Experience of 3D Transient Electromagnetics Application for Shallow and Hydrocarbon Exploration within Western Siberia

Buddo, I.V.; Misurkeeva, N.V.; Shelohov, I.A.; Agafonov, Yu. A.; Смирнов, А. С.; Zharikov, M.G.; Kulinchenko, A.S.

doi:10.3997/2214-4609.201700667

Cited by 6 publications

(3 citation statements)

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“…On the other hand, we cannot exclude the escape of early-mature gas [24] through conduits of permeable sand to pingo in West Siberia, especially given that pingos were reported to be often located above the geological gas conduits [14,32]. If it is really connected to a deeper source, then it is a seep, but we observed that the methane emission from it, although at higher initial rate, ended after two days.…”

Section: Toward An Understanding Of Methane Origin In Geologic Sectionsmentioning

confidence: 64%

Methane in Gas Shows from Boreholes in Epigenetic Permafrost of Siberian Arctic

et al. 2019

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The gas shows in the permafrost zone represent a hazard for exploration, form the surface features, and are improperly estimated in the global methane budget. They contain methane of either surficial or deep-Earth origin accumulated earlier in the form of gas or gas hydrates in lithological traps in permafrost. From these traps, it rises through conduits, which have tectonic origin or are associated with permafrost degradation. We report methane fluxes from 20-m to 30-m deep boreholes, which are the artificial conduits for gas from permafrost in Siberia. The dynamics of degassing the traps was studied using static chambers, and compared to the concentration of methane in permafrost as analyzed by the headspace method and gas chromatography. More than 53 g of CH4 could be released to the atmosphere at rates exceeding 9 g of CH4 m−2 s−1 from a trap in epigenetic permafrost disconnected from traditional geological sources over a period from a few hours to several days. The amount of methane released from a borehole exceeded the amount of the gas that was enclosed in large volumes of permafrost within a diameter up to 5 meters around the borehole. Such gas shows could be by mistake assumed as permanent gas seeps, which leads to the overestimation of the role of permafrost in global warming.

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Section: Toward An Understanding Of Methane Origin In Geologic Sectionsmentioning

confidence: 64%

Methane in Gas Shows from Boreholes in Epigenetic Permafrost of Siberian Arctic

et al. 2019

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“…Thus, the sTEM soundings are applicable to study the permafrost structure and to map cryopegs, taliks, pingoes, and vertical faults in Arctic West Siberia [46][47][48][49][50].…”

Section: Resultsmentioning

confidence: 99%

“…The permafrost is continuous and 250 m thick in the western part of the area and is almost absent in the east, where the Ob Gulf is marked by a low resistivity of around 10 Ω• m.An open talik under the Saboliyakha River is marked by a resistivity low prominent against high-resistivity permafrost. The rocks below the permafrost base and deeper than 400 m are highly resistive, possibly in the presence of clathrate or free gas.Thus, the sTEM soundings are applicable to study the permafrost structure and to map cryopegs, taliks, pingoes, and vertical faults in Arctic West Siberia[46][47][48][49][50].…”

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confidence: 99%

Applicability of Transient Electromagnetic Surveys to Permafrost Imaging in Arctic West Siberia

Buddo

Sharlov²,

Шелохов

et al. 2022

Energies

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Detection of faults and other zones of weakness in shallow permafrost to a few hundreds of meters is extremely important for ensuring the safety during the production and transportation of fuels (oil and gas). The construction of line facilities (power lines and pipelines) should be preceded by detailed surveys in order to localize major areas of potential hazard. Furthermore, reliable geophysical methods are necessary for exploration of gas hydrates. This research aims at proving that induction-based electromagnetic surveys are applicable for permafrost studies and at finding new evidence for the similarity and difference of the permafrost structure in different regions of Northern Siberia. TEM curves are collected in several regions of Northern Siberia with continuous, mostly continuous, and discontinuous permafrost. Transient electromagnetic (TEM) surveys performed in the Russian Arctic image the permafrost structure to a depth of 500 m. The data are acquired with telemetric systems that allow varying the survey design and loop configuration. Advanced processing tools are used to provide geologically essential information from late-time records, while optimized inversion algorithms are applied to obtain high-quality layered resistivity models. The resulting geoelectric models reveal evident variations in the thickness of highly resistive frozen rocks and the presence of unfrozen patches. The induction surveys, which require no galvanic contact with the earth and no grounding, are inferred to be best suitable for imaging the frozen shallow subsurface. The TEM-based resistivity patterns clearly resolve the permafrost base, as well as the contours of unfrozen zones (taliks), lenses of saline water (cryopegs), gas hydrates, and frost heaving features. The reported results can make basis for the choice of geophysical methods for permafrost studies in such harsh conditions as the Russian Arctic. Furthermore, the presented resistivity patterns can make reference for future studies of permafrost in Northern Siberia.

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Periglacial Landforms and Fluid Dynamics in the Permafrost Domain: A Case from the Taz Peninsula, West Siberia

et al. 2022

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Most of the developing oil and gas fields in Russia are located in Arctic regions and constructed on permafrost, where recent environmental changes cause multiple hazards for their infrastructure. The blowing-up of pingos, resulting in the formation of gas emission craters, is one of the disastrous processes associated both with these external changes and, likely, with deep sources of hydrocarbons. We traced the channels of fluid migration which link a gas features reservoirs with periglacial phenomena associated with such craters with the set of geophysical methods, including common depth point and shallow transient electromagnetic methods, on an area of a prospected gas field. We found correlated vertical anomalies of acoustic coherence and electrical resistivity associated with gas chimneys in the upper 500–600 m of the section. The thickness of the ice-bonded permafrost acting as a seal for fluids decreased in the chimney zone, forming 25–50 m deep pockets in the permafrost base. Three pingos out of six were located above chimneys in the study area of 200 km2. Two lakes with parapets typical for craters were found. We conclude that the combination of applied methods is efficacious in terms of identifying this type of hazard and locating potentially hazardous objects in the given territory.

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Experience of 3D Transient Electromagnetics Application for Shallow and Hydrocarbon Exploration within Western Siberia

Cited by 6 publications

References 0 publications

Methane in Gas Shows from Boreholes in Epigenetic Permafrost of Siberian Arctic

Methane in Gas Shows from Boreholes in Epigenetic Permafrost of Siberian Arctic

Applicability of Transient Electromagnetic Surveys to Permafrost Imaging in Arctic West Siberia

Periglacial Landforms and Fluid Dynamics in the Permafrost Domain: A Case from the Taz Peninsula, West Siberia

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