scholarly journals A Long Gravity-Piston Corer Developed for Seafloor Gas Hydrate Coring Utilizing an In Situ Pressure-Retained Method

Energies ◽  
2013 ◽  
Vol 6 (7) ◽  
pp. 3353-3372 ◽  
Author(s):  
Jia-Wang Chen ◽  
Wei Fan ◽  
Brian Bingham ◽  
Ying Chen ◽  
Lin-Yi Gu ◽  
...  
Keyword(s):  
2014 ◽  
Vol 53 (36) ◽  
pp. 14142-14157 ◽  
Author(s):  
Zhaoyang Chen ◽  
Jingchun Feng ◽  
Xiaosen Li ◽  
Yu Zhang ◽  
Bo Li ◽  
...  

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3403 ◽  
Author(s):  
Burwicz ◽  
Rüpke

Marine sediments of the Blake Ridge province exhibit clearly defined geophysical indications for the presence of gas hydrates and a free gas phase. Despite being one of the world’s best-studied gas hydrate provinces and having been drilled during Ocean Drilling Program (ODP) Leg 164, discrepancies between previous model predictions and reported chemical profiles as well as hydrate concentrations result in uncertainty regarding methane sources and a possible co-existence between hydrates and free gas near the base of the gas hydrate stability zone (GHSZ). Here, by using a new multi-phase finite element (FE) numerical model, we investigate different scenarios of gas hydrate formation from both single and mixed methane sources (in-situ biogenic formation and a deep methane flux). Moreover, we explore the evolution of the GHSZ base for the past 10 Myr using reconstructed sedimentation rates and non-steady-state P-T solutions. We conclude that (1) the present-day base of the GHSZ predicted by our model is located at the depth of ~450 mbsf, thereby resolving a previously reported inconsistency between the location of the BSR at ODP Site 997 and the theoretical base of the GHSZ in the Blake Ridge region, (2) a single in-situ methane source results in a good fit between the simulated and measured geochemical profiles including the anaerobic oxidation of methane (AOM) zone, and (3) previously suggested 4 vol.%–7 vol.% gas hydrate concentrations would require a deep methane flux of ~170 mM (corresponds to the mass of methane flux of 1.6 × 10−11 kg s−1 m−2) in addition to methane generated in-situ by organic carbon (POC) degradation at the cost of deteriorating the fit between observed and modelled geochemical profiles.


2016 ◽  
Author(s):  
Kathleen Sell ◽  
Erik-H. Saenger ◽  
Andrzej Falenty ◽  
Marwen Chaouachi ◽  
David Haberthür ◽  
...  

Abstract. To date, very little is known about the distribution of gas hydrates in sedimentary matrices and the resulting matrix-pore network affecting the seismic properties at low hydrate concentration. Digital rock physics offers a unique solution to this issue yet requires good quality, high resolution 3D representations for the accurate modelling of petrophysical and transport properties. Although such models are readily available via in-situ synchrotron radiation X-ray tomography the analysis of such data asks for complex workflows and high computational power to maintain valuable results. Here, we present a best-practise procedure complementing data from Chaouachi et al. (Geochemistry, Geophysics, Geosystems 2015, 16 (6), 1711–1722) with data post-processing, including image enhancement and segmentation as well as numerical simulations in 3D using the derived results as a direct model input. The method presented opens a path to a model-free deduction of the properties of gas hydrate bearing sediments when aiming for in-situ experiments linked to synchrotron-based tomography and 3D modelling.


Geology ◽  
2003 ◽  
Vol 31 (10) ◽  
pp. 833-836 ◽  
Author(s):  
A. V. Milkov ◽  
G. E. Claypool ◽  
Y.-J. Lee ◽  
W. Xu ◽  
G. R. Dickens ◽  
...  

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