Drilling-induced and logging-related features illustrated from IODP–ICDP Expedition 364 downhole logs and borehole imaging tools

Lofi, Johanna; Smith, David; Delahunty, Chris; Le Ber, Erwan; Brun, Laurent; Henry, Gilles; Paris, Jehanne; Tikoo, Sonia; Zylberman, William; Pezard, Philippe A.; Célérier, Bernard; Schmitt, Douglas R.; Nixon, Chris. 2018 Drilling-induced and logging-related features illustrated from IODP–ICDP Expedition 364 downhole logs and borehole imaging tools. Scientific Drilling, 24. 1-13. https://doi.org/10.5194/sd-24-1-2018

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Official URL: http://dx.doi.org/10.5194/sd-24-1-2018

Abstract/Summary

Expedition 364 was a joint IODP and ICDP mission-specific platform (MSP) expedition to explore the Chicxulub impact crater buried below the surface of the Yucatán continental shelf seafloor. In April and May 2016, this expedition drilled a single borehole at Site M0077 into the crater's peak ring. Excellent quality cores were recovered from ∼ 505 to ∼ 1335m below seafloor (mb.s.f.), and high-resolution open hole logs were acquired between the surface and total drill depth. Downhole logs are used to image the borehole wall, measure the physical properties of rocks that surround the borehole, and assess borehole quality during drilling and coring operations. When making geological interpretations of downhole logs, it is essential to be able to distinguish between features that are geological and those that are operation-related. During Expedition 364 some drilling-induced and logging-related features were observed and include the following: effects caused by the presence of casing and metal debris in the hole, logging-tool eccentering, drilling-induced corkscrew shape of the hole, possible re-magnetization of low-coercivity grains within sedimentary rocks, markings on the borehole wall, and drilling-induced changes in the borehole diameter and trajectory.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.5194/sd-24-1-2018
ISSN:	1816-3459
Date made live:	30 Oct 2018 16:00 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/521399

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.5194/sd-24-1-2018

ISSN:

1816-3459

Date made live:

30 Oct 2018 16:00 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/521399