Experimental Study on Dynamic Elastic Properties of Gas Hydrate Bearing Sediments

As a kind of emerging energy with massive reserves, natural gas hydrates are becoming the hot spot of global research. The elastic properties of gas hydrate bearing sediments (HBS) are the fundamental parameters for gas hydrates exploration and resource evaluations. As the original coring in HBS is difficult and expensive, experimental method is important to study the problem. An acoustic wave in-situ measuring system for HBS was developed. Using the in-situ method, hydrate bearing rock samples of different hydrate saturation were synthesized, of which the supersonic wave measurement was carried out under different confining pressure. According to the elasticity theory, the dynamic elastic parameters were obtained using the measured ultrasonic wave velocity. The results show that compressional and shear waves increase with the confining pressure and hydrate saturation increasing, and so the dynamic elastic modulus is.

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Large-scale and high-similarity experimental study of the effect of drilling fluid penetration on physical properties of gas hydrate-bearing sediments in the Gulf of Mexico

Journal of Petroleum Science and Engineering ◽

10.1016/j.petrol.2019.106832 ◽

2020 ◽

Vol 187 ◽

pp. 106832

Author(s):

Mingming Zheng ◽

Tianle Liu ◽

Guosheng Jiang ◽

Meng Wei ◽

Yuxiang Huo ◽

...

Keyword(s):

Experimental Study ◽

Gulf Of Mexico ◽

Physical Properties ◽

Gas Hydrate ◽

Large Scale ◽

Drilling Fluid ◽

High Similarity ◽

Fluid Penetration ◽

Hydrate Bearing Sediments

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A model to predict the elastic properties of gas hydrate-bearing sediments

Journal of Applied Geophysics ◽

10.1016/j.jappgeo.2019.05.003 ◽

2019 ◽

Vol 169 ◽

pp. 154-164 ◽

Cited By ~ 3

Author(s):

Tuan Nguyen-Sy ◽

Anh-Minh Tang ◽

Quy-Dong To ◽

Minh-Ngoc Vu

Keyword(s):

Elastic Properties ◽

Gas Hydrate ◽

Hydrate Bearing Sediments

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Experimental study of water-based drilling fluid disturbance on natural gas hydrate-bearing sediments

Journal of Natural Gas Science and Engineering ◽

10.1016/j.jngse.2017.08.029 ◽

2017 ◽

Vol 47 ◽

pp. 1-10 ◽

Cited By ~ 8

Author(s):

Huaiwen Zhang ◽

Yuanfang Cheng ◽

Jihui Shi ◽

Lingdong Li ◽

Menglai Li ◽

...

Keyword(s):

Experimental Study ◽

Natural Gas ◽

Gas Hydrate ◽

Drilling Fluid ◽

Natural Gas Hydrate ◽

Water Based ◽

Hydrate Bearing Sediments

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Elastic properties of gas hydrate‐bearing sediments

Geophysics ◽

10.1190/1.1444966 ◽

2001 ◽

Vol 66 (3) ◽

pp. 763-771 ◽

Cited By ~ 55

Author(s):

Myung W. Lee ◽

Timothy S. Collett

Keyword(s):

Shear Wave ◽

Elastic Properties ◽

Gas Hydrate ◽

Poisson’S Ratio ◽

Pore Space ◽

Poisson's Ratio ◽

The Arctic ◽

Wave Velocities ◽

Shear Wave Velocities ◽

Hydrate Bearing Sediments

Downhole‐measured compressional- and shear‐wave velocities acquired in the Mallik 2L-38 gas hydrate research well, northwestern Canada, reveal that the dominant effect of gas hydrate on the elastic properties of gas hydrate‐bearing sediments is as a pore‐filling constituent. As opposed to high elastic velocities predicted from a cementation theory, whereby a small amount of gas hydrate in the pore space significantly increases the elastic velocities, the velocity increase from gas hydrate saturation in the sediment pore space is small. Both the effective medium theory and a weighted equation predict a slight increase of velocities from gas hydrate concentration, similar to the field‐observed velocities; however, the weighted equation more accurately describes the compressional- and shear‐wave velocities of gas hydrate‐bearing sediments. A decrease of Poisson’s ratio with an increase in the gas hydrate concentration is similar to a decrease of Poisson’s ratio with a decrease in the sediment porosity. Poisson’s ratios greater than 0.33 for gas hydrate‐bearing sediments imply the unconsolidated nature of gas hydrate‐bearing sediments at this well site. The seismic characteristics of gas hydrate‐bearing sediments at this site can be used to compare and evaluate other gas hydrate‐bearing sediments in the Arctic.

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Biot–Gassmann theory for velocities of gas hydrate‐bearing sediments

Geophysics ◽

10.1190/1.1527072 ◽

2002 ◽

Vol 67 (6) ◽

pp. 1711-1719 ◽

Cited By ~ 75

Author(s):

Myung W. Lee

Keyword(s):

Elastic Properties ◽

Gas Hydrate ◽

Effective Medium Theory ◽

Velocity Ratio ◽

Effective Medium ◽

Unconsolidated Sediments ◽

Medium Theory ◽

Velocity Models ◽

Time Average ◽

Hydrate Bearing Sediments

Elevated elastic velocities are a distinct physical property of gas hydrate‐bearing sediments. A number of velocity models and equations (e.g., pore‐filling model, cementation model, effective medium theories, weighted equations, and time‐average equations) have been used to describe this effect. In particular, the weighted equation and effective medium theory predict reasonably well the elastic properties of unconsolidated gas hydrate‐bearing sediments. A weakness of the weighted equation is its use of the empirical relationship of the time‐average equation as one element of the equation. One drawback of the effective medium theory is its prediction of unreasonably higher shear‐wave velocity at high porosities, so that the predicted velocity ratio does not agree well with the observed velocity ratio. To overcome these weaknesses, a method is proposed, based on Biot–Gassmann theories and assuming the formation velocity ratio (shear to compressional velocity) of an unconsolidated sediment is related to the velocity ratio of the matrix material of the formation and its porosity. Using the Biot coefficient calculated from either the weighted equation or from the effective medium theory, the proposed method accurately predicts the elastic properties of unconsolidated sediments with or without gas hydrate concentration. This method was applied to the observed velocities at the Mallik 2L‐39 well, Mackenzie Delta, Canada.

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