Time–frequency spectral signature of Pelotas Basin deep water gas hydrates system

Oliveira, Sérgio Adriano Moura; Vilhena, Odilla; Costa, Emanuel da

doi:10.1007/s11001-010-9085-x

Cited by 27 publications

(12 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Gas hydrate deposits may be present at or near the base of the GHSZ in the Rio Grande Cone as suggested by the presence of ubiquitous world-class BSRs in the area (Sad et al, 1998;Fontana and Mussumeci, 1994;Clennell, 2000;Oliveira et al, 2010). Such pervasive BSRs are a substantial indication that free gas should be present in the sediments immediately below the GHSZ, having possibly migrated vertically through deep-seated faults (Fig.…”

Section: A C C E P T E D Accepted Manuscriptmentioning

confidence: 95%

See 1 more Smart Citation

Natural gas hydrates in the Rio Grande Cone (Brazil): A new province in the western South Atlantic

Miller

Ketzer

Viana

et al. 2015

Marine and Petroleum Geology

View full text Add to dashboard Cite

Section: A C C E P T E D Accepted Manuscriptmentioning

confidence: 95%

“…A more recent time-frequency spectral signature study performed by Oliveira et al (2010) in seismic lines from the Rio Grande Cone associated spectral anomalies to the possible occurrence of gas hydrate accumulations above the BSR and free gas zones, gas flux features and gas reservoirs below the BSR.…”

Section: Accepted Manuscriptmentioning

confidence: 95%

Natural gas hydrates in the Rio Grande Cone (Brazil): A new province in the western South Atlantic

Miller

Ketzer

Viana

et al. 2015

Marine and Petroleum Geology

View full text Add to dashboard Cite

“…Nevertheless, interpreted gas hydrate area offshore Uruguay is probably part of a much greater gas hydrate province, shared with Brazil, extending further north at the Pelotas Basin. This basin has the largest gas hydrate occurrence of the Brazilian coast [28,29].…”

Section: Discussionmentioning

confidence: 99%

Assessment of Marine Gas Hydrates and Associated Free Gas Distribution Offshore Uruguay

Tomasini¹,

Ana²,

Conti³

et al. 2011

Journal of Geological Research

View full text Add to dashboard Cite

Natural gas hydrates are crystalline solids formed by natural gas (mainly methane) and water that are stable under thermobaric conditions of high pressure and low temperature. Methane hydrate is found in polar areas of permafrost and in offshore basins of continental margins. These accumulations may represent an enormous source of methane. Based on global estimations of methane concentration in natural gas hydrates, the methane content may be several times greater than those of technically recoverable, conventional natural gas resources. In the continental margin of Uruguay, seismic evidence for the occurrence of gas hydrate is based on the presence of (bottom simulating reflectors) BSRs in 2D seismic reflection sections. Here we present results regarding gas hydrates and associated free gas distribution assessment offshore Uruguay, based on BSR mapping and applying a probabilistic approach. A mean value of 25,890 km2 for the area of occurrence shows a great potential for this nonconventional resource, encouraging further research.

show abstract

“…The Pelotas Basin has an area of approximately 250,000 km 2 resulted from the rifting of Gondwana and the drifting of the South American plate, having accumulated a thick sedimentary package (up to 12 km) from the Barremian to the Recent. The main structures present in the basin are normal faults in the proximal extensional domain and folds and thrust faults in the distal compressional domain (Silveira &Machado 2004).Distinct bottom simulating reflectors (BSRs) are ubiquitous in the Rio Grande Cone, and have been used as the main evidence for the occurrence of large gas hydrate deposits in the Pelotas Basin in Brazil (Sad et al 1998, Fontana & Mussumeci 1994, Clennell 2000,Oliveira et al 2010, Miller et al 2015 and in Uruguay (Tomasini et al 2011).…”

Section: Study Area and Geological Settingmentioning

confidence: 99%

The influence of methane fluxes on the sulfate/methane interface in sediments from the Rio Grande Cone Gas Hydrate Province, southern Brazil

et al. 2017

View full text Add to dashboard Cite

Much research has been published regarding the relation between major gas hydrate accumulations and the global carbon cycle. In this context, the determination of the sulfate/methane interface (SMI) depth is of primary importance in order to understand the dynamics of methane flux in the shallow section. This paper identifies the depth of the SMI in sediments based on sulfate and methane concentration profiles in cores recovered in the Rio Grande Cone Gas Hydrate Province, Pelotas Basin, southern Brazil. The shape of methane and sulfate concentration profiles in the sediments can be linked to the local methane flux rate as follows: (i) near linear, high upward-diffusing methane flux coupled with high sulfate diffusion from seawater; (ii) irregular, variable methane flux rates; and (iii) kink-type profile, which is indicative of variable rather than strictly high upward methane flux. The areas in which a high methane flux was identified are spatially associated with gas chimneys in sediments within pockmarks, whereas profiles with low methane flux are present in adjacent areas. These chimneys appear as acoustic blankings in seismic records and can therefore be mapped in subsurface. The wavy-like seismic reflection following the SMI coincides with the occurrence of authigenic carbonate nodules and concretions. In addition, high methane fluxes and the occurrence of concretions and nodules carbonates were correlated by stratigraphic position of the concretions bearing intervals and sulfate profiles. KEYWORDS: gas hydrate; methane flux; Rio Grande Cone; Brazil. RESUMO: Muitas pesquisas têm sido publicadas relacionando elevadas acumulações de hidrato de gás e o ciclo global do carbono. Nesse contexto, a determinação da profundidade da interface sulfato/metano (SMI) é importante para entender a dinâmica do fluxo de metano em locais rasos. Este artigo científico identifica a profundidade da SMI em sedimentos com base em perfis de concentração de sulfato e metano em testemunhos recuperados na Província do Hidrato de Gás do

show abstract

Time–frequency spectral signature of Pelotas Basin deep water gas hydrates system

Cited by 27 publications

References 12 publications

Natural gas hydrates in the Rio Grande Cone (Brazil): A new province in the western South Atlantic

Natural gas hydrates in the Rio Grande Cone (Brazil): A new province in the western South Atlantic

Assessment of Marine Gas Hydrates and Associated Free Gas Distribution Offshore Uruguay

The influence of methane fluxes on the sulfate/methane interface in sediments from the Rio Grande Cone Gas Hydrate Province, southern Brazil

Contact Info

Product

Resources

About