Experimental modeling of offshore gas emissions

UDK: 658.382.3:622.276

DOI: 10.24887/0028-2448-2025-11-136-139

Key words: gas hydrates, gas emissions, offshore fields, gas filtration in a granular medium

Authors: A.A. Tairova (Sadovsky Institute of Geosphere Dynamics of the RAS, RF, Moscow); N.A. Yudochkin (Sadovsky Institute of Geosphere Dynamics of the RAS, RF, Moscow); G.V. Belyakov (Sadovsky Institute of Geosphere Dynamics of the RAS, RF, Moscow)

The development of offshore hydrocarbon deposits involves the construction and operation of production platforms, oil and gas transportation, and well drilling. Shallow gas hydrate deposits, followed by their dissociation into water and gas and subsequent release, can pose a significant threat to oil and gas pipeline construction, drilling operations, and tanker traffic. Expeditions reveal gas releases over large areas of the seafloor; the release is so intense that it fails to diffuse through the seafloor and rises to the surface. This paper presents the results of a laboratory study of gas flow in a saturated granular medium. An experimental setup was created to simulate gas removal from the seafloor through a layer of loose sedimentary deposits. A unique feature of the setup was its ability to visualize the process of gas phase filtration in a granular layer saturated with liquid. The obtained results showed that, prior to the release, a branched network of thin, intricate gas-conducting channels forms in the granular medium, branching from the main channel. The lower the escaping gas pressure, the fewer and wider the branching channels. Based on the obtained data, estimates were made of the rate of release formation, the velocity of rising bubbles, and their sizes. The presented results are consistent with data obtained using hydroacoustic methods during expeditions in the East Siberian Sea.

References

1. Sergienko V.I., Lobkovskiy L.I., Semiletov I.P. et al., The degradation of submarine permafrost and the destruction of hydrates on the shelf of east arctic seas as a potential cause of the methane catastrophe: Some results of integrated studies in 2011 (In Russ.), Doklady Akademii nauk = Doklady Earth Sciences, 2012, V. 446, no. 3,

pp. 330–335.

2. Chernykh D.V., Salomatin A.S., Yusupov V.I. et al., Quantitative acoustic estimation of methane flux from the fast ice on the East Siberian shelf (In Russ.), Vestnik Dal’nevostochnogo otdeleniya Rossiyskoy akademii nauk, 2013, no. 6(172), pp. 128–133.

3. Yakushev V.S., Formirovanie skopleniy prirodnogo gaza i gazovykh gidratov v kriolitozone (Formation of accumulations of natural gas and gas hydrates in the cryolithozone): thesis of doctor of geological and mineralogical science, Moscow, 2009.

4. Bogoyavlenskiy V.I., Fundamental aspects of the catastrophic gas blowout genesis and the formation of giant craters in the Arctic (In Russ.), Arktika: ekologiya i ekonomika, 2021, no. 11(1), pp. 51–66, DOI: https://doi.org/10.25283/2223-4594-2021-1-51-66

5. Sadovskiy M.A., Adushkin V.V., Rodionov V.N., Modelling of big ejection explosions (In Russ.), Doklady Akademii nauk = Doklady Earth Sciences, 1966, V. 167, no. 6, pp. 1253–1255.

6. Shpak P.M., Turuntaev S.B., Trimonova M.A. et al., The model of cohesionless sediment blowout with an increase in the methane flow rate, Geosciences (Switzerland), 2022, V. 12, no. 11, p. 423, DOI: https://doi.org/10.3390/geosciences12110423