT is to improve the electrical efficiency with the cooling system by reducing the temperature of the cell. The performance of PV is reduced with the increase in temperature and use under the advice the absorber collector takes in the excess heat underneath the PV and transfers the heat through the working fluid such as water. The harvested heat is used for low-temperature applications such as domestic hot water supply, water preheating, and space heating. In this paper, the effects of the major control parameters on the thermal and electrical performance of PVT collectors are compiled and reviewed. Figures and tables are provided to give an overall picture of how PVT performance could be improved in terms of these parameters. Although investigators understand the effects of different parameters, the improvement of PVT performance by optimizing these parameters has not been fully realized.

Article history: Received 31 March 2019 Received in revised form 23 April 2019 Accepted 30 May 2019 Available online 6 June 2019 Heat removal factor (FR) is vital in determining the photovoltaic thermal (PVT) system thermal efficiency. (FR) represents the ratio of the actual (useful) heat gain via the heat transfer fluid that flows through a collector to the entire collector surface. In this study, simulations were conducted on three configurations using the PVT new design (dual oscillating absorber) to determine (FR) and thermal efficiency. Using different tube gaps and tube diameters D, the designs were compared using validated model, which was presented using the MATLAB programme theoretical data. The findings indicate that the shape, gap, and diameter of the absorber tubes are crucial to the PVT performance. The study was done under solar radiation level of 300-1000 W/m2 and mass flow rate of 0.01 kg/s at each solar radiation level. The results show that the best thermal efficie...

Wax deposition in production pipelines and transportation tubing from offshore to onshore is critical in the petroleum industry due to low-temperature conditions. The most significant popular approach to solve this issue is by inserting a wax inhibitor into the channel. This research aims to reduce the amount of wax formation of Malaysian crude oil by estimating the effective parameters using Design-Expert by full factorial design (FFD) method. Five parameters have been investigated, which are rotation speed (A), cold finger temperature (B), duration of experimental (C), the concentration of poly (stearyl acrylate-co-behenyl acrylate) (SABA) (D), and concentration of nano-silica SiO2 (E). The optimum conditions for reducing the amount of wax deposit have been identified using FFD at 300 rpm, 10 ℃, 1 h, 1200 ppm and 400 ppm, respectively. The amount of wax deposit estimated is 0.12 g. The regression model’s variance results revealed that the R2 value of 0.9876, showing 98.76% of the ...

Wax deposition is considered one of the most serious operational issues in the crude oil pipelines. This issue occurs when the crude oil temperature decreases below the temperature of wax appearance and paraffin wax starts to precipitate on the pipelines’ inner walls. As a result, the crude oil flow is impeded because of the precipitated wax. The use of polymeric pour point depressants has obtained significant interest among researchers as an approach of wax control for enhancing the flowability of the waxy crude oil. PPD of poly(behenyl acrylate -co-stearyl methacrylate-co- maleic anhydride) (BA-co-SMA-co-MA) was facilely synthesised by the use of free radical polymerisation. The variation of the PPD structure was studied by choosing several essential parameters like monomers ratio, reaction time, initiator concentration, and reaction temperature. Furthermore, viscosity measurement, pour point, and cold finger apparatus have been employed to evaluate the efficiency of the synthesis...

The deposition of paraffin wax from crude oil at low temperatures due to wax deposition, high pour point, high viscosity, and weak flow capability is among the critical and persisting challenges faced by the petroleum industry. In this study, a new para-decyloxy allyl benzoate (I10) was prepared, polymerized into HI10, and copolymerized with dioctadecyl maleate into MHI10 via the freeradical polymerization method employing azobisisobutyronitrile and toluene as the initiator and solvent, respectively. The prepared monomer was characterized by spectroscopic analyses (Fourier-transform infrared (FT-IR)) and proton nuclear magnetic resonance. Further, the polymers were characterized by FT-IR, and their average molecular weights were determined by gel permeation chromatography. The prepared compounds were taken in different concentrations and then tested as flow improvers of Qarun waxy crude oil using pour point depression and rheological parameters. The results of this test indicated th...

body to surround, to complete this objectives Shock Absorber test Rig was constructed. Most of shock absorber contains the air gap inside the shock absorber between internal cylinder and outer body, Air gap has lower heat transfer rate, and so Problem of overheating will be effect of damping fluid characteristics and decrease shock absorber performance, to improve heat transfer air gap is filled by fluid substance like ethylene glycol, propylene glycol and glycerol and collect Required data of improved Heat Transfer into Shock Absorber, Finally ethylene glycol as a substance can be increased heat transfer inside absorber up to 52%, And propylene glycol as a substance can be increase heat transfer inside shock absorber up to 39 but glycerol give maximum heat transfer rate up to 64 %. With increase heat transfer rate from inside absorber to surroundings problem of overheating of damper fluid should be decrease and maintain shock absorber performance for long time.

