Well drilling in permafrost regions: dynamics of the thawed zone
In the cold regions, warm mud is usually used to drill deep wells. This mud causes formation thawing around wells, and as a rule is an uncertain parameter. For frozen soils, ice serves as a cementing material, so the strength of frozen soils is significantly reduced at the ice–water transition. If t...
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Norwegian Polar Institute
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ftdoajarticles:oai:doaj.org/article:241e84ce06784f1a88e6d60419667874 2023-05-15T16:37:30+02:00 Well drilling in permafrost regions: dynamics of the thawed zone Lev V. Eppelbaum Izzy M. Kutasov 2019-06-01T00:00:00Z https://doi.org/10.33265/polar.v38.3351 https://doaj.org/article/241e84ce06784f1a88e6d60419667874 EN eng Norwegian Polar Institute https://polarresearch.net/index.php/polar/article/view/3351/9269 https://doaj.org/toc/1751-8369 1751-8369 doi:10.33265/polar.v38.3351 https://doaj.org/article/241e84ce06784f1a88e6d60419667874 Polar Research, Vol 38, Iss 0, Pp 1-9 (2019) Radius of thawing freezeback period permafrost temperature Stefan problem Environmental sciences GE1-350 Oceanography GC1-1581 article 2019 ftdoajarticles https://doi.org/10.33265/polar.v38.3351 2022-12-30T22:07:43Z In the cold regions, warm mud is usually used to drill deep wells. This mud causes formation thawing around wells, and as a rule is an uncertain parameter. For frozen soils, ice serves as a cementing material, so the strength of frozen soils is significantly reduced at the ice–water transition. If the thawing soil cannot withstand the load of overlying layers, consolidation will take place, and the corresponding settlement can cause significant surface shifts. Therefore, for long-term drilling or oil/gas production, the radius of thawing should be estimated to predict platform stability and the integrity of the well. It is known that physical properties of formations are drastically changed at the thawing–freezing transition. When interpreting geophysical logs, it is therefore important to know the radius of thawing and its dynamics during drilling and shut-in periods. We have shown earlier that for a cylindrical system the position of the phase interface in the Stefan problem can be approximated through two functions: one function determines the position of the melting-temperature isotherm in the problem without phase transitions, and the second function does not depend on time. For the drilling period, we will use this approach to estimate the radius of thawing. For the shut-in period, we will utilize an empirical equation based on the results of numerical modelling. Article in Journal/Newspaper Ice permafrost Polar Research Directory of Open Access Journals: DOAJ Articles Polar Research |
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Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Radius of thawing freezeback period permafrost temperature Stefan problem Environmental sciences GE1-350 Oceanography GC1-1581 |
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Radius of thawing freezeback period permafrost temperature Stefan problem Environmental sciences GE1-350 Oceanography GC1-1581 Lev V. Eppelbaum Izzy M. Kutasov Well drilling in permafrost regions: dynamics of the thawed zone |
topic_facet |
Radius of thawing freezeback period permafrost temperature Stefan problem Environmental sciences GE1-350 Oceanography GC1-1581 |
description |
In the cold regions, warm mud is usually used to drill deep wells. This mud causes formation thawing around wells, and as a rule is an uncertain parameter. For frozen soils, ice serves as a cementing material, so the strength of frozen soils is significantly reduced at the ice–water transition. If the thawing soil cannot withstand the load of overlying layers, consolidation will take place, and the corresponding settlement can cause significant surface shifts. Therefore, for long-term drilling or oil/gas production, the radius of thawing should be estimated to predict platform stability and the integrity of the well. It is known that physical properties of formations are drastically changed at the thawing–freezing transition. When interpreting geophysical logs, it is therefore important to know the radius of thawing and its dynamics during drilling and shut-in periods. We have shown earlier that for a cylindrical system the position of the phase interface in the Stefan problem can be approximated through two functions: one function determines the position of the melting-temperature isotherm in the problem without phase transitions, and the second function does not depend on time. For the drilling period, we will use this approach to estimate the radius of thawing. For the shut-in period, we will utilize an empirical equation based on the results of numerical modelling. |
format |
Article in Journal/Newspaper |
author |
Lev V. Eppelbaum Izzy M. Kutasov |
author_facet |
Lev V. Eppelbaum Izzy M. Kutasov |
author_sort |
Lev V. Eppelbaum |
title |
Well drilling in permafrost regions: dynamics of the thawed zone |
title_short |
Well drilling in permafrost regions: dynamics of the thawed zone |
title_full |
Well drilling in permafrost regions: dynamics of the thawed zone |
title_fullStr |
Well drilling in permafrost regions: dynamics of the thawed zone |
title_full_unstemmed |
Well drilling in permafrost regions: dynamics of the thawed zone |
title_sort |
well drilling in permafrost regions: dynamics of the thawed zone |
publisher |
Norwegian Polar Institute |
publishDate |
2019 |
url |
https://doi.org/10.33265/polar.v38.3351 https://doaj.org/article/241e84ce06784f1a88e6d60419667874 |
genre |
Ice permafrost Polar Research |
genre_facet |
Ice permafrost Polar Research |
op_source |
Polar Research, Vol 38, Iss 0, Pp 1-9 (2019) |
op_relation |
https://polarresearch.net/index.php/polar/article/view/3351/9269 https://doaj.org/toc/1751-8369 1751-8369 doi:10.33265/polar.v38.3351 https://doaj.org/article/241e84ce06784f1a88e6d60419667874 |
op_doi |
https://doi.org/10.33265/polar.v38.3351 |
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Polar Research |
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1766027787136663552 |