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Drillstring-borehole interaction: backward whirl instabilities and axial loading

K. Vijayan, N. Vlajic, M. I. Friswell, Michael Friswell

Meccanica

Swansea University Author: Michael Friswell

Abstract

A major concern within the oil drilling industry remains the interaction between the drillstring and borehole. The interaction between the drillstring and borehole wall involves nonlinearities in the form of friction and contact. The drillstring borehole interaction induces whirling behaviour of the...

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Published in: Meccanica
ISSN: 0025-6455 1572-9648
Published: 2017
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URI: https://cronfa.swan.ac.uk/Record/cronfa31985
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fullrecord <?xml version="1.0"?><rfc1807><datestamp>2017-03-02T13:45:52.3894916</datestamp><bib-version>v2</bib-version><id>31985</id><entry>2017-02-15</entry><title>Drillstring-borehole interaction: backward whirl instabilities and axial loading</title><swanseaauthors><author><sid>5894777b8f9c6e64bde3568d68078d40</sid><firstname>Michael</firstname><surname>Friswell</surname><name>Michael Friswell</name><active>true</active><ethesisStudent>false</ethesisStudent></author></swanseaauthors><date>2017-02-15</date><deptcode>FGSEN</deptcode><abstract>A major concern within the oil drilling industry remains the interaction between the drillstring and borehole. The interaction between the drillstring and borehole wall involves nonlinearities in the form of friction and contact. The drillstring borehole interaction induces whirling behaviour of the drillstring causing forward whirl, backward whirl or intermittent bouncing behaviour depending on the system parameters. The purpose of this study is to analyse the steady backward whirl behaviour within the system which reduces the fatigue life of the drillstring. Initially a two discs model was developed to analyse the behaviour of the system. The theoretical model was tuned by altering the phase of the eccentric mass. This excites each lateral modes of the system in isolation. The effects of impact, friction and mass unbalance are included in the model. For the tuned system the backward whirl behaviour was analysed by carrying out a rotor speed sweep spanning the lateral natural frequencies. The influence of rotor speed on the system dynamics is explored using a run up and run down and is analysed using a waterfall plot. The waterfall plot indicated the frequency of maximum response corresponding to each rotor speed. Depending on the whirling behaviour the dominant frequency was observed at the lateral natural frequency, the rotational speed or the backward whirl frequency. The influence of variation in whirling behaviour due to altering of the axial load was analysed for a multiple disc case consisting of five discs. A transition in behaviour along the length of the drillstring was observed due to the axial load and bending moment interactions. Depending on the mode excited impact and sustained contact initiation with the borehole varied across the different stabilizer locations.</abstract><type>Journal Article</type><journal>Meccanica</journal><publisher/><issnPrint>0025-6455</issnPrint><issnElectronic>1572-9648</issnElectronic><keywords>Rotor dynamics, Drillstring, Backward whirl</keywords><publishedDay>31</publishedDay><publishedMonth>12</publishedMonth><publishedYear>2017</publishedYear><publishedDate>2017-12-31</publishedDate><doi>10.1007/s11012-017-0623-3</doi><url/><notes/><college>COLLEGE NANME</college><department>Science and Engineering - Faculty</department><CollegeCode>COLLEGE CODE</CollegeCode><DepartmentCode>FGSEN</DepartmentCode><institution>Swansea University</institution><apcterm/><lastEdited>2017-03-02T13:45:52.3894916</lastEdited><Created>2017-02-15T09:58:54.8739024</Created><path><level id="1">Faculty of Science and Engineering</level><level id="2">School of Engineering and Applied Sciences - Uncategorised</level></path><authors><author><firstname>K.</firstname><surname>Vijayan</surname><order>1</order></author><author><firstname>N.</firstname><surname>Vlajic</surname><order>2</order></author><author><firstname>M. I.</firstname><surname>Friswell</surname><order>3</order></author><author><firstname>Michael</firstname><surname>Friswell</surname><order>4</order></author></authors><documents><document><filename>0031985-15022017105545.pdf</filename><originalFilename>vijayan2017.pdf</originalFilename><uploaded>2017-02-15T10:55:45.0500000</uploaded><type>Output</type><contentLength>1408097</contentLength><contentType>application/pdf</contentType><version>Accepted Manuscript</version><cronfaStatus>true</cronfaStatus><embargoDate>2018-01-30T00:00:00.0000000</embargoDate><copyrightCorrect>false</copyrightCorrect><language>eng</language></document></documents><OutputDurs/></rfc1807>
