Analysis of combined radiation and convection heat transfer inside a porous medium with heat source electronic devices

In this study, a numerical study is performed on the cooling phenomenon of three heat source electronic devices. The electronic devices are cooled in the form of natural heat transfer by the airflow in a porous medium. Electronic devices are installed on the boundary walls of a square environment. Cooling simulations are performed by drawing flow lines and constant temperature lines. Our main goal is to find the highest cooling rate in different Darcy numbers and different Rayleigh numbers in our investigation. The range of Darcy numbers and Rayleigh numbers is between 0.0001 to 0.01 and 1000 to 100,000, respectively. Our investigation showed the maximum cooling is obtained at the Darcy number of about 0.01. And also, by decreasing the value of Darcy number, a higher cooling rate for the hot boundary walls is achieved.

Design and Construction of an ALD Reactor by Growth of Al2O3 Nanostructure Films

Objective: This project focuses on designing, building and commissioning work the atomic layer deposition (ALD) reactor for Al2O3 ultrathin film, which it will be contain specific components and a system's own control unit. Methodology: The ALD reactor was designed under a system to minimize components, flow lines and connections; to reduce manufacturing costs, volume of precursors, among others. Currently, ALD reactors are expensive to sell, maintain and replace parts. The design and manufacture of the ALD reactor manufactured at the University of Sonora (UNISON) is based on the state art with sequential binary reactions of the precursors, for the proposal for the manufacture of solar cells. Contribution: It was possible to build and commission the ALD reactor for the deposition of ultra-thin films, with the characteristics of being reproducible and scalable, which makes it attractive for commercialization. The homemade ALD reactor at UNISON is considered a very interesting equipment for the semiconductor research area, since it is possible to combine different types of materials in the form of films such as oxides and nitrides in the order of Angstroms (Ǻ).

Using the Kriging Response Surface Method for the Estimation of Failure Values of Carbon-Fibre-Epoxy Subsea Composite Flowlines under the Influence of Stochastic Processes

This paper investigates the use of the Kriging response surface method to estimate failure values in carbon-fibre-epoxy composite flow-lines under the influence of stochastic processes. A case study of a 125 mm flow-line was investigated. The maximum stress, Tsai-Wu and Hashin failure criteria was used to assess the burst design under combined loading with axial forces, torsion and bending moments. An extensive set of measured values was generated using Monte Carlo simulation and used as the base case population to which the results from the response surfaces was compared. The response surfaces were evaluated in detail in their ability to reproduce the statistical moments, probability and cumulative distributions and failure values at low probabilities of failure. In addition, the optimisation of the response surface calculation was investigated in terms of reducing the number of input parameters and size of the response surface. Finally, a decision chart that can be used to build a response surface to calculate failures in a carbon fibre-epoxy-composite (CFEC) flow-line was proposed based on the findings obtained. The results show that the response surface method is suitable and can calculate failure values close to that calculated using a large set of measured values. The results from this paper provide an analytical framework for identifying the principal design parameters, response surface generation, and failure prediction for CFEC flow-lines.

The Selection and Optimum Well Testing Practices to Achieve Zero Flaring & Venting in Malaysian Water for a Petronas Field Development

Increased HSE concerns and global economic efficiency from well testing activities especially on its environmental impact have left several oil and gas industries’ facing critical challenges to develop and monetize oil reserves. Some of these challenges include handling well effluents from well test unloading operations after well completion with high contaminants such as H2S and CO2 which will exacerbate environmental impact to safety, pollution, and oil spill risks. In addition, mitigation to environmental impact will be constrained to limited deck space and topside loads for offshore wellhead facilities and eventually restricts the footprint of well test unloading equipment. The scope of the paper is to examine the evolution of well deliverability testing from conventional well test facilities’ flaring practices to contemporary smokeless and zero flaring operations applied in a giant sand stones oil field in Malaysian water, which is surrounded by a world class environmentally protected marine and coastal ecosystem. The zero-flaring approach allows a demonstration of the safety & emission reduction, cost saving, technical viability, and economic benefits over traditional flaring techniques for 20 to 30 well testing during the life of field. Previous wells clean up method require flaring of oil and gas before the production facilities and flow lines were operational.commissioned. The application of environment friendly well testing system using the completed flow lines and production facilities enable zero-flaring option to be technically and economically viable. Zero-flaring well testing system provides several attractive benefits, with potential reduction in flaring equivalent of ±1000 barrels of oil, pollution avoidance, 40 - 50% schedule reduction and over 40% reduction in total project costs for the field development..

