Fate of Fugitive Natural Gas in Heterogeneous Near‐surface Sediments in a Region of Extensive Petroleum Resource Development

2021 ◽  
Author(s):  
Jessie Tse‐Hua Chao ◽  
Aaron G. Cahill ◽  
Cole J.C. Van De Ven ◽  
Roger D. Beckie
Keyword(s):  
Natural Gas ◽  
Surface Sediments ◽  
Resource Development ◽  
Near Surface ◽  
Petroleum Resource

scholarly journals Time-lapse imaging of CO2 migration within near-surface sediments during a controlled sub-seabed release experiment

2021 ◽  
Vol 109 ◽  
pp. 103363
Author(s):  
Ben Roche ◽  
Jonathan M. Bull ◽  
Hector Marin-Moreno ◽  
Timothy G. Leighton ◽  
Ismael H. Falcon-Suarez ◽  
...  
Keyword(s):  
Surface Sediments ◽  
Time Lapse ◽  
Near Surface ◽  
Release Experiment ◽  
Time Lapse Imaging

Route selection for natural gas pipelines in Ireland

1987 ◽  
Vol 4 (1) ◽  
pp. 467-474
Author(s):  
J. H. Redding
Keyword(s):  
Natural Gas ◽  
Rural Areas ◽  
Site Investigation ◽  
Geological Mapping ◽  
Route Selection ◽  
Construction Costs ◽  
Near Surface ◽  
Natural Gas Pipelines ◽  
Potential Difficulty ◽  
Ground Conditions

AbstractBy the end of 1986, over 400 km of high pressure (70 bar) natural gas pipeline will have been constructed in the Irish Republic, much of it laid in sparsely populated rural areas where topography, hydrology, near surface geology and ground conditions can significantly influence construction feasibility and cost. Identifying, quantifying and (where possible) avoiding areas of potential difficulty or hazard are aspects of route selection to which engineering geology can make an important contribution. This contribution is discussed in relation to the Cork-Dublin pipeline completed in 1982, and the Limerick, Waterford and Mallow lines due for completion this year. In particular, the application and merits of stereo aerial photographic interpretation, superficial geological mapping and field study are outlined, together with the use of more traditional methods of site investigation. Attention is focussed on indigenous engineering geological problems associated with shallow rock, limestone karst, peat bog and poorly drained alluvial and morainic soils. Data acquisition and presentation are discussed within the overall context of civil engineering contract preparation and administration. The usefulness of this approach, particularly for predicting and minimising construction costs, forestalling claims and generally facilitating on-site supervision, is emphasised.

scholarly journals Fracture-controlled fluid transport supports microbial methaneoxidizing communities at the Vestnesa Ridge

2018 ◽  
Author(s):  
Haoyi Yao ◽  
Wei-Li Hong ◽  
Giuliana Panieri ◽  
Simone Sauer ◽  
Marta E. Torres ◽  
...  
Keyword(s):  
Fluid Transport ◽  
Surface Sediments ◽  
Dissolved Inorganic Carbon ◽  
Total Alkalinity ◽  
Anaerobic Oxidation Of Methane ◽  
Gas Migration ◽  
Near Surface ◽  
Recent Onset ◽  
Oxidation Of Methane ◽  
Lipid Biomarker

Abstract. We report on a rare observation of a mini-fracture in near-surface sediments (30 cm below the seafloor) visualized using rotational scanning X-ray of a core recovered from the Lomvi pockmark, Vestnesa Ridge west of Svalbard (1200 m water depth). Porewater geochemistry and lipid biomarker signatures revealed clear differences in the geochemical and biogeochemical regimes of this core compared with two additional ones recovered from pockmarks sites at Vestnesa Ridge, which we attribute to differential methane transport mechanisms. In the sediments core featuring the shallow mini-fracture at pockmark Lomvi, we observed high concentrations of both methane and sulfate throughout the core in tandem with moderately elevated values for total alkalinity, 13C-depleted dissolved inorganic carbon (DIC), and 13C-depleted lipid biomarkers (diagnostic for the slow-growing microbial communities mediating the anaerobic oxidation of methane with sulfate – AOM). In another core recovered from the same pockmark about 80 m away from the fractured core, we observed complete sulfate depletion in the top centimeters of the sediment and much more pronounced signatures of AOM than in the fractured core. Our data indicate a gas advection-dominated transport mode in both cores facilitating methane migration into sulfate-rich surface sediments. However, the more moderate expression of AOM signals suggest a rather recent onset of gas migration at the site of the fractured core, while the geochemical evidence for a well-established AOM community at the second coring site at the Lomvi pockmark suggest that gas migration has been going on for a longer period of time. A third core recovered from Lunde pockmark was dominated by diffusive transport with only weak geochemical and biogeochemical evidence for AOM. Our study highlights that advective fluid and gas transport supported by mini-fractures can be important in modulating methane dynamics in surface sediments.

