Derivative-Free Optimization with Proxy Models for Oil Production Platforms Sharing a Subsea Gas Network

The deployment of offshore platforms for the extraction of oil and gas from subsea reservoirs presents unique challenges, particularly when multiple platforms are connected by a subsea gas network. In the Santos basin, the aim is to maximize oil production while maintaining safe and sustainable levels of CO2 content and pressure in the gas stream. To address these challenges, a novel methodology has been proposed that uses boundary conditions to coordinate the use of shared resources among the platforms. This approach decouples the optimization of oil production in platforms from the coordination of shared resources, allowing for more efficient and effective operation of the offshore oilfield. In addition to this methodology, a fast and accurate proxy model has been developed for gas pipeline networks. This model allows for efficient optimization of the gas flow through the network, taking into account the physical and operational constraints of the system. In experiments, the use of the proposed proxy model in tandem with derivativefree optimization algorithms resulted in an average error of less than 5% in pressure calculations, and a processing time that was over up to 1000 times faster than the phenomenological simulator. These results demonstrate the effectiveness and efficiency of the proposed methodology in optimizing oil production in offshore platforms connected by a subsea gas network, while maintaining safe and sustainable levels of CO2 content and pressure in the gas stream.N/

Multiphase flow modelling for enhanced oil and gas drilling and production

From the exploration to the abandonment of an oil and gas discovery, operators and engineers are constantly faced with the challenge of achieving the best commercial potential of oil fields. Although the petroleum engineering community has significantly contributed towards maximising the potential of discovered prospects, the approach adopted so far has been compartmentalised with little (heuristics-based) or no quality integration. The highly interconnected nature of the decision factors affecting the management of any field requires increased implementation of Computer-Aided Process Engineering (CAPE) methods, thus presenting a task for which chemical engineers have the background to make useful contributions. Drilling and production are the two primary challenging operations of oilfield activities, which span through different time horizons with both fast and slow-paced dynamics. These attributes of these systems make the application of modelling, simulation, and optimisation tasks difficult. This PhD project aims to improve field planning and development decisions from a Process Systems Engineering (PSE) perspective via numerical (fluid dynamics) simulations and modelbased deterministic optimisation of drilling and production operations, respectively. Also demonstrated in this work is the importance of deterministic optimisation as a reliable alternative to classical heuristic methods. From a drilling operation perspective, this project focuses on the application of Computational Fluid Dynamics (CFD) as a tool to understand the intricacies of cuttings transport (during wellbore cleaning) with drilling fluids of non-Newtonian rheology. Simulations of two-phase solid-liquid flows in an annular domain are carried out, with a detailed analysis on the impact of several drilling parameters (drill pipe eccentricity, inclination angle, drill pipe rotation, bit penetration rate, fluid rheology, and particle properties) on the cuttings concentration, pressure drop profiles, axial fluid, and solid velocities. The influence of the flow regime (laminar and turbulent) on cuttings transport efficiency is also examined using the Eulerian-Eulerian and Lagrangian-Eulerian modelling methods. With experimentally validated simulations, this aspect of the PhD project provides new understanding on the interdependence of these parameters; thus facilitating industrial wellbore cleaning operations. The second part of this project applies mathematical optimisation techniques via reduced-order modelling strategies for the enhancement of petroleum recovery under complex constraints that characterise production operations. The motivation for this aspect of the project stems from the observation that previous PSE-based contributions aimed at enhancing field profitability, often apply over-simplifications of the actual process or neglect some key performance indices due to problem complexity. However, this project focuses on a more detailed computational integration and optimisation of the models describing the whole field development process from the reservoir to the surface facilities to ensure optimal field operations. Nonlinear Programs (NLPs), Mixed-Integer Linear Programs (MILPs), and Mixed-Integer Nonlinear Programs (MINLPs) are formulated for this purpose and solved using high-fidelity simulators and algorithms in open-source and commercial solvers. Compared to previous studies, more flow physics are incorporated and rapid computations obtained, thus enabling real-time decision support for enhanced production in the oil and gas industry