Highly paraffinic (or waxy) crude oil can cause significant problems in the pipelines due to wax-oil gel blockage resulting from the precipitation of the wax components. Once blockage of the pipeline occurs and flow ceases, the pipeline flow cannot be restarted with the original steady state operating pressure but instead requires significantly higher pressures to restart the flow. Due to this, it is important to maintain the oil at a temperature above its natural pour point. The incorporation of chemical products known as wax inhibitors and pour point depressant (PPD) reduce the pour point and viscosity of oil. This paper introduces an indigenously synthesized wax inhibitor from the hydrophobically modified polybetaines (zwitterionic) family for treating waxy crude A located in Peninsular Malaysia. The synthesized wax inhibitor had been evaluated as flow improver, crystal modifier and pour point depressant. The wax inhibitor coded CRODDA-AA, works efficiently since it can reduce the pour point of waxy crude A by 12°C and the viscosity about half of the original value at 1000 ppm concentration, as well as lowering the yield stress by 8 Pa at 51°C. In order to assess the use of the CRODDA-AA wax inhibitor for squeeze applications, a core flood study was conducted to determine its adsorption capability onto formation. A formation damage study was also conducted to ensure that there is no formation damage coupled with the injection of wax inhibitor. It was found that wax inhibitor CRODDA-AA can be retained in the formation up to 88.5% without significant formation damage. As a next step, it is planned to run the core flood and wax inhibitor release tests to refine the design of squeeze treatment.

Highly paraffinic (or waxy) crude oil can cause significant problems in the pipelines due to wax-oil gel blockage resulting from the precipitation of the wax components. Once blockage of the pipeline occurs and flow ceases, the pipeline flow cannot be restarted with the original steady state operating pressure but instead requires significantly higher pressures to restart the flow. Due to this, it is important to maintain the oil at a temperature above its natural pour point. The incorporation of chemical products known as wax inhibitors and pour point depressant (PPD) reduce the pour point and viscosity of oil. This paper introduces an indigenously synthesized wax inhibitor from the hydrophobically modified polybetaines (zwitterionic) family for treating waxy crude A located in Peninsular Malaysia. The synthesized wax inhibitor had been evaluated as flow improver, crystal modifier and pour point depressant. The wax inhibitor coded CRODDA-AA, works efficiently since it can reduce the pour point of waxy crude A by 12°C and the viscosity about half of the original value at 1000 ppm concentration, as well as lowering the yield stress by 8 Pa at 51°C. In order to assess the use of the CRODDA-AA wax inhibitor for squeeze applications, a core flood study was conducted to determine its adsorption capability onto formation. A formation damage study was also conducted to ensure that there is no formation damage coupled with the injection of wax inhibitor. It was found that wax inhibitor CRODDA-AA can be retained in the formation up to 88.5% without significant formation damage. As a next step, it is planned to run the core flood and wax inhibitor release tests to refine the design of squeeze treatment.

Wax deposition is considered one of the most serious operational issues in the crude oil pipelines. This issue occurs when the crude oil temperature decreases below the temperature of wax appearance and paraffin wax starts to precipitate on the pipelines’ inner walls. As a result, the crude oil flow is impeded because of the precipitated wax. The use of polymeric pour point depressants has obtained significant interest among researchers as an approach of wax control for enhancing the flowability of the waxy crude oil. PPD of poly(behenyl acrylate -co-stearyl methacrylate-co- maleic anhydride) (BA-co-SMA-co-MA) was facilely synthesised by the use of free radical polymerisation. The variation of the PPD structure was studied by choosing several essential parameters like monomers ratio, reaction time, initiator concentration, and reaction temperature. Furthermore, viscosity measurement, pour point, and cold finger apparatus have been employed to evaluate the efficiency of the synthesis...

This paper presents an innovative machine learning methodology that leverages on long-term vibroacoustic measurements to perform automated predictions of the needed pigging operations in crude oil trunklines. Historical pressure signals have been collected by Eni (evpms® monitoring system) for two years on discrete points at a relative distance of 30-35 km along an oil pipeline (100 km length, 16” ID diameter pipes) located in Northern Italy. In order to speed up the activity and to check the operation logs, a tool has been implemented to automatically highlight the historical pig operations performed on the line. Such a tool is capable of detecting, in the observed pressure measurements, the acoustic noise generated by the travelling pig. All the data sets have been reanalyzed and exploited by using field data validations to guide a decision tree regressor (DTR). Several statistical indicators, computed from pressure head loss between line segments, are fed to the DTR, which automa...

