Porosity and free gas estimates from controlled source electromagnetic data at the Scanner Pockmark in the North Sea

Core-scale geophysical and hydromechanical analysis of seabed sediments affected by CO2 venting

“…For comparison, in Figure 5b we display two additional models considering m = 1.5 and m = 1.9, with a =1 in both cases, to frame the accepted cementation range for high porosity unconsolidated granular sediments (Jackson et al, 1978;Mavko et al, 2009)). As a reference, the former case (i.e., m = 1.5) coincides with that adopted by Gehrmann et al (2021) to estimate the porosity of the Witch Ground Formation from MSCL resistivity data, while the latter case is closer to that used by Schwalenberg et al (2020) for the Danube deep-sea fan, Black Sea.…”

“…A complementary project funded by NERC UK entitled Characterization of Major Overburden Leakage Pathways above Sub-seafloor CO2 Storage Reservoirs in the North Sea (CHIMNEY (Bull et al, 2018)), focused on improving the understanding of subsurface fluid pathways, and developing tools to identify seal bypass systems and quantify partial gas saturation. During both STEMM-CCS and CHIMNEY several geophysical surveys were carried out in the North Sea (Achterberg and Esposito, 2018;Böttner et al, 2020;Gehrmann et al, 2021;Karstens et al, 2019), including seismic and electromagnetic data acquisition. These geophysical data which together with in situ samples and modelling result in a comprehensive amount of information about the shallower part of the sediment column (Robinson et al, 2021).…”

An Introduction to the Application of Marine Controlled-Source Electromagnetic Methods for Natural Gas Hydrate Exploration

“…CSEM has been a useful geophysical method to discriminate between high and low hydrocarbon saturation in a potential reservoir [31,50,[63][64][65][66]. Many applications in natural gas hydrate detection have been published from, e.g., the North Sea [67,68], Taiwan [69], the Gulf of Mexico and Canada [70], the Danube Paleo-Delta [20], Norway [44], the South China Sea [71], and the Western Black Sea [54].…”

Diversidade e Estrutura de Comunidades Microbianas em Áreas de Pockmarks e Diápiros de Sal na Margem Continental Brasileira (Sudoeste do Oceano Atlântico)

“…The gas and/or fluid existing in the subsurface can migrate to more superficial layers through tectonic faults or porous lithology until it finds more resistant layers that block its passage or until they are emitted to the surface (GEHRMANN et al, 2021). The tension of the sedimentary layers controls the flow of these gases from their reservoirs to the surface.…”

“…Pockmarks are thought to form quickly when a pressurised subsurface containing gases or fluid is suddenly released to the sediment surface GEHRMANN et al, 2021;MICALLEF et al, 2022).…”