Hydrate Remediation Philosophy for a New Flowline Intervention System Based on Active Heating

2019 ◽  
Author(s):  
Geoffrey Guindeuil ◽  
Arnaud Sanchis ◽  
Stephanie Harchambois ◽  
Romain Vivet ◽  
Thierry Palermo ◽  
...  
Keyword(s):  
Experimental Validation ◽  
Electrical Power ◽  
Insulation Layer ◽  
Successful Operation ◽  
Joule Effect ◽  
Hydrate Dissociation ◽  
Complete Melting ◽  
Large Pressure ◽  
Dissociation Temperature ◽  
Hydrate Plug

Abstract The Electrically Trace Heated Blanket (ETH-Blanket) is a new offshore intervention system currently in development by TechnipFMC for the efficient remediation of plugs due to hydrates or wax deposit in subsea production and injection flowlines. The ETH-Blanket consists of a network of heating cables placed underneath an insulation layer which is laid onto the seabed above the plugged flowline. By applying electrical power to the cables, heat is generated by Joule effect which warms up the flowline content until hydrate dissociation or wax plug remediation through softening or complete melting. The ETH-Blanket is currently developed within a Joint Industry project (JIP) between TechnipFMC and Total. The dissociation of hydrate plugs using active heating incurs a number of risks for the integrity of the flowline and for the restoration of production to nominal conditions. As the flowline content is warmed up from ambient to hydrate dissociation temperature and during the dissociation of the hydrate plug, the pressure inside the flowline may potentially increase above design limits due to hydrate degassing and fluid volume expansion. Also, plug run-away scenarios may occur if a large pressure difference exists between both sides of the plug. The remediation operation may fail because of insufficient power or misplacement of the ETH-Blanket. Lastly, even following successful operation of the ETH Blanket, new flowline blockage may occur during subsequent operations such as cold re-start. To mitigate those risks, a hydrate remediation philosophy has been developed specifically for the ETH-Blanket Service. It is based on the development of in-house tools and procedures and builds upon experimental and modelling work performed as part of a previous JIP focusing on the dissociation of hydrate plugs using an ETH-Pipe-in-Pipe [1]. This paper introduces the different elements of the hydrate remediation philosophy, including the development and experimental validation of the dedicated tools used to define the appropriate heating sequence for the safe and efficient dissociation of hydrate plugs.

Full Scale Thermal Testing of a New Flowline Intervention System

2019 ◽  
Author(s):  
Stéphanie Harchambois ◽  
Vincent Le Toux ◽  
Geoffrey Guindeuil ◽  
Romain Vivet ◽  
François-Xavier Pasquet ◽  
...  
Keyword(s):  
Electrical Power ◽  
Data Gathering ◽  
Full Scale ◽  
Thermal Testing ◽  
Burial Depth ◽  
Joule Effect ◽  
Hydrate Dissociation ◽  
Heating Efficiency ◽  
Cfd Models ◽  
The Impact

Abstract The Electrically Trace Heated Blanket (ETH-Blanket) is a new offshore intervention/remediation system currently in development by TechnipFMC for the efficient remediation of plugs due to hydrates or wax in subsea production and injection flowlines. The ETH-Blanket consists of a network of heating cables placed underneath an insulation layer which is laid onto the seabed above the plugged flowline. By applying electrical power to the cables, heat is generated by Joule effect which warms up the flowline content until hydrate dissociation or wax plug remediation through softening or complete melting. As part of a Joint Industry Project (JIP) between TechnipFMC, Shell and Total, full-scale thermal testing of an ETH-Blanket prototype was carried out in Artelia facilities (in Grenoble, France). This testing was performed to verify the capability of the ETH-Blanket system to increase the temperature of the fluid inside a pipe sample above a target temperature (hydrate dissociation temperature or wax disappearance temperature) for various conditions. The impact of lateral misalignment of the ETH-blanket on the pipe and of the pipe burial depth were studied. Moreover, the tests were carried out on two pipe samples, with different designs and insulation properties. In parallel, CFD models of the test set-up were built to replicate the thermal behaviour of the ETH-Blanket. The combination of these models with the measured heating efficiency of the prototype allowed characterising the performances of the system in real subsea conditions. This paper presents the description of the full scale thermal testing conditions. Results of the different tests are detailed and the impact of the different parameters on the ETH-Blanket thermal performances are assessed, focusing on natural convection effects, thermal losses and the overall data gathering process.

