Focussed fluid flow on the Hikurangi Margin, New Zealand — Evidence from possible local upwarping of the base of gas hydrate stability

Pecher, Ingo; Henrys, S. A.; Wood, W. T.; Kukowski, Nina; Crutchley, Gareth; Fohrmann, Miko; Kilner, J.; Senger, Kim; Gorman, A. R.; Coffin, Richard B.; Greinert, Jens; Faure, Kevin

doi:10.1016/j.margeo.2009.10.006

Cited by 102 publications

(119 citation statements)

References 56 publications

Supporting

Mentioning

102

Contrasting

Order By: Relevance

“…Furthermore, it is shown that the gas is overlain by gas hydrates. This indicates that the dipping high-amplitude zone marks the phase boundary for gas hydrates, an observation that is consistent with the interpretation of Pecher et al (2010) that it marks a local thermal anomaly caused by fluid expulsion leading to shoaling of the BGHS. We can state quite confidently that the high reflectivity is not caused by gas hydrate-bearing sands (like those observed on the Nankai Trough e Nouze et al, 2004).…”

Section: Western Porangahau Ridge E What Causes the Highly Reflectivesupporting

confidence: 85%

“…Improved imaging of the interior of Western Porangahau Ridge, achieved through dip-moveout correction, high-resolution 2D velocity analysis and depth conversion (Toulmin et al, 2010), reveals a very disrupted reflectivity character as a result of pervasive faulting. Pecher et al (2010) also suggest that the lower reflectivity of Western Porangahau Ridge (compared to surrounding basin fill) is likely attributable to deformation-induced destruction of sedimentary fabric. Therefore, the predicted highpermeability facilitating enhanced fluid flux through this ridge is likely to be secondary permeability associated with fracturing and faulting.…”

Section: Anticlinesmentioning

confidence: 94%

“…4E). Pecher et al (2010) proposed two alternative scenarios to explain the presence of gas above the level of the regional BGHS:…”

Section: Western Porangahau Ridgementioning

confidence: 99%

See 2 more Smart Citations

Geological controls on focused fluid flow through the gas hydrate stability zone on the southern Hikurangi Margin of New Zealand, evidenced from multi-channel seismic data

Crutchley

Gorman

Pecher

et al. 2011

Marine and Petroleum Geology

View full text Add to dashboard Cite

Section: Western Porangahau Ridge E What Causes the Highly Reflectivesupporting

confidence: 85%

Section: Anticlinesmentioning

confidence: 94%

See 1 more Smart Citation

Geological controls on focused fluid flow through the gas hydrate stability zone on the southern Hikurangi Margin of New Zealand, evidenced from multi-channel seismic data

Crutchley

Gorman

Pecher

et al. 2011

Marine and Petroleum Geology

View full text Add to dashboard Cite

“…The Hikurangi Margin, east of New Zealand's North Island, is a large marine gas hydrate province. The BSRs were identified on the multichannel seismic data and there is a strong correlation between BSR strength and geological features indicating the fluid migration [12,13]. Geophysical parameters show that gas hydrate-bearing sediments have high elastic impedance, high P-impedance, and high P-wave velocity; and the sediments containing free gas have low elastic impedance, low P-impedance, and low P-wave velocity [14].…”

Section: Introductionmentioning

confidence: 98%

Geophysical Indicators of Gas Hydrate in the Northern Continental Margin, South China Sea

Wang

Guo

et al. 2011

Journal of Geological Research

View full text Add to dashboard Cite

Gas hydrate drilling results show that gas hydrate has a close relationship with strong bottom-simulating reflectors (BSRs) identified from seismic data in the Baiyun sag, South China Sea. The BSRs observed on seismic profiles at the crests of submarine canyons indicate the likely existence of gas hydrate. We calculate the acoustic impedance using constrained sparse spike inversion (CSSI), the interval velocity, and the seismic reflection characteristics such as reflection strength, instantaneous frequency, blanking, and enhanced reflection to demonstrate the presence of gas hydrate. Higher acoustic impedance and P-wave velocity were identified above the BSR. A remarkable low impedance, low frequency, and acoustic blanking indicated the presence of gas below gas hydrate stability zone. The occurrence of gas hydrate at the crests of canyons suggests that the abundance of gas hydrate in Baiyun sag may be due to the migrating submarine canyons providing the structural reliefs and the topographic ridges.

show abstract

“…As such, gas hydrates have been identified as a very important potential energy resource in the 21 st century (Collett, 2014;Chong et al, 2015). Geophysical exploration techniques are widely used for natural gas hydrate exploration and resource evaluation (Shipley et al, 1979;Holbrook et al, 1996Holbrook et al, , 2002Careione and Gei, 2004) because gas hydrates show higher P and S wave velocities than the sediment/rock pore fluid, typically brine (Stoll, 1974;Tueholke, 1977;Holbrook et al, 1996;Michael, 2003;Waite et al, 2009;Pecher et al, 2010). Since gas hydrates are unstable at room temperatures and pressures, it is rare for both hydrate saturation (S h ) and elastic wave velocities of hydrate-bearing sediments to be measured on core samples recovered in the field, without specialist pressurized coring technologies.…”

Section: Introductionmentioning

confidence: 99%

The elastic wave velocity response of methane gas hydrate formation in vertical gas migration systems

et al. 2017

J. Geophys. Eng.

View full text Add to dashboard Cite

Knowledge of the elastic wave velocities of hydrate-bearing sediments is important for geophysical exploration and resource evaluation. Methane gas migration processes play an important role in geological hydrate accumulation systems, whether on the seafloor or in terrestrial permafrost regions, and their impact on elastic wave velocities in sediments needs further study. Hence, a high pressure laboratory apparatus was developed to simulate natural continuous vertical methane gas migration through sediments. Hydrate saturation (S h ) and ultrasonic P-and S-wave velocities (V p & V s ) were measured synchronously by time domain reflectometry (TDR) and by ultrasonic transmission methods respectively during gas hydrate formation in sediment. The results were compared to previously published laboratory data obtained in a static closed system. This indicated that the velocities of hydrate-bearing sediments in vertical gas migration systems are slightly lower than 2 those in closed systems during hydrate formation. While velocities increase at a constant rate with hydrate saturation in the closed system, P-wave velocities show a fast-slow-fast variation with increasing hydrate saturation in the vertical gas migration system. The observed velocities are well described by an effective medium velocity model, from which changing hydrate morphology was inferred to cause the fast-slow-fast velocity response in the gas migration system. Hydrate forms firstly at the grain contacts as cement, then grows within the pore space (floating), then finally grows into contact with the pore walls again. We conclude that hydrate morphology is the key factor that influences the elastic wave velocity response of methane gas hydrates formation in vertical gas migration systems.

show abstract

Focussed fluid flow on the Hikurangi Margin, New Zealand — Evidence from possible local upwarping of the base of gas hydrate stability

Cited by 102 publications

References 56 publications

Geological controls on focused fluid flow through the gas hydrate stability zone on the southern Hikurangi Margin of New Zealand, evidenced from multi-channel seismic data

Geological controls on focused fluid flow through the gas hydrate stability zone on the southern Hikurangi Margin of New Zealand, evidenced from multi-channel seismic data

Geophysical Indicators of Gas Hydrate in the Northern Continental Margin, South China Sea

The elastic wave velocity response of methane gas hydrate formation in vertical gas migration systems

Contact Info

Product

Resources

About