Multi-functional oilfield production chemicals: maleic-based polymers for gas hydrate and corrosion inhibition

Several chemical problems can occur during the production of oil and gas through flow lines. This includes corrosion, scale deposition and gas hydrate plugging. Three separate chemicals may be needed to treat these issues. Kinetic hydrate inhibitors (KHIs) are used in cold oil or natural gas production flow lines to prevent the formation and plugging of the line with gas hydrates. They are often injected concomitantly with other production chemicals such as corrosion and scale inhibitors. KHIs are specific low molecular weight water-soluble polymers with amphiphilic groups formulated with synergists and solvents. However, many corrosion inhibitors (CIs) are antagonistic to the KHI polymer, severely reducing the KHI performance. It would be preferable and economic if the KHI also could act as a CI. We have explored the use of maleic-based copolymers as KHIs as well as their use as film-forming CIs. KHIs were tested using a natural gas mixture in high pressure rocking cells using the slow constant cooling test method. A terpolymer from reaction of vinyl acetate:maleic anhydride copolymer with cyclohexy lamine and 3,3-di-n-butylaminopropylamine (VA:MA-60% cHex-40% DBAPA), gave excellent performance as a KHI, better than the commercially available poly(N-vinyl caprolactam) (PVCap). CO2 corrosion inhibition was measured by Linear Polarization Resistance (LPR) in a 1 litre CO2 bubble test equipment using C1018 steel coupons. The new terpolymer gave good CO2 corrosion inhibition in 3.6 wt% brine, significantly better than PVCap, but not as good as a commercial imidazoline-based surfactant corrosion inhibitor. The terpolymer also showed good corrosion inhibition efficiency at high salinity conditions, (density 1.12 g/cm3). VA:MA-60% cHex-40% DBAPA shifted the open-circuit potential to more positive values and significantly decreased the corrosion rate.

The Choice of the Optimal Strategy for the Use of Solvents of High-Molecular Organic Deposits, Considering their Complex Composition and the Effect on the Oil Dispersion System

The long-term practice of operating wells producing oil rich in paraffins and asphaltenes has shown that the optimization of technologies for the removal of solid high-molecular organic deposits (asphaltene-resin-paraffin deposits) in oilfield equipment, lifting pipes and flow lines makes it possible to effectively solve the issues of improving the environmental friendliness and energy efficiency of oil production. The use of composite hydrocarbon solvents is one of the most well-known methods used to remove asphaltene-resin-paraffin deposits. Thus, to date, there is no systemic solution to this issue. This paper is aimed at discussing the provisions that determine the possible prospects for the development of an optimal strategy for the use of solvents for the removal of asphaltene-resin-paraffin deposits.

Novel Simulator for Design and Analysis of Wax Removal Treatment from Well Flow Lines Using Thermochemical Fluids

Treatment of well flow lines with thermochemical/exothermic fluid has shown good results for wax removal compared to conventional hot oil, hot water or solvent treatments. However, the technique has not gained widespread use due to lack sufficient scientific publications that can give more insights over its use and help in designing a safe and effective treatment. This paper presents a novel transient mathematical model for design and analysis of thermochemical treatment for well flow lines by taking into account the chemical kinetics, heat transfer, fusion of wax and associated two-phase flow. The governing equations have been solved using tools of computational fluid dynamics and heat transfer (CFD - HT). The resulting simulator can be used to prepare an optimum thermochemical plan by analysing the effects of important factors including wax details, deposition profile, heat loss, formulation composition and injection strategy. Simulation results with the developed model indicate that entire filling of flowline with thermochemical fluid is not necessary for complete wax removal. Injection of a small thermochemical spacer in the flow line followed by its displacement with crude oil can be suffice in case of short flowlines of onshore fields. Selection of initial reactant concentration and pH has to be done judiciously based on the maximum allowed temperature in the flowline and the desired extent of chemical utilization. A sensitivity analysis has shown the existence of an optimum range of injection rate below which wax removal efficiency is compromised by excessive heat loss and above which it is reduced by insufficient residence time. The major limitation of this technique is encountered for large flowlines where a possibility of re-solidification of removed wax deposits exist due to excessive heat loss. Flowlines of length less than 5 km are found to be ideal candidates as in that case, sufficiently high temperatures can be maintained throughout the journey of thermochemical spacer in the flowline which will prevent re-solidification. The simulator has been validated with field implementation results of two well flow lines where the designed jobs have been successful in removing the entire wax deposits as predicted by the simulator.