paul oluwunmi | The University of Auckland (original) (raw)
Papers by paul oluwunmi
Transport in Porous Media
Pressure reduction following uplift may lead to dissociation of gas hydrates. The dynamics of hyd... more Pressure reduction following uplift may lead to dissociation of gas hydrates. The dynamics of hydrate dissociation in such settings, however, are poorly understood. We used TOUGH+HYDRATE to investigate the response of gas hydrates to an uplift of 0.009 myr$$^{-1}$$ - 1 over the last 8 kyrs, the approximate end of the postglacial sea-level rise. Geological parameters for the simulations are based on hydrate deposits from the Nankai Trough subduction zone. Our results suggest stabilisation from endothermic cooling, elevated pore pressure, and pore water freshening significantly slows hydrate dissociation such that the hydrate remains in place at its pre-uplift level. A shallower hydrate layer forms from upward-migrating gas when assuming moderate to high permeability (10$$^{-15}$$ - 15 and 10$$^{-13}$$ - 13 m$$^{2}$$ 2 ), while gas remains trapped for low permeability (10$$^{-17}$$ - 17 m$$^{2}$$ 2 ). In the latter case, we predict elevated pore pressure with potential implications fo...
Attached are all TOUGH+HYDRATE input and output files for the uplift paper.
Canadian Journal of Chemistry, 2015
The development of polymeric and oligomeric chemical additives that can control the nucleation an... more The development of polymeric and oligomeric chemical additives that can control the nucleation and growth of gas hydrates remains a topic of major research interest, with important implications for energy security and the environment. In this paper we present a molecular dynamics study of eight different oligomeric compounds that have been proposed as potential kinetic inhibitors for methane hydrate. The results show that statistically significant variations in hydrate formation, induced by the chemical additive, can be observed within a relatively modest series of molecular dynamics simulations, thus opening the way for computational screening for optimal additives to control hydrate formation. One amino acid oligomer, asparagine, was found to be more active than a number of synthetic inhibitors, including PVCap.
The development of polymeric and oligomeric chemical additives that can control the nucleation an... more The development of polymeric and oligomeric chemical additives that can control the nucleation and growth of gas hydrates remains a topic of major research interest, with important implications for energy security and the environment. In this paper we present a molecular dynamics study of eight different oligomeric compounds that have been proposed as potential kinetic inhibitors for methane hydrate. The results show that statistically significant variations in hydrate formation, induced by the chemical additive, can be observed within a relatively modest series of molecular dynamics simulations, thus opening the way for computational screening for optimal additives to control hydrate formation. One amino acid oligomer, asparagine, was found to be more active than a number of synthetic inhibitors, including PVCap. Résumé : La mise au point d'additifs chimiques polymériques et oligomériques permettant de maîtrise la nucléation et la croissance des hydrates de gaz demeure un sujet de recherche suscitant un grand intérêt, et dont les retombées auront une incidence importante sur la sécurité énergétique et l'environnement. Dans le présent article, nous présentons une étude de dynamique moléculaire portant sur huit composés oligomériques différents qui sont proposés en tant qu'éventuels inhibiteurs cinétiques de la formation de l'hydrate de méthane. Les résultats indiquent que l'on peut observer des variations quant a ` la formation de l'hydrate, significatives sur le plan statistique et induites par l'additif chimique, dans une série relativement restreinte de simulations de dynamique moléculaire. Ces résultats ouvrent ainsi la voie au criblage in silico d'additifs possédant les propriétés optimales pour maîtriser la formation des hydrates. Un oligomère d'acide aminé, a ` base d'asparagine, s'est révélé plus actif que plusieurs inhibiteurs synthétiques, dont le PVCap. [Traduit par la Rédaction] Mots-clés : hydrate de méthane, hydrates de gaz, clathrates, dynamique moléculaire, inhibiteurs cinétiques, nucléation.
Transport in Porous Media
Pressure reduction following uplift may lead to dissociation of gas hydrates. The dynamics of hyd... more Pressure reduction following uplift may lead to dissociation of gas hydrates. The dynamics of hydrate dissociation in such settings, however, are poorly understood. We used TOUGH+HYDRATE to investigate the response of gas hydrates to an uplift of 0.009 myr$$^{-1}$$ - 1 over the last 8 kyrs, the approximate end of the postglacial sea-level rise. Geological parameters for the simulations are based on hydrate deposits from the Nankai Trough subduction zone. Our results suggest stabilisation from endothermic cooling, elevated pore pressure, and pore water freshening significantly slows hydrate dissociation such that the hydrate remains in place at its pre-uplift level. A shallower hydrate layer forms from upward-migrating gas when assuming moderate to high permeability (10$$^{-15}$$ - 15 and 10$$^{-13}$$ - 13 m$$^{2}$$ 2 ), while gas remains trapped for low permeability (10$$^{-17}$$ - 17 m$$^{2}$$ 2 ). In the latter case, we predict elevated pore pressure with potential implications fo...
Attached are all TOUGH+HYDRATE input and output files for the uplift paper.
Canadian Journal of Chemistry, 2015
The development of polymeric and oligomeric chemical additives that can control the nucleation an... more The development of polymeric and oligomeric chemical additives that can control the nucleation and growth of gas hydrates remains a topic of major research interest, with important implications for energy security and the environment. In this paper we present a molecular dynamics study of eight different oligomeric compounds that have been proposed as potential kinetic inhibitors for methane hydrate. The results show that statistically significant variations in hydrate formation, induced by the chemical additive, can be observed within a relatively modest series of molecular dynamics simulations, thus opening the way for computational screening for optimal additives to control hydrate formation. One amino acid oligomer, asparagine, was found to be more active than a number of synthetic inhibitors, including PVCap.
The development of polymeric and oligomeric chemical additives that can control the nucleation an... more The development of polymeric and oligomeric chemical additives that can control the nucleation and growth of gas hydrates remains a topic of major research interest, with important implications for energy security and the environment. In this paper we present a molecular dynamics study of eight different oligomeric compounds that have been proposed as potential kinetic inhibitors for methane hydrate. The results show that statistically significant variations in hydrate formation, induced by the chemical additive, can be observed within a relatively modest series of molecular dynamics simulations, thus opening the way for computational screening for optimal additives to control hydrate formation. One amino acid oligomer, asparagine, was found to be more active than a number of synthetic inhibitors, including PVCap. Résumé : La mise au point d'additifs chimiques polymériques et oligomériques permettant de maîtrise la nucléation et la croissance des hydrates de gaz demeure un sujet de recherche suscitant un grand intérêt, et dont les retombées auront une incidence importante sur la sécurité énergétique et l'environnement. Dans le présent article, nous présentons une étude de dynamique moléculaire portant sur huit composés oligomériques différents qui sont proposés en tant qu'éventuels inhibiteurs cinétiques de la formation de l'hydrate de méthane. Les résultats indiquent que l'on peut observer des variations quant a ` la formation de l'hydrate, significatives sur le plan statistique et induites par l'additif chimique, dans une série relativement restreinte de simulations de dynamique moléculaire. Ces résultats ouvrent ainsi la voie au criblage in silico d'additifs possédant les propriétés optimales pour maîtriser la formation des hydrates. Un oligomère d'acide aminé, a ` base d'asparagine, s'est révélé plus actif que plusieurs inhibiteurs synthétiques, dont le PVCap. [Traduit par la Rédaction] Mots-clés : hydrate de méthane, hydrates de gaz, clathrates, dynamique moléculaire, inhibiteurs cinétiques, nucléation.