TY - JOUR

T1 - Old core, new tricks

T2 - a comparative study of old and new mudstone cores for applications in the energy transition

AU - Bensing, Joel

AU - Misch, David

AU - Skerbisch, Lukas

AU - Hujer, Wolfgang

AU - Gumpenberger, Thomas

AU - Mekonnen, Elias

AU - Kostoglou, Nikolaos

AU - Gier, Susanne

PY - 2023/8/8

Y1 - 2023/8/8

N2 - Repurposing depleted oil and gas reservoirs for secondary storage may play an important role in the transition tolow-carbon energy. The integrity of the cap rocks overlying the reservoirs is an important factor for gas storage and needs to beunderstood prior to repurposing. In some cases, old cap-rock cores collected during exploration and development of oil and gasfields may be available for characterization using modern techniques but after being stored for decades these cores are likely tohave experienced many changes in moisture, which can lead to physical changes. A comparative study of samples taken fromold, unpreserved mudstone core and samples from a recently acquired and preserved core taken from the same formation showsthat the mineralogy, porosity and permeability results are relatively similar between the two cores. The differences in theporosity measurements between the old and new core samples are primarily due to natural variations in grain size, rather thanthe preservation status of the cores. Geomechanical data, however, show significant and non-systematic differences between theold samples and the new samples, suggesting that old core samples are not suitable for geomechanical characterization. In theabsence of new, well-preserved core, old core samples may provide suitable porosity, permeability and mineralogical data,whereas the old, unpreserved core is unlikely to provide reliable geomechanical data

AB - Repurposing depleted oil and gas reservoirs for secondary storage may play an important role in the transition tolow-carbon energy. The integrity of the cap rocks overlying the reservoirs is an important factor for gas storage and needs to beunderstood prior to repurposing. In some cases, old cap-rock cores collected during exploration and development of oil and gasfields may be available for characterization using modern techniques but after being stored for decades these cores are likely tohave experienced many changes in moisture, which can lead to physical changes. A comparative study of samples taken fromold, unpreserved mudstone core and samples from a recently acquired and preserved core taken from the same formation showsthat the mineralogy, porosity and permeability results are relatively similar between the two cores. The differences in theporosity measurements between the old and new core samples are primarily due to natural variations in grain size, rather thanthe preservation status of the cores. Geomechanical data, however, show significant and non-systematic differences between theold samples and the new samples, suggesting that old core samples are not suitable for geomechanical characterization. In theabsence of new, well-preserved core, old core samples may provide suitable porosity, permeability and mineralogical data,whereas the old, unpreserved core is unlikely to provide reliable geomechanical data

U2 - 10.1144/geoenergy2023-013

DO - 10.1144/geoenergy2023-013

M3 - Article

VL - 1.2023

JO - Geoenergy

JF - Geoenergy

SN - 2755-1725

IS - 1

ER -