scholarly journals Numerical simulation of CH4 hydrate formation in fractures

2018 ◽  
Vol 36 (5) ◽  
pp. 1279-1294 ◽  
Author(s):  
Sheng-Li Li ◽  
You-Hong Sun ◽  
Kai Su ◽  
Wei Guo ◽  
You-Hai Zhu
Keyword(s):  
Methane Hydrate ◽  
Hydrate Formation ◽  
Growth Behavior ◽  
Fractured Media ◽  
Initial Condition ◽  
Insulation Layer ◽  
Hydrate Dissociation ◽  
Fracture Size ◽  
The Media ◽  
Gas Supply

Fracture-hosted methane hydrate deposits exist at many sites worldwide. The growth behavior of CH4 hydrate in fractured media was simulated by TOUGH + HYDRATE (T + H) code. The effects of fracture size, initial condition, and salinity on the growth behavior of hydrate in fractures were investigated. In general, the hydrate layer grew from the two ends and gradually covered on the surface of the fracture. With the formation of hydrate in fractures, the temperature increased sharply since the hydrate acted as a thermal insulation layer. In longer fractures, fast growth of hydrate at the ends of the fracture led to the formation of hydrate plugs with high saturation (called as stopper). In narrower fractures, hydrate dissociation occurred in the middle of the fracture during hydrate growing in the whole fracture due to the cutoff of gas supply by the stopper at the ends. At a low initial subcooling, hydrate formed both on the surface and in the micropores of the media, which was different from that at higher subcooling. In salt solution, the formation of hydrate stopper was inhibited by the salt-removing effect of hydrate formation and the growth of hydrate was more sustainable.

Combustion System Development for the Ramgen Engine

2003 ◽  
Vol 125 (4) ◽  
pp. 885-894 ◽  
Author(s):  
D. W. Kendrick ◽  
B. C. Chenevert ◽  
B. Trueblood ◽  
J. Tonouchi ◽  
S. P. Lawlor ◽  
...  
Keyword(s):  
Bluff Body ◽  
Fuel Injection ◽  
Combustion Engine ◽  
System Development ◽  
Electrical Power ◽  
Combustion Efficiency ◽  
Lessons Learned ◽  
Successful Operation ◽  
Injection Methods ◽  
The Individual

The research and development of a unique combustion engine is presented. The engine converts the thrust from ramjet modules located on the rim of a disk into shaft torque, which in turn can be used for electrical power generation or mechanical drive applications. A test program was undertaken that included evaluation of the pre-prototype engine and incorporation of improvements to the thrust modules and supporting systems. Fuel mixing studies with vortex generators and bluff-body flame holders demonstrated the importance of increasing the shear-layer area and spreading angle to augment flame volume. Evaluation of flame-holding configurations (with variable fuel injection methods) concluded that the heat release zone, and therefore combustion efficiency, could be manipulated by judicious selection of bluff-body geometry, and is less influenced by fuel injection distribution. Finally, successful operation of novel fuel and cooling air delivery systems have resolved issues of gas (fuel and air) delivery to the individual rotor segments. The lessons learned from the pre-prototype engine are currently being applied to the development of a 2.8MW engine.

Frequency Dependent Ion Rejection Properties of Active Nanoporous Membranes

2013 ◽  
Author(s):  
Vishnu-Baba Sundaresan
Keyword(s):  
Pressure Gradient ◽  
Flow Rate ◽  
Electrical Power ◽  
Water Desalination ◽  
Small Scale ◽  
Feed Water ◽  
Ion Rejection ◽  
Large Pressure ◽  
Dissolved Ions ◽  
Neck Diameter

Selective rejection of dissolved salts in water is achieved by large pressure gradient driven flows through tortuous structures and cylindrical nanopores. The flow rate through the membrane is dependent on the area of the membrane and pressure gradient that can be sustained by the membrane. The electrical power required for generating large pressure gradients increases the operational cost for desalination units and limits application of contemporary technologies in a wide variety of applications. Due to this limitation, small scale operation of these desalination systems is not economical and portable. Further, recently proposed desalination systems using carbon nanotubes and nanofluidic diodes have limited lifetime due to clogging and fouling from contaminants in feed water. In order to develop a desalination system that is not limited by cost, scale of operation and application, an active nanopore membrane that uses multiphysics interactions in a surface-functionalized hyperboloidal nanopore is developed. An active nanopore is a shape-changing hyperboloidal pore that is formed in a rugged electroactive composite membrane and utilizes coupled electrostatic, hydrodynamic and mechanical interactions due to reversible mechanical oscillations between the charged pore walls and dissolved ions in water for desalination. This novel approach takes advantage of the shape of the pore to create a pumping action in the hyperboloidal channel to selectively transport water molecules. In order to demonstrate the applicability of this novel concept for water desalination, the paper will use a theoretical model to model the ion rejection properties and flow rate of purified water through an active nanoporous membrane. This article examines the effect of the geometry of the nanopore and frequency of operation to reject dissolved ions in water through a multiphysics model. It is estimated that the neck diameter of the active nanopores is the most dominant geometrical feature for achieving ion rejection, and the flux linearly increases with the frequency of operation (between 2–50Hz). The threshold neck diameter of the nanopore required for achieving rejection from multiphysics simulation is observed to be 100nm. The flux through the membrane decreases significantly with decreasing diameter and becomes negligible at 10nm effective neck diameter.

