Dear DPS member
Our June meeting will be held on June 13th
The meeting will be held at KIVI Den Haag (Prinsessegracht 23, 2514 AP) at 16:00h
Doors open at 15:30 and the talks begin at 16:00h
We are hosting two speakers sharing their expertise on
‘’Hydrogen Storage’’
Talk 1: An Introduction to Underground Hydrogen Storage
by Karin de Borst, Hydrogen Storage Lead, Shell
Abstract:
Hydrogen is considered a key enabler of a net-zero emission energy system. It provides a balance between energy supply and demand over possibly long distances and periods of time and, thus, allows the introduction of a higher share of renewable energy sources in the overall energy mix. Offering a balancing mechanism to the energy system will require a large-scale storage of hydrogen, which can be most cost-effectively realized in the subsurface using mined salt caverns, depleted reservoirs, or aquifers. This presentation will deliver an introduction to H2 subsurface storage technologies and highlight the critical role of the geosciences and petroleum engineering in their de-risking and further development. It will address performance characteristics, remaining challenges, suitable geological resources, and ongoing piloting activities and commercial-scale developments.
Speaker Bio:
Karin de Borst is a subsurface specialist at Shell with experience in CO2 storage and H2 storage. She currently holds the position of Hydrogen Storage Lead, in which she is developing subsurface storage technologies with an interdisciplinary team in support of Shell’s evolving H2 business.
Karin has a PhD in Computational Mechanics and was pursuing an academic career in the field of material science before joining Shell in 2015, having been Reader in the School of Engineering at University of Glasgow in her last role.
Talk 2: Creep-Cyclic Stress Tests in Salts for Underground Storage
by Michael T. Myers, Professor of Petroleum Engineering, University of Houston, USA
Abstract:
Salt is an elastoviscoplastic material with low permeability and exhibits time-dependent deformation. These properties are beneficial for predicting the stability of salt caverns as a storage medium for CO2 and H2 storage projects. The brittle deformation associated with cyclical loading could result in pore collapse, and the ductile deformation from creep could lead to cavern closure. It is necessary to predict the geomechanical changes during creep-cyclical stress tests in salts. In this study, we conducted combined creep and cyclic tests on salts. The resultant visual microstructural damage was also investigated.
The combined creep-cyclic tests were conducted on servo-controlled triaxial testing apparatus in the University of Houston laboratories. The samples were subjected to confining stress, short holding time, cyclic loading-unloading, and increased to a new confining stress regime. This procedure is repeated for multiple loading-unloading cycles and maximum axial loading at a constant axial strain rate. The pre- and post-test thin sections and microcomputed tomography (CT) scan data are obtained to visualize the degree of microstructural damage.
The fountain plots (axial stress vs. axial, lateral, and volumetric strain) show the degree of stress hysteresis as a function of the opening and closing of microcracks. The initial isostatic loading of confining stress results in microcrack closure. The following hold time (creep) results in strain hardening transitioning to a steady-state ductile deformation characterized by the modified Cam Clay model and stress-strain profiles. This stress path will show the evolution of the yield surface towards strain hardening and increasing irrecoverable strains at each confining stress stage. The thin sections and micro-CT scans show signs of compaction strains, grain boundary microcracks, and increased crystal dislocation densities (formation or reorganization of subgrains) due to accumulated microstructural damage or irrecoverable strains from both creep and stress cycling.
The experiment provides a means of predicting the long-term geomechanical response and damage characteristics associated with rock salts under multiple stress cycles for CO2 or H2 storage projects to ensure the stability and serviceability of underground salt caverns.
Speaker Bio:
Mike Myers is a professor of petroleum engineering in the petroleum engineering department at the University of Houston, where his research interests are in digital rocks, rock mechanics, transport in porous media and acoustics. Prior to that, he spent 25 years at Shell International Exploration and Production as a researcher in rock and fluid properties. He also served as an adjunct professor at the University of Houston during this period.
Mike Myers has a BS degree in physics at Michigan Technological University and MS and PhD degrees at the University of Michigan.
We are looking forward to seeing you there,
DPS board