Day 1 :
Keynote Forum
Hartmut R Fischer
TNO Technical Sciences, The Netherlands
Keynote: Asphaltene and wax precipitation – Common principles of structuring
Time : 9:15-10:00
Biography:
Hartmut R Fischer is a Senior Research Scientist in TNO Technical Sciences and monitors materials’ performance and as such connected with all kinds of materials, their testing and evaluation with a focus on materials under extreme environments and the high end equipment applications. His areas of current activities are the assessment of pavement durability as well as adhesion and surface studies, the study and design of self-healing systems, the investigation and understanding of the micro structure of building materials leading to the design of modern building materials for applications under extreme circumstances. He acts as co-Promoter for PhD students and Mentor of Post-Docs at the TU Eindhoven and Delft in the areas polymer nanocomposites, self-healing systems and transport in porous media. He is also a referee for the German and Dutch Research Council as well as for about 40 scientific journals. He has authored 185 refereed publications, 35 patents and 8 book chapters.
Abstract:
Asphaltenes are a complex mixture of different molecules with similar chemical characteristics which are insoluble in aliphatic solvents (e.g. heptane) but soluble in aromatic ones (e.g. toluene). However, being also known as the ‘cholesterol’ of crude oil, they precipitate, adhere to surfaces and, in the worst cases, cause costly pipe blockages and alter the wetting characteristics of mineral surfaces within the reservoir, hindering oil recovery efficiency. Similar effects are also observed with respect to waxes. Even at very low concentrations in ‘good’ solvents, both still have a strong tendency to form nanoaggregates or nanocrystallites which transfer to micro- and macro-aggregates whose structure and formation remain largely unknown despite much research. Aggregation proceeds from specific strong interaction sites located at the periphery of the asphaltene molecules. They drive the reversible association in two-dimensional sheets, a morphology which is consistent with reported scattering and viscosity data. Precipitation eventually occurs, determined by van der Waals attractions between aggregates, when the solubility parameter of the solvent is shifted. In our current research, we have focused on the several steps to tackle this problem which can heavily impact the economic value of a project, especially in harsh sub-sea environments, where deposition can halt production altogether. For example, intervention costs for asphaltene removal for a land-based well up to $0.5 MM US translates to more than $3 MM US for off-shore well production, and the economic loss as a result of lost/delayed production can amount to $1.2 MM US per day. The ability to predict the occurrence and magnitude of asphaltene deposition in wellbores is critical to forecast the related flow assurance challenges for deep and ultradeep water production. We therefore have the goal to find a solution (chemical, mechanical or otherwise) namely to: a) Understand the issues and help characterize the problem, b) Prevent or inhibit deposition (asphaltene alone or in combination
Keynote Forum
Fabrizio Paolacci
Roma Tre University, Italy
Keynote: Seismic isolation of elevated steel storage tanks by sliding concave bearings
Time : 10:00-10:45
Biography:
Fabrizio Paolacci graduated in Civil Engineering in 1992 at the University of Rome "La Sapienza" and completed his PhD in Structural Engineering in 1997. He is currently working as an Assistant Professor in Structural Engineering at University Roma Tre, Department of Engineering. He gained a long standing experience in the management of research projects about experimental assessment of the seismic response of structures. He is currently PI of many European projects. From 2008 to 2013, he assumed the role of Scientific Coordinator of the Laboratory of Testing Materials and Structures of the Department of Structures of the University Roma Tre. He has received a Fellowship provided by CNR (National Research Council) for a research activity of six months at the Department of Civil and Environmental Engineering of University of California at Berkeley from September 1999 to February 2000 as a Visiting Scholar. He is author of more than 100 publications on international peer-reviewed journals and conferences.