The Development of the Ramgen Engine Combustion System

2002 ◽  
Author(s):  
Blake C. Chenevert ◽  
Donald W. Kendrick ◽  
Ben Trueblood ◽  
Jon Tonouchi ◽  
Shawn P. Lawlor ◽  
...  
Keyword(s):  
Bluff Body ◽  
Fuel Injection ◽  
Combustion Engine ◽  
Electrical Power ◽  
Combustion Efficiency ◽  
Lessons Learned ◽  
Successful Operation ◽  
Injection Methods ◽  
The Individual ◽  
Cooling Air

The research and development of a unique combustion engine is presented. The engine converts the thrust from ramjet modules located on the rim of a disk into shaft torque, which in turn can be used for electrical power generation or mechanical drive applications. A test program was undertaken that included evaluation of the pre-prototype engine and incorporation of improvements to the thrust modules and supporting systems. Fuel mixing studies with vortex generators and bluff body flame holders demonstrated the importance of increasing the shear-layer area and spreading angle to augment flame volume. Evaluation of flame-holding configurations (with variable fuel injection methods) concluded that the heat release zone, and therefore combustion efficiency, could be manipulated by judicious selection of bluff body geometry, and is less influenced by fuel injection distribution. Finally, successful operation of novel fuel and cooling air delivery systems have resolved issues of gas (fuel and air) delivery to the individual rotor segments. The lessons learned from the pre-prototype engine are currently being applied to the development of a 2.8MW engine.

scholarly journals Study of the Critical Pore Radius That Results in Critical Gas Saturation during Methane Hydrate Dissociation at the Single-Pore Scale: Analytical Solutions for Small Pores and Potential Implications to Methane Production from Geological Media

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 210
Author(s):  
Ioannis Nikolaos Tsimpanogiannis ◽  
Emmanuel Stamatakis ◽  
Athanasios Konstantinos Stubos
Keyword(s):  
Porous Media ◽  
Analytical Solutions ◽  
Methane Production ◽  
Methane Hydrate ◽  
Pore Radius ◽  
Hydrate Dissociation ◽  
Gas Saturation ◽  
Dissociation Temperature ◽  
Critical Gas Saturation ◽  
Pore Body

We examine the critical pore radius that results in critical gas saturation during pure methane hydrate dissociation within geologic porous media. Critical gas saturation is defined as the fraction of gas volume inside a pore system when the methane gas phase spans the system. Analytical solutions for the critical pore radii are obtained for two, simple pore systems consisting of either a single pore-body or a single pore-body connected with a number of pore-throats. Further, we obtain critical values for pore sizes above which the production of methane gas is possible. Results shown in the current study correspond to the case when the depression of the dissociation temperature (due to the presence of small-sized pores; namely, with a pore radius of less than 100 nm) is considered. The temperature shift due to confinement in porous media is estimated through the well-known Gibbs-Thompson equation. The particular results are of interest to geological media and particularly in the methane production from the dissociation of natural hydrate deposits within off-shore oceanic or on-shore permafrost locations. It is found that the contribution of the depression of the dissociation temperature on the calculated values of the critical pore sizes for gas production is limited to less than 10% when compared to our earlier study where the porous media effects have been ignored.

scholarly journals The Role of Front-End AC/DC Converters in Hybrid AC/DC Smart Homes: Analysis and Experimental Validation

Electronics ◽  
2021 ◽  
Vol 10 (21) ◽  
pp. 2601
Author(s):  
Vitor Monteiro ◽  
Luis F. C. Monteiro ◽  
Francesco Lo Franco ◽  
Riccardo Mandrioli ◽  
Mattia Ricco ◽  
...  
Keyword(s):  
Smart Grids ◽  
Experimental Validation ◽  
Grid Point ◽  
Electrical Power ◽  
Smart Homes ◽  
Electric Mobility ◽  
Control Algorithms ◽  
New Paradigm ◽  
Front End

