Evaluating reservoir properties and seal capacities of volcaniclastic rocks for hydrocarbon containment and their application to CO 2 storage ...

• Main Authors: Passey, Simon R., McLean, Charlotte E.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Geological Society of London 2023
• Subjects: Geology; FOS Earth and related environmental sciences; Faroe Islands; Greenland; East Greenland
• Online Access: https://dx.doi.org/10.6084/m9.figshare.c.6986188; https://geolsoc.figshare.com/collections/Evaluating_reservoir_properties_and_seal_capacities_of_volcaniclastic_rocks_for_hydrocarbon_containment_and_their_application_to_CO_sub_2_sub_storage/6986188

Volcaniclastic rocks are commonly overlooked as reservoirs or seals in hydrocarbon plays because their compositions are variably unstable and reactive during burial diagenesis. This study investigated the petrography and petrophysical characteristics of 60 volcaniclastic and 4 siliciclastic samples from three Paleogene volcanic provinces – East Greenland, Faroe Islands and Ethiopia. The volcaniclastic samples have highly variable helium porosities (average: 25.2%), but negligible total optical porosities (average: 1.9%) implying reduced reservoir potential. The samples have, however, highly variable air permeabilities (average: 11 mD) suggesting they could make tight reservoirs. The permeabilities are related to either early calcite cements or the devitrification of volcanic glass. Mercury Injection Capillary Pressure (MICP) data was collected for a subset of 33 samples that at leakage/breakthrough saturations could, under near-surface conditions, hold oil column heights of between 4 m and 1181 m (average: ...