Abstract:
Liquid steel storage tanks are strategic structures for industrial facilities and have been widely used both in nuclear and non-nuclear power plants. Typical damage to tanks occurred during past earthquakes such as cracking at the bottom plate, elastic or elastoplastic buckling of the tank wall, failure of the ground anchorage system and sloshing damage around the roof, etc. Due to their potential and substantial economic losses as well as environmental hazards, implementations of seismic isolation and energy dissipation systems have been recently extended to liquid storage tanks. Although the benefits of seismic isolation systems have been well known in reducing seismic demands of tanks; however, these benefits have been rarely investigated in literature in terms of reduction in the probability of failure. In this paper, a vulnerability-based design approach of a sliding concave bearing system for an existing elevated liquid steel storage tank is presented by evaluating the probability of exceeding specific limit states. Firstly, nonlinear time history analyses of a three dimensional stick model for the examined case study are performed using a set of ground motion records. Fragility curves of different failure modes of the tank are then obtained by the well-known cloud method. In the following, a seismic isolation system based on concave sliding bearings is proposed. The effectiveness of the isolation system in mitigating the seismic response of the tank is investigated by means of fragility curves. Finally, an optimization of design parameters for sliding concave bearings is determined based on the reduction of the tank vulnerability or the probability of failure.
Keynote Forum
Bjørn Kvamme
University of Bergen, Norway
Keynote: Combined CO2 storage in hydrate with simultaneous release of CH4 and limitations of adding N2 to the CO2
Time : 11:15-11:45
Biography:
Bjørn Kvamme obtained his MSc in Chemical Engineering (1981) and PhD in Chemical Engineering (1984) from the Norwegian University of Technology and Natural Sciences. After a short period with SINTEF and two years at Bergen University College, he was appointed as full Professor in 1987 and started education of MSc and PhD in Process Technology in Telemark. He is appointed as a Professor in Gas Processing at the Department of Physics, University of Bergen in March 2000. He is the author/co-author of 422 publications during last 25 years, of which 148 are in good international scientific journals. He has 2270 citations as per May 1, 2017, and has presented numerous papers at international conferences.
Abstract:
Huge resources of energy in the form of natural gas hydrates are widely distributed worldwide in permafrost sediments as well as in on shore sediments. A novel technology for combined production of these resources and safe long-term storage of carbon dioxide is based on the injection of carbon dioxide into in situ methane hydrate-filled sediments. This will lead to an exchange of the in situ methane hydrate over to carbon dioxide- dominated hydrate and a simultaneous release of methane gas. Recent theoretical and experimental results indicate that the conversion from natural gas hydrate to carbon dioxide hydrate and mixed carbon dioxide/methane hydrate follows two primary mechanisms. Direct solid state transformation is possible, but very slow. The dominating mechanism involves formation of a new hydrate from injected carbon dioxide and associated dissociation of the in situ natural gas hydrate by the released heat. Nitrogen is frequently added in order to increase gas permeability and to reduce blocking due to new hydrate formation, and will as such also reduce the relative impact of the fast mechanism on the conversion rates. In addition to carbon dioxide, other sour gases, such as hydrogen sulfide, may follow the carbon dioxide from the sour gas removal process. Hydrogen sulfide is a very aggressive hydrate former. It is abundant in various amounts in thermogenic hydrocarbon systems. In this work, we investigate the sensitivity of possible additions of hydrogen sulfide in carbon dioxide/nitrogen mixtures, and how the ability to form new hydrate changes with the additions of hydrogen sulfide. This analysis is applied to four case studies: (1) Bjørnøya gas hydrate basin, (2) the Nankai field in Japan, (3) the Hikurangi Margin in New Zealand, and (4) a gas hydrate basin in South-West Taiwan. The hydrate saturations found in these fields vary over a range from 25−80%. Pressures range from 4−22.6 MPa and temperatures from 275.15−292.77 K. For all these ranges of conditions, even 1% H2S will substantially increase the ability to form new hydrate from an injected CO2/N2 mixture containing H2S. Except for the most shallow of the reservoirs (Bjørnøya) 1% H2S results in formation of a new hydrate for all concentrations of CO2 in N2 above 1%. Implementation of results from this work into a reservoir simulator is a natural follow-up which can shed light on the macroscopic consequences in term of possible local blocking of the flow due to content of H2S. The mass transport, mass balances, and energy balances in a reservoir simulator are also needed for a more detailed evaluation on how the content of H2S and CO2 changes over time and location in the reservoir due to various processes in addition to hydrate formation. H2S and CO2 dissolves significantly in pore water, and also adsorbs well on various sediment minerals.