Spiral tubes are widely used in various engineering applications like heat transfer among various fluids, refrigeration applications and many more. The optimum spiral tube can improve efficiency of the system. So various research is carried out on spiral tubes design and process parameters in previous decades. In present paper effect of friction factor is studied for spiral tube by chaining its process and design parameters. The present study is based on CFD simulation technique. Experiments are designed using "Taguchi Method". The three process parameters which are identified for this study is wall temperature of surface, fluid inlet temperature and mass flow rate of fluid. Three design parameter which are selected for this study are inner diameter of tube, pitch of tube and curvature ratio of tube. Total six parameters are selected and then experiment table is generated using Taguchi method and 36 experiments are generated which are then simulated using Ansys Fluent (Version 14.5) software. Experiment validation is performed using previous experiment work on spiral tube. Friction factor is response parameter selected for this study and the analysis is performed using Signal to noise ratio parameter. To improve the effect of pressure-drop or decrease the friction factor in spiral tube the most reliable parameter is inner diameter of tube and least parameter is wall temperature of tube. Pitch is another important parameter for friction factor analysis.

In present research work the effect of process and design parameters of the horizontal spirally coiled flow tube, are investigated using CFD simulation and DOE techniques. In this research work total, six parameters are selected which are mass flow rate of water flow in the tube, water inlet temperature, heating surface temperature which is made of copper tube, tube inner diameter having 3 mm thickness, curvature ratio of tube and pitch of tube. The experiment table is made by using a mixed Taguchi method which generates a total of 36 cases for this research study. Experimental validation is also performed with previously published research work [01] to show a good agreement among CFD simulation and experiment results. The error among the simulation and experiment results are in a range of 3% to 12% max, which is acceptable for further research work. The results are then analyzed by using the signal to noise ratio which shows the rank among all parameters and as well as the best optimal solution for a selective response. In the present study, the research work is focused on Nusselt Number analysis.

Paraffin deposition within petroleum reservoir during crude oil production can cause a decrease in reservoir performance, consequently the need to predict wax deposition is a major concern to all petroleum producers. The paper presents the development processes of a numerical simulator to model the deposition of Paraffin in the reservoir and it also shows the effects of the Paraffin (wax) deposition on the skin factor in the reservoir. A one-dimensional, three-phase and four-pseudo-component model for paraffin deposition was developed. The paraffin retention by static and dynamic pore surface depositions and pore throat plugging were considered. A fully implicit finite difference numerical scheme was developed and solved by a double iteration procedure. The model when applied to a typical field condition showed that the wax precipitation and consequently deposition to be a near well-bore phenomenon where the pressure gradient is relatively higher than those attainable far in the res...

Article history: Received 25 October 2018 Received in revised form 14 November 2018 Accepted 12 December 2018 Available online 13 April 2019 Solar radiation could be harnessed to produce thermal and electrical energy. The solar thermal radiation is very advantageous as it can be harnessed easily and at an affordable cost. Electrical energy could be produced from the solar radiation by photovoltaic process and have an efficiency of 20-40%. This process is currently limited to its material and manufacturing costs, inefficiency under thermal load and relatively lower performance under low clearness index conditions. By using both properties, a solar photovoltaic-thermal (PV/T) hybrid could be designed to increase thermal and electrical efficiency during low clearness index. The study of the potential application of Thermoelectric Generator (TEG) in PV/T applications is highlighted to see the opportunities that are available in this field of study. Computational Fluid Dynamics (CFD) sim...

This paper reports the outcome of a study investigating four electrical heat-tracing strategies that can be employed to avoid wax deposition in subsea flowlines transporting untreated crude oil from subsea wells to a host installation. The strategies, described in the paper, are distinct by the configuration of deploying the heat tracing along the pipe and by the activation schedule (continuous or alternating heating cycles). The study demonstrates quantitatively that the electrical power required for maintaining wax-free flow depends strongly on the employed strategy. The complex thermo-hydraulic flow was modeled using a commercial Dynamic Multiphase Flow Simulator with wax deposition option and thermal insulation as an input parameter. In conclusion, the paper ranks the strategies according to their computed energy efficiency, thus providing quantitative benchmarks for preliminary wax control assessment.

This work is a thermo-fluid numerical case study to investigate the size and performance of a system that eliminates needs for insulating, heating and inhibiting chemically the deposition of wax in subsea tie-in flowlines. For short, we call this type of systems "Cold Flow". The particular system analyzed in this study consists of a reactor unit at the inlet to the flowline, where the thermal solubility of the wax-creating molecules is reduced by cooling. Subsequently, solid wax is deposited in the reactor piping and wax free crude is entering the flowline. The reactor is regenerated periodically. The reactor-pipeline system was modelled using a commercial flowline simulator, with transient, thermal, multiphase and deposition capabilities. The basic layout used was a transportation pipeline of 8 km and 6.69 in ID with a mass flow rate of 17.51 kg/s, a water cut (WC) of zero and an inlet temperature of 70˚C. The wax appearance temperature (cloud point) of the crude is 22˚C and the seabed temperature is 4˚C. Three types of reactors have been simulated: a non-insulated pipe section, a passive cooler with a bundle of parallel pipes and an active cooler. Sensitivity analyses have been performed for all three cases varying the external convective coefficient, the reactor pipeline diameter and the WC. For a non-insulated pipeline section cooler, the required length is of the same order of magnitude as the main flowline, implying that such a solution is impractical for short flowline distances or when a compact deployment is desired. For the passive cooler case, the required length was half of that in the previous case; thus it is still significant. For the active cooler reactor, the required cooling duty was 2.2 MW. In all three cases, the pipe-flow dynamics were analyzed, and the pigging arrangement complexity has been qualitatively addressed. However, the detailed design falls out of the scope of this study.