Operational Research IO2017, Valença, Portugal, June 28-30

This proceedings book presents selected contributions from the XVIII Congress of APDIO (the Portuguese Association of Operational Research) held in Valença on June 28–30, 2017. Prepared by leading Portuguese and international researchers in the field of operations research, it covers a wide range of complex real-world applications of operations research methods using recent theoretical techniques, in order to narrow the gap between academic research and practical applications. Of particular interest are the applications of, nonlinear and mixed-integer programming, data envelopment analysis, clustering techniques, hybrid heuristics, supply chain management, and lot sizing and job scheduling problems. In most chapters, the problems, methods and methodologies described are complemented by supporting figures, tables and algorithms. The XVIII Congress of APDIO marked the 18th installment of the regular biannual meetings of APDIO – the Portuguese Association of Operational Research. The meetings bring together researchers, scholars and practitioners, as well as MSc and PhD students, working in the field of operations research to present and discuss their latest works. The main theme of the latest meeting was Operational Research Pro Bono. Given the breadth of topics covered, the book offers a valuable resource for all researchers, students and practitioners interested in the latest trends in this field.info:eu-repo/semantics/publishedVersio

Transporte de combustível refinado em África : caso de Angola

Dissertação de mestrado em Negócios InternacionaisO transporte rodoviário serve de elo entre a região litoral e o planalto central de Angola, no que se refere o transporte de produtos petrolíferos. Além deste modo, o transporte ferroviário tornou-se numa realidade após a reabilitação do caminho-de-ferro de Benguela. Hoje em dia, os produtos petrolíferos são transportados por via marítima até a província de Benguela, sendo posteriormente transportados à província do Huambo, por via rodoviária. O transporte rodoviário acarreta enormes custos à SONANGOL por causa da grande distância entre essas duas localidades. Por se tratar de produtos perigosos, o transporte por estrada representa um potencial risco à saúde de pessoas, segurança pública e ambiente, visto que o país apresenta uma das mais elevadas taxas de sinistralidade rodoviária do mundo. O objetivo geral do trabalho visava analisar o desempenho do modo rodoviário, ferroviário e hipoteticamente o dutoviário, no que tange o transporte de gasóleo a patir do município de Lobito (Benguela) até ao município do Huambo (Huambo), sob ponto de vista económico e socioambiental, sendo este o caso de estudo. Para o efeito, os métodos multicritério de auxílio à tomada de decisão, TOPSIS e GRA, foram utilizados como instrumentos para o estabelecimento de uma ordem hierárquica entre as alternativas de transporte, visando auxiliar os agentes de decisão no processo de escolha modal. Os resultados confirmam que o transporte rodoviário não é a melhor alternativa para o transporte de gasóleo numa perspetiva de curto e longo prazo, sendo no entanto o transporte ferroviário aquele que apresenta melhores resultados, isto, no cenário atual. Contudo, num cenário hipotético ou de longo prazo, o modo dutoviário possui o melhor desempenho em comparação com os modos rodoviário e ferroviário, sob ponto de vista económico e socioambiental.Road transport serves as a link between the coastal region and the central plateau of Angola, regarding the transport of petroleum products. In addition to this mode of transport, rail is now available after the rehabilitation of Benguela’s railroad. Nowadays, petroleum products are transported by sea to the province of Benguela, where they are transported to Huambo province by road. Road transport carries enormous costs to SONANGOL because of the great distance between these two locations. Since those are hazardous materials, road transport represents a potential risk to human health, public safety and the environment because the country’s traffic-related death rates are among the highest in the world. The overall objective of this work was to analyze the performance of road and rail modes as well as the hypothesis of pipeline transport in relation to the shipment of diesel from Lobito municipality, (Benguela) to Huambo municipality (Huambo), from an economic and socio-environmental standpoint, this being the case study. To this end, multi-criteria decision making methods such as TOPSIS and GRA were used as tools in order to establish a ranking order among the transport alternatives, with the goal of helping decision makers in the process of modal choice. The results confirm that road transport is not the best alternative for the transfer of diesel whether in a short or long-term perspective. Railroad is the transport mode that presents better results in the current scenario. However, in a hypothetical scenario or longterm scenario, pipeline transport shows the best performance vis-à-vis road and rail modes, from an economic and socio-environmental standpoint