scholarly journals Geochemistry and related studies of Clyde Estuary sediments

2017 ◽  
Vol 108 (2-3) ◽  
pp. 269-288 ◽  
Author(s):  
David G. Jones ◽  
Christopher H. Vane ◽  
Solveigh Lass-Evans ◽  
Simon Chenery ◽  
Bob Lister ◽  
...  
Keyword(s):  
Seismic Data ◽  
Surface Sediments ◽  
Sidescan Sonar ◽  
Near Surface ◽  
Glacial Sediments ◽  
Shallow Seismic ◽  
Limited Success ◽  
Shallow Layer ◽  
Quaternary History ◽  
Different Sources

ABSTRACTGeochemical and related studies have been made of near-surface sediments from the River Clyde estuary and adjoining areas, extending from Glasgow to the N, and W as far as the Holy Loch on the W coast of Scotland, UK. Multibeam echosounder, sidescan sonar and shallow seismic data, taken with core information, indicate that a shallow layer of modern sediment, often less than a metre thick, rests on earlier glacial and post-glacial sediments. The offshore Quaternary history can be aligned with onshore sequences, with the recognition of buried drumlins, settlement of muds from quieter water, probably behind an ice dam, and later tidal delta deposits. The geochemistry of contaminants within the cores also indicates shallow contaminated sediments, often resting on pristine pre-industrial deposits at depths less than 1m. The distribution of different contaminants with depth in the sediment, such as Pb (and Pb isotopes), organics and radionuclides, allow chronologies of contamination from different sources to be suggested. Dating was also attempted using microfossils, radiocarbon and 210Pb, but with limited success. Some of the spatial distribution of contaminants in the surface sediments can be related to grain-size variations. Contaminants are highest, both in absolute terms and in enrichment relative to the natural background, in the urban and inner estuary and in the Holy Loch, reflecting the concentration of industrial activity.

Direct determination of resonant properties of near-surface sediments using microtremor

2019 ◽  
Vol 125 ◽  
pp. 105739 ◽  
Author(s):  
Yury I. Kolesnikov ◽  
Кonstantin V. Fedin ◽  
Luckymore Ngomayezwe
Keyword(s):  
Surface Sediments ◽  
Direct Determination ◽  
Near Surface

Shear-Wave Velocity and Seismic Response of Near-Surface Sediments in Charleston, South Carolina

2006 ◽  
Vol 96 (5) ◽  
pp. 1897-1914 ◽  
Author(s):  
R. D. Andrus ◽  
C. D. Fairbanks ◽  
J. Zhang ◽  
W. M. Camp ◽  
T. J. Casey ◽  
...  
Keyword(s):  
South Carolina ◽  
Seismic Response ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Surface Sediments ◽  
Near Surface

Assessment of the Effect of Increasing Temperature On the Ecology and Assemblage Structure of Modern Planktic Foraminifers in the Caribbean and Surrounding Seas

2018 ◽  
Vol 48 (3) ◽  
pp. 251-272 ◽  
Author(s):  
Anna Jentzen ◽  
Joachim Schönfeld ◽  
Ralf Schiebel
Keyword(s):  
Surface Waters ◽  
Surface Sediments ◽  
Seawater Temperature ◽  
Chlorophyll Concentration ◽  
Caribbean Sea ◽  
Trophic Conditions ◽  
Near Surface ◽  
The Caribbean ◽  
Standing Stocks ◽  
The 1960S

Abstract Habitat patterns of subtropical and tropical planktic foraminifers in the Caribbean Sea were obtained from plankton samples collected in spring 2009 and 2013. The spatial distribution in surface waters (3.5 m water depth) and depth habitat patterns (surface to 400 m) of 33 species were compared with prevailing water-mass conditions (temperature, salinity, and chlorophyll-a concentration) and planktic foraminiferal test assemblages in surface sediments. Distribution patterns indicate a significant relationship with seawater temperature and trophic conditions. A reduction in standing stocks was observed close to the Orinoco River plume and in the Gulf of Paria, associated with high turbidity and concomitant low surface-water salinity. In contrast, a transient mesoscale patch of high chlorophyll concentration in the eastern Caribbean Sea was associated with higher standing stocks in near surface waters, including high abundances of Globigerinita glutinata and Neogloboquadrina dutertrei. Globorotalia truncatulinoides mainly lives close to the seasonal pycnocline and can be linked to winter conditions indicated by lower sea-surface temperatures (SSTs) of ∼20°C. Globigerinoides sacculifer and Globoturborotalita rubescens were associated with oligotrophic conditions in the pelagic Caribbean Sea during early spring and showed a synodic lunar reproduction cycle. The live assemblages in the water column from 2009 and 2013 were similar to those reported in earlier studies from the 1960s and 1990s and to assemblages of tests in the surface sediments. Minor differences in faunal proportions were attributed to seasonal variability and environmental differences at the local scale. An exception was the low relative abundance of Globigerinoides ruber in the Caribbean Sea in 2009 compared to surface sediment samples and plankton net samples collected in the 1960s and 1990s. Decreasing abundance of Gs. ruber white in the Caribbean Sea may be associated with increasing SSTs over past decades and changes in nutrient flux and primary production.

Thermogenic Gases In Near-Surface Sediments Of Norton Sound, Alaska

1978 ◽  
Author(s):  
Hans Nelson ◽  
Keith A. Kvenvolden ◽  
Edward C. Clukey
Keyword(s):  
Surface Sediments ◽  
Near Surface
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