Building Integrated Photovoltaic thermal solar collector (BIPVT) with Spiral flow absorber design is a collector not only used to generate electricity and thermal energy simultaneously but also can be integrated with the roof. Due to it characteristic as a roof, the collector is exposed to the direct sunlight resulting from a higher temperature on it surfaces. The temperature increased will simultaneously decrease it efficiency. An experiment has been conducted outdoor at Universiti Kebangsaan Malaysia to examine and evaluate the efficiency of the collector. Data for the experiment has been collected and gathered from 08:00 to 17:00 respectively. Results from the experiment recorded the best total efficiency of 65.10% (53.64% thermal efficiency and 11.46% electrical efficiency from the PV panel) at mass flow rate of 0.041kg/s and solar radiation of 1148W/m 2. The effect of mass flow rates on open circuit voltage (V oc) and the modules short circuit current (I sc) are also presented.

This work is presents in brief an introduction to wax deposition process to give a general understand of this problem because of arising the challenges of growing wax deposition in the hydrocarbon pipelines by increasing production in the cold environment due to increasing demand for energy. Background and identification of wax deposition problem in the hydrocarbon pipelines are presented. Mitigation methods are used to address this problem, such as chemical, mechanical and thermal methods, but despite the available inhibition methods, many oil companies currently suffer from wax deposition problems and are still looking for a good solution to solve this issue. This research presents some of the case studies of wax deposition around the world and the methods followed to mitigate wax deposition of each case study. Numerous researchers have used various different types of chemical inhibitors, such as polyacrylate polymer, copolymer esters, polyethylene, olefin/ester copolymers, ethylene/vinyl acetate copolymers, ester/vinyl acetate copolymers, polymethacrylates, alkyl phenol resins, xylene and toluene, to studying their influence on the rheology of crude oil and to evaluate the suitable inhibitor for the waxy crude oil that provides the desired results in preventing wax deposition. The decent understanding and managing of wax deposition phenomena before it happens is strongly required in order to overcome the challenges in production and transportation of pipelines in the cold environment.

– The main obstacle of using the earth's enormous solar energy potential is its low conversion efficiency. The conversion efficiency from solar irradiation to electricity by the photovoltaic (PV) cell is around 5–20%. The remaining energy that falls on the PV surface becomes waste and increases the PV surface temperature. In this experimental work, we have modified a solar Photovoltaic (PV) system into a Photovoltaic-thermal collector (PVT) co-generation system and examined the effects on its performance. A coolant (water) has been circulated underneath the PV surface to extract heat and keep the PV surface temperature low. In the modified system, a glass cover was also placed on the top of the PVT to minimize the heat loss. This study found that electrical efficiency of the PV decreases linearly with surface temperature. In the modified PVT, when heat is extracted from the PV surface, the total efficiency increased to a significant level (i.e. 82%). The top loss of the PVT system was minimised effectively by putting a transparent glass cover on the PVT top. Although the top cover glass of PVT costs about 1% of electrical efficiency due to the glass's transmission factor, it significantly increases thermal efficiency i.e. from 48 % to 75%. The overall efficiency (electrical and thermal) of the co-generation system is much higher than the standalone PV or solar collector system.

Jordan has excellent potential for solar energy with 2080 kWh/m²
global radiation and more than 300 sunny days a year. An integrated
Hybrid Photovoltaic-Thermal (PV/T) solar collector system was constructed
and operated at Mutah University in Jordan. The performance
of the integrated Hybrid Photovoltaic-solar collector system was evaluated
analytically and experimentally. The total sun insolation and various
inlet, outlet and tank temperatures were recorded instantaneously
every hour of the day for several months in 2010. The discretized temperature
distribution of the integrated system and the stratification of
the tank were solved numerically. The integrated system was discretized
using forward finite difference. The Runge-Kutta fourth order method
was used to solve the discretized nodes. Computational Fluid Dynamics
(CFD) calculations were used to predict and to evaluate the inlet velocity,
temperature, operating pressure of the integrated Hybrid PV/T solar
collector system. Good agreement was found to exits between simulated
and measured data.