View in EDS

Perforation drilling for easing spudcan–footprint interaction issues.

Saved in:
Bibliographic Details
Title: Perforation drilling for easing spudcan–footprint interaction issues.
Authors: Hossain, M.S.1 muhammad.hossain@uwa.edu.au, Stainforth, R.2 20263038@student.uwa.edu.au
Source: Ocean Engineering. Feb2016, Vol. 113, p308-318. 11p.
Subjects: Oil well drilling, Advection, Mechanical loads, Shear strength of soils, Ocean bottom
Abstract: The interaction between a spudcan and an existing footprint is a major concern during jack-up rig installation. No guidelines were provided in the recently finalised version of ISO guidelines 19905-1 in regards to mitigating spudcan–footprint interaction issues except some proposed considerations due to scarce of detailed investigation. This paper reports a measure for easing spudcan–footprint interaction issues, with the efficiency of perforation drilling tested through model tests carried out at 1 g. The soil conditions tested simulate soft seabed strength profiles close to the mudline, varying the undrained shear strength. The most critical reinstallation locations of 0.5 D and 1 D ( D =spudcan diameter) and existing footprint depth of 0.33 D were investigated. The removal of soil (through perforation) inside the spudcan perimeter, with an area of 9% perforated, reduced the induced maximum moment, horizontal force, and horizontal sliding distance by up to 80%, 83%, and 76% respectively. [ABSTRACT FROM AUTHOR]
Copyright of Ocean Engineering is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:The interaction between a spudcan and an existing footprint is a major concern during jack-up rig installation. No guidelines were provided in the recently finalised version of ISO guidelines 19905-1 in regards to mitigating spudcan–footprint interaction issues except some proposed considerations due to scarce of detailed investigation. This paper reports a measure for easing spudcan–footprint interaction issues, with the efficiency of perforation drilling tested through model tests carried out at 1 g. The soil conditions tested simulate soft seabed strength profiles close to the mudline, varying the undrained shear strength. The most critical reinstallation locations of 0.5 D and 1 D ( D =spudcan diameter) and existing footprint depth of 0.33 D were investigated. The removal of soil (through perforation) inside the spudcan perimeter, with an area of 9% perforated, reduced the induced maximum moment, horizontal force, and horizontal sliding distance by up to 80%, 83%, and 76% respectively. [ABSTRACT FROM AUTHOR]
ISSN:00298018
DOI:10.1016/j.oceaneng.2016.01.002