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http://hdl.handle.net/2122/7884
DC Field | Value | Language |
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dc.contributor.authorall | Montone, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia | en |
dc.contributor.authorall | Pierdominici, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia | en |
dc.contributor.authorall | Jarrard, R.D.; University of Utah, Salt Lake City | en |
dc.contributor.authorall | Wilson, T.; School of Earth Sciences, Ohio State University, 125 S. Oval Mall, Columbus, OH 43210 - USA | en |
dc.contributor.authorall | Paulsen, T.; University of Wisconsin – Oshkosh, | en |
dc.contributor.authorall | Wonik, T.; Inst. für Geowissen. Gemein., Hannover, Germany | en |
dc.contributor.authorall | Handwerger, D.; TerraTek, A Schlumberger Co., Salt Lake City | en |
dc.date.accessioned | 2012-03-15T19:35:13Z | en |
dc.date.available | 2012-03-15T19:35:13Z | en |
dc.date.issued | 2010 | en |
dc.identifier.uri | http://hdl.handle.net/2122/7884 | en |
dc.description.abstract | To define the present-day stress field in the upper crust and to understand the recent tectonic activity in Antarctica, a study of breakout measurements along AND-2A well was performed. The borehole breakout is an important indicator of horizontal stress orientation and occurs when the stresses around the borehole exceed that required to cause compressive failure of the borehole wall (Bell and Gough, 1979; Zoback et al., 1985, Bell, 1990). The enlargement of the wellbore is caused by the development of intersecting conjugate shear planes that cause pieces of the borehole wall to spall off. Around a vertical borehole, stress concentration is greatest in the direction of the minimum horizontal stress (Shmin), hence, the long axes of borehole breakouts are oriented approximately perpendicular to the maximum horizontal stress orientation (SHmax). The orientation of breakouts along the AND-2A well was measured using acoustic (BHTV) and mechanical (Four-Arm Caliper) tools. Borehole televiewer (BHTV) provides an acoustic "image" of the borehole wall (360 degree coverage) and gives detailed information for investigation of fractures and stress analysis. The four-arm caliper is the oldest technique for borehole breakout identification and it is included in routine dipmeter logs. A quality value has been assigned to the well results in agreement with the World Stress Map quality ranking scheme (Zoback, 1992; Heidback et al., 2010) based mainly on the number, accuracy, and length of breakout measurements. The result is presented as rose diagram of the breakout directions where the length of each peak is proportional to the frequency and the width to the variance of its gaussian curve. We have analyzed the following curves to recognize the breakout: the azimuth of Pad 1 (P1az), the drift azimuth (HAZI), the two calipers with respect to the bit size (BZ) curve and the curve relative to the deviation of the well. The AND-2A Four-Arm Caliper data cover a depth interval between 637 down to 997 mbsl, that corresponds to 360 m of logged interval. We have distinguished breakouts and some washouts only in the interval from 753 to 825 mbsl. From borehole televiewer images, we have data from 398 mbsl down to 1136 mbsl. The BHTV worked well showing a lot of interesting features such as many bedding, lamination and fractures (natural and induced) but poor breakouts. The rare breakouts have also a small size (called protobreakouts) but they are consistent with induced features. Considering the breakout result from caliper and BHTV, the AND-2A borehole is unfortunately classified as D quality. This means that to obtain a reliable active stress field of the area it is necessary to compare this result with other available data. | en |
dc.language.iso | English | en |
dc.relation.ispartof | AGU Fall Meeting 2010 | en |
dc.subject | Borehole breakout | en |
dc.subject | Stress analysis | en |
dc.title | Borehole breakout analysis: results from the AND-2A Well | en |
dc.type | Poster session | en |
dc.description.status | Unpublished | en |
dc.subject.INGV | 04. Solid Earth::04.02. Exploration geophysics::04.02.05. Downhole, radioactivity, remote sensing, and other methods | en |
dc.subject.INGV | 04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress | en |
dc.subject.INGV | 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics | en |
dc.description.ConferenceLocation | San Francisco (California, USA) | en |
dc.description.obiettivoSpecifico | 3.2. Tettonica attiva | en |
dc.description.fulltext | open | en |
dc.contributor.author | Montone, P. | en |
dc.contributor.author | Pierdominici, S. | en |
dc.contributor.author | Jarrard, R.D. | en |
dc.contributor.author | Wilson, T. | en |
dc.contributor.author | Paulsen, T. | en |
dc.contributor.author | Wonik, T. | en |
dc.contributor.author | Handwerger, D. | en |
dc.contributor.department | Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia | en |
dc.contributor.department | Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia | en |
dc.contributor.department | University of Utah, Salt Lake City | en |
dc.contributor.department | School of Earth Sciences, Ohio State University, 125 S. Oval Mall, Columbus, OH 43210 - USA | en |
dc.contributor.department | University of Wisconsin – Oshkosh, | en |
dc.contributor.department | Inst. für Geowissen. Gemein., Hannover, Germany | en |
dc.contributor.department | TerraTek, A Schlumberger Co., Salt Lake City | en |
item.openairetype | Poster session | - |
item.cerifentitytype | Publications | - |
item.languageiso639-1 | en | - |
item.grantfulltext | open | - |
item.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
item.fulltext | With Fulltext | - |
crisitem.author.dept | Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sezione Roma1, Roma, Italia | - |
crisitem.author.dept | Department of Geology and Geophysics, 383 FASB, University of Utah, 115 S. 1460 East, Salt Lake City, Utah 84112-0102, USA | - |
crisitem.author.dept | Byrd Polar Research Centre, The Ohio State University, Columbus, OH 43210, USA | - |
crisitem.author.dept | Department of Geology, University of Wisconsin Oshkosh, Oshkosh, Wisconsin 54901, USA | - |
crisitem.author.dept | Leibniz Institute for Applied Geophysics (LIAG), Hanover, Germany | - |
crisitem.author.dept | TerraTek, A Schlumberger Co., Salt Lake City | - |
crisitem.author.orcid | 0000-0002-9297-1730 | - |
crisitem.author.orcid | 0000-0002-5368-4536 | - |
crisitem.author.orcid | 0000-0003-4140-5904 | - |
crisitem.author.parentorg | Istituto Nazionale di Geofisica e Vulcanologia | - |
crisitem.classification.parent | 04. Solid Earth | - |
crisitem.classification.parent | 04. Solid Earth | - |
crisitem.classification.parent | 04. Solid Earth | - |
crisitem.department.parentorg | Istituto Nazionale di Geofisica e Vulcanologia | - |
crisitem.department.parentorg | Istituto Nazionale di Geofisica e Vulcanologia | - |
Appears in Collections: | Conference materials |
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Poster_2010_AGU.pdf | 1.51 MB | Adobe PDF | View/Open |
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