Electrical power grids are rapidly evolving into smart grids, with smart homes also making an important contribution to this. In fact, the well-known and emerging technologies of renewables, energy storage systems and electric mobility are each time more distributed throughout the power grid and included in smart homes. In such circumstances, since these technologies are natively operating in DC, it is predictable for a revolution in the electrical grid craving a convergence to DC grids. Nevertheless, traditional loads natively operating in AC will continue to be used, highlighting the importance of hybrid AC/DC grids. Considering this new paradigm, this paper has as main innovation points the proposed control algorithms regarding the role of front-end AC/DC converters in hybrid AC/DC smart homes, demonstrating their importance for providing unipolar or bipolar DC grids for interfacing native DC technologies, such as renewables and electric mobility, including concerns regarding the power quality from a smart grid point of view. Furthermore, the paper presents a clear description of the proposed control algorithms, aligned with distinct possibilities of complementary operation of front-end AC/DC converters in the perspective of smart homes framed within smart grids, e.g., enabling the control of smart homes in a coordinated way. The analysis and experimental results confirmed the suitability of the proposed innovative operation modes for hybrid AC/DC smart homes, based on two different AC/DC converters in the experimental validation.

CFD Modelling of an Electrically Trace Heated Blanket

2019 ◽  
Author(s):  
Vincent Le Toux ◽  
Stéphanie Harchambois ◽  
Geoffrey Guindeuil ◽  
Romain Vivet ◽  
François-Xavier Pasquet ◽  
...  
Keyword(s):  
Natural Convection ◽  
Full Scale ◽  
Operating Conditions ◽  
Burial Depth ◽  
Test Results ◽  
Cfd Modelling ◽  
Joule Effect ◽  
Hydrate Dissociation ◽  
Cfd Models ◽  
The Impact

Abstract The Electrically Trace Heated Blanket (ETH-Blanket) is a new offshore intervention/remediation system currently in development by TechnipFMC for the efficient remediation of plugs due to hydrates or wax in subsea production and injection flowlines. The ETH-Blanket consists of a network of heating cables placed underneath an insulation layer which is laid onto the seabed above the plugged flowline. By applying electrical power to the cables, heat is generated by Joule effect which warms up the flowline content until hydrate dissociation or wax plug remediation through softening or complete melting. As part of a Joint Industry Project (JIP) between TechnipFMC, Shell and Total, full-scale thermal testing of an ETH-Blanket prototype was carried out in Artelia facilities (Grenoble, France). This testing was performed to verify the capability of the ETH-Blanket system to increase the temperature of the fluid inside a pipe sample above a target temperature (hydrate dissociation temperature or wax disappearance temperature) for various conditions. The impact of lateral misalignment of the ETH-blanket on the pipe and of the pipe burial depth were studied. Moreover, the tests were carried out on two pipe samples, with different designs and insulation properties. CFD models of the test set-up have been built to replicate the thermal behaviour of the ETH-Blanket prototype. Once validated against the test results, the final aim of CFD modelling is to be able to calculate the performances of the system in real subsea conditions. The modelling of the prototype includes a 3D geometry of the system including the soil, natural convection of water between the ETH-blanket and the pipe sample and natural convection of fluid in the pipe sample. The present paper focuses on the CFD work performed to match the full-scale thermal test results and to predict the ETH-Blanket performances for real subsea operating conditions. It will describe the various CFD models used, the sensitivities and findings in terms of local and global heat transfer and flow effects and the comparison to the experimental data.

Experimental Validation of Temperature Distributions Across a Heat Exchanger for a Thermoelectric Generator

2012 ◽  
Author(s):  
Megan Dove ◽  
Jaideep Pandit ◽  
Srinath Ekkad ◽  
Scott Huxtable
Keyword(s):  
Heat Exchanger ◽  
Thermoelectric Generator ◽  
Experimental Validation ◽  
Electrical Power ◽  
Thermoelectric Generators ◽  
Cfd Model ◽  
Temperature Distributions ◽  
Performance Predictions ◽  
Computational Fluid Dynamics Cfd ◽  
The Difference

Thermoelectric generators (TEGs) are currently a topic of interest in the field of energy harvesting for automobiles. In applying TEGs to the outside of the exhaust tailpipe of a vehicle, the difference in temperature between the hot exhaust gases and the automobile coolant can be used to generate a small amount of electrical power to be used in the vehicle. The amount of power is anticipated to be a few hundred watts based on the temperatures expected and the properties of the materials for the TEG. This study focuses on developing efficient heat exchanger modules in order to maximize the power generation for a given vehicle and TEG. A computational fluid dynamics (CFD) model run by the authors has provided performance predictions for various cases on the cooling side of the heat exchanger. This paper discusses the setup and results of the experimental validation for the CFD model for the proposed TEG heat exchanger module.

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