spelling 2017-03-02T13:45:52.3894916 v2 31985 2017-02-15 Drillstring-borehole interaction: backward whirl instabilities and axial loading 5894777b8f9c6e64bde3568d68078d40 Michael Friswell Michael Friswell true false 2017-02-15 FGSEN A major concern within the oil drilling industry remains the interaction between the drillstring and borehole. The interaction between the drillstring and borehole wall involves nonlinearities in the form of friction and contact. The drillstring borehole interaction induces whirling behaviour of the drillstring causing forward whirl, backward whirl or intermittent bouncing behaviour depending on the system parameters. The purpose of this study is to analyse the steady backward whirl behaviour within the system which reduces the fatigue life of the drillstring. Initially a two discs model was developed to analyse the behaviour of the system. The theoretical model was tuned by altering the phase of the eccentric mass. This excites each lateral modes of the system in isolation. The effects of impact, friction and mass unbalance are included in the model. For the tuned system the backward whirl behaviour was analysed by carrying out a rotor speed sweep spanning the lateral natural frequencies. The influence of rotor speed on the system dynamics is explored using a run up and run down and is analysed using a waterfall plot. The waterfall plot indicated the frequency of maximum response corresponding to each rotor speed. Depending on the whirling behaviour the dominant frequency was observed at the lateral natural frequency, the rotational speed or the backward whirl frequency. The influence of variation in whirling behaviour due to altering of the axial load was analysed for a multiple disc case consisting of five discs. A transition in behaviour along the length of the drillstring was observed due to the axial load and bending moment interactions. Depending on the mode excited impact and sustained contact initiation with the borehole varied across the different stabilizer locations. Journal Article Meccanica 0025-6455 1572-9648 Rotor dynamics, Drillstring, Backward whirl 31 12 2017 2017-12-31 10.1007/s11012-017-0623-3 COLLEGE NANME Science and Engineering - Faculty COLLEGE CODE FGSEN Swansea University 2017-03-02T13:45:52.3894916 2017-02-15T09:58:54.8739024 Faculty of Science and Engineering School of Engineering and Applied Sciences - Uncategorised K. Vijayan 1 N. Vlajic 2 M. I. Friswell 3 Michael Friswell 4 0031985-15022017105545.pdf vijayan2017.pdf 2017-02-15T10:55:45.0500000 Output 1408097 application/pdf Accepted Manuscript true 2018-01-30T00:00:00.0000000 false eng
title Drillstring-borehole interaction: backward whirl instabilities and axial loading
spellingShingle Drillstring-borehole interaction: backward whirl instabilities and axial loading
Michael Friswell
title_short Drillstring-borehole interaction: backward whirl instabilities and axial loading
title_full Drillstring-borehole interaction: backward whirl instabilities and axial loading
title_fullStr Drillstring-borehole interaction: backward whirl instabilities and axial loading
title_full_unstemmed Drillstring-borehole interaction: backward whirl instabilities and axial loading
title_sort Drillstring-borehole interaction: backward whirl instabilities and axial loading
author_id_str_mv 5894777b8f9c6e64bde3568d68078d40
author_id_fullname_str_mv 5894777b8f9c6e64bde3568d68078d40_***_Michael Friswell
author Michael Friswell
author2 K. Vijayan
N. Vlajic
M. I. Friswell
Michael Friswell
format Journal article
container_title Meccanica
publishDate 2017
institution Swansea University
issn 0025-6455
1572-9648
doi_str_mv 10.1007/s11012-017-0623-3
college_str Faculty of Science and Engineering
hierarchytype
hierarchy_top_id facultyofscienceandengineering
hierarchy_top_title Faculty of Science and Engineering
hierarchy_parent_id facultyofscienceandengineering
hierarchy_parent_title Faculty of Science and Engineering
department_str School of Engineering and Applied Sciences - Uncategorised{{{_:::_}}}Faculty of Science and Engineering{{{_:::_}}}School of Engineering and Applied Sciences - Uncategorised
document_store_str 1
active_str 0
description A major concern within the oil drilling industry remains the interaction between the drillstring and borehole. The interaction between the drillstring and borehole wall involves nonlinearities in the form of friction and contact. The drillstring borehole interaction induces whirling behaviour of the drillstring causing forward whirl, backward whirl or intermittent bouncing behaviour depending on the system parameters. The purpose of this study is to analyse the steady backward whirl behaviour within the system which reduces the fatigue life of the drillstring. Initially a two discs model was developed to analyse the behaviour of the system. The theoretical model was tuned by altering the phase of the eccentric mass. This excites each lateral modes of the system in isolation. The effects of impact, friction and mass unbalance are included in the model. For the tuned system the backward whirl behaviour was analysed by carrying out a rotor speed sweep spanning the lateral natural frequencies. The influence of rotor speed on the system dynamics is explored using a run up and run down and is analysed using a waterfall plot. The waterfall plot indicated the frequency of maximum response corresponding to each rotor speed. Depending on the whirling behaviour the dominant frequency was observed at the lateral natural frequency, the rotational speed or the backward whirl frequency. The influence of variation in whirling behaviour due to altering of the axial load was analysed for a multiple disc case consisting of five discs. A transition in behaviour along the length of the drillstring was observed due to the axial load and bending moment interactions. Depending on the mode excited impact and sustained contact initiation with the borehole varied across the different stabilizer locations.
published_date 2017-12-31T03:39:06Z
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score 10.993443