UT-GOM2-2 Drilling Fluid (Technical Note)
It is proposed that a salt-saturated, water-based mud might improve borehole stability for UT-GOM2-2 relative to a fresh-water-based mud. However, the primary objective for UT-GOM2-2 is to safely and successfully acquire uncompromised hydrate-bearing sediment cores. This can only be done if conditio...
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ftosti:oai:osti.gov:1773344 2023-07-30T04:04:56+02:00 UT-GOM2-2 Drilling Fluid (Technical Note) Thomas, Carla Peter, Flemings B You, Kehua 2022-02-04 application/pdf http://www.osti.gov/servlets/purl/1773344 https://www.osti.gov/biblio/1773344 https://doi.org/10.2172/1773344 unknown http://www.osti.gov/servlets/purl/1773344 https://www.osti.gov/biblio/1773344 https://doi.org/10.2172/1773344 doi:10.2172/1773344 03 NATURAL GAS 58 GEOSCIENCES 37 INORGANIC ORGANIC PHYSICAL AND ANALYTICAL CHEMISTRY 42 ENGINEERING 97 MATHEMATICS AND COMPUTING 2022 ftosti https://doi.org/10.2172/1773344 2023-07-11T10:02:15Z It is proposed that a salt-saturated, water-based mud might improve borehole stability for UT-GOM2-2 relative to a fresh-water-based mud. However, the primary objective for UT-GOM2-2 is to safely and successfully acquire uncompromised hydrate-bearing sediment cores. This can only be done if conditions stay within the hydrate stability zone, and well away from the hydrate stability boundary. The addition of salt to the drilling mud, shifts the hydrate stability boundary closer to estimated conditions. This shift, by some estimates of pressure and temperature, where conditions now fall outside of the hydrate stability zone, may result in borehole enlargement and the release of free gas into the borehole. This shift by all estimates, even when coring conditions stay inside the hydrate stability zone, shrinks the window between the estimated conditions and the hydrate stability boundary. This shift is likely to compromise the hydrate-bearing cores while they are being recovered from the bottom-hole to the rig floor. In this report we present two examples: 1) Assuming temperature and pressure from in-situ estimates: Hydrate within the target reservoirs (Orange and Blue) at Walker Ridge Block 313 (WR 313) will be outside the hydrate stability zone in the presence of a drilling mud with 9.5 wt.% salinity (the salinity of the proposed 10.5 ppg salt-based mud) at in situ pressure and temperature. Thus, the hydrate will be unstable. A 10.5 ppg salt-based mud may result in dissociation of the hydrate into its components: water and gas. 10.5 ppg salt-based mud may enlarge the borehole, release free gas into the borehole, and compromise the cores. 2) Assuming temperatures equal to the measured LWD borehole temperatures at this location: Hydrate within the target reservoirs will be stable with a salinity of 9.5 wt.% (the salinity of the proposed 10.5 ppg salt-based mud), but possibly unstable (just at the methane hydrate stability boundary) for a salinity of 17.2 wt.% (the salinity of the proposed 13.5 ppg salt-based kill ... Other/Unknown Material Methane hydrate SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Walker Ridge ENVELOPE(168.367,168.367,-72.567,-72.567) |
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Open Polar |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
topic |
03 NATURAL GAS 58 GEOSCIENCES 37 INORGANIC ORGANIC PHYSICAL AND ANALYTICAL CHEMISTRY 42 ENGINEERING 97 MATHEMATICS AND COMPUTING |
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03 NATURAL GAS 58 GEOSCIENCES 37 INORGANIC ORGANIC PHYSICAL AND ANALYTICAL CHEMISTRY 42 ENGINEERING 97 MATHEMATICS AND COMPUTING Thomas, Carla Peter, Flemings B You, Kehua UT-GOM2-2 Drilling Fluid (Technical Note) |
topic_facet |
03 NATURAL GAS 58 GEOSCIENCES 37 INORGANIC ORGANIC PHYSICAL AND ANALYTICAL CHEMISTRY 42 ENGINEERING 97 MATHEMATICS AND COMPUTING |
description |
It is proposed that a salt-saturated, water-based mud might improve borehole stability for UT-GOM2-2 relative to a fresh-water-based mud. However, the primary objective for UT-GOM2-2 is to safely and successfully acquire uncompromised hydrate-bearing sediment cores. This can only be done if conditions stay within the hydrate stability zone, and well away from the hydrate stability boundary. The addition of salt to the drilling mud, shifts the hydrate stability boundary closer to estimated conditions. This shift, by some estimates of pressure and temperature, where conditions now fall outside of the hydrate stability zone, may result in borehole enlargement and the release of free gas into the borehole. This shift by all estimates, even when coring conditions stay inside the hydrate stability zone, shrinks the window between the estimated conditions and the hydrate stability boundary. This shift is likely to compromise the hydrate-bearing cores while they are being recovered from the bottom-hole to the rig floor. In this report we present two examples: 1) Assuming temperature and pressure from in-situ estimates: Hydrate within the target reservoirs (Orange and Blue) at Walker Ridge Block 313 (WR 313) will be outside the hydrate stability zone in the presence of a drilling mud with 9.5 wt.% salinity (the salinity of the proposed 10.5 ppg salt-based mud) at in situ pressure and temperature. Thus, the hydrate will be unstable. A 10.5 ppg salt-based mud may result in dissociation of the hydrate into its components: water and gas. 10.5 ppg salt-based mud may enlarge the borehole, release free gas into the borehole, and compromise the cores. 2) Assuming temperatures equal to the measured LWD borehole temperatures at this location: Hydrate within the target reservoirs will be stable with a salinity of 9.5 wt.% (the salinity of the proposed 10.5 ppg salt-based mud), but possibly unstable (just at the methane hydrate stability boundary) for a salinity of 17.2 wt.% (the salinity of the proposed 13.5 ppg salt-based kill ... |
author |
Thomas, Carla Peter, Flemings B You, Kehua |
author_facet |
Thomas, Carla Peter, Flemings B You, Kehua |
author_sort |
Thomas, Carla |
title |
UT-GOM2-2 Drilling Fluid (Technical Note) |
title_short |
UT-GOM2-2 Drilling Fluid (Technical Note) |
title_full |
UT-GOM2-2 Drilling Fluid (Technical Note) |
title_fullStr |
UT-GOM2-2 Drilling Fluid (Technical Note) |
title_full_unstemmed |
UT-GOM2-2 Drilling Fluid (Technical Note) |
title_sort |
ut-gom2-2 drilling fluid (technical note) |
publishDate |
2022 |
url |
http://www.osti.gov/servlets/purl/1773344 https://www.osti.gov/biblio/1773344 https://doi.org/10.2172/1773344 |
long_lat |
ENVELOPE(168.367,168.367,-72.567,-72.567) |
geographic |
Walker Ridge |
geographic_facet |
Walker Ridge |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_relation |
http://www.osti.gov/servlets/purl/1773344 https://www.osti.gov/biblio/1773344 https://doi.org/10.2172/1773344 doi:10.2172/1773344 |
op_doi |
https://doi.org/10.2172/1773344 |
_version_ |
1772816573744021504 |