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Expired European patentEurope

An improvement in placing cement slurry in wells in the presence of geological zones containing swelling clays or mud residues containing clays

EP 1038090 B1 · Applicant: Schlumberger Canada Limited

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Overview

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Listed from its EPO record in Patent Yard's archive of European patents past their term. Its claims, description and drawings are in the EPO PDF and on Google Patents, and the Claude kit works from them.

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Why it's free to use

  • Filed November 19, 1998 and granted August 27, 2003. A European patent lasts at most 20 years from filing, so its term ended November 19, 2018.
  • A supplementary protection certificate, which can extend a medicine or crop-protection patent, adds at most five and a half years, so even that would have ended by May 19, 2024.
  • We check European rights only. A US or other national patent in its family could still be in force: check its family on Espacenet or Google Patents.
FiledNovember 19, 1998
PublishedSeptember 27, 2000
GrantedAugust 27, 2003
Term endedNovember 19, 2018
Application numberEP 98965171
Classification (CPC)E21B33/13

Timeline

Timeline From EPO dates

1999200120032005200720092011201320152017Application filedNov 19, 1998PublishedSep 27, 2000Patent grantedAug 27, 2003Term endedNov 19, 2018

Sources & verification

Official EPO records

Full published documentClaims, description and drawings as a PDF.EPOEuropean Patent RegisterProcedure, status, file inspection and legal events.EPOLinked open EP data recordThe bibliographic record this page is built from.EPO

Cross-check elsewhere

Google PatentsFull text, worldwide family, citing patents and legal events.patents.google.comEspacenetNational family members and their legal status.European Patent Office

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