Simulation and analysis of wellbore stability in permafrost formation with FLAC
Master's Project (M.S.) University of Alaska Fairbanks, 2015 Permafrost underlies approximately 80% of Alaska. Permafrost's high sensitivity to temperature variations plays a significant role in the stability of wellbores drilled through permafrost formations. Wellbore instability may caus...
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ftunivalaska:oai:scholarworks.alaska.edu:11122/8866 2023-05-15T14:59:24+02:00 Simulation and analysis of wellbore stability in permafrost formation with FLAC Wang, Kai Patil, Shirish Chen, Gang 2015-07 http://hdl.handle.net/11122/8866 en_US eng http://hdl.handle.net/11122/8866 Petroleum Engineering Department Oil well drilling Stability Arctic regions Cold regions Permafrost Drilling muds Master's Project ms 2015 ftunivalaska 2023-02-23T21:37:08Z Master's Project (M.S.) University of Alaska Fairbanks, 2015 Permafrost underlies approximately 80% of Alaska. Permafrost's high sensitivity to temperature variations plays a significant role in the stability of wellbores drilled through permafrost formations. Wellbore instability may cause stuck pipes, lost circulation, and/or collapse of the wellbore, resulting in extra cost and time loss. In order to minimize the influence of the heat produced during drilling, a vertical well is the only choice to penetrate permafrost formation. Fast Lagrangian Analysis of Continua (FLAC) was used in this simulation to test the minimum wellbore pressure to maintain stability in a permafrost formation. Three layers were set in the simulation model: clay, silt, and sand. With the drilling fluid temperature set at 343K and a 267K initial formation temperature, four different thermal times, i.e. 1 week, 1 month, 1 year, and 5 years, were tested to determine the minimum stable pressure. Pore pressure of the formation has the strongest effect on this pressure. And in a short operation period, drilling fluid temperature will not influence the minimum mud pressure value significantly. A regression analysis was conducted on the simulation results, and the minimum wellbore stable pressure was found to be a function of pore pressure, cohesion, frictional angle, temperature difference, conductivity difference, thermal time, and wellbore radius. With the help of this function, engineers could calculate stable pressure for wells in arctic area before drilling based on drilling fluid temperature. Other/Unknown Material Arctic permafrost Alaska University of Alaska: ScholarWorks@UA Arctic Fairbanks |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
English |
topic |
Oil well drilling Stability Arctic regions Cold regions Permafrost Drilling muds |
spellingShingle |
Oil well drilling Stability Arctic regions Cold regions Permafrost Drilling muds Wang, Kai Simulation and analysis of wellbore stability in permafrost formation with FLAC |
topic_facet |
Oil well drilling Stability Arctic regions Cold regions Permafrost Drilling muds |
description |
Master's Project (M.S.) University of Alaska Fairbanks, 2015 Permafrost underlies approximately 80% of Alaska. Permafrost's high sensitivity to temperature variations plays a significant role in the stability of wellbores drilled through permafrost formations. Wellbore instability may cause stuck pipes, lost circulation, and/or collapse of the wellbore, resulting in extra cost and time loss. In order to minimize the influence of the heat produced during drilling, a vertical well is the only choice to penetrate permafrost formation. Fast Lagrangian Analysis of Continua (FLAC) was used in this simulation to test the minimum wellbore pressure to maintain stability in a permafrost formation. Three layers were set in the simulation model: clay, silt, and sand. With the drilling fluid temperature set at 343K and a 267K initial formation temperature, four different thermal times, i.e. 1 week, 1 month, 1 year, and 5 years, were tested to determine the minimum stable pressure. Pore pressure of the formation has the strongest effect on this pressure. And in a short operation period, drilling fluid temperature will not influence the minimum mud pressure value significantly. A regression analysis was conducted on the simulation results, and the minimum wellbore stable pressure was found to be a function of pore pressure, cohesion, frictional angle, temperature difference, conductivity difference, thermal time, and wellbore radius. With the help of this function, engineers could calculate stable pressure for wells in arctic area before drilling based on drilling fluid temperature. |
author2 |
Patil, Shirish Chen, Gang |
format |
Other/Unknown Material |
author |
Wang, Kai |
author_facet |
Wang, Kai |
author_sort |
Wang, Kai |
title |
Simulation and analysis of wellbore stability in permafrost formation with FLAC |
title_short |
Simulation and analysis of wellbore stability in permafrost formation with FLAC |
title_full |
Simulation and analysis of wellbore stability in permafrost formation with FLAC |
title_fullStr |
Simulation and analysis of wellbore stability in permafrost formation with FLAC |
title_full_unstemmed |
Simulation and analysis of wellbore stability in permafrost formation with FLAC |
title_sort |
simulation and analysis of wellbore stability in permafrost formation with flac |
publishDate |
2015 |
url |
http://hdl.handle.net/11122/8866 |
geographic |
Arctic Fairbanks |
geographic_facet |
Arctic Fairbanks |
genre |
Arctic permafrost Alaska |
genre_facet |
Arctic permafrost Alaska |
op_relation |
http://hdl.handle.net/11122/8866 Petroleum Engineering Department |
_version_ |
1766331510081716224 |